Vehicular rearview mirror elements and assemblies incorporating these elements

[0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 12/750,357 filed on Mar. 30, 2010, now abandoned which is a continuation of U.S. patent application Ser. No. 12/154,736, filed on May 27, 2008, now U.S. Pat. No. 7,719,750 which is a continuation of U.S. patent application Ser. No. 11/477,312 filed on Jun. 29, 2006 and now issued as U.S. Pat. No. 7,379,225, which is a continuation of U.S. patent application Ser. No. 11/066,903 filed on Feb. 25, 2005 and now issued as U.S. Pat. No. 7,372,611, which in turn claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. Nos. 60/548,472 filed on Feb. 27, 2004, and 60/605,111 filed on Aug. 27, 2004, and 60/614,150 filed on Sep. 29, 2004. The U.S. patent application Ser. No. 11/066,903 is also a continuation-in-part of U.S. patent Application Ser. Nos. 10/260,741 filed Sep. 30, 2002 and now issued as U.S. Pat. Nos. 7,064,882 and 10/430,885 filed on May 6, 2003 and now issued as U.S. Pat. No. 7,324,261. The disclosure of each of the abovementioned patent applications is incorporated herein by reference in its entirety.

[0002] The present invention generally relates to electro-optic devices and apparatus incorporating such devices. In particular, the invention relates to electro-optic devices used in architectural windows or vehicular rearview mirror elements.

[0003] Electro-optic rearview mirror elements are becoming more common in vehicular applications with regard to both inside and outside rearview mirrors and mirror assemblies, whether on the driver's or the passenger's side. Such electro-optic rearview mirrors are automatically controlled to vary the reflectivity of the mirror in response to rearward and forward aimed light sensors so as to reduce the glare of headlamps in the image reflected to the driver's eyes. Typical electro-optic elements, when incorporated in vehicular rearview mirror assemblies, will have an effective field of view (as defined by relevant laws, codes and specifications) that is less than the area defined by the perimeter of the element itself. Often, the effective field of view of the element is limited, at least in part, by the construction of the element itself and/or an associated bezel.

[0004] Various attempts have been made to provide an electro-optic element having an effective field of view substantially equal to the area defined by its perimeter. Assemblies incorporating these elements have also been proposed. FIG. 1A shows an exploded view of a portion of a rearview mirror subassembly 100 as used in a typical exterior rearview mirror assembly. As shown in FIG. 1B, the subassembly 100 includes an electrochromic mirror element 110, a bezel 115, and a carrier plate 117. The subassembly may further include gaskets 120 and 122 that are placed on either side of electrochromic mirror element 110 to form a secondary seal around the periphery of the mirror element 110. As shown in FIG. 1B, electrochromic element 110 includes a front substantially transparent element 130 typically formed of glass and having a front surface 130a and a rear surface 130b. Electrochromic element 110 further includes a rear element 140, which is spaced slightly apart from the element 130. A seal 146 is formed between elements 130 and 140 about their periphery so as to define a sealed chamber 147 therebetween, in which an electrochromic medium is provided. Elements 130 and 140 preferably have electrically conductive layers (serving as electrodes, not shown) on the surfaces facing the chamber such that an electrical potential may be applied across the electrochromic medium. These electrodes are electrically isolated from one another and separately coupled to a power source by means of first and second bus connectors 148a and 148b. To facilitate connection of bus connectors 148a and 148b, elements 130 and 140 are typically vertically offset so that one bus connector may be secured along a bottom edge of one of the elements and another bus connector may be secured to the top edge of the other element. The bus connectors 148a and 148b are typically spring clips (similar to those disclosed in commonly-assigned U.S. Pat. Nos. 6,064,509 and 6,062,920) and are configured to ensure that they remain physically and electrically coupled to the electrode layers on the inward-facing surfaces of elements 130 and 140. Once the electrochromic element 110 has been manufactured and bus clips 148a and 148b attached, then the mirror subassembly 100 may be formed. As shown in FIGS. 1A and 1B, bezel 115 includes a front lip 151, which extends over a portion of the front surface 130a of the front element 130. Typically, the front lip 151 extends over a sufficient portion of front surface 130a to obscure a person's view of the seal 146 and protect the seal 146 from possible degradation caused by ambient UV light. As apparent from FIG. 1B, the width D₁ of the front lip 151 of the bezel 115 depends upon a number of factors including an offset distance D₂ between the elements 130 and 140. The width D₁ may also depend on the degree to which the bus connector clips 148a and 148b extend beyond the peripheral edges of elements 130 and 140. Typical bezels in the related art have a front lip with a width D₁ of 5 mm or more.

[0005] Prior to inserting the electrochromic mirror element 110 in the bezel 115, an optional front gasket 120 may be provided behind the front lip 151 so as to be pressed between the front surface 130a of the front element 130 and the inner surface of the front lip 151 of bezel 50. The mirror element 110 is then placed in bezel 115 and an optional rear gasket 122 may be provided along the periphery of the back surface of element 140. In lieu of, or in addition to front and/or rear gaskets 120, 122 the bezel/mirror interface area may be filled or potted with a sealing material such as urethane, silicone, or epoxy. A carrier plate 117, which is typically formed of an engineering grade rigid plastic or a similar material as used for bezel 115, is then pressed against the rear surface of element 140 with the gasket 122 compressed therebetween. A plurality of tabs 152 may be formed inside of the bezel such that carrier plate 70 is snapped in place so as to secure mirror element 110 within the bezel. The carrier plate 117 is typically used to mount the mirror subassembly within an exterior mirror housing. More specifically, a positioner (shown below as element 6540 in FIG. 65) may also be mounted within the mirror housing and mechanically coupled to the carrier plate 117 for enabling remote adjustment of the position of the mirror subassembly within the housing.

[0006] While the above-described structure is readily manufacturable, styling concerns have arisen with respect to the width of the front lip of the bezel of an electrochromic mirror subassembly. Specifically, the width of the front lip of the bezel of an EC-mirror has been typically made wider than that of any bezel used on non-dimming (non-electro-optic) mirrors due to the need to obscure and hide from view a mutual positional offset of elements 130 and 140 (introduced to accommodate electrical buss clips) and the seal between the substrates. In fact, in non-dimming mirrors bezels are often not used at all. In some vehicles, only the exterior mirror on the driver's side is electro-optic, while the passenger side mirror is non-dimming. Thus, there exists the need for an improved electro-optic mirror element and an improved electro-optic exterior mirror subassembly that has a reduced bezel front width or that does not include a front bezel at all.

[0007] At least one embodiment of the present invention provides improved electro-optic mirror elements. A related embodiment has an effective field of view area substantially equal to the field of view associated with an area defined by the perimeter of the element.

[0008] At least one embodiment of the present invention provides improved assemblies incorporating electro-optic elements. A related embodiment has an effective field of view area substantially equal to the area of the element itself as defined by its outer most perimeter.

[0009] Other advantages of the present invention will become apparent while reading the detailed description of the invention in light of the figures and appended claims.

[0112] Definitions: As used in this description and the accompanying claims, the following terms shall have the meanings indicated, unless the context otherwise requires:

[0113] “Transflective” describes an optical element or component that has a useful non-zero level of transmittance and also has a useful, non-zero level of reflectance in a specified spectral region. In the context of an image-forming reflector, such as a mirror for viewing reflected images, for example, the viewer in front of the mirror may not only observe an image of the ambient objects, formed in reflection from such transflective area but also receive information contained in the displayed image delivered with light from the light source located behind the transflective area of the mirror.

[0114] The spectrum of light reflected (and that of light transmitted) by an embodiment of the mirror system of the invention can be tuned or modified by adjusting the thickness of the reflectance-enhancing layers. The peak reflectance will vary with optical design wavelength and this will result in a change in color gamut of the reflected (and transmitted) light. In discussing color distributions (i.e., spectra of light), it is useful to refer to the Commission Internationale de I′Eclairage's (CIE) 1976 CIELAB Chromaticity Diagram (commonly referred to the L*a*b* chart or quantification scheme). The technology of color is relatively complex, but a fairly comprehensive discussion is given by F. W. Billmeyer and M. Saltzman in Principles of Color Technology, 2^nd Edition, J. Wiley and Sons Inc. (1981). The present disclosure, as it relates to color technology and uses appropriate terminology, generally follows that discussion. As used in this application, Y (sometimes also referred to as Cap Y), represents either the overall reflectance or the overall transmittance, depending on context. L*, a*, and b* can be used to characterize parameters of light in either transmission or reflection. According to the L*a*b* quantification scheme, L* represents brightness and is related to the eye-weighted value of either reflectance or transmittance (also known as normalized Y Tristimulus value) by the Y Tristimulus value of a white reference, Yref: L*=116*(Y/Yref)−16. The a*-parameter is a color coordinate that denotes the color gamut ranging from red (positive a*) to green (negative a*), and b* is a color coordinate that denotes the color gamut ranging from yellow and blue (positive and negative values of b*, respectively). For example, absorption spectra of an electrochromic medium, as measured at any particular voltage applied to the medium, may be converted to a three-number designation corresponding to a set of L*a*b* values. To calculate a set of color coordinates, such as L*a*b* values, from the spectral transmission or reflectance, two additional parameters are required. One is the spectral power distribution of the source or illuminant. The present disclosure uses CIE Standard Illuminant A to simulate light from automobile headlamps and uses CIE Standard Illuminant D₆₅ to simulate daylight. The second parameter is the spectral response of the observer. Many of the examples below refer to a (reflectance) value Y from the 1931 CIE Standard since it corresponds more closely to the spectral reflectance than L*. The value of “color magnitude”, or C*, is defined as C*=√{square root over ((a*)²+(b*)²)}{square root over ((a*)²+(b*)²)} and provides a measure for quantifying color neutrality. The metric of “color difference”, or ΔC* is defined as ΔC*=√{square root over ((a*−a*′)²+(b*−b*′)²)}{square root over ((a*−a*′)²+(b*−b*′)²)}, where (a*, b*) and (a*′,b*′) describe color of light obtained in two different measurements. Additional CIELAB metric is defined as ΔE*=(Δa*²+Δb*²+ΔL*²)^1/2. The color values described herein are based, unless stated otherwise, on the CIE Standard D65 illuminant and the 10-degree observer.

[0115] An optical element such as a mirror is said to be relatively color neutral in reflected light if the corresponding C* value of the element is generally less than 20. Preferably, however, a color-neutral optical element is characterized by the C* value of less than 15, and more preferably of less than about 10.

[0116] As broadly used and described herein, the reference to an electrode or a material layer as being “carried” on a surface of an element refers to such an electrode or layer that is disposed either directly on the surface of an underlying element or on another coating, layer or layers that are disposed directly on the surface of the element.

[0117] The following disclosure describes embodiments of the invention with reference to the corresponding drawings, in which like numbers represent the same or similar elements wherever possible. In the drawings, the depicted structural elements are not to scale and certain components are enlarged relative to the other components for purposes of emphasis and understanding. References throughout this specification to “one embodiment,” “an embodiment,” or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0118] The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. For example, to simplify a particular drawing of an electro-optical device of the invention not all thin-film coatings (whether electrically conductive, reflective, or absorptive or other functional coatings such as alignment coatings or passivation coatings), electrical interconnections between or among various elements or coating layers, elements of structural support (such as holders, clips, supporting plates, or elements of housing, for example), or auxiliary devices (such as sensors, for example) may be depicted in a single drawing. It is understood, however, that practical implementations of discussed embodiments may contain some or all of these features and, therefore, such coatings, interconnections, structural support elements, or auxiliary devices are implied in a particular drawing, unless stated otherwise, as they may be required for proper operation of the particular embodiment. In the following description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, or materials.

[0119] Numbering of structural surfaces. In describing the order of elements or components in embodiments of a vehicular rearview assembly or a sub-set of a vehicular rearview assembly, the following convention will be generally followed herein, unless stated otherwise. The order in which the surfaces of sequentially positioned structural elements of the assembly (such as substrates made of glass or other translucent material) are viewed is the order in which these surfaces are referred to as the first surface, the second surface, the third surface, and other surfaces if present referred to in ascending order. Generally, therefore, surfaces of the structural elements (such as substrates) of an embodiment of the invention are numerically labeled starting with a surface that corresponds to the front portion of a rearview assembly and that is proximal to the observer or user of the assembly and ending with a surface that corresponds to the back portion of an assembly and that is distal to the user. Accordingly, the term “behind” refers to a position, in space, following something else and suggests that one element or thing is at the back of another as viewed from the front of the rearview assembly. Similarly, the term “in front of” refers to a forward place or position, with respect to a particular element as viewed from the front of the assembly.

[0120] The present disclosure refers to U.S. Pat. Nos. 4,902,108; 5,128,799; 5,151,824; 5,278,693; 5,280,380; 5,282,077; 5,294,376; 5,336,448; 5,448,397; 5,679,283; 5,682,267; 5,689,370; 5,803,579; 5,808,778; 5,818,625; 5,825,527; 5,837,994; 5,888,431; 5,923,027; 5,923,457; 5,928,572; 5,940,201; 5,956,012; 5,990,469; 5,998,617; 6,002,511; 6,008,486; 6,020,987; 6,023,229; 6,037,471; 6,049,171; 6,057,956; 6,062,920; 6,064,509; 6,084,700; 6,102,546; 6,111,683; 6,111,684; 6,129,507; 6,130,421; 6,130,448; 6,132,072; 6,140,933; 6,166,848; 6,170,956; 6,188,505; 6,193,378; 6,193,912; 6,195,194; 6,222,177; 6,224,716; 6,229,435; 6,238,898; 6,239,898; 6,244,716; 6,246,507; 6,247,819; 6,249,369; 6,255,639; 6,262,831; 6,262,832; 6,268,950; 6,281,632; 6,291,812; 6,313,457; 6,335,548; 6,356,376; 6,359,274; 6,379,013; 6,392,783; 6,399,049; 6,402,328; 6,403,942; 6,407,468; 6,420,800; 6,426,485; 6,429,594; 6,441,943; 6,465,963; 6,469,739; 6,471,362; 6,504,142; 6,512,624; 6,521,916; 6,523,976; 6,614,579; 6,471,362; 6,477,123; 6,521,916; 6,545,794; 6,587,573; 6,614,579; 6,635,194; 6,657,767; 6,774,988; 6,816,297; 6,861,809; 6,968,273; 6,700,692; 7,064,882; 7,287,868; 7,324,261; 7,342,707; 7,417,717; 7,663,798 and D410,607. The present application also refers to the International Patent Applications nos. PCT/WO97/EP498; PCT/WO98/EP3862 and U.S. Patent Applications Nos. 60/360,723; 60/404,879; Ser. Nos. 11/682,121; 11/713,849; 11/833,701; 12/138,206; 12/154,824; 12/370,909; 12/629,757; 12/774,721. The disclosure of each of the abovementioned patent documents is incorporated herein by reference in its entirety. All these patent documents may be collectively referred to herein as “Our Prior Applications”.

[0121] Referring initially to FIG. 2, there is shown a controlled vehicle 200 having a driver's side outside rearview mirror 210a, a passenger's side outside rearview mirror 210b and an inside rearview mirror 215. Details of these and other features will be described herein. Preferably, the controlled vehicle comprises an inside rearview mirror of unit magnification. A unit magnification mirror, as used herein, refers to a mirror with a plane or flat reflective element producing an image having perceived angular and linear sizes equal to those of the object. A prismatic day-night adjustment rearview mirror wherein at least one associated position provides unit magnification is considered herein to be a unit magnification mirror. Preferably, the mirror provides a field of view with an included horizontal angle measured from the projected eye point of at least 20 degrees and a sufficient vertical angle to provide a view of a level road surface extending to the horizon beginning at a point not greater than 61 m to the rear of the controlled vehicle when the controlled vehicle is occupied by a driver and four passengers or the designated occupant capacity, if less, based on an average occupant weight of 68 kg. It should be understood that the line of sight may be partially obscured by seated occupants or by head restraints. The location of the driver's eye reference points are preferably in accordance with regulation or a nominal location appropriate for any 95th percentile male driver. Preferably, the controlled vehicle comprises at least one outside mirror of unit magnification. Preferably, the outside mirror provides a driver of a controlled vehicle a view of a level road surface extending to the horizon from a line, perpendicular to a longitudinal plane tangent to the driver's side of the controlled vehicle at the widest point, extending 2.4 m out from the tangent plane 10.7 m behind the driver's eyes, with the seat in the rearmost position. It should be understood that the line of sight may be partially obscured by rear body or fender contours of the controlled vehicle. Preferably, the locations of the driver's eye reference points are in accordance with regulation or a nominal location appropriate for any 95th percentile male driver. Preferably, the passenger's side mirror is not obscured by an unwiped portion of a corresponding windshield and is preferably adjustable by tilting in both horizontal and vertical directions from the driver's seated position. In at least one embodiment, the controlled vehicle comprises a convex mirror installed on the passenger's side. Preferably, the mirror is configured for adjustment by tilting in both horizontal and vertical directions. Preferably, each outside mirror comprises not less than 126 cm of reflective surface and is located so as to provide the driver a view to the rear along an associated side of the controlled vehicle. Preferably, the average reflectance of any mirror, as determined in accordance with SAE Recommended Practice J964, OCT84, is at least 35 percent (40 percent for many European Countries). In embodiments where the mirror element is capable of operating at multiple reflectance levels, the minimum reflectance level in the day mode shall be at least 35 percent (40 percent when mirror is fabricated according to European standards) and the minimum reflectance level in the night mode shall be at least 4 percent.

[0122] With further reference to FIG. 2, the controlled vehicle 200 may comprise a variety of exterior lights, such as, headlight assemblies 220a, 220b; foul condition lights 230a, 230b; front turn-signal indicators 235a, 235b; taillight assembly 225a, 225b; rear turn signal indicators 226a, 226b; rear emergency flashers 227a, 227b; backup lights 240a, 240b and center high-mounted stop light (CHMSL) 245.

[0123] As described in detail herein, the controlled vehicle may comprise at least one control system incorporating various components that provide shared functions with other vehicle equipment. An example of one control system described herein integrates various components associated with automatic control of the reflectivity of at least one rearview mirror element and automatic control of at least one exterior light. Such systems may comprise at least one image sensor within a rearview mirror, an A-pillar, a B-pillar, a C-pillar, a CHMSL or elsewhere within or upon the controlled vehicle. Images acquired, or portions thereof, by a sensor may be used for automatic vehicle equipment control. The images, or portions thereof, may alternatively or additionally be displayed on one or more displays. At least one display may be covertly positioned behind a transflective, or at least partially transmissive, electro-optic element. A common controller may be configured to generate at least one mirror element drive signal and at least one other equipment control signal.

Exterior and Interior Rearview Assemblies.

[0124] Turning now to FIGS. 3a and 3b, various components of an outside (or exterior) rearview mirror assembly 310a, 310b are depicted. As described in detail herein, an electro-optic mirror element may comprise a first substrate 320a, 320b secured in a spaced apart relationship with a second substrate 325 via a primary seal 330 to form a chamber there between. At least a portion of the primary seal is left void to form at least one chamber fill port 335. An electro-optic medium is enclosed in the chamber and the fill port(s) are sealingly closed via a plug material 340. Preferably, the plug material is a UV-curable epoxy or acrylic material. Also shown is a spectral filter material 345a, 345b located near the periphery of the element. Generally, this optical thin-film spectral filter material 345a, 345b is circumferentially disposed in a peripheral area, next to a corresponding perimeter-defining edge, of either of the first and the second surface of the system, and is configured as a ring. Such ring of the spectral filter material will be interchangeably referred to herein as a peripheral ring. The electrical clips 350, 355 are preferably secured to the element, respectively, via first adhesive material 351, 352. The element is secured to a carrier plate 360 via second adhesive material 365. Electrical connections from the outside rearview mirror to other components of the controlled vehicle are preferably made via a connector 370. The carrier is attached to an associated housing mount 376 via a positioner 380. Preferably, the housing mount is engaged with a housing 375a, 375b and secured via at least one fastener 376b. Preferably, the housing mount comprises a swivel portion configured to engage a swivel mount 377a, 377b. The swivel mount is preferably configured to engage a vehicle mount 378 via at least one fastener 378b. Additional details of these components, additional components, their interconnections and operation are discussed below.

[0125] With further reference to FIG. 3a, the outside rearview mirror assembly 310a is oriented such that a view of the first substrate 320a is shown with the spectral filter material 345a positioned between the viewer and the primary seal material (not shown). A blind spot indicator 385, a keyhole illuminator 390, a puddle light 392, a turn signal 394, a photo sensor 396, any one thereof, a subcombination thereof or a combination thereof may be incorporated within the rearview mirror assembly such that they are positioned behind the mirror element with respect to the viewer. Preferably, the devices 385, 390, 392, 394, 396 are configured in combination with the mirror element to be at least partially covert as discussed in detail within various references incorporated by reference herein. Additional details of these components, additional components, their interconnections and operation are further discussed in reference to FIG. 65, below.

[0126] Turning now to FIG. 4, there is shown an inside (or interior) rearview mirror assembly 410, as viewed when looking at the first substrate 420, with a spectral filter material 445 positioned between the viewer and a primary seal material (not shown). The mirror element is shown to be positioned within a movable housing 475 and combined with a stationary housing 477 on a mounting structure 481. A first indicator 486, a second indicator 487, operator interfaces 491 and a first photo sensor 496 are positioned in a chin portion 490 of the movable housing. A first information display 488, a second information display 489 and a second photo sensor 497 are incorporated within the assembly behind the mirror element with respect to the viewer. As described with regard to the outside rearview mirror assembly, it is preferable to have devices 488, 489, 497 at least partially covert. For example, a “window” may be formed in third and/or fourth surface coatings of the associated mirror element and configured to provide a layer of a platinum group metal (PGM) (i.e. iridium, osmium, palladium, platinum, rhodium, and ruthenium) only on the third surface. Thereby, light rays impinging upon the associated “covert” photo sensor “glare” will first pass through the first surface stack, if any, the first substrate, the second surface stack, the electro-optic medium, the platinum group metal and, finally, the second substrate. The platinum group metal functions to impart continuity in the third surface conductive electrode, thereby reducing electro-optic medium coloring variations associated with the window.

[0127] FIG. 5 shows a front elevational view schematically illustrating an interior mirror assembly 510 and two exterior rearview mirror assemblies 210a and 210b for the driver side and passenger side, respectively, all of which are adapted to be installed on a motor vehicle in a conventional manner and where the mirrors face the rear of the vehicle and can be viewed by the driver of the vehicle to provide a rearward view. As mentioned above, the interior mirror assembly 410 and exterior rearview mirror assemblies 210a and 210b may incorporate light-sensing electronic circuitry of the type illustrated and described in the Canadian Patent No. 1,300,945, U.S. Pat. No. 5,204,778, U.S. Pat. No. 5,451,822, U.S. Pat. No. 6,402,328, or U.S. Pat. No. 6,386,713 and other circuits capable of sensing glare and ambient light and supplying a drive voltage to the electro-optic element. The disclosure of each of these patent documents is incorporated herein by reference in its entirety.

[0128] Mirror assemblies 410, 210a, and 210b are essentially similar in that like numbers identify components of the inside and outside mirrors. These components may be slightly different in configuration, but they function in substantially the same manner and obtain substantially the same results as similarly numbered components. For example, the shape of the front glass element of inside mirror 410 is generally longer and narrower than outside mirrors 210a and 210b. There are also some different performance standards placed on inside mirror 410 compared with outside mirrors 210a and 210b. For example, inside mirror 410 generally, when fully cleared, should have a reflectance value of about 70 percent to about 85 percent or even higher, whereas the outside mirrors often have a reflectance of about 50 percent to about 65 percent. Also, in the United States (as supplied by the automobile manufacturers), the passenger-side mirror 210b typically has a spherically bent or convex shape, whereas the driver-side mirror 210a and inside mirror 410 are presently required to be flat. In Europe, the driver-side mirror 210a is commonly flat or aspheric, whereas the passenger-side mirror 210b has a convex shape. In Japan, both outside mirrors have a convex shape. While the focus of the invention is generally towards exterior mirrors, the following description is generally applicable to all mirror assemblies of the present invention including inside mirror assemblies. Moreover, certain aspects of the present invention may be implemented in electro-optic elements used in other applications such as architectural windows, or the like, or even in other forms of electro-optic devices.

[0129] An embodiment of a rearview mirror of the present invention may include a housing having a bezel 544, which may extend around the entire periphery of each of individual assemblies 410, 210a, and/or 210b. However, as discussed below, the scope of the present invention also includes embodiments having no bezel. When present, the bezel 544 visually conceals and protects the buss connector and the seal. A wide variety of bezel designs are well known in the art, such as, for example, the bezel taught and claimed in above-referenced U.S. Pat. No. 5,448,397.

[0130] In the following description of various embodiments, accompanied by FIGS. 6 through 16, references are made to only those elements and components that are necessary for understanding of a particular feature of an embodiment being discussed. Corresponding drawings illustrate only these referenced elements and components while other elements (such as additional thin-film coatings, for example) are omitted from the drawings for clarity of the presentation. It would be understood, however, that such other elements are implied and not excluded from the scope of a particular embodiment being described, unless stated otherwise.

[0131] FIG. 6A shows a cross-sectional view 600 of an exterior mirror assembly 210 (a or b) of FIG. 5, constructed in accordance with at least one embodiment of the present invention. A shown, an embodiment of FIG. 6A includes a front substantially transparent element (such as a glass substrate, for example) 612 that corresponds to the outer, or front, portion of the mirror assembly 210 facing the driver and a rear element 614 (such as another glass substrate, for example) that corresponds to the back portion of the mirror assembly 210. The front element 612 has a front surface 612a and a rear surface 612b, and a rear element 614 has a front surface 614a and a rear surface 614b. For clarity of description of such a structure, the following designations will be generally used hereinafter in this disclosure. The front surface 612a of the front glass element 612 will be referred to as the first surface, and the back surface 612b of the front glass element 612 as the second surface. The front surface 614a of the rear glass element 614 will be referred to as the third surface, and the back surface 614b of the rear glass element as the fourth surface. Generally, therefore, the first surface corresponds to a front of the mirror element while the fourth surface corresponds to a back of the mirror element. Similar designations are used throughout this disclosure in description of any embodiment. A chamber or gap 625 between the two elements 612 and 614 is defined by an inner circumferential wall 632 of sealing member 616a and lined with a layer of substantially transparent conductor electrode 628 (carried on second surface 612b) and a reflecting electrode 620 (carried on third surface 614a). An electrochromic medium 626 is contained within the chamber 625. The edges of the elements 612 and 614 preferably have a “zero offset” in a transverse direction, which as used herein means they are on average less than about 1-mm from being in perfect alignment, or more preferably are within about 0.5-mm from being in perfect alignment. The zero offset may extend (and be maintained) completely around the elements 612 and 614, or, alternatively, may extend along portions thereof, such as along edge portions having a bus connector or electrical conductor for the electrochromic material circuit. In embodiments of the invention, such small or zero offset is employed to further reduce a total width or size of the edge bezel (see, for example, items 3944 of FIG. 39, 4044a of FIG. 40, 2282 of FIG. 22B, 2282b of FIG. 22E, 1366 of FIG. 23, or 4244-4244P of FIGS. 42-59).

[0132] The front transparent element 612 may be made of any material which is substantially transparent to visible light and has sufficient strength to be able to operate in the conditions commonly found in the automotive environment (e.g., varying temperatures and pressures). The front element 612 is preferably a sheet of glass and may comprise any type of borosilicate glass, soda lime glass, float glass, or any other material, such as, for example, a polymer or plastic, that is transparent in the visible region of the electromagnetic spectrum. The rear element 614 must meet the operational conditions outlined above, except that it does not need to be transparent in all applications, and therefore may comprise polymers, metals, glass, ceramics. In a preferred embodiment, however, the rear element 614 is a sheet of glass.

[0133] As shown in FIG. 6A, the electrode 620 on the third surface 614a is sealably bonded to the electrode 628 on the second surface 612b by a seal member 616 disposed near the outer perimeter of both the second surface 612b and the third surface 614a so as to keep the substrates 612, 614 in a spaced-apart and parallel relationship. The seal member 616 may incorporate any material that is capable of adhesively bonding coatings on the second surface 612b to coatings on the third surface 614a in order to seal the perimeter of the chamber 625 to prevent the leakage of the electrochromic material 626 from the chamber 625. In alternative embodiments, as described below, the layer of transparent conductive coating 628 and/or the layer of electrode 620 may be removed from a portion of the chamber where the seal member is disposed. In such a case, the seal member 616 should be configured to bond well to glass.

[0134] The performance requirements for a perimeter seal member 616 used in an electrochromic device are similar to those for a perimeter seal used in a liquid crystal device (LCD), which are well known in the art. The seal must have good adhesion to glass, metals and metal oxides; must have low permeabilities for oxygen, moisture vapor, and other detrimental vapors and gases; and must not interact with or poison the electrochromic or liquid crystal material it is meant to contain and protect. The perimeter seal can be applied by means commonly used in the LCD industry, such as by silk-screening or dispensing. Because of their lower processing temperatures, thermoplastic, thermosetting or UV curing organic sealing resins are preferred. Such organic resin sealing systems for LCDs are described in U.S. Pat. Nos. 4,297,401, 4,418,102, 4,695,490, 5,596,023, and 5,596,024. Because of their excellent adhesion to glass, low oxygen permeability and good solvent resistance, epoxy-based organic sealing resins are preferred. These epoxy resin seals may be UV curing, such as described in U.S. Pat. No. 4,297,401, or thermally curing, such as with mixtures of liquid epoxy resin with liquid polyamide resin or dicyandiamide, or they can be homopolymerized. The epoxy resin may contain fillers or thickeners to reduce flow and shrinkage such as fumed silica, silica, mica, clay, calcium carbonate, alumina, etc., and/or pigments to add color. Fillers pretreated with hydrophobic or silane surface treatments are preferred. Cured resin crosslink density can be controlled by use of mixtures of mono-functional, di-functional, and multi-functional epoxy resins and curing agents. Additives such as silanes, titanates, or sulfur or phosphorous compounds can be used to improve the seal's hydrolytic stability and adhesion, and spacers such as glass or plastic beads or rods can be used to control final seal thickness and substrate spacing. Suitable epoxy resins for use in a perimeter seal member 616 include, but are not limited to: “EPON RESIN” 813, 825, 826, 828, 830, 834, 862, 1001F, 1002F, 2012, DPS-155, 164, 1031, 1074, 58005, 58006, 58034, 58901, 871, 872, and DPL-862 available from Shell Chemical Co., Houston, Tex.; “ARALITE” GY 6010, GY 6020, CY 9579, GT 7071, XU 248, EPN 1139, EPN 1138, PY 307, ECN 1235, ECN 1273, ECN 1280, MT 0163, MY 720, MY 0500, MY 0510, and PT 810 available from Ciba Geigy, Hawthorne, N.Y.; and “D.E.R.” 331, 317, 361, 383, 661, 662, 667, 732, 736, “D.E.N.” 354, 354LV, 431, 438, 439 and 444 available from Dow Chemical Co., Midland, Mich. Suitable epoxy curing agents include V-15, V-25, and V-40 polyamides from Shell Chemical Co.; “AJICURE” PN-23, PN-34, and VDH available from Ajinomoto Co., Tokyo, Japan; “CUREZOL” AMZ, 2MZ, 2E4MZ, C11Z, C17Z, 2PZ, 2IZ, and 2P4MZ available from Shikoku Fine Chemicals, Tokyo, Japan; “ERISYS” DDA or DDA accelerated with U-405, 24EMI, U-410, and U-415 available from CVC Specialty Chemicals, Maple Shade, N.J.; and “AMICURE” PACM, 2049, 352, CG, CG-325, and CG-1200 available from Air Products, Allentown, Pa. Suitable fillers include fumed silica such as “CAB-O-SIL” L-90, LM-130, LM-5, PTG, M-5, MS-7, MS-55, TS-720, HS-5, and EH-5 available from Cabot Corporation, Tuscola, Ill.; “AEROSIL” R972, R974, R805, R812, R812S, 8202, US204, and US206 available from Degussa, Akron, Ohio. Suitable clay fillers include BUCA, CATALPO, ASP NC, SATINTONE 5, SATINTONE SP-33, TRANSLINK 37, TRANSLINK 77, TRANSLINK 445, and TRANSLINK 555 available from Engelhard Corporation, Edison, N.J. Suitable silica fillers are SILCRON G-130, G-300, G-100-T, and G-100 available from SCM Chemicals, Baltimore, Md. Suitable silane coupling agents to improve the seal's hydrolytic stability are Z-6020, Z-6030, Z-6032, Z-6040, Z-6075, and Z-6076 available from Dow Corning Corporation, Midland, Mich. Suitable precision glass microbead spacers are available in an assortment of sizes from Duke Scientific, Palo Alto, Calif. The seal may be constructed in accordance with the teachings in U.S. Pat. Nos. 5,790,298 and 6,157,480, the disclosure of each of which is incorporated herein by reference in its entirety.

[0135] Another suitable way to maintain precision spacing between the two pieces of glass is by adding plastic fibers to the seal material. These fibers if cut from monofilament in an aspect ratio of about 2.5-3 to 1 (length to diameter) are particularly effective in keeping the two substrates from sliding during the seal cure process. The glass spheres act as ball bearings that can enable movement between the substrates during seal cure. Plastic fibers made of high temperature polyester (PEN) or polyetherimide (Ultem) when added to the seal material at around a 1% by weight loading help prevent substrate movement because they are randomly orientated and some will not be positioned to roll. These plastic spacers have another benefit in that they more closely match the thermal expansion of cured organic seal material and consequently will generate less seal stress during thermal cycling.

[0136] In further reference to FIG. 6A, the layer 628 of a substantially transparent electrically conductive material is deposited on the second surface 612b to act as an electrode of the electrochromic device. The substantially transparent conductive material 628 may be any material which bonds well to the front element 612, is resistant to corrosion caused by any materials within the electrochromic device, is resistant to corrosion by the atmosphere or road salts, has minimal diffuse or specular reflectance, high light transmission, near neutral coloration, and good electrical conductance. The transparent conductive material used for the layer 628 may be fluorine-doped tin oxide, doped zinc oxide, indium zinc oxide (Zn₃In₂O₆), indium tin oxide (ITO), ITO/metal/ITO (IMI) as disclosed in “Transparent Conductive Multilayer-Systems for FPD Applications,” by J. Stollenwerk, B. Ocker, K. H. Kretschmer of LEYBOLD AG, Alzenau, Germany; it may further include the materials described in above-referenced U.S. Pat. No. 5,202,787, such as TEC 20 or TEC 15, available from Libbey Owens-Ford Co. of Toledo, Ohio, other transparent conductive metal oxides, or other transparent conductors. Generally, the conductivity of the transparent conductive layer 628 will depend on its thickness and material composition. In one embodiment, the layer 628 may include an insulator-metal-insulator (IMI) film structure (or stack) that generally has superior conductivity compared with the other materials. The IMI stack, however, is known to undergo more rapid environmental degradation and suffer from interlayer delamination. The thicknesses of the various layers in the IMI structure may vary, but generally the thickness of the first insulator layer (e.g., ITO) ranges from about 10 Å to about 200 Å, the thickness of the metal layer ranges from about 10 Å to about 200 Å, and the thickness of the second insulator layer (e.g., ITO) ranges from about 10 Å to about 200 Å. If desired, an optional layer or layers of a color suppression material (not shown) may be deposited between the layer 628 and the second surface 612b to suppress the reflection of any unwanted portions of the electromagnetic spectrum.

[0137] In further reference to FIG. 6A, a reflector/electrode (or, reflecting electrode) 620 includes reflecting layer(s) and electrically conducting layer(s), referred to herein as a reflector/electrode or reflecting electrode and is preferably disposed on the third surface 614a. The reflector/electrode 620 comprises at least one layer of a reflective material, which serves as a reflecting layer and also forms an integral electrode in contact with and in a chemically and electrochemically stable relationship with any constituents in an electrochromic medium. The reflector/electrode 620 may be mostly reflective or may be partially transmissive/partially reflective (or “transflective”) as disclosed in commonly-assigned U.S. Pat. No. 6,700,692, the entire disclosure of which is incorporated herein by reference. As an alternative, the electrochromic device could incorporate a transparent electrically conductive material on the third surface, which acts as an electrode, and incorporate a reflector on the fourth surface of an embodiment. However, combining the “reflector” and “electrode” into a reflecting electrode 620 and placing both on the third surface is preferred because it makes the device manufacture less complex and allows the device to operate at higher performance levels. The combined reflector/electrode 620 on the third surface generally has higher conductivity than a single conventional transparent electrode used on the third surface.

[0138] With respect to the transparent electrode 628, its material composition may be changed to generally lower its conductivity while maintaining coloration speeds of the EC-element that are similar to those obtainable with a fourth surface reflector device (this results in a substantial decreased of the overall cost and time of production of an electrochromic device). Improvement of performance of the device, on the other hand, may require a transparent electrode 628 on the second surface to have moderate to high value of conductivity. For this purpose, materials such as ITO or IMI may be used for the construction of the electrode 628. The combination of a high conductivity (i.e., the conductivity corresponding to sheet resistance of less than 250 Ω/square, preferably less than 15 Ω/square and most preferably between approximately 15 Ω/square and approximately 0.01 Ω/square) of the reflector/electrode 620 on the third surface and a high conductivity of the substantially transparent electrode 628 on the second surface will not only result in an electrochromic device having more even distribution of color across the device, but will also allow for increased speed of coloration. Furthermore, in mirror assemblies utilizing a fourth surface reflector, both the electrode on the second surface and the electrode on the third surface are substantially transparent electrodes with relatively low conductivity. In previously used mirrors having third-surface reflector, there is a substantially transparent electrode and a reflector/electrode with relatively low conductance and, as such, a long bus bar on the front and rear element to bring current in and out is necessary to ensure adequate coloring speed and coloring uniformity. In contradistinction, the third surface electrode of at least some embodiments of the present invention are metallic and may have a higher conductance and therefore has a very even voltage or potential distribution across the conductive surface, even with a small or irregular contact area. Thus, the present invention provides greater design flexibility by allowing the electrical contact for the third surface electrode to be very small (if desired) while still maintaining adequate coloring speed and coloring uniformity.

[0139] In construction of outside rearview mirrors it is desirable to use thinner glass substrates in order to decrease the overall weight of a mirror so that the mechanisms used to manipulate the orientation of the mirror are not overloaded. Decreasing the weight of the device additionally improves the dynamic stability of the mirror assembly when it is exposed to vibrations. Alternatively, decreasing the weight of the mirror element may permit more electronic circuitry to be provided in the mirror housing without increasing the weight of the mirror housing. Thin glass may be prone to warpage or breakage, especially when exposed to extreme environments. In embodiments of the present invention substantially this problem is substantially alleviated by the use of two thin glass elements and an improved gel material. Such improved electrochromic device is disclosed in commonly assigned U.S. Pat. No. 5,940,201, the entire disclosure of which is incorporated herein by reference.

[0140] The addition of the combined reflector/electrode onto the third surface of the device further helps to remove any residual double or spurious imaging resulting from the two glass elements having non-parallel surfaces. Thus, chamber 625 preferably contains a free-standing gel that cooperatively interacts with thin glass elements 612 and 614 to produce a mirror that acts as one thick unitary member rather than two thin glass elements held together only by a seal member. In free-standing gels, which contain a solution and a cross-linked polymer matrix, the solution is interspersed in a polymer matrix and continues to function as a solution. Also, at least one solution-phase electrochromic material is in solution in the solvent and therefore as part of the solution is interspersed in the polymer matrix (this generally being referred to as “gelled electrochromic medium” 626). This allows one to construct a rearview mirror with thinner glass in order to decrease the overall weight of the mirror while maintaining sufficient structural integrity so that the mirror will survive the extreme conditions common to the automobile environment. This also helps maintain uniform spacing between the thin glass elements, which improves uniformity in the appearance (e.g., coloration) of the mirror. This structural integrity results because the free-standing gel 626, the first glass element 612, and the second glass element 614, which individually have insufficient strength characteristics to work effectively in an electrochromic mirror, are coupled in such a manner that they no longer move independently but act as one thick unitary member. This structural integrity leads to increased mechanical stability of the mirror that includes, but is not limited to, resistance to flexing, warping, bowing and breaking, as well as improved image quality of the reflected image, e.g., less distortion, double image, color uniformity, and independent vibration of each glass element. However, while it is important to couple the front and rear glass elements, it is equally important (if not more so) to ensure that the electrochromic mirror functions properly. To assure such performance, the free-standing gel must bond to the electrode layers of the electrochromic element (including the reflector/electrode if the mirror has a third surface reflector) on the walls of such a device, but at the same time not interfere with the electron transfer between the electrode layers and the electrochromic material(s) disposed in the chamber 625. Further, the gel must not shrink, craze, or weep over time such that the gel itself causes poor image quality. Ensuring that the free-standing gel bonds well enough to the electrode layers to couple the front and rear glass elements and does not deteriorate over time while allowing the electrochromic reactions to take place as though they were in solution, is an important aspect of the present invention. When using a 1^st surface reflector around the perimeter of an electro-optic mirror where the primary reflector is on one of the other surfaces, the distance between the two reflective surfaces causes a dark shadow area to be formed when viewing the mirror from an angle. The shadow increases in size with thicker substrates and decreases in size for thinner substrates. The shadow creates a region on discontinuous reflection and is undesirable when viewing an object in the mirror. To minimize this shadow, the first substrate 612 with a thickness of less than 2.0 mm may be used. It is more preferred to use the first substrate of approximately 1.8 mm or less, and most preferred to use a first substrate of approximately 1.1 mm or less.

[0141] To perform adequately, a mirror must accurately represent the reflected image, and this cannot be accomplished when the glass elements (to which the reflector is attached) tend to bend or bow while the driver is viewing the reflected image. The bending or bowing occurs mainly due to pressure points exerted by the mirror mounting and adjusting mechanisms and by differences in the coefficients of thermal expansion of the various components that are used to house the exterior mirror element. These components include a carrier plate used to attach the mirror element to the mechanism used to manipulate or adjust the position of the mirror (bonded to the mirror by an adhesive), a bezel, and a housing. Many mirrors also typically have a potting material as a secondary seal. Each of these components, materials, and adhesives has varying coefficients of thermal expansion that will expand and shrink to varying degrees during heating and cooling and will exert stress on the glass elements 612 and 614. On very large mirrors, hydrostatic pressure becomes a concern and may lead to double imaging problems when the front and rear glass elements bow out at the bottom and bow in at the top of the mirror. By coupling the front and rear glass elements, the thin glass/free-standing gel/thin glass combination acts as one thick unitary member (while still allowing proper operation of the electrochromic mirror) and thereby reduces or eliminates the bending, bowing, flexing, double image, and distortion problems and non-uniform coloring of the electrochromic medium.

[0142] The cooperative interaction between the freestanding gel and the thin glass elements of the present invention also improves the safety aspects of an electrochromic mirror having thin glass elements. In addition to being more flexible, thin glass is more prone to breakage than thick glass. By coupling the free-standing gel with the thin glass, the overall strength is improved (as discussed above) and further restricts shattering and scattering and eases clean-up in the case of breakage of the device.

[0143] An improved cross-linked polymer matrix used in at least one embodiment of the present invention is disclosed in commonly assigned U.S. Pat. No. 5,928,572, the entire disclosure of which is incorporated herein by reference.

[0144] Typically, electrochromic mirrors are made with glass elements having a thickness of about 2.3-mm. The preferred thin glass elements according to at least one embodiment of the present invention have thicknesses of about 1.1 mm, which results in a substrate weight savings of more than 50 percent. This decreased weight ensures that the mechanisms used to manipulate the orientation of the mirror, commonly referred to as carrier plates, are not overloaded and further provides significant improvement in the vibrational stability of the mirror.

[0145] Therefore, in at least one embodiment, the front transparent element 612 is preferably a sheet of glass with a thickness ranging from 0.5 mm to about 1.8 mm, preferably from about 0.5 mm to 1.6 mm, more preferably from about 0.5 mm to 1.5 mm, even more preferably from about 0.8 mm to about 1.2 mm, with the presently most preferred thickness about 1.1 mm. The rear element 614 preferably is a sheet of glass with a thickness in the same ranges as element 612.

[0146] Vibrations that result from the engine running and/or the vehicle moving affect the rearview mirror, such that the mirror essentially acts as a weight at the end of a vibrating cantilever beam. This vibrating mirror causes blurring of the reflected image, which is a safety concern as well as a phenomenon that is displeasing to the driver. As the weight on the end of the cantilever beam (i.e., the mirror element attached to the carrier plate on the outside mirror or the mirror mount on the inside mirror) is decreased, the frequency at which the mirror vibrates increases. If the frequency of the mirror vibration increases to around 60 Hertz or greater, the blurring of the reflected image is not visually displeasing to the vehicle occupants. Moreover, as the frequency at which the mirror vibrates increases, the distance the mirror travels while vibrating decreases significantly. Thus, by decreasing the weight of the mirror element, the complete mirror becomes more vibrationally stable and improves the ability of the driver to view what is behind the vehicle. When both glass elements are made thin, the resistance to vibrations of an interior or exterior mirror improves, which is particularly important for exterior mirrors. For example, an interior mirror with two glass elements having a thickness of 1.1 mm has a first mode horizontal frequency of about 55 Hertz whereas a mirror with two glass elements of 2.3 mm has a first mode horizontal frequency of about 45 Hertz. This 10 Hertz difference produces a significant improvement in how a driver views a reflected image.

[0147] A resistive heater (not shown in FIG. 6A) may be disposed on the fourth glass surface 614b to heat the mirror and thereby clear the mirror of ice, snow, fog, or mist. The resistive heater may optionally be a layer of ITO, fluorine-doped tin oxide applied to the first and, or, fourth surface, or may be other heater layers or structures well known in the art.

[0148] An electrical circuit such as those taught in the above-referenced Canadian Patent No. 1,300,945 and U.S. Pat. Nos. 5,204,778, 5,434,407, 5,451,822, 6,402,328, and 6,386,713, is connected to and allows control of the potential to be applied across electrode 620 and transparent electrode 628, such that electrochromic medium 626 will darken and thereby attenuate various amounts of light traveling therethrough and thus vary the reflectance of the mirror containing electrochromic medium 626. The electrical circuit used to control the reflectivity of the electrochromic mirrors preferably incorporates an ambient light sensor (not shown) and a glare light sensor 515 of FIG. 5, the glare light sensor being positioned either behind the mirror glass and looking through a section of the mirror with the reflective material completely or partially removed, or the glare light sensor can be positioned outside the reflective surfaces (e.g., in the bezel 544) or, as described below, behind a uniformly deposited transflective coating. Additionally, in some area(s) of the mirror element the electrodes 628, 620 may be partially or completely removed to permit a light-emitting display 545 of FIG. 5 (corresponding to a compass, clock, or other indicia) to show through the mirror element to the driver of the vehicle. Alternatively, as described below, this light-emitting display assembly can be shown through a uniformly deposited transflective coating. In one embodiment of the invention, a mirror utilizes only one video chip light sensor to measure both glare and ambient light and is equipped with means for determination of the direction of glare. An automatic mirror on the inside of a vehicle, constructed according to this invention, can also control one or both outside mirrors as slaves in an automatic mirror system wherein the individual mirror elements are independently controllable.

[0149] FIG. 6B shows a top plan view of the second transparent element 614 with then reflecting electrode 620 deposited thereon, as may be used with the structure shown in FIG. 6A. As shown, the electrode 620 is separated into two distinct electrode areas—a first portion 620a and a second portion 620b that are electrically isolated and physically separated by an area 620c, which is devoid of electrode material or any other electrically conductive material. As a result, no current flows from the first portion 620a to the second portion 620b of the electrode 620. Removal of the electrode material 620 from the area 620c may be achieved, for example, by chemical etching, laser ablation, or scraping. Alternatively, the deposition of the electrode material in the area 620c can also be initially avoided by masking the area 620c during the deposition process.

[0150] As shown in FIG. 6A, the second portion 620b of the electrode 620 is in electrical contact with the electrochromic medium 626 at the third surface 614a of the electrochromic device. At the same time, the first portion 620a of the electrode 620 is physically isolated from the electrochromic medium 626 by either the area 620c, seal 616, or both. The first portion 620a, however, is electrically coupled to a portion of the transparent electrode 628 on the second surface 612b of the electrochromic device by means of an electrical conductor, which may extend around some or most of the periphery of the seal 616. Thus, a short circuit is effectively provided between portions of the electrode layers 620, 628. This short circuit allows the bus clip normally attached to a peripheral edge of the first transparent element 612 to be attached instead to the second element 614. More specifically, as shown in FIG. 6B, an electrical connection between the power supply and transparent electrode 628 on the second surface may be made by connecting the bus bars (or clips 619a) to the first portion 620a of electrode layer 620. An electrical connection to the second portion 620b may be made using a clip 619b that is attached to an extension 620d, of the portion 620b, that extends to the peripheral edge of the element 614. Such configuration is advantageous in that it provides an electrical connection to and communication with the transparent conductive material 628 nearly all the way around the circumference of the electrochromic element, which improves the speed of dimming and clearing of the electrochromic media 626. As will be described further below with respect to other embodiments, clips 619a and 619b may be replaced with other types of electrical connectors.

[0151] FIG. 6A is drawn to simultaneously show two different implementations of electrical conductors providing for electrical coupling of the first portion 620a of the electrode 620 to a portion of electrode 628. Specifically, the left side of an embodiment 600 of FIG. 6A demonstrates that conductive particles 616b may be distributed through at least part of the seal material 616 such that a portion of the seal 616 is electrically conductive. In one embodiment, the seal 616 is not electrically conductive across its entire width, but rather has a non-conductive portion that electrically insulates the conductive portion containing the conductive particles from the electrochromic medium 626 and prevents a short circuit between the electrode 628 and second portion 620b of the electrode 620. In this manner, the drive potential from the power supply is provided through the first portion 620a of the electrode 620 and conductive particles 616b in the seal 616 before reaching the transparent conductor 628. In such a configuration, the seal 616 comprises a typical sealing material (e.g., epoxy 616a), with the conductive particles 616b interdispersed therein. The conductive particles may be small, such as, for example, gold, silver, copper, metal-coated plastic particles with a diameter ranging from about 5 microns to about 80 microns, in which case there must be a sufficient number of particles to ensure sufficient conductivity between the first portion 620a of electrode 620 and the transparent electrode 628. Alternatively, the conductive particles may be large enough to act as spacers, such as, for example, gold, silver, copper, or metal-coated glass or plastic beads. The conductive particles may further be in the form of flakes or other suitable shapes or combination of different shapes.

[0152] To ensure that no conductive particles 616b are in contact with the area 620b of the reflecting electrode, a variety of methods may be used. For example, a non-conductive material may be disposed into the area 620c separating the portions 620a and 620b of the electrode 620. A dual dispenser could be used to deposit the seal 616 with conductive particles 616b onto the first portion 620a of the electrode 620 and to simultaneously deposit the nonconductive material into the area 620c. One general method of ensuring that no conductive particles reach the electrode area 620b is to make sure that the seal 616 has appropriate flow characteristics such that the conductive portion 616b tends to stay behind as the sealant is squeezed out during the assembly process, and that only the non-conductive portion of the seal 616 flows into the area 620b. Another method would be to dispense the non-conductive seal material(s) between the substrates, separately cure, or partially cure, the dispensed non-conductive seal, and then inject the conductive epoxy between the two substrates.

[0153] In an alternative implementation, shown on the right side of the embodiment 600 of FIG. 6A, a larger electrical conductor 616b is provided, which may also serve as a spacer. Such a larger electrical conductor may be a single wire, a braided wire, a conductive strip, or simply large particles or beads that are either electrically conductive throughout or coated with an electrically conductive material. In this implementation, the seal 616 need not contain conductive particles or other electrical conductor 616b and, instead, a conductive member or material 616c may be placed on or in the outer edge of the seal 616 to interconnect the transparent conductive material layer 628 to the first portion 620a of the electrode 620. Alternatively, such a conductive member 616c may also be used in combination with conductors dispersed within the seal or otherwise between the elements 612 and 614.

[0154] Yet another embodiment 700 of an improved electrical interconnection technique is illustrated in FIG. 7, where a seal member 616 is applied in two steps. A first portion of a seal member is applied directly onto the third surface 614a and is cured prior to the application of the electrode 620. After the electrode 620 is deposited onto the third surface 614a over the first portion of the cured seal member 616, a portion of the cured seal member 616 is machined off to leave a sub-portion 616i, as shown, having a predetermined thickness (which will vary depending on the desired cell spacing between the second surface 612b and the third surface 614a). Generally, the cell spacing ranges from about 20 microns to about 1500 microns, and preferably ranges from about 90 microns to about 750 microns. By curing the first portion of seal member and machining it to a predetermined thickness (616i), the need for glass beads to ensure a constant cell spacing is eliminated. Although, as discussed above, glass beads are useful to provide cell spacing, they provide mechanical stress at the points of contact with the electrodes 620 and 628. In absence of glass beads, these stress points are eliminated. During the machining of the cured first portion of the seal member 616, a portion of the electrode 620 that is coated on the first portion of seal member is removed to leave an area devoid of the electrode layer 620. Subsequently, a second portion of seal member 616ii is deposited onto the machined area of the first portion of seal member 616i or, alternatively, on the coatings covering the second surface 612b in the area corresponding to 616i. The first and second substrates 612, 614 are then appropriately assembled, following by curing the second portion 616ii of the seal member 616. Finally, an outer electrically conductive seal member 717 may optionally be deposited on the outer peripheral portion of the seal member 616 to provide for an electrical contact between the outer edge of the electrode 620 and the outer peripheral edge of the transparent conductive material layer 628. This configuration is advantageous in that it provide for an electrical connection to the transparent conductive material 628 nearly all the way around the circumference of the embodiment of the device, and, therefore, improves the speed of dimming and clearing of the electrochromic media 626.

[0155] Another implementation of electrical interconnections in an embodiment of the present invention is shown in FIG. 8A. This implementation 800 differs from the embodiments of FIGS. 6A and 7 in that the electrical conductor connecting the first portion 620a of the electrode 620 to a portion of the transparent electrode 628 is a wire or a strip 850 that may be coated with a conductive material 852 to improve contact to the electrode layers 620, 628 and to thereby ensure contact stability. The conductive material 852 may be conductive pressure-sensitive adhesive (PSA), conductive ink or an epoxy either of which may loaded with conductive particles, flakes, or fibers made of materials such as silver, gold, copper, nickel, or carbon. If the conductive material 852 has sufficient conductivity, a wire/strip 850 would not be needed. For coloring uniformity it is desirable to keep the measured resistance along the long edge of a mirror element below 5 Ohms, more preferably below 1 Ohm and most preferably below 0.5 Ohm. Many conductive inks or adhesives that are formulated for the electronics industry are suitable for this application. The ink or adhesive is preferably filled with conductive flakes, fibers or particles or a combination thereof to have a sufficient filler loading and is deposited with sufficient width and thickness to achieve the desired level of conductivity. An epoxy adhesive formulation with suitable conductivity is (by weight) between approximately 10% and approximately 20%, most preferably approximately 13.5%, epoxy resin D.E.R. 354 or 354 LV (Dow Chemical Company), between approximately 3% and approximately 7%, and most preferably approximately 4.5%, Ancamine 2049 (Air Products and Chemicals Inc.) and between approximately 70% and approximately 85%, and most preferably approximately 82%, sliver flake LCP 1-19 (Ames-Goldsmith). It is preferable to keep the bulk conductivity of the filler material below approximately 20 microOhm-cm, more preferably below approximately 10 microOhm-cm and most preferably below approximately 5 microOhm-cm. Similarly to the embodiments of FIGS. 6B and 7, the electrode 620 of the embodiment of FIG. 8 is separated into the first and second portions 620a, 620b by an area 620c that is devoid of any electrically conductive material.

[0156] FIG. 8B provides, in the same drawing, a showing of two alternative implementations of electrical interconnections that are related to the embodiment 800 of FIG. 8A. One implementation is shown on the left side of a structure 860. Here, at least one portion of the peripheral edge of the front surface 614a of the element 614 may be beveled to provide a heavy seam 854 between the elements 612 and 614. By forming this large seam 854, a larger diameter wire 850 may be inserted between the elements 612 and 614, without otherwise having to increase the spacing between the elements 612 and 614 which would result in increase of the width of the chamber 625. Such a heavy seam 854 may be provided by beveling either the front surface 614a of the element 614 or the rear surface 612b of the front element 612. An alternative second implementation is shown on the right side of the structure 860. Here, rather than providing a single large diameter wire 850, a plurality of smaller-diameter wires 850′ or wire strands of a braided wire may be provided as the electrical conductor between portions of the electrodes 620 and 628. The use of wires twisted together makes it easier to apply the adhesive 852. The wires 850′ need not be made of the same material. For instance, a copper wire could be twisted with a stainless steel, nylon, KEVLAR, or carbon fiber or wire to impart strength or other desirable properties to the seal region of the embodiment of a mirror element. The seam 854 could extend, for example, 0.020 inch in from side edges of the elements 612 and 614. Using the left portion of the structure 860 as an example, although the seam could extend far enough into the device such that the nonconductive seal portion 616 would cover the beveled portion of the electrode 620b, it still would be beneficial to laser etch the region 620c to ensure there is no electrical shorting between the electrodes 628 and 620b through the conductive material 852. It should be noted that if conductive adhesive 852 were of sufficient conductivity, the wire 850 would not be necessary. In this case, the heavy seam 854 would allow for use of a greater amount of the conductive material 852 between the substrates 612, 614 to improve the overall conductivity of the contact area.

[0157] FIG. 8C illustrates yet another embodiment of the present invention that is similar to that shown in FIG. 8A. However, in comparison with the embodiment 800 of FIG. 8A, rather than etching a portion of electrode 620 to provide for separate electrode regions 620a and 620b, an electrically nonconductive coating or material 856 is disposed between the electrode 620 and the coated wire 850. The coating or material 856 could be formed of a thin layer of organic resin such as epoxy, polyester, polyamide, or acrylic, or of inorganic material such as SiO₂, Ta₂O₅, etc. Such a nonconductive material may also help to hold the wire in place.

[0158] FIG. 8D shows another embodiment of the present invention. As shown, not only is the second substrate reflective electrode 620 etched in one region along a perimeter portion on the third surface, but also the transparent electrode 628 on the second surface is configured in a similar way. Specifically, the electrode 628 is etched to form a first portion 628a and a second portion 628b separated by an area 628c that is devoid of conductive material. The transparent electrode 628 may be etched along any perimeter portion of the second surface which does not coincide with the etching of electrode 620 over it's entire length. The front transparent electrode 628 may be etched along any side other than that on which electrode 620 is etched. Here, the edges of the elements 612 and 614 would be even with one another (i.e., have zero-offset). An electrically nonconductive seal 616 would thus be formed about the periphery and over the etched portions 628c and 620c of the two electrodes. The epoxy seal 616 would preferably be dispensed in from the edges of elements 612 and 614 approximately 0.010 to 0.015 inch on the top and bottom and even with the glass edges on the sides. The conductive material 852 could then be dispensed into the 0.010-0.015 inch channel at the top and bottom of the device. A foil, copper webbing material, or other highly conductive material 860 could then be adhered to the conductive epoxy/adhesive for each of the top and bottom regions to provide for electrical contact to electrodes 620 and 628. The webbing with its high surface area, or a foil, or thin conductive material with holes in it or roughened up exterior would enhance the adhesion of such a material to the conductive material 852 and to the edges of the device.

[0159] Additional description of establishing the electrical interconnections within the described-above embodiments of a mirror element is further provided with respect to FIGS. 9 (A, B) and 10(A-D), in reference to top views of the first and/or second substrates of the embodiments of a mirror element.

[0160] FIG. 9A shows a top plan view of the rear element 614 having the electrode coating 620 deposited thereon. To create the first and second portions 620a, 620b, a portion of the electrode material may be removed with the use of, e.g., laser ablation, chemical etching, physical scraping, or similar methods to form may be used to remove a portion of the electrode material to form the area 620c that is devoid of any electrically conductive material. The area 620c may be shaped differently, e.g. as a thin line that has a trench-like profile in the electrode 620. As shown in FIG. 9A, the first portion 620a is defined along one side of the element 614. FIG. 9B shows the electrically non-conductive seal 616 that is further disposed about the entire periphery of the substrate 614 to define the outer bounds of the chamber 625 in which the electrochromic medium 626 is disposed. The conductive material 852, which may in some embodiment also function as a sealing member, is then disposed with or without a wire/strip 850 along the peripheral edge of the substrate 614 on which the first portion 620a of the electrode 620 has been defined. Generally, the conductive material 852 may be deposited prior to or after substrates 612 and 614 are assembled together.

[0161] An alternative implementation of the electrical interconnections discussed in reference to FIGS. 6A and 8 (A, B) is shown in top views of the substrate 614 in FIGS. 10A and 10B, where two first portions 620a, 620a′ are defined at opposite sides of element 614 and separated by two corresponding nonconductive separation areas 620c, 620c′. Such an arrangement would allow for an electrical connection to the electrode 628 at two opposite sides of the element 614. The non-conducting seals 616 and the material 852, which is also an electrically conducting seal in this embodiment, would be disposed in a similar manner but with the conducting seal 852 being dispensed over all or part of both portions 620a and 620a′. The electrical wire(s) 850 (not shown) may extend from the conductive seal material 852 and be soldered to electrical clips or directly to a circuit board through which power is supplied to the electrochromic mirror. To coat the wire and deposit it between the substrates 612 and 614, the wire 850 may be fed through the middle of a dispensing nozzle that is used to dispense the seal material 852 directly onto the required portion of coated element 614.

[0162] FIGS. 10C and 10D provide additional illustrations of an embodiment having a two-part (conductive and non-conductive) seal. Specifically, FIG. 10C illustrates etching of both electrodes 620 and 628, while FIG. 10D shows the two portions 616′ and 616″ of the seal 616. The outer portion of the seal is conductive and the inner portion is nonconductive similar to the seal portions 616a,b shown in FIG. 6A. (Although, in an alternative embodiment, the entire seal 616 could be conductive and the electrochromic device would function, such alternative construction is not preferred with solution-phase electrochromic devices because of the segregation of the electrochromic species is enhanced when coloration of the electrochromic media occurs on the inside edge of the conductive seal and exposed portion of electrodes 628a and 620a.) As shown in FIG. 10D, there are two fill ports 1095 and 1096, provided at opposite ends of the electrochromic device, that allow for filling the chamber 625 with electrochromic material and additionally provide for electrical isolation of the corresponding conductive portions of seal portions 616′ and 616″. The plug material 1097 used to plug the fill ports 1095 and 1096 would also be made of an electrically nonconductive material to provide for the necessary electrical isolation. A fill port is typically plugged with an adhesive that is preferably UV-curable but that may also be a hot-melt or thermally-curable, or a combination of UV- and thermal-cure adhesive. The UV-curable adhesive generally is an acrylate base, epoxy base or vinyl ether base or a combination thereof and is generally cured by free radical or cationic polymerization.

[0163] FIG. 11 shows another embodiment 1100 of the present invention. This embodiment, which would apply to both electrochromic mirror and window applications, includes the conductive seal material 852 deposited and cured on each of the electrodes 620 and 628. The electrically nonconductive seal 616 is then dispensed between the two portions of the conductive seal 852, which are applied respectively to the second and third surfaces. The nonconductive seal 616 would be dispensed inward the gap 625 so as to provide for electrical isolation, if desired, between the seal 852 and the electrochromic medium 626. Alternatively, a dual dispense could be used for simultaneously dispensing the conductive and non-conductive seal materials. As a result, a portion of the height of an aggregate seal is used as both the seal and the electrically conductive bus. An advantage of this construction is that the seal/conductive bus 852 may extend about the entire periphery of the electrochromic device for each of the two electrodes 620 and 628. Preferably, the conductive seal material 852 would be formed of epoxy loaded with silver.

[0164] Embodiment 1200 of FIG. 12 shows a slight variant to the embodiment 1100 depicted in FIG. 11. Specifically, if the conductive material added to the epoxy seal portions 852 is less environmentally friendly than silver, the nonconductive seal could be formed either in two stages or using two separate nonconductive seal materials. For example, the nonconductive epoxy seal 616 could be provided in the conventional manner between the electrochromic medium 626 and the two conductive seals 852. Subsequently, a nonconductive material 1262 could be used to fill the gap between the conductive seal portions 852 and could extend along the edge of glass elements 612 and 614. A benefit of using this process is that the seal material 816 may be selected from those materials that are least susceptible to degradation from the electrochromic medium while seal material 1262 could be selected from materials that are perhaps more moisture and oxygen impermeable.

[0165] FIG. 13 shows yet another embodiment of the present invention. This embodiment, which would be equally suitable for mirrors or windows, provides for a nonconductive seal 616 between the electrodes 628 and 620 while defining the outer bounds of the chamber 625 in which electrochromic medium 626 is disposed. Between the seal 616 and the edge of elements 612 and 614 is provided an electrically insulating material 1364 made of ethylene-propylene-diene monomer (EPDM), polyester, polyamide, or other insulating material, and having conductive materials 1366 such as a foil or copper web or other highly conductive material attached to opposite sides thereof. Conductors 1366 may be secured to opposite sides of the insulator 1364 using a PSA. A conductive ink or epoxy 852 could be used to increase the contact stability between the conductors 1366 and electrodes 628 and 620. The seal 616 is not necessary if materials 852, 1366, and 1364 provide for adequate environmental protection and do not interfere with the electrochromic medium.

Concealment of the Seal.

[0166] FIG. 14 shows an enhancement to the embodiment described above with respect to FIG. 8D. It will be appreciated, however, that this enhancement approach may be used with any of the other embodiments described above or below. Specifically, as shown in an embodiment 1400, the structure of FIG. 8D is modified such that the first surface 612a is beveled around its periphery to provide for a beveled peripheral edge surface 1470 that is of sufficient width to obscure the view of the dual seal 616/852. With such a design, it may be possible to completely eliminate the need in a bezel in an embodiment of the invention. As will be appreciated by those skilled in the art, the conductive foil or web 860 may extend rearwardly and wrap around the second substrate 614 for electrical contact to a printed circuit board or the heater circuit through which power may be supplied to selectively vary the reflectivity of the mirror element. To further mask the view of the seal, a reflective coating 1472 may be applied to the beveled surface 1470.

[0167] FIG. 15 shows a slightly different approach for obscuring the view of the seal (as shown, a non-conductive seal 616). Specifically, a peripheral portion 1575 of the first surface 612a of the front element 612 is sandblasted, roughened, or modified to obscure the view of the portion of the device where the seal could otherwise be seen. Yet another approach is shown in FIG. 16A where a reflective or opaque paint/coating 1676 is provided on the peripheral region 1575 of the first surface 612a of the front element 612. Alternatively, as shown in FIG. 16B, such a reflective or opaque coating, paint, or film 1676 could be provided on the second surface 612b.

[0168] Yet another way to conceal the seal is to use a seal material that is transparent as disclosed in commonly assigned U.S. Pat. No. 5,790,298, the entire disclosure of which is incorporated herein by reference.

[0169] Each of the different methods for obscuring the view of the seal described above in connection with FIGS. 14-16B may be combined or used separately, and may be used with any of the other embodiments described herein. For example, the beveled surface 1470 shown in FIG. 14 could be sandblasted. Likewise, the sandblasted portion 1575 of the surface 612a could be painted or coated with a reflective or high refractive index material. Paint or other material could be applied by silk-screening or other suitable methods. The reflective material in combination with the roughened surface provides a diffuse reflector.

Peripheral Ring and Sealing Material.

[0170] Turning now to FIGS. 17(A-E) and 18, a discussion of additional features of the present invention is provided. FIG. 17A depicts an embodiment of the rearview mirror element 1700a, as viewed from the first substrate 1702a, with a spectral filter material 1796a positioned between the viewer and a primary seal material 1778a. A first separation area 1740a that is devoid of any electrically-conductive material is provided to substantially electrically insulate a first conductive portion 1708a from a second conductive portion 1730a. A perimeter material 1760a is applied to the edge of the element. FIG. 17B depicts the same embodiment of a rearview mirror element, now labeled as 1700b, as viewed from the second substrate 1712b with a primary seal material 1778b positioned between the viewer and a spectral filter material 1796b, disposed as a peripheral ring. A second separation area 1786b is provided to substantially electrically insulate a third conductive portion 1718b from a fourth conductive portion 1787b. A perimeter material 1760b is applied to the edge of the element. FIG. 17C depicts the same embodiment of a rearview mirror element, now labeled as 1700c, viewed from a section line FIG. 17C-FIG. 17C of either the element of FIG. 17A or 17B. In this view, a first substrate 1702c is shown to be secured to a second substrate 1712c in a spaced-apart relation via a primary seal material 1778c. A spectral filter material 1796c is positioned between the viewer and the primary seal material 1778c. First and second electrical clips 1763c, 1784c, respectively, are provided to facilitate electrical connections to the element. A perimeter material 1760c is applied to the edge of the element 1700c. It should be understood that the primary seal material 1778c may be applied by means commonly used in the LCD industry such as, e.g., by silk-screening or dispensing. U.S. Pat. No. 4,094,058 to Yasutake et al., the disclosure of which is incorporated in its entirety herein by reference, describes applicable methods. Using these techniques, the primary seal material may be applied to an individually cut-to-shape substrate or it can be applied as multiple primary seal shapes on a large substrate. The large substrate with multiple primary seals applied may then be laminated to another large substrate and the individual mirror shapes can be cut out of the laminate after at least partially curing the primary seal material. This multiple processing technique is a commonly used method for manufacturing LCDs and is sometimes referred to as an array process. Electro-optic devices can be made using a similar process. All coatings such as the transparent conductors, reflectors, spectral filters and, in the case of solid state electro-optic devices, the electro-optic layer or layers may be applied to a large substrate and patterned if necessary. The coatings can be patterned using a number of techniques such as by applying the coatings through a mask, by selectively applying a patterned soluble layer under the coating and removing it and the coating on top of it after coating application, laser ablation or etching. These patterns can contain registration marks or targets that can be used to accurately align or position the substrates throughout the manufacturing process. This is usually done optically, for instance, with a vision system using pattern recognition technology. The registration marks or targets may also be applied to the glass directly such as by sand blasting, or laser or diamond scribing if desired. Spacing media for controlling the spacing between the laminated substrates may be placed into the primary seal material or applied to a substrate prior to lamination. The spacing media or means may be applied to areas of the laminate that will be cut away from the finished singulated mirror assemblies. The laminated arrays can be cut to shape before or after filling with electro-optic material and plugging the fill port if the devices are solution phase electro-optic mirror elements.

[0171] FIG. 17D depicts a plan view of a second substrate 1712d comprising a stack of materials on a third surface, or a fourth surface, or both third and fourth surfaces. In at least one embodiment, at least a portion 1720d1 of a stack of materials, or at least the substantially opaque layers of a stack of materials, is removed, or masked, beneath the primary seal material. At least a portion 1720d2 of at least a layer of the stack of materials extends substantially to the outer edge of the substrate or extends to an area to facilitate electrical contact between the third surface stack and an element drive circuit (not shown). Related embodiments provide for inspection of the seal and, or, plug viewing and, or, plug curing the rear of the element subsequent to element assembly. In at least one embodiment, at least a portion of an outer edge 1720d1 of a stack of materials 1720d is located between an outer edge 1778d1 and an inner edge 1778d2 of a primary seal material 1778d. In at least one embodiment, the portion 1720d1 of a stack of materials, or at least the substantially opaque layers of a stack of materials, are removed, or masked, beneath the primary seal material between approximately 2 mm and approximately 8 mm wide, preferably approximately 5 mm wide. At least a portion 1720d2 of at least a layer of the stack of materials extends substantially to the outer edge of the substrate or extends to an area to facilitate electrical contact between the third surface stack and an element drive circuit (not shown) between approximately 0.5 mm and approximately 5 mm wide, preferably approximately 1 mm. It should be understood that any of the first, second, third and fourth surface layers or stacks of materials may be configured as disclosed either below or in the references incorporated herein by reference.

[0172] FIG. 17E depicts a plan view of the second substrate 412E comprising a third surface stack of materials. In at least one embodiment, at least a portion of an outer edge 1720e1 of a third surface stack of materials 1720e is located between an outer edge 1778e1 and an inner edge 1778e2 of a primary seal material 1778e. In at least one related embodiment, a conductive tab portion 1782e extends from an edge of the second substrate inboard of an outer edge 1778e1 of a primary seal material 1778e. In at least one related embodiment, a conductive tab portion 1782e1 overlaps with at least a portion of a third surface stack of materials beneath a primary seal material 1778e. In at least one embodiment, a substantially transparent conductive layer (not shown individually), such as a conductive metal oxide, of a third surface stack of materials extends beyond an outer edge 1720e1 of a remainder of the third surface stack and is in electrical communication with a conductive tab portion as depicted in FIG. 35K. It should be understood that the conductive tab may be deposited along any of the substrate peripheral areas as shown in FIGS. 35D-35N. In at least one embodiment, a conductive tab portion comprises chrome. It should be understood that the conductive tab portion improves conductivity over the conductive electrode; as long as a conductive electrode layer is provided with sufficient conductivity, the conductive tab portion is optional. In at least one embodiment, the conductive electrode layer imparts the desired color-specific characteristics of the corresponding reflected light rays in addition to providing the desired conductivity. Therefore, when the conductive electrode is omitted, color characteristics are controlled via the underlayer material specifications. It should be understood that any of the first, second, third and fourth surface layers or stacks of materials may be as disclosed herein or within the references incorporated elsewhere herein by reference.

[0173] FIG. 18 depicts an embodiment 1800 of a rearview mirror element, which is an enlarged view of the element depicted in FIG. 17C to provide greater detail. The embodiment 1800 comprises a first substrate 1802 having a first surface 1804 and a second surface 1806. A first conductive electrode portion 1808 and a second conductive electrode portion 1830 applied to the second surface 1806 are substantially electrically insulated from one another via a first separation area 1840. As can be seen, in at least one embodiment the separation area is located such that the spectral filter material 1896 and a corresponding adhesion promotion material 1893 are also substantially electrically insulated to define first and second spectral filter material portions 1824, 1836, respectively, and first and second adhesion promotion material portions 1827, 1839, respectively. A portion of the first separation area 1840, (1740a, 1740b, 1740c in FIG. 17) is shown to be extending parallel within a portion of the primary seal material 1878 located near the center thereof. It should be understood that this portion of the separation area 1840 may lie such that a viewer would not readily perceive a line within the spectral filter material; for example, a portion of the separation area may be substantially aligned with an inboard edge 1897 of spectral filter material 1896. It should be understood that when any portion of the separation area 1840 is located inboard of the primary seal material, as is described in more detail elsewhere herein, a discontinuity in the electro-optic material coloring and, or, clearing may be observed. This operational characteristic may be manipulated to derive a subjectively visually appealing element.

[0174] With further reference to FIG. 18, the embodiment 1800 is depicted to comprise a second substrate 1812 having a third surface 1815 and a fourth surface 1814. It should be noted that the first substrate may be larger than the second substrate to create an offset along at least a portion of the perimeter of the mirror. Third and fourth conductive electrode portions 1818, 1887, respectively, are shown proximate the third surface 1815 and are substantially electrically insulated from one another via the second separation area 1886. A portion of the second separation area 1886 (1786a, 1786b, 1786c in FIG. 17) is shown to be extending parallel within a portion of the primary seal material 1878 located near the center thereof. It should be understood that this portion of the separation area 1886 may lie such that a viewer would not readily perceive a line within the spectral filter material; for example, a portion of the separation area may be substantially aligned with an inboard edge 1897 of spectral filter material 1796. As further shown in FIG. 18, a reflective material 1820 may be applied between an optional overcoat material 1822 and the third conductive electrode portion 1818. It should be understood that any of the materials as disclosed in commonly assigned U.S. Pat. Nos. 6,111,684, 6,166,848, 6,356,376, 6,441,943, 6,700,692, 5,825,527, 6,111,683, 6,193,378, 6,816,297, 7,064,882 and 7,324,261, the disclosure of each of which is incorporated herein by reference, may be employed to define a unitary surface coating, such as a hydrophilic coating on a first surface, or a composite stack of coatings, such as conductive electrode material, spectral filter material, adhesion promotion material, reflective material, overcoat material applied to the first, second, third and fourth surfaces. It should be additionally understood that a hydrophobic coating, such as a fluorinated alkyl saline or polymer, a silicone containing coating or a specially textured surface may be applied to the first surface. Either a hydrophilic or hydrophobic coating will alter the contact angle of moisture impinging upon the first surface relative to glass with no such coating and will enhance rear vision when moisture is present. It should be understood that both third surface and fourth surface reflector embodiments are within the scope of the present invention. In at least one embodiment, the materials applied to the third surface and, or, fourth surface are configured to provide a partially reflective/partially transmissive characteristic for at least a portion of the corresponding surface stack. In at least one embodiment, the materials applied to the third surface are integrated to provide a combination reflector/conductive electrode. It should be understood that additional “third surface” materials may extend outboard of the primary seal, in which case, it should be understood that the corresponding separation area extends through the additional materials. Having at least a portion of the primary seal visible from the fourth surface, as depicted in FIG. 17D for example, facilitates inspection and UV curing of plug material. In at least one embodiment, at least a portion of a stack of materials 1720d, or at least the substantially opaque layers of a stack of materials, are removed, or masked, beneath the primary seal material to provide for inspection of at least 25 percent of the primary seal width around at least a portion of the perimeter. It is more preferred to provide for inspection of 50 percent of the primary seal width around at least a portion of the perimeter. It is most preferred to provide for inspection of at least 75 percent of the primary seal width around at least a portion of the perimeter. Various embodiments of the present invention will incorporate portions of a particular surface having a coating or stack of coatings different from other portions; for example, a “window” in front of a light source, information display, a photo sensor, or a combination thereof may be formed to selectively transmit a particular spectral band or bands of wavelengths as described in many of the references incorporated herein.

[0175] With further reference to FIGS. 17 (A, B) and 18, the first separation area 1840 cooperates with a portion of the primary seal material 1878 to define the second conductive electrode portion 1830, the second spectral filter material portion 1836 and the second adhesion promotion material portion 1839 substantially electrically insulated from the first conductive electrode portion 1808, the first spectral filter material portion 1824 and first adhesion promotion material portion 1827. This configuration allows for placement of an electrically conductive material 1848 such that the first electrical clip 1863 is in electrical communication with the third conductive electrode portion 1818, the reflective material 1820, the optional overcoat 1822 and the electro-optic medium 1810. It should be apparent, particularly in embodiments wherein the electrically conductive material 1848 is applied to the element prior to placement of the first electrical clip 1869, that electrically conductive material may at least partially separate the interfaces 1857, 1866, 1872, 1875. Preferably, the material, or composition of materials, forming the third conductive electrode portion 1818, the first electrical clip 1863 and the electrically conductive material 1848 are chosen to promote durable electrical communication between the clip and the materials leading to the electro-optic medium. The second separation area 1886 cooperates with a portion of the primary seal material 1875 to define the fourth conductive electrode portion 1887 substantially electrically insulated from the third conductive electrode portion 1818, the reflective layer 1820, the optional overcoat material 1822 and the electro-optic medium 1810. This configuration allows for placement of an electrically conductive material 1890 such that the second electrical clip 1884 is in electrical communication with the first adhesion promotion material portion 1893, the first spectral filter material portion 1896, the first conductive electrode portion 1808 and the electro-optic medium 1810. It should be apparent, particularly in embodiments wherein the electrically conductive material 1890 is applied to the element prior to placement of the first electrical clip 1884, that electrically conductive material may at least partially separate the interfaces 1885, 1888, 1889. Preferably, the material, or composition of materials, forming the first conductive electrode portion 1808, the first electrical clip 1884, the adhesion promotion material 1893, the spectral filter material 1896 and the electrically conductive material 1890 are chosen to promote durable electrical communication between the clip and the materials leading to the electro-optic medium.

[0176] Preferably, the perimeter material 1860 is selected such that the resulting visible edge surface is visually appealing and such that good adhesion is obtained at interfaces 1833, 1845, 1854. It should be understood that at least a portion of the first substrate 1802 in the areas proximate the first corner 1803, the edge 1805, the second corner 1807 and combinations thereof may be treated to smooth protrusions and depressions noticeable to a viewer. It is within the scope of the present invention to treat at least a portion of a surface, a corner, an edge or a combination thereof to define “beveled,” “rounded,” or combinations thereof. Commonly assigned U.S. Pat. Nos. 7,064,882 and 7,324,261 describe various mechanisms for carrying out the edge treatment. The corresponding treatment improves the visual appearance and durability of the element.

[0177] Turning to FIG. 19 and Tables 1-4a, the color rendered as a result of having an indium-tin-oxide (ITO) conductive electrode between the second surface of the first substrate and a spectral filter material (also referred to herein as a “ring”) is described. In the example mirror element description contained herein, the reflectivity associated with the spectral filter material with respect to that of the third surface reflector results, in at least one embodiment, in a more blue hue for the spectral filter material when the electro-optic medium is in a “clear” sate. As depicted in the tables contained herein, the b* associated with the reflector is higher than the b* associated with the spectral filter material. When there is mismatch between the hue of the main reflector and spectral filter material, it is often desirable to have a spectral filter material with a lower b* value than the main reflective area. Many outside mirrors are designed to have a bluish hue in the main reflective area. As described in at least one embodiment herein, the use of aluminum in combination with, or in lieu of, chrome for the spectral filter material provides additional color rendering options. Other options, or embodiments, are depicted which provide a better match between the ring and the mirror viewing area. In these other cases the spectral filter or ring has virtually identical reflectance and color allowing a seamless match between the viewing area and the ring.

[0178] Table 1 summarizes various color characteristics, namely, Y specular (specular reflectance, R) included (A10); a*; b*; C* and Y specular (specular reflectance, R) excluded, for seven uniquely configured spectral filter materials, second surface conductive electrode and related materials.

[0179]

TABLE 1
			D65-2 Macbeth
			Color Eye 7000
Reflectance	A10	D65-2 (specular included)	Y specular
Trial	Y	a*	b*	C*	excluded
1	856csito	11.665	2.088	−5.491	5.874	0.01
2	cswchr	38.312	−3.477	4.183	5.439	0.133
3	cswchral	61.366	−3.108	6.965	7.627	0.186
4	halfchral	61.679	−4.484	12.279	13.072	0.376
5	halfchr	41	−5.929	12.809	14.114	0.073
6	Tec15Chr	23.76	0.984	8.603	8.659	1.322
7	Tec 15	11.284	−3.363	0.442	3.392	0.162
1—Glass/856 Ang. Al203/Half wave (Optical thickness) ITO
2—1 plus opaque chrome layer
3—1 plus approx 30 Ang. Chrome/250 Ang. Aluminum
4—Glass/Half wave ITO/30 Ang. Chrome/250Ang. Aluminum
5—Glass/Half wave ITO/Opaque Chrome layer
6—Glass/Tec15/Opaque chrome
7—Tec 15

[0180] Tables 1a through 1d contain variations for the spectral filter materials. The reflectance is shown for a CIE-D65 standard illuminant. Individual layer thicknesses are shown in nanometers. Table 1a shows the effect of chrome thickness on the stack Glass/ITO/Cr/Ru/Rh. The reflectance of the stack increases as the thickness of the chrome is thinned. In this example the refractive index of the chrome is n=3.4559 and k=3.9808, where n represents the real portion and k represents the imaginary portion of a complex number. The refractive index of the chrome in part defines the reflectivity of the stack and will be discussed in more detail later. Also, as the chrome is thinned, the reflected a* values increase, leading to a better match for the ring material.

[0181] In at least one embodiment, the reflectivity of the spectral filter is increased by putting rhodium next to the first chrome layer instead of ruthenium. Table 1b shows the effect of chrome thickness on the reflectance and color of the ring as the chrome thickness is changed. Similarly to the previous example, the reflectance increases as the chrome layer is thinned. This embodiment is preferred when the reflectance of the center of the mirror reflectance is relatively high.

[0182] Typical production mirror properties are shown below:

[0183]

Full Mirror Reference Color
	Reflectance	a*	b*
	Typical Outside Mirror	56.3	−2.2	2.4
	Typical Inside Mirror	85.0	−3.0	5.0

[0184]

TABLE 1a
alternate stacks—chrome thickness with ruthenium
								R %
Run #	ITO	Cr	Ru	Rh	Cr	Ru	Rh	(CIE-D65)	a*	b*
1	118	60	20	3.5				45.5	−6.1	−3.1
2	118	20	20	3.5				47.5	−4.9	−2.8
3	118	10	20	3.5				50.24	−4.3	−2.3
4	118	5	20	3.5				51.16	−4.3	−2.1
5	118	2.5	20	3.5				51.17	−4.3	−1.9

[0185]

TABLE 1b
alternate stacks—chrome thickness with rhodium/ruthenium
								R %
Run #	ITO	Cr	Ru	Rh	Cr	Ru	Rh	(CIE-D65)	a*	b*
17	118	0		5		30		59.82	−3.3	−0.14
18	118	2.5		5		30		57.36	−3.2	−0.6
19	118	5		5		30		54.9	−3.3	−1.1
20	118	7.5		5		30		52.64	−3.6	−1.6
21	118	10		5		30		50.66	−3.9	−2.2
22	118	12.5		5		30		49.02	−4.3	−2.6

[0186] Table 1c depicts the effect of ruthenium thickness when a thin rhodium layer is used next to a thin chrome layer. A particular benefit is attained when the ruthenium layer is approximately 20 nm. The minimum requirement for ruthenium will vary with rhodium thickness, the thin chrome thickness and the target reflectivity value.

[0187]

TABLE 1c
alternate stacks—varying ruthenium behind rhodium
								R %
Run #	ITO	Cr	Ru	Rh	Cr	Ru	Rh	(CIE-D65)	a*	b*
11	118	5		2.5		0		19.63	−8.5	−3.4
12	118	5		2.5		10		44.46	−4.7	−2.8
13	118	5		2.5		20		52.9	−3.7	−1.6
14	118	5		2.5		30		53.97	−3.6	−1.3
15	118	5		2.5		40		53.4	−3.9	−1.6

[0188] Table 1d depicts the how the reflectance will change with rhodium thickness at a fixed chrome and ruthenium thickness. The intensity of the reflectance increases with increasing rhodium thickness and the reflected a* increases. The increase in a* value of reflected light may be exploited to help improve the color match between the center of glass and the ring. The change in reflectance with changing rhodium thickness will differ depending on the thickness of the chrome layer between the rhodium and the ITO. The thicker the chrome layer, the more the rhodium reflectance will be dampened. Also in Table 1d are alternate metals between a thin and thick chrome layer. Palladium, iridium, cadmium and platinum are shown. The reflectance versus metal thickness is shown along with the effect of changing the thin chrome base layer thickness.

[0189]

TABLE 1d
alternate stacks—varying rhodium thickness
								R %
Run #	ITO	Cr	Ru	Rh	Cr	Ru	Rh	(CIE-D65)	a*	b*
	118	5		0		30		52.59	−4	−1.6
14	118	5		2.5		30		53.97	−3.6	−1.3
16	118	5		5		30		54.9	−3.3	−1.1
19	118	5		7.5		30		55.5	−3.1	−0.9
Glass	1.2 mm	1.2 mm	1.2 mm	1.2 mm	1.2 mm	1.2 mm
ITO	120	120	120	120	120	120
IRIDIUM	3	6	9	12	15	18
CR	40	40	40	40	40	40
R (cap Y)	50.5	52.8	54.3	55.4	56.0	56.4
ITO	120	120	120	120	120	120
Chrome	1	2	4	6	8	10
IRIDIUM	15	15	15	15	15	15
CR	40	40	40	40	40	40
R (cap Y)	55.3	54.5	53.3	52.2	51.4	50.8
ITO	120	120	120	120	120	120
Palladium	3	6	9	12	15	18
CR	40	40	40	40	40	40
R (cap Y)	50.9	53.6	55.6	57.0	58.0	58.7
ITO	120	120	120	120	120	120
Chrome	1	2	4	6	8	10
Palladium	15	15	15	15	15	15
CR	40	40	40	40	40	40
R (cap Y)	56.5	55.2	53.0	51.5	50.4	49.6
ITO	120	120	120	120	120	120
Platinum	3	6	9	12	15	18
CR	40	40	40	40	40	40
R (cap Y)	49.7	51.3	52.3	52.9	53.1	53.2
ITO	120	120	120	120	120	120
Chrome	1	2	4	6	8	10
Platinum	15	15	15	15	15	15
CR	40	40	40	40	40	40
R (cap Y)	52.3	51.6	50.5	49.7	49.2	48.9
ITO	120	120	120	120	120	120
Cadmium	3	6	9	12	15	18
CR	40	40	40	40	40	40
R (cap Y)	52.3	56.5	59.9	62.5	64.6	66.1
ITO	120	120	120	120	120	120
Chrome	1	2	4	6	8	10
Cadmium	15	15	15	15	15	15
CR	40	40	40	40	40	40
R (cap Y)	62.2	60.1	56.6	54.0	52.0	50.7

[0190] Different metals or mixtures of metals may be used next to the thin chrome layer. The thin chrome layer may be considered optional. Generally, the thin chrome layer is used when an adhesion promoter layer is desired. Alternate adhesion promoting metals or materials may fulfill a comparable function. The different metals are selected to alter the reflectance, either higher or lower, depending on the match desired with respect to the center of the viewing area. The metal can have another benefit, that of altering the color or hue of the ring area. The presence of the ITO or other dielectric layer under the metals tends to move the color to a more negative b* direction. The use of a “red” high reflectance metal such as copper may enhance reflectivity while simultaneously facilitating a color match to the viewing area. Table 1e shows the effect of a thin copper layer placed between two chrome layers. The reflectance is substantially increased while simultaneously making the ring color more neutral. A copper gold alloy has similar properties.

[0191]

TABLE 1E
Color and reflectance effects of copper addition to stack
	ITO	114	114
	Chrome	1	1
	Copper	0	15
	Chrome	40	40
	R	47.3	56.2
	a*	−5.2	−0.7
	b*	−3.5	2.3

[0192] Suitable metals, which will result in increased reflectance, include cadmium, cobalt, copper, palladium, silver, gold, aluminum and iridium or other high reflectance metals, their alloys and/or mixtures of metals.

[0193] Table 2 summarizes various color characteristics, namely, a*; b*; C* and reflectance (Y specular included (A10)) for the combinations of various indium-tin-oxide second surface conductive electrodes positioned between a first substrate and a substantially opaque chrome spectral filter material. The data contained in this table depict the ability to control the resulting b* value by varying the ITO thickness from approximately 65 percent to approximately 100 percent of a half-wave thickness. Specific thicknesses anticipated to obtain a given color may vary somewhat based on deposition parameters that affect the optical constants. The color of a particular stack may vary, to some degree, based on choice of process parameters, as well as process fluctuations that result in small but sometimes significant shifts in the optical constants of the materials used. For example, the half-wave optical thickness of ITO will correspond to a lesser physical thickness if the physical density of the coating is increased and an increase in absorption in the ITO coating would decrease the reflectivity of a second surface ITO plus chrome stack. This does not negate the fact that over the range of optical constants usually associated with ITO, a half wave optical thickness of ITO (relative to 550 nm) when coated with, for example, chrome, will tend to produce a reflection having a yellowish hue. Table 2a shows the same effect over a narrower range of ITO thicknesses and with a modified metal stack. As the ITO is increased in thickness, the reflectance increases providing a better intensity match. The a* value decreases and the b* value increases. The net effect is that the color match will be improved with the appropriate ITO thickness. Or, if a color mismatch is chosen, the color of the spectral filter material can be made to have a lower b* value than the main reflective area.

[0194]

TABLE 2
TCO plus Chrome Specular Included
	Trial	a*	b*	C*	A10Y
	85CHR	−6.801	2.486	7.241	44.829
	80CHR	−6.717	−0.829	6.768	44.375
	75CHR	−6.024	−4.031	7.248	43.759
	70CHR	−5.613	−5.426	7.807	42.917
	65CHR	−5.227	−6.639	8.45	42.64
	100CHR	−7.06	12.85	14.662	45.255

[0195]

TABLE 2a
Effect of ITO with modified metal stack
								R %
Run #	ITO	Cr	Ru	Rh	Cr	Ru	Rh	(CIE-D65)	a*	b*
	108	5		2.5		30		52.3	−2.5	−4.5
	113	5		2.5		30		53.2	−3.1	−3.0
	118	5		2.5		30		54.0	−3.6	−1.3
	123	5		2.5		30		54.5	−4.1	0.6
	128	5		2.5		30		54.9	−4.5	2.6
	133	5		2.5		30		55.1	−4.7	4.7

[0196] Table 3 summarizes various color characteristics, namely, a*; b*; C* and reflectance R (Y specular included (A10)) for various indium-tin-oxide second surface conductive electrodes. The data contained in this table depicts the resulting values produced by varying the ITO thickness from approximately 65 percent to approximately 100 percent of a half-wave thickness.

[0197]

TABLE 3
TCO Specular Included
				Y	Thickness
Trial	a*	b*	C*	(A10)	(Å)
65CLR	−0.988	15.535	15.567	15.678	1095
100CLR	13.588	−17.765	22.366	8.967	1480
85CLR	8.376	2.896	8.863	11.352	1306
80CLR	4.481	11.34	12.193	12.892	1253
75CLR	1.565	15.019	15.101	14.275	1194
70CLR	−0.276	15.654	15.656	15.259	1135

[0198] Materials used for transparent second surface conductive electrodes are typically materials with an approximately 1.9 index of refraction, or greater. It is known to minimize color impact of these conductive electrode materials by using half wave thickness multiples, using the thinnest layer possible for the application or by the use of one of several “non-iridescent glass structures.” Non-iridescent structures will typically use either a high and low index layer under the high index conductive coating (see, for example, U.S. Pat. Nos. 4,377,613 and 4,419,386 by Roy Gordon), or an intermediate index layer (see U.S. Pat. No. 4,308,316 by Roy Gordon) or graded index layer (see U.S. Pat. No. 4,440,822 by Roy Gordon) to minimize color impact. The intensity of the ring with a color suppression layer is lower than the center of the part. The color suppression layer helps the color of the ring but the ring would still be visible because of the intensity contrast. The color suppressed ITO would therefore benefit from the use of a different sequence of metal layers on top of the ITO. Table 3a shows the color for a range of different metal options. The top chrome layer is optional and it does not contribute to the color or reflectance match of the ring. The top chrome layer is added to minimize the transmittance of the layer stack and to minimize the amount of UV light that would reach the seal, thus extending the lifetime of the product. A chrome/rhodium/ruthenium stack is shown but it is understood that other metals, alloys, and high reflectors described elsewhere in this document can be used.

[0199] The results of varying the thickness of the ITO with and without a color suppression layer are shown in Table 3a2. The colors shown in the table represent the changes which occur with an ITO thickness between 100 and 300 nm. Therefore, the use of a color suppression layer allows a broader thickness range for the ITO layer without causing the strong color variations experienced without the color suppression layer.

[0200]

TABLE 3a
Effect of metal layers with color suppressed ITO—Reflectance in CIE-D65
									Exam-	Exam-	Exam-
	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Example 7	Example 8	ple 9	ple 10	ple 11
Color Suppression Layer	80	80	80	80	80	80	80	80	80	80	80
ITO ½ Wave	148.7	148.7	148.7	148.7	148.7	148.7	148.7	148.7	148.7	148.7	148.7
Chrome Layer	0	3	5	5	5	5	5	4	3	2	60
Rhodium	0	0	0	3	6	9	12	12	12	12	0
Ruthenium	30	30	30	30	30	30	30	30	30	30	30
Chrome Layer	25	25	25	25	25	25	25	25	25	25	0
Reflectance Cap Y	48.8	49.2	49.3	51.1	52.2	52.9	53.2	54.3	55.5	56.8	45.7
a*	−2.2	−1.6	−1.4	−0.9	−0.5	−0.2	0.0	0.0	−0.1	−0.2	−1.8
b*	2.1	0.5	−0.3	−0.3	−0.3	−0.2	−0.2	0.4	1.0	1.7	−3.3

[0201]

TABLE 3a2
Effect of color suppressed ITO thickness on color—200 nm ITO +/− 100 nm
	Stack
	Case 1	Case 2	Case 3	Case 4	Case 5	Case 6	Case 7	Case 8
1.670	80	80	80	80	80	80	80	80
ITO	100	130	150	180	210	240	270	300
Chrome	2	2	2	2	2	2	2	2
Rhodium	5	5	5	5	5	5	5	5
Ruthenium	30	30	30	30	30	30	30	30
a*	1.15	0.54	−0.76	−1.5	0	0.54	−0.84	−1.1
b*	0.9	0.14	1.7	3.22	0.92	−0.16	2.17	3.1
1.670	0	0	0	0	0	0	0	0
ITO	100	130	150	180	210	240	270	300
Chrome	2	2	2	2	2	2	2	2
Rhodium	5	5	5	5	5	5	5	5
Ruthenium	30	30	30	30	30	30	30	30
a*	−1	−3.9	−3.4	5.5	8	−4	−10.1	−0.9
b*	−5.4	3.19	9.9	3.8	−8.6	−4.3	7.6	5.5

[0202] A partially transmissive layer such as thin chrome adjacent to the glass may be used to provide adhesion benefits compared to metals that might be used for better reflectivity compared to chrome such as a platinum group metal (PGM) (i.e. iridium, osmium, palladium, platinum, rhodium, and ruthenium), silver, aluminum and various alloys of such metals with each other, such as silver-gold, white gold, or other metals. When these other metals or alloys are placed behind the partially transmissive adhesion promoting layer, some of the improved reflectance of the second material will be realized. It may also be beneficial to overcoat the spectral filter material with a material that improves the durability of the spectral filter material whether it is in contact with a transparent conductor overcoat or if it is in direct contact with the electro-optic medium. It should be understood that the reflector may be a dichroic stack. The spectral filter material may comprise a single material such as chrome or may comprise a stack of materials such as: 1) chrome, rhodium, ITO; 2) moly; 3) chrome, rhodium, TCO; 4) chrome, platinum group metal, ITO; 5) ITO, silver, ITO; 6) ITO, silver alloy, ITO; 7) Z_NO, silver/silver alloy, Z_NO; 8) transparent conductor, metal reflector, transparent conductor; silicon, ITO; 9) silicon, Z_NO; 10) chrome, ruthenium, ITO and 11) chrome/rhodium/ruthenium/ITO or other metals, metal alloys or combinations described elsewhere in this document can be used.

[0203] There may also be advantages to applying the transparent conductive oxide(s) on the second surface of the mirror in more than one step. For example, a zinc oxide layer may be deposited initially to form a layer to which silver or its alloys bond well. This is preferably chosen at a thickness that produced a desirable color and reflectivity when combined with silver, silver alloy or other metals and their alloys. Then the metal layer(s) are applied around the perimeter of the part followed by additional transparent conductive oxide(s) over at least the electrochromic area. The additional applications of oxides improve the conductivity in the electrochromic area and may be chosen at a thickness which yields a desirable range of hue when going from bright state to dark state, in the electrochromic area, but particularly in the fully darkened state. If the conductive oxide adjacent to the electrochromic medium has sufficient conductivity, not all of the metal oxides in the stack would necessarily need to be conductive.

[0204] For example, using an optical model, opaque silver deposited over 100 nm of ITO, the color of a reflective ring would be about, using CIELAB D65 standard illuminant, 2 degree observer a*=−1, b*=−2 and Y value of 89. For purposes of this discussion, the silver is masked such that it is only applied in a ring around the electrochromic area. The color of the electrochromic area with only the 100 nm ITO on glass using a material of index 1.43 as the electrochromic medium and no reflection from a 3^rd or 4^th surface models as a*=−3, b*=8 with a Y value of 8. To make the electrochromic area less yellow and more conductive, 40 nm of ITO coating may be added in the electrochromic area. This brings the coating in the electrochromic area to about half wave optical thickness, which is approximately the second surface coating thickness that most electrochromic elements have. The model for the electrochromic area then yields a color of a*=11, b*=−14, and Y value of 5. Either, or both, of these applications of transparent conductive oxides may be of another material such as aluminum doped zinc oxide. There might also be additional layer(s) such as nickel chromium or nickel chromium suboxide, niobium or niobium suboxide, titanium or titanium suboxide, as well as other means known in the art that would protect or preserve a metal layer such as silver during subsequent steps of the coating and assembly process such as thermal processing steps.

[0205] Note that by using such a stack, the reflective ring will more closely match the brightness of electrochromic areas in the undarkened state that are more highly reflective such as devices that have 3^rd surface coatings incorporating silver or silver alloys. In particular, aluminum that is in direct contact with the electro-optic medium tends to degrade upon being subjected to multiple coloring/clearing cycles. An overcoat of chrome has been demonstrated to improve that durability. When an ITO overcoat is used, a material such as silicon may improve the strength of the bond between the ITO and the substances closer to the glass. Other materials, such as a platinum group metal (PGM) (i.e. iridium, osmium, palladium, platinum, rhodium, and ruthenium), may be overcoated to improve any of adhesion, reflection, conductivity, and electrode stability characteristics of an embodiment. Not all material have adequate durability to be used in configuring a peripheral ring on the second surface of the EC-element, which is usually maintained as an anode. For example, silver is known to be susceptible to de-plating when deposited on the anodic side of an EC-cell and when exposed to EC-medium, but has adequate mechanical and electro-chemical stability when used as part of a reflective electrode on the third surface of the EC-cell that is typically maintained as a cathode. Therefore, in order to expand a group of materials practically usable for construction of a peripheral ring, in one embodiment of the invention the transparent electrode of an EC-cell is maintained as a cathode, while the reflective electrode of the EC-cell is maintained as an anode.

[0206] As revealed in the above figures and tables, the thickness of ITO may be chosen to produce a desired reflection color. If the ITO coating is about 25 percent thinner, that is about 120 Å. Instead of 140 Å, then a more bluish hue results (i.e. lower b*). This, however, will also result in decreased conductivity of the ITO coating. The reflectivity of the coating will also be slightly to somewhat higher than for coatings of the traditional half-wave optical thickness where the reference is to a minimum reflectivity near 550 nm.

[0207] The compromise between optimal color and sheet resistance of the ITO may be mitigated by the use of partial deletion of the ITO layer. For instance, the ITO may be applied to any thickness needed to give adequate color in the center of the viewing area and the required sheet resistance. Then, the ring portion of the ITO coating may be ion etched or removed in any other viable method so that the final thickness of the ITO in the ring is at a point where we have the desired aesthetics. The etching or removal process for the ITO may be conducted in the same process as the deposition of the subsequent metal layers or it may be done in a separate step.

[0208] It is known in the art that a chrome layer may be applied beneath the ITO layer to provide a marginal match between the viewing area and the ring. The degree of match between the ring in this case and the viewing area is a function of the reflectance in the viewing area and properties of the chrome. What has not been taught in the art is how the properties of the chrome layer affect the match of the ring to the viewing area. For instance, in some cases, the reflectance of the viewing area may be specified by law to be greater than 55 percent. The reflectance of the chrome ring is a function of the thickness of the chrome and, more importantly, the refractive index of the chrome. For a given refractive index dispersion formula, the reflectance can be dropped from its maximum value by reducing the thickness of the chrome layer. This can have a detrimental effect because the transmittance of the chrome layer will increase thus allowing more UV light to penetrate to the EC unit seal. The UV light can damage the seal leading to a shorter lifetime of the product.

[0209] The reflectance of the ring may be enhanced by tuning the optical properties of the chrome layer. Table 3b shows the dependence of the reflectance of chrome under ITO on the optical properties of the chrome layer. Two sets of optical constants were obtained from the open literature and were mixed in different proportions to assess the effect of the optical constants on the reflectivity. The optical constants vary with wavelength and the values in Table 3b are values at 550 nm for reference. The thickness of the chrome layer is 80 nm and the ITO is 148.7 nm. In at least one embodiment, the glass thickness is 1.2 mm and the reflectance quoted is for viewing through the glass to the coating stack.

[0210] The reflectance, in this example, varies from a low of 48.6 to a high of 54.2 percent. This clearly demonstrates that some chrome layers may not necessarily attain the reflectance needed for a match to the reflectance in the viewing when relatively high reflectance is present in the viewing area. In addition, there is a finite maximum reflectance attainable by a single layer of chrome under the ITO. The preferred chrome layers are defined by the refractive indices of the chrome layer.

[0211]

TABLE 3b
Performance of the chrome layer under ITO versus chrome for
various chrome optical constants
Chrome	80	80	80	80	80	(nm)
Layer
Chrome n	3.456	3.366	3.279	3.196	3.116	@550 nm
Chrome k	3.981	4.089	4.199	4.310	4.423	@550 nm
ITO-B18	148.7	148.7	148.7	148.7	148.7	(nm)
Reflectance	48.6	49.9	51.3	52.8	54.2	(percent)

[0212] In order to define the appropriate optical constants for the chrome layer, a series of calculations were performed. A simplified analysis was conducted where the refractive index of the chrome is held constant over the visible region. The analysis shows the relationship between the real and imaginary refractive indices of the chrome and the resultant reflectance. In actual practice, this may deviate from theoretical analysis by up to +/−20 percent to account for the effects of the dispersion in the chrome optical constants. Table 3c shows the reflectance for various combinations of n and k and the ratio of n/k.

[0213]

TABLE 3C
Reflectance for chrome under ITO as a function of the optical
constants of the chrome
@550 nm
Example	n	k	ratio	Reflectance
1	3.00	3.90	0.77	49.8
2	3.00	4.10	0.73	51.7
3	3.00	4.20	0.72	52.7
4	3.00	4.20	0.71	52.7
5	3.00	4.30	0.70	53.7
6	3.00	4.50	0.67	55.5
7	2.70	4.20	0.64	54.2
8	2.90	4.20	0.69	53.1
9	3.00	4.20	0.71	52.7
10	3.00	4.20	0.72	52.7
11	3.10	4.20	0.74	52.2
12	3.50	4.20	0.83	50.9
13	3.70	4.20	0.88	50.4
14	3.90	4.20	0.93	50.1
15	4.10	4.20	0.98	49.8
16	3.30	4.20	0.79	51.5
17	3.30	3.90	0.85	48.7
18	2.70	3.50	0.77	46.8
19	2.70	3.70	0.73	49.0
20	2.70	3.90	0.69	51.2
21	2.70	4.10	0.66	53.2
22	2.70	4.30	0.63	55.2
23	2.70	4.50	0.60	57.2
24	3.30	4.04	0.82	50.0

[0214] Analysis of this data set was conducted to determine an equation relating n and k to reflectance. Again, the reflectance is calculated when viewed through the glass.

[0215] Reflectance=9.21972−8.39545*n+20.3495*k+1.76122*n^2−0.711437*k^2−1.59563*n*k.

[0216] The results can also be shown graphically. Using the equation and/or graph we can determine the needed n and k values necessary to attain a desired degree of reflectivity for a chrome layer.

[0217] Aesthetically, it is desirable for the ring to match the viewing area as closely as possible. The eye is then not drawn to the ring and can better focus on the object in the viewing area. It is somewhat subjective what difference in appearance between the ring and viewing area is objectionable. The intensity between the ring and viewing area is preferably within 10 percent, more preferably within 6 percent and most preferably within 3 percent. Similarly, the color of the ring may be objectionable. The color difference between the ring and viewing area should be less than 30, preferably less than 15 and most preferably less than 10 C* units.

[0218] There may be situations where, due to processing limitation or restrictions, it is not possible to attain the desired chrome optical constants, but a match is still desired between the ring and the viewing area. In other situations it may be desirable to attain a reflectance for the ring which is higher than what is possible with chrome alone. In these circumstances an approach similar to what was discussed above for the case of the metals on top of the chrome may be applied. To attain higher reflectance, a relatively thin layer of chrome is applied to the glass followed by a higher reflecting metal layer such as rhodium, ruthenium, iridium, cadmium, palladium, platinum or other appropriate metal or alloy which has an inherent higher reflectance than chrome.

[0219] Table 3d shows the effect of chrome thickness on the reflectance for a fixed n and k value for the chrome layer. The optical constants for the chrome were selected to produce a reflectance less than 50 percent with the goal to match a viewing area reflectance of 56 percent. The reflectance varies with the thickness of the first chrome layer with, essentially, a perfect match when the chrome layer thickness is reduced to 2.5 nm.

[0220]

TABLE 3d
Chrome thickness effect on reflectance
Modified stack to compensate for change in chrome properties
Chrome optical constants n 3.456 k 3.981
Chrome Layer	40	30	20	10	5	2.5	(nm)
Ruthenium	35	35	35	35	35	35	(nm)
Chrome Layer	0	10	20	30	35	37.5	(nm)
ITO-B18	148.7	148.7	148.7	148.7	148.7	148.7	(nm)
Reflectance	48.4	48.5	49.7	52.8	54.9	55.8	(percent)

[0221] The optical constants of the chrome layer also have an effect on the reflectance of this stack. The reflectance may be attenuated significantly with the optical constants of the chrome but with the use of a thin chrome layer backed by a higher reflectance metal layer, ruthenium in this case, the reflectance may be significantly increased compared to the case where the high reflectance metal is not present. Table 3e shows the effect of optical constants of the chrome on the reflectance.

[0222]

TABLE 3E
Effect of Chrome optical constants on reflectance
Effect of Chrome base layer optical constants on reflectance
	Chrome Layer	10	10	10	10
	Ruthenium	35	35	35	35
	Chrome Layer	30	30	30	30
	ITO-B18	148.7	148.7	148.7	148.7
	Reflectance	53.5	54.9	55.9	56.9
	Chrome n	3.366	3.279	3.196	3.116
	Chrome k	4.089	4.199	4.310	4.423

[0223] Another option for enhancing the reflectance of the ring and improving the aesthetic match to the viewing area consists of putting a low index material between the ITO and the metal layers. The low index layer may be silica, alumina, MgO, polymer or other suitable low index material. At least options for the low index material exist. A first is to control the thickness of the silica layer to provide an interferential increase in reflectance. Table 3f compares the color of the ring with and without the addition of the low index layer. In this case, the low index layer is silica but, as mentioned above, any appropriate low index material is suitable for this application. The thickness of the ITO and low index layers may be adjusted to alter the color while simultaneously increasing the reflectance. The reflectance may be further increased by combining this technique with the different metal stacks described elsewhere in this document.

[0224]

TABLE 3F
Effect of addition of low index layer between the ITO and metal layers
	Case 1	Case 2
	ITO	125	125
	SIO2	0	55
	Chrome	60	60
	R	46.6	54.2
	a*	−6.6	−0.5
	b*	0.9	3.0

[0225] Another option is to insert a relatively thick low index material between the ITO and the metal reflectors of the ring. In this case, it is desirable that the low index layer be thick enough to act as a bulk layer. The necessary thickness is dependent, at least in part, on the material properties of the bulk layer, particularly if the inhomogeneities help to eliminate the phase information of the light. The thickness of the layer may be as thin as ¼ micron or thicker to get the desired effect.

[0226] Other options to provide a match between the ring and the viewing area include the use of a High/Low/High dielectric stack. A series of dielectric layers with alternating refractive indices may be used to provide a high reflectance coating. For example, TiO2/SiO2/TiO2 alternating layers may be used. Table 3g shows a stack consisting of TiO2, SiO2 and ITO (thicknesses in nm) which provides a reflectance of the ring of 60.5 percent with a neutral color. The color and reflectance may be modified by adjusting the thickness of the layers. A second option, with ITO as the base layer, is also shown in Table 3g. The stack may be adjusted with both configurations to give both the desired color and reflectance values. The thickness of the ITO may be adjusted to provide for a more conductive layer. The thickness and indices of the other layers may be adjusted to compensate for the changes in the ITO thickness. This increases the utility of this design option.

[0227]

TABLE 3G
High/Low/High stack for ring match
	Glass	1.6 mm	Glass	1.6 mm
	TIO2	55.3	ITO	148.7
	SIO2	94.5	SIO2	90
	TIO2	55.3	TIO2	50
	SIO2	94.5	SIO2	90
	ITO	148.7	TIO2	55
	Reflectance	60.5	Reflectance	60.7
	a*	−5.3	a*	−4.9
	b*	5.64	b*	−1.9

[0228] Another option for the ring is the use of an IMI, or insulator/metal/insulator, stack for the electrode. Some particular IMI stacks and ring materials are noted below but other versions are also viable. In the context of this invention, it may be assumed that an IMI stack may be substituted for ITO or another TCO. A metal or dielectric stack is then put between the IMI stack and the substrate or the seal material. Both scenarios will work well. When the reflecting stack is put between the IMI and the glass, a more flexible situation for the IMI stack is achieved, particularly if the metal reflectors are essentially opaque. The IMI is shielded by the metal reflectors and may be adjusted as needed for the center viewing area. When the IMI is in between the glass and the reflecting stack, it is desirable to ensure that the requirements in the viewing area and ring are compatible. This may be accomplished but it does impose limitations on the IMI stack which are not present when the reflectors are between the IMI and the glass.

[0229] In the IMI stack the insulator may be a dielectric layer such as TiO2, SiO2, ZnO, SnO2, Niobium oxide, silicon metal, ZrOx, SiN or other suitable material. Mixed oxides, oxynitrides or other composites may be used. The metal is preferably Ag or an alloy of Ag. The Ag may be alloyed or doped with Au, Pd, Pt, Si, Ti, Cu or other materials selected to provide the proper electrochemical, chemical or physical properties. Protective layers may be placed between the metal layer and the dielectrics to improve adhesion, chemical stability of the metal or thermal stability of the IMI coating during heat treatment. Multiple different dielectrics may be used to attenuate color and reflectance in the viewing area and in the ring.

[0230]

TABLE 3h
IMI stacks and ring reflectance. Thicknesses are in nm unless noted
Glass	1.6 mm	Glass	1.6 mm	Glass	1.6 mm	Glass	1.6 mm	Glass	1.6 mm	Glass	1.6 mm
Cr	45.0	Cr	30.0	Cr	20.0	Cr	0.0	Cr	0.0	Cr	40.0
ZnO	39.8	ZnO	39.8	Ru	15.0	Ru	0.0	Ru	0.0	Ru	0.0
Ag	9.0	Ag	9.0	ZnO	39.8	ZnO	39.8	TiO2	23.5	TiO2	23.5
ITO	52.8	ITO	52.8	Ag	9.0	Ag	9.0	ZnO	10.5	ZnO	10.5
Cr	0.0	Cr	0.0	ITO	52.8	ITO	52.8	Ag	9.0	Ag	9.0
R	54.2	R	53.2	Cr	0.0	Cr	10.0	ITO	35.7	ITO	35.7
a*	−4.9	a*	−5.6	R	55.9	AL	40.0	Ru	0.0	Ru	0.0
b*	0.5	b*	1.3	a*	−4.3	R	57.5	Cr	25.0	Cr	0.0
				b*	0.9	a*	−1.5	R	54.3	R	55.1
						b*	8.4	a*	−3.4	a*	−5.0
								b*	−0.2	b*	0.8

[0231] When the ITO thickness is increased from a half-wave to the point where a bluish color is achieved for the ITO plus chrome stack, the color is much more susceptible to shifts due to thickness variations during deposition and/or due to viewing angle differences in actual use. ITO coatings deposited intentionally thinner than half-wave optical thickness, per the discussion above, also exhibited relatively low levels of haze when overcoated with chrome as depicted in Table 2.

[0232] The difference between coatings may be measured by using the specular excluded option available on some reflectance spectrophotometers. It is important to check that such measurements are actually measuring scattered light and not primarily small amounts of the specular component. In general, shorter wavelengths of light scatter more readily. That fact is a good indicator when used to determine whether a given reading is actually the expected scattered light intensity being measured. A MacBeth Color Eye 7000 is one spectrophotometer that gives good haze measurement results in this regard.

[0233] As used herein, the terms “haziness” and “haze” should be understood to refer to the property of scattering, or non-specular reflection, in thin films. Haziness may be caused by a number of factors, including, less than fully oxidized layers, crystal sizes within a layer, surface roughness, layer interface properties, quality of cleaning of the substrate, subcombinations thereof and combinations thereof.

[0234] These properties may vary due to processing conditions and/or the materials. This is especially true with processing conditions, in that the level of haze may vary substantially even within a single process “batch” or “load” of coatings. Nonetheless, for an ITO layer overcoated with chrome and viewed through the glass, whether with or without color suppression or anti-iridescent underlayers, it has been shown to be possible to produce coatings much less hazy than those similarly obtained with Tec 15 glass from Libbey-Owens-Ford.

[0235] Aluminum oxide may be used as an underlayer to assist in controlling the hue of the spectral filter material stack, as well as mixtures of oxides yielding an appropriate refractive index. It may be particularly advantageous to use a mixture of ITO and SiO₂ and/or SiO as an underlayer for ITO to control the resulting hue of the spectral filter material stack. The use of ceramic targets for ITO is often considered capable of tighter process control for properties such as film thickness. A sputter target comprising ITO and Si and/or Si in a mixture of oxidation states may be employed. Such an underlayer potentially enables one to use an in-line coating system that does not have substantial gas flow isolation from either pumping or intervening doors between the cathodes used for depositing the underlayer and the ITO layer. A mixture of ITO and SiO₂ to at least some percentage of SiO₂ will retain sufficient conductivity such that RF sputtering is not necessary. Radio Frequency (RF) sputtering, as compared to Medium Frequency (MF) sputtering or direct current (DC) sputtering, often requires electrical isolation and impedance matching that is not trivial to include in a thin film coating system.

[0236] Since there are regulatory requirements for 35 percent (40 percent in many European countries) reflectivity for vehicular rearview mirrors (clear state for electro-optic mirror elements), in order for the perimeter area to be included in the field of view calculations, it needs to have such a level of reflectance. In the data provided herein with respect to chrome over Tec 15 glass, this minimum is not met.

[0237] Use of a measurably hazy CVD deposited flourine doped tin oxide that is part of an anti-iridescent structure for use in electro-optic devices is known. Various thicknesses of ITO are known for providing a conductive electrode. It has not previously been known that the b* of an indium-tin-oxide conductive electrode and chrome spectral filter material stack may be predictably controlled by varying the thickness of the ITO. Pyrolitically deposited fluorine doped tin oxide with an anti-iridescent structure (Tec 15 from L.O.F) is substantially more hazy when overcoated with chrome compared with ITO deposited over a layer of aluminum oxide as shown in Table 1.

[0238] In embodiments where the spectral filter material is located proximate the first surface, it can be advantageous to minimize the distance between the first surface and the third or fourth surface reflector. The greater the distance between the reflector and the first surface, the greater the discontinuity will be in the image reflected by the element when transitioning from the main reflector to the spectral filter material. This will be accentuated as the viewing angle increases.

[0239] In embodiments where a spectral filter material is located proximate the second surface of the element and an additional coating, such as a hydrophilic coating, is on the first surface, the optical properties of both coatings will affect the appearance of the perimeter of the device and may require adjustments to the layers for optimal appearance of the perimeter. In the case of an electro-optic element with a hydrophilic coating as described in commonly assigned U.S. Pat. Nos. 6,447,123, 6,193,378 and 6,816,297 hereby incorporated in their entireties by reference, the first surface coating will have a reflectance substantially lower than the reflectance of the preferred embodiments of a second surface spectral filter material as described herein. This will result in the hue and/or chroma of the color of the perimeter of the device being more dependent on the second surface coatings than those on the first surface. Nonetheless, especially when color is chosen near a point of transition from perceived yellowish to bluish, +b* to −b*, respectively, or reddish to greenish, +a* to −a*, respectively, these differences tend to become more perceivable. When attempting to match the hue of the spectral filter material to that of the overall field of view of the reflector, small differences in the materials that result in transitions from more yellow to less yellow, or less blue to more blue, when compared to the overall field of view of the element may be avoided by practicing the teachings herein. A similar contrast in reddish or greenish hue may be managed.

[0240] For example, the color and reflectance of the ring and viewing area with and without a hydrophilic surface coating were modeled with a thin film program. The spectral filter ring consists of 126 nm of ITO, 3 nm of Cr, 5 nm of Rh, 30 nm of Ru and 40 nm of Cr. The exit medium or material next to the metals and dielectric layers is an electrochromic fluid with an index of approximately 1.365. The hydrophilic layer consists of a 65 nm color suppression layer next to the glass, a 234 nm TiO2 layer with a surface morphology and 10 nm of SiO2.

[0241] Table 4a shows the reflectance and color of various portions of the mirror. The first two rows show the effect of the presence or absence of the hydrophilic layer on the appearance of the ring. The color and reflectance are essentially unchanged with the application of the hydrophilic layer on the first surface of the mirror. In rows 3 and 4 we see the change of color in the viewing area when the mirror is in the darkened state. In the undarkened state the higher reflectance of the back reflector dominates the appearance. The reflectance increases with the hydrophilic layer which may have advantages in certain markets. The color of the viewing area without the hydrophilic layer in this case is somewhat objectionable because the thickness of the ITO is selected to optimize the color of the ring. This results in a somewhat compromised color in the viewing area. By adding the hydrophilic coating on surface one the color becomes more neutral, a positive benefit to the combination. The fifth row shows the color of the hydrophilic layer without any other coatings on surface two of the glass and with an electrochromic fluid as the exit medium for reference.

[0242]

TABLE 4A
Color and reflectance of different mirror components
	Structure	R	a*	b*
	Hydro/Glass/ITO/Cr/Rh/Ru/Cr	58.46	−4.20	3.23
	Glass/ITO/Cr/Rh/Ru/Cr	58.23	−4.20	1.96
	Hydro/Glass/ITO	13.50	0.69	−3.10
	Glass/ITO	5.65	4.69	1.92
	Hydro/Glass	12.47	−1.70	−4.60

[0243] A particularly advantageous element configuration in conformance with FIGS. 17A-17C and 18 comprises a first substrate of glass approximately 1.6 mm thick having a conductive electrode approximately 0.4 wavelengths (approximately 80 percent of half-wave) thick of indium-tin-oxide applied over substantially the entire second surface by sputtering. At least a portion of the first corner, the edge and the second corner are treated such that approximately 0.25 mm of material is removed from the second surface and approximately 0.5 mm of material is removed from the first surface. It should be apparent that a portion of conductive electrode is removed during treatment. A spectral filter material approximately 400 Å thick of chrome is applied approximately 4.5 mm wide near the perimeter of the first substrate proximate the conductive electrode. An electrical conduction stabilizing material approximately 100 Å thick of a platinum group metal (PGM) (i.e., iridium, osmium, palladium, platinum, rhodium, and ruthenium) is applied approximately 2.0 cm wide near the perimeter of the first substrate proximate the spectral filter material. A first separation area is laser etched approximately 0.025 mm wide with a portion thereof extending parallel to, and within the width of, a portion of a primary seal material area to substantially electrically insulate the first and second conductive electrode portions, spectral filter material portions and adhesion promotion material portions. A second substrate of glass approximately 1.6 mm thick having a conductive electrode approximately 0.5 wavelengths thick over substantially all of the third surface is provided. A second separation area is laser etched approximately 0.025 mm wide with a portion thereof extending parallel to, and within the width of, a portion of a primary seal material to substantially electrically insulate the third and fourth conductive electrode portions. A reflective material approximately 400 Å thick of chrome is applied proximate the third conductive electrode portion substantially defined by the inboard edge of the primary seal. An optional overcoat approximately 120 Å thick of ruthenium is applied proximate the reflective material substantially defined by the inboard edge of the primary seal. A primary seal material, comprising an epoxy having a cycloaliphatic amine curing agent and approximately 155 μm substantially spherical glass balls, is provided to secure the first and second substrates together in a spaced apart relation to define a chamber. A substantially rigid polymer matrix electro-optic medium, as taught in many commonly assigned U.S. Pat. Nos. 5,679,283, 5,888,431, 5,928,572, 5,940,201, 6,545,794, and 6,635,194, the disclosures which are incorporated in their entireties herein by reference, is provided between the first conductive electrode portion and the optional overcoat material within the chamber through a plug opening in the primary seal material. The plug opening is sealingly closed using ultra-violet light curable material with UV light irradiating the plug bottom through the third and fourth surface. The cured primary seal material and the plug material are inspected by viewing the element looking toward the fourth surface. An electrically conductive material comprising a bisphenol F epoxy functional resin, viscosity of approximately 4000 cP having a cycloaliphatic amine curing agent, viscosity of approximately 60 cP, and a silver flake, tap density approximately 3 g/cc and average particle size of approximately 9 μm is applied proximate the outboard edge of the primary seal material between the second adhesion promotion material portion, the third conductive electrode portion and the first electrical clip. This same electrically conductive material is applied proximate the outboard edge of the primary seal material between the first adhesion promotion material portion, the fourth conductive electrode portion and the second electrical clip. A double sided, pressure sensitive, adhesive material is provided between the electrical clip and the fourth surface of the second substrate. The electrically conductive material is cured after placement of the first and second electrical clips. The primary seal material is partially cured prior to application of the electrically conductive material; additional primary seal material curing coincides with curing the electrically conductive material. This curing process is beneficial to prevent warping of the element and improves overall related adhesion, sealing and conductivity characteristics.

[0244] This example mirror element description is provided for illustrative purposes and in no way should be construed to limit the scope of the present invention. As described throughout this disclosure, there are many variants for the individual components of a given element and associated rearview mirror assembly.

[0245] In embodiments of the present invention having a highly reflective spectral filter material applied between the second surface of the first substrate and the primary seal, it has proven advantageous to use specifically selected spacer material to eliminate bead distortion. Glass beads are typically added to the primary seal material to control the spacing between the substrates that form the chamber containing the electro-optic medium. The diameter of preferably substantially spherically shaped glass beads is a function of the desired “cell” spacing.

[0246] These glass beads function well as spacers in electro-optic devices that have two transparent substrates, a transparent front substrate and a reflector positioned on surface three or four. These spacers also function well in devices with a spectral filter material on the first surface or within the first substrate. However, when the spectral filter material is applied proximate the primary seal material and the second surface, “dimples”, or small distortions in the chrome spectral filter material, are created by typical glass spacer beads and are visible in the seal area of a resulting mirror element. These dimples are also visible in mirror elements having a third surface reflector; however, they can only be seen if the mirror element is viewed looking at the fourth surface. These third surface dimples in a reflector are not visible in a resulting mirror element when viewed once installed in a vehicle.

[0247] In contrast, these dimples are readily visible in a resulting mirror element when the spectral filter material is proximate the second surface and covers the primary seal material area. These dimples are created, at least in part, by high stress areas proximate the glass spacer beads. Typically, the primary seal material comprises a substantially rigid thermal curing epoxy; preferably comprising a cycloaliphatic amine curing agent. The curing temperature of the epoxy material is often greater than 150 degrees Centigrade. There is often a significant difference in thermal expansion between the customarily used ceramic glass bead (low coefficient of thermal expansion) and the epoxy material (high coefficient of thermal expansion). At least a portion of the glass spacer beads are in contact with the top material of a respective stack of materials proximate the second and third surfaces of the substrates when the seal solidifies and cures at high temperatures. As the mirror element cools in the post primary seal material cure cycle, the seal material shrinks much more than the spacer beads and stress develops around the bead creating a distorted area, or dimple, in the substrate stack. When the substrate comprises a reflector on a surface that is in contact with the primary seal material, these distorted areas or dimples are visually perceptible.

[0248] These distorted areas can be eliminated in a number of ways. A more elastomeric or flexible primary seal material may be used that inherently does not build areas of high stress. A spacer that is more compressible may be used such that the spacer flexes as stress develops. A breakable spacer may also be used such that the spacer breaks to relieve the localized stress during primary seal material curing. A room or low temperature curing seal material with low cure shrinkage may be used that will eliminate or minimize the thermal expansion-related stress. A seal material and spacers that are a closer match in thermal expansion may be used to eliminate or minimize the thermal expansion-related stress, such as plastic spacer beads and plastic seal material, ceramic spacer beads and ceramic seal material or seal material and/or spacer beads containing a thermal expansion modifying filler. The spacer beads in the seal material may be eliminated altogether if proper methods of element manufacturing are used to control the element gap (“cell” spacing). For example, a spacing media, such as a PMMA bead or fiber that dissolves in the electro-optic media, could be applied to the area internal the primary seal to control the element gap during primary seal material curing. The element substrates may also be held apart mechanically until the seal solidifies.

[0249] A master batch of thermal cure epoxy was made using 96 parts by weight Dow 431 epoxy novolac resin, 4 parts fumed silica and 4 parts 2 ethyl 4 methyl imidazole. To small portions of the above master batch 2 parts by weight of the following spacer materials were added. A dab of the epoxy/spacer mixture was then put on a 1″×2″×0.085″ thick piece of chrome coated glass such that the epoxy mixture was in contact with the chrome reflector. A 1″×1″×0.85″ piece of ITO coated glass was placed on top and the glass sandwich was clamped such that the glass pieces bottomed out to the spacer material. The element was then cured at about 180 degrees Centigrade for about 15 minutes. Subsequently, once the element returned to room temperature, it was visually inspected for dimples looking at the chrome as if it were on surface two.

[0250] Using the thermal cure epoxy of Example 1 with 140 um glass beads caused a very heavy dimple pattern to be visible.

[0251] Using the thermal cure epoxy of Example 1 with plastic beads (Techpolymer, Grade XX-264-Z, 180 um mean particle size, Sekisui Plastics Co. Ltd., Tokyo, Japan) caused no dimple pattern to be visible.

[0252] Using the thermal cure epoxy of Example 1 with plastic fibers (Trilene, 140 um diameter monofilament line cut to 450 um lengths, Berkley, Spring Lake, Iowa) caused no dimple pattern to be visible.

[0253] Using the thermal cure epoxy of Example 1 with hollow ceramic beads (Envirospheres, 165 um mean particle size, Envirospheres PTY Ltd., Lindfield, Australia) caused very slight, but acceptable, dimple pattern to be visible.

[0254] Using an epoxy cured at room temperature caused no dimple pattern to be visible after 1 week at room temperature.

[0255] Using two parts by weight glass beads (140 um) added to a UV curable adhesive, Dymax 628 from Dymax Corporation, Torrington, Conn., and compressing the adhesive between two glass substrates as described above caused a very slight, but acceptable, dimple pattern to be visible. The adhesive was UV cured at room temperature.

[0256] Turning now to FIG. 20A, a cross sectional view of an embodiment of an electro-optic mirror element 545 is depicted to include a light source 2030 mounted to a circuit board 2031 positioned such that light rays emitted by the light source 2030 are transmitted through the element 545 to a viewer (not shown) observing the first surface 612a. In a preferred embodiment of the electro-optical mirror element of the invention, where high dimming/clearing speeds and/or short electrical contacts are desired, the substantially transparent layer 628 (which in an alternative embodiment may comprise multiple layers, such as, e.g., layers 628a and 628b as shown) on the second surface must have high conductivity (which corresponds to a low sheet resistance). Therefore, the sheet resistance of the electrode layer 628a (or layers 628 a,b) is preferably chosen to be between approximately 1 Ω/square and approximately 10 Ω/square, preferably between approximately 2 Ω/square and approximately 6 Ω/square, and most preferably approximately 3 Ω/square. Typically ½ wave ITO or full wave SnO(F) with a sheet resistance of 10 to 15 Ω/square is used on the second surface in electro-optic mirrors made today. Such low sheet resistance can be achieved by providing thicker layers of conventional materials such as ITO, tin-oxide, zinc-oxide, or combinations thereof. If the optical thickness of the coatings is two waves or greater, there are also benefits in the color intensity and color variation that is contributed to the low end reflectance of the associated mirror element when compared to thinner coatings that are not color suppressed thicker layers, approximately two wave or above, provide benefits with regard to manufacturing variances. Other suitable low sheet resistance substantially transparent conductors can be made by combining layers of conductive metal oxides with metals or metal alloys. These stacks may be ITO/silver/ITO or ITO/silver alloy/ITO or may be stacks such as those used as low E coatings in the IG industries such as ZnO/Ag/ZnO/Ag/ZnO. Unlike low E-coatings for windows, to be useful in an electrochromic device, the conductivity interlayer should be continuous and the conductivity must reach the surface. To improve interlayer conductivity, dopants may be added such as aluminum or gallium. These dopants enhance the conductivity of the zinc oxide layers. To prevent the oxidation of the metal or metal alloy, thin layers of a protective metal such as titanium or zinc can be applied during the deposition process. The embodiment 2000 shown in FIG. 20 comprises a four layer stack coating 2020b, 2020c, 2020d, 2020e applied to the third surface 614a of the second substrate 614. A layer of opaque material 2015 is applied to the fourth surface 614b with a cut-out for the light from the light source 2030 to be projected through. Many alternate coatings and reflective, transflective and substantially transparent layers are disclosed in various U.S. patents and U.S. patent applications incorporated herein by reference. It should be understood that a lower sheet resistance coating may be provided in an area proximate the associated electrical contact or around a perimeter area and allow the sheet resistance to increase as the distance from the electrical contact increases; this is particularly applicable when point contacts are utilized.

[0257] Turning now to FIG. 20B, a cross sectional view of an embodiment of an mirror element is shown to include the first substantially transparent substrate 612 in a spaced-apart relationship to the second substrate 614 with the seal member 616 therebetween. The substantially transparent electrically conductive layer 628 is applied to the second surface 612b and the reflective electrode layer 628 is applied to the third surface 114a. Preferably, the substantially opaque material 1676 is applied to the first surface 612a substantially circumferentially (i.e., configured as a ring) in a peripheral area of the first surface such that ambient light incident through the first surface 612a is prevented from impinging upon the seal member 616. Electrical contacts 2080, 2082 are provided to facilitate electrical connection to the electrically conductive layers on the third and second surfaces, respectively. In a preferred embodiment, the substantially opaque material 1676 has a reflectivity substantially equivalent to that of the reflective electrode layer 620 disposed on the third surface. In an alternative embodiment, the substantially opaque material 1676 may be transmissive to all wavelengths of light except those in the ultra-violate and/or the infrared region(s) of the spectrum, while the seal material 616 is substantially transparent. In another alternative embodiment, the substantially opaque material 1676 may be provided on the second surface 112b (not shown) in lieu of the first surface 112a or it may be embedded in the first substrate. The use of such substantially opaque material 1676 applied to the perimeter of a mirror on the first surface or the second surface of the front substrate 612 the edge of which has been properly treated may allow for production of an EC-mirror assembly that requires no bezel or a bezel with a vary narrow lip. Materials such as, for instance, chrome, molybdenum, stainless steel, nickel or titanium applied can be chosen to form the element 1676. The chosen material needs to exhibit good adhesion to glass or to coatings on the glass, and if used on surface one, good abrasion resistance and good environmental stability (water, salt, etc.). It is also desirable to have the ring of material 1676 closely match the color and reflectivity of the interior of the EC-mirror system. If the EC mirror proper has a reflectivity between around 50% to 70%, a front surface chrome perimeter coating 1676 matches well. If the EC-mirror system has a reflectivity greater than 70%, it may be necessary to increase the reflectivity of the perimeter ring. The latter can be done without compromising the abrasion resistance and chemical durability by making the ring out of highly reflective hard metals (hardness of 5 mhos or above) such as metals from the platinum metals group that includes rhodium, platinum and ruthenium. Because these metals do not adhere well to glass or glass like metal oxide coatings it is preferred that these highly reflective metals are put over a layer such as chrome that has good glass adhesion. Therefore a combination such as a base layer of chrome, molybdenum or nickel over coated with a hard high reflectance material such as rhodium, ruthenium or platinum will adhere well to glass like materials, resist abrasion and have good environmental durability. If a ring with low reflectivity that is dark or black is desired a coating of materials such as “black chrome” or oxides of Cr, Cu, Mn, Mo, and Fe or their combinations can be used. A ring that is a particular color can be made in a similar fashion.

[0258] FIGS. 21A and 21B depict plan views of mirror elements having substantially zero positional offset between the front substrate 612 and the rear substrate 614 except for in the tab/recess areas 2134, 2135 where contact is made to corresponding second and third surface conductive layers (not shown). The first and second substrates are secured in spaced apart relationship with one another via seal member 616. The substantially opaque material 1676 is provided as described with reference to FIG. 20B. In a preferred embodiment, low sheet resistance stacks, as described herein, are provided on both the second and third surface such that relatively short electrical contacts, leading to the electrically conductive layers on the second and third surfaces, are sufficient. In at least one preferred embodiment, the length of the contacts to the second and third surfaces combined are less than approximately 50 percent, and preferably less than approximately 25 percent, of the length of the perimeter of the associated mirror element. In at least one alternate embodiment, a point contact is provided to either the second surface conductive layer, the third surface conductive layer or both the second and third surface conductive layers. In at least one embodiment, the contact to the second electrically conductive layer is approximately 60 to approximately 75 percent of the total length of both contacts combined. In at least one embodiment anyone of these, “short electrical contact” systems may be combined with a carrier with integrated bezel as described herein with regard to FIGS. 60 and 61. Optionally, a substantially transparent seal member and, or, a substantially opaque material may be provided, as described herein, in combination with the short electrical contact(s). U.S. Pat. No. 5,923,457, the entire disclosure of which is incorporated herein by reference, discloses optional structures for mirror elements in accordance with various embodiments of the present invention.

Edge Treatment.

[0259] If any coating and/or a reflective peripheral ring of material is applied around the perimeter of the mirror on the first or second surface to mask the seal and/or contact areas, as discussed in reference to FIGS. 20A, 20B, 21A, 21B and other embodiments described herein, the aesthetics of this ring and edge of the ring become very important. Appearance of the edge of the first substrate plays a special role in assuring that the user's perception of the mirror is satisfying. Following the practical consideration and the trends in users' preferences in appearance of the vehicular rearview assemblies, the edge of the first substrate should be configured to be optically diffusive for at least two reasons.

[0260] 1) In majority of cases, glass substrates of a mirror element of a rearview assembly are produced through scribing and breaking process that generally results in a reflective perimeter edge having specular reflective properties and reflecting about 4 percent of the incident light. (It is understood that this reflectivity level is inevitably increased if the specularly reflecting edge is overcoated with a peripheral ring of material such as Chrome.) The smooth specular reflective edge can give a bright or shiny appearance to the glass edge in many ambient light conditions, which is generally aesthetically objectionable.

[0261] 1) Moreover, if the edge of a mirror element is chipped or cracked and is overcoated with a reflective peripheral ring of spectral filter material (such as chromium, for example), the chipping becomes extremely visible and stands out like a beacon scattering incident light in all different directions. This shortcoming becomes particularly aggravated if a chip or a crack extends onto the perimeter of the first or second surface. Similarly, if the perimeter and/or edge is chipped after the chrome peripheral ring coating is applied, the chip visually stands out in reflected light as a dark void on otherwise a smooth bright surface.

[0262] It is appreciated that both the specularly reflecting edge and imperfections associated with chipping of the edge of the mirror element become especially problematic in embodiments having either a narrow bezel or no bezel at all, because in such embodiments the chipping are not concealed. At least for the reasons discussed above it is preferred, therefore, to configure the first substrate so as to improve both the mechanical quality and the visual appearance of the edge of the mirror element in order to produce a high quality mirror. Both of these goals may be achieved by modifying the surface properties of the edge of the first substrate. Required modifications are produced, for example, by re-shaping the edge either after the coating has been applied to the edge or, preferably, right after the mirror substrates are cut to shape. Re-shaping may be performed by grinding, sanding, or seaming the edge with flat or contoured wheels containing abrasive particles or with a moving belt coated with abrasive particles. Depending on a configuration of the carrier and whether or not a bezel component extends onto the first surface of the mirror element, a light edge treatment that removes as little as 0.005″—or as much as 0.010″ to 0.075″—of the front edge of the first may be all that is necessary to achieve a desired result.

[0263] Abrasive materials include but are not limited to diamond, silicon carbide or oxides of aluminum, cerium, zirconium and iron in the size range of about 100 to 1-200 mesh. The size of the particles used affects the roughness of the finished glass edge. The larger the abrasive particle the rougher the surface that is created. Generally 80 to 120 mesh size abrasive particles produce a very rough surface, 300 to 500 mesh size particles produce a smooth surface and 600 mesh and above produce a near polished finish. The abrasive particles can be embedded in a metal, resin or rubber medium. An example of abrasives loaded in metal or resin binder are diamond wheels available from GlassLine Corp., 28905 Glenwood Rd., Perrysburg, Ohio 43551 or Salem Corp., 5901 Gun Club Rd., Winston-Salem, N.C. 27103. An example of abrasives loaded in a rubber binder are Cratex M or Cratex F wheels available from Cratex/Brightboy Abrasives Co., 328 Encinitas Blvd. Suite 200, Encinitas, Calif. 92024. Abrasive coated belts are available from 3M Corp., St. Paul, Minn. 55144. Modification of the surface properties of the edge not only increases the mechanical durability of the edge by removing the micro-cracks but also makes the edge optically diffusive. The re-shaping is generally done in the presence of a coolant to remove the heat generated during grinding or seaming. The edge can also be reshaped by rubbing the glass against a substrate flooded with an abrasive slurry loaded with particles such as diamond, silicon carbide or oxides of aluminum, cerium, zirconium and iron. Equipment for edge polishing using the abrasive slurry method is available from SpeedFam Co., Kanagawa, Japan. Alternatively, the edge can be reshaped by cutting or blasting the edge with a high pressure liquid containing abrasive particles of diamond, silicon carbide or oxides of aluminum, cerium, zirconium and iron. Equipment for frosting glass using this method is available from Bystronic, 185 Commerce Dr., Hauppauge, N.Y. 11788. Alternative way of reshaping the edge may include blasting the edge with abrasive particles of diamond, silicon carbide or oxides of aluminum, cerium, zirconium and iron carried by a high velocity gas stream. A modified glass edge can also be produced by chemically etching the glass with a chemical solution designed to leave a frosty surface such as Superfine Glass Frosting Powder which a mixture of ammonium hydrogen fluoride and barium sulfate that is mixed with HCl available from Above Glass Corp., 18341 4^th Ct., Miami, Fla. 33179. A modified glass edge can also be produced by coating the glass edge with a diffuse or pigmented paint such as 935 UV Series available from Ruco, Wood Dale, Ill. or UV 420 Series available from Fluorital Italy, Italy or Ultraglass UVGO Series available from Marabu, Germany or Crystal GLS Series available from Sun Chemical, Parsippany, N.J. or SpecTruLite UV Series available from Ferro Corp., Cleveland, Ohio.

[0264] Turning now to FIG. 21C, an embodiment of a mirror element is shown to have the first substrate 612 that is larger than the second substrate 614 such that an electrical contact to the second and third surface electrically conductive layers (not shown) is made inside the perimeter of the first substrate and is not visible when the element is viewed from the front of the mirror element. A seal member 616, and optionally, a substantially opaque material 1676 is provided as described with regard to other embodiments. It should be understood that alternate embodiments may be provided with a front substrate that is in positional alignment with the rear substrate on all put one edge and that contact to the second and third surface electrically conductive layer(s) is made on the edge having the extended front substrate. In addition to the “J” and “C” type electrical contact clips described and depicted below, a “Z” type contact clip may be provided (which is especially useful in an embodiment having a larger first substrate). The Z-type clip has a portion of one end secured to the second surface of the front substrate where the front substrate extends beyond the rear substrate, the Z clip then steps up along the edge of the rear substrate and the opposing end of the Z clip then extends along the fourth surface. In at least one embodiment, a Z clip is provided to make contact to the second surface and a J or C clip is employed to make contact to the third surface. For embodiments with larger, wide, clips that are bonded to the substrate, the thermal coefficient of expansion of the clip(s) and the thermal coefficient of the substrate are substantially matched, for example, if the substrate is glass, a Kovar, stainless steel or a laminate of Mo/Cu/Mo clip may be employed.

Additional Embodiments of Electrical Connectors.

[0265] FIG. 22A illustrates one technique for providing for electrical coupling to an electrochromic device such as that of the first embodiment. As shown, a first electrically conductive clip 2280 is clipped to element 614 so as to be in electrical contact with second portion 620b of electrode 620. A second electrically conductive clip 2282 is provided that clips around the entire device and thus contacts front surface 612a of front element 612 and rear surface 614b of rear element 614. Electrical contact is made to electrode 628 via first portion 620a of electrode 620, and via electrically conductive material 852. A variation of this construction is shown in FIG. 22B in which 2282 is made of an identical construction as that of clip 2280 so as to clip only to rear element 614. Again, electrical coupling between clip 2282 and electrode 628 is through electrically conductive seal 852 and any wire 850 that may be disposed therein. As shown in FIG. 22C, one or a plurality of such clips may be provided for electrical connection to each electrode 620 or 628. Clips 2280 and 2282 may be directly soldered or otherwise connected to a circuit board or wires extending therebetween may be soldered to clips 2280 and 2282. FIGS. 22D and 22E show two additional variants of the clips 2280 and 2282 discussed above. In FIG. 22D, clips 2280a and 2282a are modified such that they do not extend around rear surface 614b of rear element 614. In FIG. 22E, clips 2280b and 282b are modified so as to extend over and around front surface 612a of front element 612 while also extending around rear surface 614b of rear element 614. As will be apparent to those skilled in the art, various modifications can be made to the disclosed clip designs without departing from the scope of the present invention.

[0266] FIG. 23 shows a variation of the embodiment shown in FIG. 13 described above. The structure shown in FIG. 23 differs in that one of the layers of conductive foil or web 1366 extends outward beyond the edges of elements 612 and 614 and wraps around element 614 for connection to either a printed circuit board or a heater circuit. Additionally, the rear surface 614b of rear element 614 may be patterned with conductive electrodes for supplying power to foil 1366. The foil 1366 on the opposite side of insulator 1364 may likewise extend outward for connection to the other of electrodes 628 and 620. Foil 1366 may be cut using pinking shears and effectively bent to form one or more connector clips. Foil 1366 may be configured as an electrical bus with tabs extending into the seal.

[0267] FIG. 24 shows yet another embodiment in which a conductive coating 2390 is deposited on the peripheral edge of rear element 614. Such a coating may be made of metal and applied with solder. Alternatively, the material may be rolled onto the edge of element 614. Such a construction allows contact merely to the edges of element 614 to provide electrical coupling to one or both of electrodes 620 and 628.

[0268] Yet another embodiment is shown in FIG. 25. In this embodiment, the majority of the sealing member is moved from between the front and rear elements 612 and 614 to the edge of the front and rear elements. Thus, the seal is provided predominately on the peripheral edges of the front and rear elements. As shown in FIG. 25, the seal 2500 contacts the front element 612 both on the peripheral edge and the rear surface of the front element. Likewise, the seal 2500 contacts the rear element 614 both on the peripheral edge and the front surface of the rear element. A first contact area in which seal 2500 contacts the peripheral edge of front element 612 is larger than a second contact area in which seal 2500 contacts the rear surface of front element 612. Likewise, a third contact area in which seal 2500 contacts the peripheral edge of rear element 614 is larger than a fourth contact area in which seal 2600 contacts the front surface of rear element 614. As a result, an interface between seal 2600 and front element 612 defines an oxygen penetration path length through which oxygen would have to travel to enter chamber 626, wherein the portion of the path length extending along the peripheral edge of front element 612 is longer than the portion of the path length extending along the rear surface of front element 612. Similarly, an interface between seal 2500 and rear element 614 defines another oxygen penetration path length through which oxygen would have to travel to enter chamber 626 wherein the portion of this path length extending along the peripheral edge of rear element 614 is longer than the portion of the path length extending along the front surface of rear element 614. By forming seal 2500 of a thin member 2502 of a first material having an oxygen permeability of less than 2.0 cm³·mm/m²·day·atm and/or by increasing the oxygen penetration path length as compared to other electrochromic cells, the amount of oxygen penetration into chamber 626 may be significantly reduced. Typical prior art seals are made of epoxy resins, which have oxygen permeabilities of 2.0-3.9 cm³·mm/m²·day·atm and water permeabilities of 0.7-0.94 gm·mm/m²·day, and are predominately positioned between the front and rear elements thereby having a shorter oxygen penetration path length.

[0269] First material forming thin member 2502 may be made of a material selected from the group of: metal, metal alloy, plastic, glass, and combinations thereof. First material 2502 is adhered to the peripheral edges of the front and rear elements with a second material 2504. The second material may have a higher oxygen permeability than said first material, and may be an electrically conductive adhesive or an electrically conductive epoxy that makes electrical contact with at least one of first and second electrically conductive layers 620 and 628.

[0270] In the preferred embodiment of the invention, the sealing member 2500 includes a thin member 2502 with low gas permeability that is adhered to the edge of the front and rear elements. An adhesive 2504 such as an epoxy adhesive, PSA or hot melt can be applied in a thin film to a thin member 2502 with low gas permeability such as a metal foil or plastic film. Examples of materials that may be used as thin member 2502 include polycarbonate (oxygen permeability of 90.6-124 cm³·mm/m²·day·atm and water permeability of 3.82-4.33 gm·mm/m²·day), polyvinylidene chloride (oxygen permeability of 0.0152-0.2533 cm³·mm/m²·day·atm and water permeability of 0.01-0.08 gm·mm/m²·day), and a multilayer film of plastic and/or metal. Such a film may include inorganic layers or a coating such as SiO₂, Al₂O₃, Ta₂O₅, Al, chrome, etc. that is bonded to the edges of the front and rear glass elements with an adhesive or glass frit. An example of a suitable multilayer film is the SARANEX brand PE/PVC-PVDC film, which has an oxygen permeability of 0.2-0.79 cm³·mm/m²·day·atm and water permeability of 0.06-0.16 gm·mm/m²·day.

[0271] This foil or film 2502 is then wrapped around the front and rear substrates that are held in the proper spaced apart relationship. The adhesive 2504 bonds the foil or film 2502 primarily to the substrate edges to form a gas and liquid tight seal around the perimeter of the electrochromic device. A fill port 2606 (FIG. 26) could be added by leaving a gap in the foil or film edge sealing member or punching a hole through it. The fill hole could be soldered shut if a metal foil is used for the edge-sealing member. Alternatively, the fill hole could be plugged with an UV or visible light curing adhesive or hot melt or an additional thin sealing member such as a foil or film could be glued over the fill hole. If a light transparent film is used, a UV or visible light curing adhesive could be used to adhere the film. If a non-transparent metal foil is used a hot melt, PSA or other self-curing adhesive can be used. In this way the area that is required for a seal that is primarily between the substrates is eliminated and a bezel that had been designed to cover that area can be made narrower or eliminated.

[0272] If the low gas permeability member adhered to the side of the substrates has areas that are electrically conductive this member could also serve as an electrical bus to make contact to the conductive electrodes of the electrochromic device. Electrical isolation of the electrodes could be maintained by creating gaps in the electrical continuity of the edge seal member. For example, if a metal foil was used, small slits or gaps 2606 (FIG. 26) could be created in the foil such as one to be used as a fill hole and another opposite the fill hole to electrically isolate top and bottom electrode buses. Electrical continuity between the conductive edge sealing member and the electrode could be established in any number of ways. The conductive electrode coating(s) 620 and/or 628 could wrap around the side of the substrate(s) (FIGS. 27 and 28) or an electrically conductive coating or adhesive 3008 (FIG. 30A-33) could be applied in areas that electrical connection to the edge bus is desired. The conductive sealing member 2502 could have a dimple or crease 2710 (FIG. 27) or include an inward protruding extension 2914 (FIG. 29) to make contact through the adhesive bonding of the sealing member to the side of the substrate to make contact to the electrode coating or edge coating 620,628. Conductive particles in the adhesive or a conductive adhesive 3008 could be used to make electrical contact between the conductive edge sealing member and the electrode coating or edge coating. A wire (2812 in FIG. 28), metal clip (3416 in FIG. 34) or other conductor could then be used to make contact between the electrically conductive edge seal 2502 and the electrochromic device drive electronics. An electrochromic device made in this manor would require little or no bezel to cover the seal and contact area. A more detailed discussion of FIGS. 30A-34, is provided below.

[0273] As shown in FIGS. 30(A, B), thin seal member 2502 may be secured to the peripheral edges of elements 612 and 614 using both an electrically conductive material 3008 and a nonconductive material 2504. As depicted in FIG. 30A, the conductive material 3008 provides an electrical connection from conductive layer 628 to a first portion 2502a (see FIG. 26) of seal member 2502. As depicted in FIG. 30B, the conductive material 3008 provides an electrical connection from conductive layer 620 to a second portion 2502b of seal member 2502. As mentioned above, fill ports, gaps or slits in the thin seal member and conductive material 3008 may be used to electrically isolate portions 2502a and 2502b of thin seal member 2502.

[0274] In the embodiment shown in FIG. 31, conductive layers 628 and 620 are configured and oriented as shown in FIG. 10C, such that the conductive material 3008 provides an electrical connection from conductive layer 628 to a first portion 2502a (see FIG. 26) of seal member 2502, and the conductive material 3008 also provides an electrical connection from conductive layer 620 to a second portion 2502b of seal member 2502. As mentioned above, fill ports, gaps or slits in the thin seal member and conductive material 3008 may be used to electrically isolate portions 2502a and 2502b of thin seal member 2502.

[0275] FIG. 32 shows an embodiment similar to FIG. 31 with the exception that regions 628a and 620a of conductive layers 120 and 628 are eliminated.

[0276] FIG. 33 shows an embodiment wherein only the center portion of the adhesive material disposed between layers 620 and 628 is electrically conductive, while nonconductive is used to adhere seal member 2502 to the peripheral edges of elements 612 and 614. This provides the advantage that electrically conductive material 3008 may not need to be as effective as an adhesive with respect to thin member 2502.

[0277] FIG. 34 shows an embodiment wherein a clip 3416 (similar to clip 2282 in FIGS. 22B and 22C) used in combination with thin seal member 2502, which may be a metal foil or the like. As illustrated, a solder bump 3420 may be provided for soldering thin foil 2502 to clip 3416.

Electrical Communication with the Back of the Mirror System.

[0278] As follows from the description of the embodiment shown in FIG. 18, the electrically conductive material (e.g., 1848) may be in electrical contact with either of the second and third surface conductive electrode portions. Turning to FIGS. 35(A-N), there are shown various options for selectively contacting a particular portion of the second and third surface conductive electrode portions 3505, 3510.

[0279] The element construction depicted in FIG. 35(A) comprises a first substrate 3502a having a second surface stack of materials 3508a and a second substrate 3512a having a third surface stack of materials 3522a. The third surface stack of materials is shown to have an isolation area 3583a such that a portion of the third surface stack of materials that is in contact with a conductive epoxy 3548a is isolated from the remainder of the third surface stack of materials. The first and second substrates are held in spaced-apart relationship to one another via a primary seal material 3578a. It should be understood that another side of the element may have a similar isolation area associated with the second surface stack of materials for providing contact to the third surface stack of materials within the viewing area. It should be understood that either the second or third surface stack of materials may be a single layer of on materials as described elsewhere herein and within references incorporated herein by reference.

[0280] The element construction depicted in FIG. 35(B) comprises a first substrate 3502b having a second surface stack of materials 3508b and a second substrate 3512b having a third surface stack of materials 3522b. The first and second substrates are held in a spaced-apart relationship with respect to one another via a primary seal material 3578b. An electrically conductive epoxy 3548b is in contact with the third surface stack of materials and electrically insulated from the second surface stack of materials via the insulating material 3583b. It should be understood that another side of the element may have a similar isolation area associated with the second surface stack of materials for providing contact to the third surface stack of materials within the viewing area. It should be understood that either the second or third surface stack of materials may be a single layer of on materials as described elsewhere herein and within references incorporated herein by reference.

[0281] The element of FIG. 35(C) comprises a first substrate 3502c having a second surface stack of materials 3508c and a second substrate 3512c having a third surface stack of materials 3522c. The first and second substrates are held in spaced apart relationship with respect to one another via a primary seal material 3578c. The second surface stack of materials extends toward the edge of the first substrate beyond the primary seal material such that it is in electrical contact with a first electrically conductive epoxy, or first solder, 3548c1. The third surface stack of materials extends toward the edge of the second substrate beyond the primary seal material such that it is in electrical contact with a second electrically conductive epoxy, or second solder, 3548c2. It should be understood that another side of the element may have a similar isolation area associated with the second surface stack of materials for providing contact to the third surface stack of materials within the viewing area. It should be understood that either the second or third surface stack of materials may be a single layer of on materials as described elsewhere herein and within references incorporated herein by reference.

[0282] FIG. 35(D) depicts the second surface electrical contact 3548d1 being made on an opposite side of the element from a third surface electrical contact 3548d2. FIG. 35(E) depicts the second surface electrical contact 3548e1 being made on a side of the element and the third surface electrical contact being made on an end of the element. FIG. 35(F) depicts the second surface electrical contact 3548f1 being made on one side and continuously with one end of the element and the third surface electrical contact 3548f2 being made on an opposite side and continuously with an opposite end of the element. FIG. 35(G) depicts the second surface electrical contact 3548g1 being made on opposite sides of the element and the third surface electrical contact 3548g2 being made on an end of the element. FIG. 35(H) depicts the second surface electrical contact 3548h1 being made on opposite sides of the element and the third surface electrical contact 3548h2 being made on opposite ends of the element. FIG. 35(I) depicts the second surface electrical contact 3548i1 being made continuously on opposite ends and one side of the element and the third surface electrical contact 3548i2 being made on one side of the element. It should be understood that, in at least one embodiment, the longer electrical contact will correspond to the surface having the highest sheet resistance stack of materials. It should be understood that the electrical contact may be via electrical conductive epoxy, solder or an electrically conductive adhesive.

[0283] FIG. 35(J) depicts an element comprising a first substrate 3502j having a second surface stack of materials 3508j and a second substrate 3512j having a third surface stack of materials 3522j. The first and second substrates are held in spaced apart relationship with respect to one another via perimeter first and second primary seals 3548j1, 3548j2. The first primary seal functions to make electrical contact with the second surface stack of materials and the second primary seal functions to make electrical contact with the third surface stack of materials. The first and second primary seals hold the first and second substrates in a spaced apart relationship with respect to one another and preferably both primary seals are substantially outside the edge of each substrate.

[0284] With reference to FIG. 35(K), a profile view of a portion of a rearview mirror element is depicted comprising a first substrate 3502k having at least one layer 3508k of a substantially transparent conductive material deposited on the second surface and a second substrate 3512k having a stack of materials deposited on the third surface secured in a spaced apart relationship with respect to one another via a primary seal material 3578k to define a chamber there between. In at least one embodiment, an electro-optic medium 3510k is located within said chamber. In at least one embodiment, the third surface stack of materials comprises an underlayer 3518k, a conductive electrode layer 3520k, a metallic layer 3522k and a conductive tab portion 3582k having an overlap portion 3583k underneath the metallic layer and primary seal material. It should be noted that the conductive tab portion 3582k could alternatively be deposited over the metallic coating 3522k to create the overlap portion. In at least one embodiment, the underlayer is titanium-dioxide. In at least one embodiment, the underlayer is not used. In at least one embodiment, the conductive electrode layer is indium-tin-oxide. In at least one embodiment, the conductive electrode layer is omitted. In at least one embodiment, the conductive electrode layer emitted and the underlayer is either a thicker layer of titanium-dioxide or some other substantially transparent material having a relatively high index of refraction (i.e., higher index of refraction than ITO), such as, silicon carbide. In at least one embodiment, the conductive tab portion comprises chrome. It should be understood that the conductive tab portion may comprise any conductive material that adheres well to glass and is resistant to corrosion under vehicular mirror testing conditions. As can be appreciated, when the third surface stack of materials, or at least those layers within the stack that are susceptible to corrosion, are kept within an area defined by an outer edge of the primary seal material, the element will be substantially immune to problems associated with third surface corrosion. It should be understood that the layer, or layers, susceptible to corrosion may extend beyond the primary seal material provided a protective overcoat or sealant is incorporated, such as, conductive epoxy or an overcoat layer. It should be understood that any of the first, second, third and fourth surface layers or stacks of materials may be as disclosed herein or within the references incorporated elsewhere herein by reference. It should be understood that the conductive tab portion improves conductivity over the conductive electrode; as long as a conductive electrode layer is provided with sufficient conductivity, the conductive tab portion is optional. In at least one embodiment, the conductive electrode layer imparts the desired color specific characteristics of the corresponding reflected light rays in addition to providing the desired conductivity. Therefore, when the conductive electrode is omitted, color characteristics are controlled via the underlayer material specifications.

[0285] Turning to FIG. 35(L), a profile view of a portion of a rearview mirror element is depicted comprising a first substrate 3502l having at least one layer 3508l of a substantially transparent conductive material deposited on the second surface and a second substrate 3512l having a stack of materials deposited on the third surface secured in a spaced apart relationship with respect to one another via a primary seal material 3578l to define a chamber there between. In at least one embodiment, an electro-optic medium 3510l is located within said chamber. In at least one embodiment, the third surface stack of materials comprises an underlayer 3518l, a conductive electrode layer 3520l, a metallic layer 3522l and a conductive tab portion underneath the primary seal material. In at least one embodiment, a void area 3583l is defined between the metallic layer and the conductive tab portion, the conductive electrode provides electrical continuity there between. In at least one embodiment, the underlayer is titanium-dioxide. In at least one embodiment, the underlayer is not used. In at least one embodiment, the conductive electrode layer is indium-tin-oxide. In at least one embodiment, the conductive tab portion comprises chrome. It should be understood that the conductive tab portion may comprise any conductive material that adheres well to glass and is resistant to corrosion under vehicular mirror testing conditions. As can be appreciated, when the third surface stack of materials, or at least those layers within the stack that are susceptible to corrosion, are kept within an area defined by an outer edge of the primary seal material, the element will be substantially immune to problems associated with third surface corrosion. It should be understood that any of the first, second, third and fourth surface layers or stacks of materials may be as disclosed herein or within the references incorporated elsewhere herein by reference.

[0286] With reference to FIG. 35(M), a profile view of a portion of a rearview mirror element is depicted comprising a first substrate 3502m having at least one layer 3508m of a substantially transparent conductive material deposited on the second surface and a second substrate 3512m having a stack of materials deposited on the third surface secured in a spaced apart relationship with respect to one another via a primary seal material 3578m to define a chamber there between. In at least one embodiment, an electro-optic medium 3510m is located within said chamber. In at least one embodiment, a first metallic layer 3518m is deposited over substantially the entire third surface. In at least one embodiment, a second metallic layer 3520m is deposited over the first metallic layer such that an outer edge of the second metallic layer is located within an area defined by an outer edge of a primary seal material 3578m. In at least one embodiment, the first metallic layer comprises chrome. In at least one embodiment, the second metallic layer comprises silver or a silver alloy. It should be understood that any of the first, second, third and fourth surface layers or stacks of materials may be as disclosed herein or within the references incorporated elsewhere herein by reference.

[0287] Turning to FIG. 35(N), a second substrate 3512n is depicted comprising a stack of materials having an eyehole 3522n1 substantially in front of a light sensor or information display. In at least one embodiment, a first metallic layer 3518n is provided with a void area in the eyehole area. In at least one embodiment, a second metallic layer 3520n is provided with a void area in the eyehole area. In at least one embodiment, a third metallic layer 3522n is provided. In at least one embodiment, only the third metallic layer is deposited in the eyehole area. In at least one embodiment, the first metallic layer comprises chrome. In at least one embodiment, the second metallic layer comprises silver or silver alloy. In at least one embodiment, the third metallic layer comprises a thin silver, chrome or silver alloy. It should be understood that any of the first, second, third and fourth surface layers or stacks of materials may be as disclosed herein or within the references incorporated elsewhere herein by reference.

[0288] One way the spectral filter material 3515, proximate a first surface conductive electrode, can be electrically insulated from other conductive electrode portions is by overcoating at least portions of the spectral filter material with an organic or inorganic insulating material as depicted in FIG. 35(B).

[0289] When a spectral filter material, such as chrome metal, is applied on top of the transparent conductor of the second surface through a mask in a coating operation (e.g., by vacuum sputtering or evaporation), a non-conductive coating may be applied through a mask in the same process to electrically isolate the second surface conductive electrode from the third surface conductive electrode in the conductive seal area.

[0290] A spectral filter material comprising metal, metal alloy, layers of metals, layers of metal alloys or combinations thereof, such as chrome, molybdenum, stainless steel, or aluminum, rhodium, platinum, palladium, silver/gold, white gold and ruthenium, often over an adhesion promotion material such as chrome, is vacuum deposited through a mask over a transparent conductor (such as ITO) to cover the seal area. An insulating material such as silicon, silicon dioxide, chromium oxide, aluminum oxide, titanium oxide, tantalum oxide, zirconium oxide, or yttrium oxide can be applied with use of a mask over the top of the metal layer to electrically isolate the desired spectral filter material area from other conductive portions. This electrical insulation material is not applied to, or removed from, portions of the spectral filter material or admission/conductivity promotion material where electrical conductivity is desired.

[0291] One method to reduce the size of, or to eliminate the need for, the bezel is to make an element with substantially no offset between the peripheral edges of the first and second substrates using an electrically conductive material as a portion of the electrical bus. In order to use the preferred electrically conductive material, an isolation of a portion of the conductive materials on the second and/or third surfaces needs to take place. The second and third surfaces would be shorted together by the electrically conductive material if one portion of each surface were not isolated in non-overlapping areas. The third surface may be electrically isolated on one side of the element and the second surface would be electrically isolated on an opposite or adjacent side of the element. Preferably, a laser is employed to remove conductive material from the desired areas. The laser separation is preferably located between the electrically conductive material and the visibly active area of the element. More preferably the separation area is located such that an anode and cathode are not coexistent on the same surface and in contact with the electro-optic medium. When an anode and cathode are located on the same surface with the addition of an anode or a cathode on the adjacent surface, a residual slow to erase color will be present along the separation area. Additionally, with an anode on the second surface and the third surface between the seal and the separation area, the color produced by the anode is visible between the primary seal material and the separation area. Likewise, if a cathode is located on the third surface and the second surface between the primary seal material and the separation area, the color produced by the cathode is visible from the front between the separation area and the primary seal material.

[0292] In mirror elements having a spectral filter material between the viewer and the primary seal material, a separation area may be incorporated. With the spectral filter material on the first surface, the mirror element is made much the same as described with regards to elements that do not include a spectral filter material. The separation areas are not visible when looking at the first surface. When the spectral filter material is proximate the second surface, the separation area is visible when looking at the first surface.

[0293] A typical laser defined separation area is between 0.005-0.010 inches wide. By making the separation area 0.002-0.004 inches wide, it is much less noticeable. Even more preferable would be an isolation line of less than 0.002 inches so as to be virtually unnoticeable from the driver's perspective. Material can be removed to create an electrical isolation line using a variety of techniques including masking during coating deposition, media blasting, laser ablation, mechanical abrasion, chemical etching, or other methods known in the art. Photolithography in combination with chemical, reactive ion or other etching method could produce isolation lines below 1 um in width. It should also be noted that shorter wavelength lasers can be focused to create a smaller spot size. This provides for a more narrow and less visible electrical isolation line. As the isolation line becomes more narrow, it may become increasingly difficult to achieve complete electrical isolation between the first and second conductive portions. The resistance between the two conductive portions can be easily measured using an ohmmeter. For a typical electro-optic mirror element it is preferred that this resistance is greater than 30 ohms. It is more preferred that this resistance is greater than 100 ohms. Complete electrical isolation is most preferred. The separation area is preferably located within the primary seal material area and extends the length of the element to provide a large electrical contact area. When the separation area is located over the top of the primary seal material area, the color or transparency of the seal can be adjusted to help hide the separation area. This separation area may be incorporated into artwork or text on the mirror element. A separation area may be incorporated into a disclaimer on the mirror element, a manufacturer's emblem, or other graphic and/or text. It should be understood that the laser line may be positioned along the inner edge of the spectral filter material. In this configuration, the majority of the laser line is not visible because the laser line coincides with the edge of the spectral filter material. Some residual color is present after clearing the electro-optic media on the same substrate; however, most of the colored area is hidden from view behind the spectral filter material. The only laser line portions that are visible are short line segments made through the spectral filter material near the edge in two places.

[0294] It is also generally desirable to position the electrode isolation line, such as a laser ablation line in an area of the mirror, outside of the specified field of view of the mirror. There are legal guidelines in the United States, Europe and in other countries for the minimum area to the side and rear of a vehicle that must be visible in a mirror. This area can be projected onto the surface of the mirror and objects that are within the boundaries of that projection must be visible to the driver. This projection generally takes the shape of a triangle and the size of the projection can be larger or smaller depending on whether the mirror surface is flat or bent. FIG. 3(A) details the shape (identified with dashed line 311a) of a typical specified minimum field of view projection for a left hand outside electrochromic mirror with a bezel. Since the bezel area is not reflective it cannot be included in the field of view of the mirror. However, the bezel area can be covered with a spectrally reflective coating such as a metallic ring on surface two. As long as this reflective ring has a high enough reflectance to meet the minimum reflectance standards for the particular country, this area could be considered field of view. As described previously, the mirror could then be made smaller by the bezel width while maintaining the same specified field of view. Again, it would be preferable to locate any visible electrode isolation lines outside of the projection of the specified field of view of the mirror.

[0295] Another way to isolate the electrically conductive material is to use a nonconductive layer between the electrically conductive material and the surface to be isolated, such as a vacuum deposited dielectric ink, or a thinned layer of a nonconductive epoxy or other resin. It may be desirable to employ a separation area proximate the third surface because the separation area is not visible looking at the first surface. By using a nonconductive material on the second surface, there is no need for a first separation area. This is particularly desirable when the second surface has a spectral filter material. By thinning a nonconductive epoxy, a very thin layer can be obtained. This is important because enough area needs to be provided to apply the electrically conductive material. Preferably, the nonconductive epoxy is only flash cured. For example, place the material in an 85° C. oven for approximately two minutes. If the nonconductive epoxy is fully cured and is partially covering an area that is in contact with the primary associated spacer beads, an undesirable, non-uniform cell spacing may be created. By not curing the nonconductive material completely, the spacer beads will more easily penetrate the layer during the final cure, and not affect the cell spacing.

[0296] An external electrical connection may be made to the third surface of an electro-optic mirror element having a second surface spectral filter material by extending at least a portion of the third surface conductive electrode under the primary seal material area and over the perimeter edge of the second substrate. When coating (such as by vacuum sputtering) over the edge of a piece of glass, the conductivity of the coating tends to decrease over a sharp edge or rough surface. Also, the coating process does not typically provide a durable coating on the side or edge of the glass. To do this without losing conductivity, a good seam or polish on the substrate corner and/or edge is helpful to provide a smooth transition from the third surface to the edge. A rough ground surface without polishing has lower conductivity at a typical third surface coating thickness. The smoother the surface and transition from the third surface to the edge, the better the conductivity. A sputter target mounted to coat the edge of the glass during the coating process is also helpful to provide a more uniform and durable coating.

[0297] It is conceivable that the coating could be extended over the edge of the glass and onto the back of the glass such that the electrical connection to the third surface could be made on that back of the mirror element. A reflective third surface is typically more conductive than a second surface conductive electrode; therefore, an electrically conductive material may not be needed. Therefore, the primary seal material may be dispensed up to the edge of the substrate. Having the third surface material extending onto the edge may only be on one side. The opposite substrate may comprise a separation area and electrically conductive material to the third surface since it is not visible.

[0298] With the third surface material extended onto the edge of the substrate, an L clip in lieu of a J clip can be used since there is no need to have a clip portion inserted between the second and third surfaces. The L clip only needs to be long enough to contact the conductive portion on the edge. A conductive epoxy could be used to bond to the third surface material on the edge to the L clip. A pressure sensitive adhesive could be used on the back of the L clip to secure it to the fourth surface. Alternatively, solder could be applied directly to the coating on the edge or back of the mirror. In one embodiment, the solder could be used as both the contact and as a conductive bus system.

[0299] One advantage of making external electrical contact to the third surface material extended onto the edge of the substrate is that a conductive material is no longer required adjacent to the primary seal for filter material on the first or second surface may be narrower while still covering the primary. Although a typical spectral filter material may vary from 4 to 8 mm in width, it may be aesthetically pleasing to reduce this width below 4 mm. As the width of the primary seal is reduced, the width of the spectral filter material may also be reduced. Using assembly and sealing techniques previously disclosed, it is possible to reduce the primary seal with to less than 1 mm which allows for a spectral filter width of less than 1 mm.

[0300] Another way to make electrical connection to the third surface isolated from the second surface is to use a conductive ink or epoxy to connect the third surface to the edge. Thinning the conductive ink or epoxy and applying it to the edge of the substrate contacts the third surface, without contacting the second surface. With this thinned conductive epoxy, a conductive path can be applied such that contact is made on the edge or the back of the mirror element. An L clip may be applied contact and cured in place. A pressure sensitive adhesive may be used to secure the L clip in place during the curing process and to provide strain relief with connecting wires.

[0301] If the corrosive effects of the environment on the metal can be minimized, very thin metal films or foils can be used to establish a stable interconnect to the conductive adhesive or bus. This metal foil or metal film on a plastic foil could be conformed to the shape of the J clip or other desired shape (without the need of expensive forming dies) and adhered to the substrate with an adhesive such as a pressure sensitive. This metal foil or metal film on plastic foil may be in the form of a roll of adhesive tape that is cut to size and applied to the EC element substrate such that one end comes in contact with the conductive bus that is in contact with the front and/or back electrode(s). A spade connect or wire may be attached to the other end of the metal foil or film by traditional methods such as soldering or conductive adhesive, or the end of the metal foil or tape may connect directly to the voltage source for the EC element such as a printed circuit board.

[0302] At least one embodiment of a formable contact comprises 0.001″ palladium foil (Aldrich chemical Milwaukee, Wis.) laminated to 0.002″ acrylic double-sided adhesive tape with a release liner (product 9495 200MP series adhesive 3M Corporation, Minneapolis, Minn.). The metal foil tape may be cut to an acceptable size for application on an electrochromic device. The metal foil or metal film on plastic foil tape may also be precut to a form or shape if desired.

[0303] At least one embodiment of a formable contact may be made from a plastic film and metallized with a metal such as gold, silver, titanium, nickel, stainless steel, tantalum, tungsten, molybdenum, zirconium, alloys of the above, or other metals or metal alloys that resist salt spray corrosion. Also, palladium or other platinum group metals such as rhodium, iridium, ruthenium, or osmium may be used.

[0304] At least one embodiment of a formable contact uses a polymer carrier comprising 0.002″ polyimide tape (#7648A42 McMasterCarr, Chicago, Ill.) coated with chrome and with any platinum group metal such as rhodium, indium, ruthenium, or osmium as the base, and then coated with a layer of silver, gold or alloys thereof. This system is solderable and has sufficient flexibility to wrap around the glass edge from one substrate surface to another surface.

[0305] At least one embodiment comprises a conductive coated polymer film produced for the flexible circuit industry. In at least one embodiment, Sheldahl (Northfield, Minn.) produces combinations of polyimide (Kapton) and polyester films coated with ITO, aluminum, copper, and gold. Polyimide tapes coated with a base metal may be plated or coated with different metals or alloys to improve durability and/or solderability. These films can be coated with an adhesive or laminated to double-sided tape as described above. This metallized foil can be bent around a glass edge and maintain good conductivity.

[0306] At least one embodiment using a fibrous substrate is comprised of a solvent-based ink placed onto a fiber backing. The conductive ink is comprised of 10 parts methyl carbitol (Aldrich Milwaukee, Wis.), 2 parts Bis A-epichlorhydrin copolymer (Aldrich Milwaukee, Wis.), and 88 parts of LCP1-19VS silver epoxy flake. The conductive ink may be applied to fibrous material such as those comprising glass, metal, or cellulose. The system is heated sufficiently to evaporate the solvent. The conductive and flexible formable contact is then applied to one surface, wrapping around to another surface.

[0307] At least one embodiment of a polymeric formable contact incorporates a construction mechanism to either protect the metal, hide the metal color, or offer another color more appealing to the outside appearance of the glass edge. This construction would incorporate a polymeric film on the outside, followed inwardly by the metal coating, and followed inwardly by an adhesive. The metal coating within the system would need to have an exposed edge for making contact to one of the glass inside conductive surfaces. Contact to this end could be made with an applied conductive adhesive, solder, or other method to make a stable electrical contact. The opposite end could have contact made with conductive adhesive, solder, or other mechanical means.

[0308] In relation to the conductivity of a conductive polymer or composite, there are methods to describe the conductive polymer or composite's conductivity. Those skilled in the art of Isotropic and anisotropic conductive adhesives commonly use a 4-pin probe for the resistance measurement. A common unit of measurement in the field of conductive adhesives is ohms/square/mil. This measurement is expressed as not only a factor of width, but also of thickness. This measurement, when performed on a nonconductive substrate, expresses the linear conductivity of a conductive polymer or composite such as a metal or carbon or metal oxide conductive particle-filled epoxy.

[0309] Another method by which to determine conductive polymer effectiveness for use as a bus is to utilize isolated conductive pads and bridge these isolated pads using the conductive polymer. A particular way to perform this test is to isolate conductive coatings on glass with laser ablating, physical scoring, or chemical removal. The uncured conductive polymer is applied to bridge the conductive pads so that the current path must pass through multiple contact interfaces, but is still isolated from itself so as to not short the bridges together. A resistance reading is taken at the ends across the test piece.

[0310] Not all conductive polymers with high conductivity measured by the ohm/sq/mil method have adequate interfacial electric contact to the electrode surfaces used in an electrochromic device. Based on the above coupon using an ITO electrode as the isolated conductive pad, an acceptable resistance would be less than 1000 ohms. A more preferred resistance is less than 500 ohms, and an even more preferred resistance is less than 200 ohms.

[0311] There are methods to affect this interfacial conductivity through the selection of conductive polymer components. The shape of the metal powder or flake can affect the interfacial contact. Additives can also affect the interfacial contact. Coupling agents, curing catalysts or cross linkers, epoxy resin systems, and methods by which to process the silver epoxy can have an affect on the conductive polymer's ability to make electrical contact to an adjacent conductive surface.

[0312] In at least one embodiment, a silver epoxy comprises 3 parts Hexahydrophthalic anhydride (Aldrich, Milwaukee, Wis.), 2.14 parts Aniline glycidyl ether (Pacific Epoxy Polymers), 0.1 parts Benzyl dimethyl amine (Aldrich chemical, Milwaukee, Wis.), and 23.9 parts silver flake LCP1-19VS (Ames Goldsmith, Glens Falls, N.Y.). When tested using an ohm/square/mil conductivity measurement, results are acceptable (approximately 0.020 ohm/sq/mil).

[0313] In another embodiment, U.S. Pat. Nos. 6,344,157 and 6,583,201 disclose the use of corrosion inhibitors, oxygen scavengers or metal chelating agents for use in conductive adhesives.

[0314] In some cases, additives can be added to silver epoxies to stabilize or improve conductivity. In at least one embodiment, a silver epoxy comprising 3.4 parts Bis F epoxy resin (Dow Corporation, Midland, Mich.), 1.1 parts (Air Products and Chemicals, Allentown, Pa.), 20.5 parts silver flake (Ames Goldsmith, Glens Falls, N.Y.), and 0.03 parts Diethanolamine (Aldrich, Milwaukee, Wis.). Results are acceptable for both conductivity (approximately 0.020 ohms/square/mil) and interfacial contact (approximately 190 ohms).

[0315] As mentioned elsewhere in this patent, a sputtered or vacuum-applied metal coating can be extended beyond the seal and over the edge of the glass to be used as an electrical connection. The metal coating should meet the criteria of corrosion-resistant metals listed above. The electrical connection to this coating could be made with a spring clip, or solder could be applied directly to the metal coating.

[0316] At least one embodiment of a solderable metal coating on glass, chrome is coated as the base layer then coated with any platinum group metal such as rhodium, irridium, palladium, ruthenium, or osmium, or copper, silver or gold, or alloys of the above are solderable using tin/lead solders.

[0317] In another embodiment, chrome is coated as the base layer, then coated with any platinum group metal such as rhodium, irridium, palladium, ruthenium, or osmium, then coated with copper, silver or gold or alloys of the above are solderable using tin/lead solders.

[0318] In current automotive construction, restrictions exist using lead-based components such as solders. Other solders such as tin/zinc tin/silver, indium-based solders containing silver, bismuth, tin, zinc, copper, and or antimony; silver solders or other non-lead containing alloys may be used as a solder material. Soldering systems that may be employed are inductive heat, IR heat, ultrasonic, wave soldering or a soldering iron.

[0319] Another advantage to having a thinner conformable conductive bus clip material as an electrical interconnect to the conductive epoxy is to reduce distortion in the reflection of the first substrate particularly when the first element is larger than the second element. Distortion can be generated as a result of high temperature seal curing and differences in the coefficients of thermal expansion between the seal and the conductive clips. The thicker the clip material, the more distortion is seen, particularly when using more flexible substrates. A thinner clip material also has the advantage of being less noticeable if it is used to wrap around the 3^rd surface to the back of the mirror. This is particularly relevant if the first and second elements are aligned at the point the clip wraps around. When the first element extends past the second element, the clip can be hidden entirely from view.

[0320] Example: An electrochromic mirror was made with flat 1.6 mm thick glass for both front and rear elements. The front element was cut 0.040″ larger (offset) on three sides. The inboard side (the side closest to the driver) had no offset to facilitate easier filling and plugging of the part. A 0.001″×0.5″×0.75″ silver foil with 0.002″ thick pressure sensitive adhesive was applied on the top and bottom of the second element. The conformable conductor contacted 0.010″-0.030″ of surface three then wrapped around to the fourth surface. A primary seal material was then dispensed around the perimeter of the first element leaving approximately 0.040″ for an offset on three sides and an additional 0.040″ between the seal material and the edge of the glass element on both the top and bottom edge of the second surface of the first element. The second element was then attached to the first element leaving a 0.006″ space between the elements. The seal material was cured to fix the elements in this spaced-apart relationship. After cure of the primary seal, a conductive epoxy was then injected into the part from the edge on the top and bottom of the part, thereby encapsulating and making electrical contact with the third surface portion of the conformable conductor. It should be noted that this process of dispensing a primary seal and a conductive seal could be accomplished more readily and easily on a dual dispense system, dispensing both epoxies at the same time. The conductive epoxy was then cured. The mirror was inspected for distortion of the first surface reflection over the conformable conductor, and no distortion was found. When similar mirrors were constructed using either nickel, stainless steel or copper clips with a 0.003″ thickness, visual distortion can be seen near the perimeter of the first surface in the area directly above the clip.

[0321] As mentioned elsewhere herein, establishing electrical contact to the second and third surface conductive electrodes typically involves coordination of a number of individually designed components. Turning to FIGS. 36(A-I), various options for electrical clips are depicted. The placement of the electrical clips is discussed throughout this disclosure in concert with the electrically conductive material.

[0322] A preferred electrically conductive material comprises 27.0 g Dow 354 resin—a bis phenol F epoxy functional resin. Viscosity is preferably ˜4000 cP 9.03 g Air Products Ancamine 2049—a cycloaliphatic amine cure agent. Viscosity preferably is ˜60 cP, 164 g Ames Goldsmith LCP 1-19VS silver—a silver flake with tap density ˜3 g/cc and average particle size ˜6 microns.

[0323] As described herein, at least one embodiment comprises a perimeter material surrounding the periphery of the element. A preferred perimeter material comprises 120 g Dymax 429 with some fillers added (i.e., 0.40 g 6-24 silver flake available from Ames Goldsmith, 1.00 g silver-coated glass flake (i.e., Conduct-o-fil available from Potters Industries), 12.0 g crushed SK-5 glass filler available from Schott Glass or a combination thereof crushed into a powder and sieved with a 325 mesh). This material can be applied to the mirror edge using a number of techniques. One technique is to load the material into a 30 cc syringe with a needle (˜18 gage). The needle can be oriented in a vertical position such that the perimeter material is dispensed with air pressure (<50 psi) onto the edge of the element while the element is being mechanically rotated on a robot arm or other mechanical device. The applied edge material can then be cured with UV light. Complete cure can be accomplished in 20 seconds or less. A robot may also be employed to rotate the part as it is being cured to prevent sagging.

[0324] The intent of the perimeter material is to protect the bus components; hide visible components like electrically conductive materials, clips, seals, glass edges; to protect the cut edge of glass and offer an appealing visual appearance of the mirror element. This may also be achieved with use of conventional plastic bezels, grommets, elastomeric bezels and the like.

[0325] Many different materials (such as epoxy, silicone, urethane, acrylate, rubber, hotmelt) and cure mechanisms can be used for this edge treatment. The preferred cure method is by UV radiation. If fillers, dyes, or pigments that are partially opaque to UV radiation are used, a combination UV thermal cure can be used. Fillers such as glass or reflective silver aid the penetration of UV light by transmission, scattering or internal reflection, and are preferred for good depth of cure. Preferably the perimeter material has a gray color or appearance similar to that of a ground glass edge or is dark or black in color. Colors may be varied by use of organic dyes, micas, impregnated micas, pigments, and other fillers. A darker, more charcoal appearance may be achieved by selecting different fillers and different amounts of filler. Less crushed glass will darken and flatten the color of the above formulation. Use of only crushed glass (or flakes or other glass particle) with a different refractive index than the edge material resin binder will give the appearance of a ground glass edge, or rough pencil edge. Some additives are denser than the media they are contained in. Fumed silicas can be added to help prevent settling of the heavier components (metal and glass particles); 2 percent by weight of fumed silica was found to be sufficient in the preferred method.

[0326] Other ways to apply the perimeter material to the element edge include applying the material with a roll, wheel, brush, doctor bar or shaped trowel, spraying or printing.

[0327] The perimeter edge materials chosen for a vehicular exterior application preferably meet the following test criteria. These criteria simulate the exterior environment associated with a typical motor vehicle: UV stability (2500 kJ in UV weatherometer)—no yellowing or cracking or crazing of material when exposed to direct UV; heat resistance—little or no color change, no loss of adhesion; humidity resistance—little or no color change, no loss of adhesion; thermal-cycling—no loss of adhesion, no cracking; CASS or salt spray—protection of the underlying metal coatings and conductive epoxy systems, no loss of adhesion and no visible sign of underlying corrosion; and high pressure water test (Steam Autoclave Test, at least 200 F/10 psi—described in more detail elsewhere in this document)—no loss of adhesion after parts have been tested in previous stated testing.

[0328] With further reference to FIGS. 35(A-N), various embodiments for configuration of second and third surface electrode contacts are shown. FIGS. 35(A-N) depict configurations similar to that discussed elsewhere herein having a first surface stack of materials, a second surface stack of materials, a third surface stack of materials and/or a fourth surface stack of materials. The word “stack” is used herein to refer to materials placed proximate a given surface of a substrate. It should be understood that any of the materials as disclosed in commonly assigned U.S. Pat. Nos. 6,111,684, 6,166,848, 6,356,376, 6,441,943, 6,700,692, 5,825,527, 6,111,683, 6,193,378, 6,816,297, 7,064,882 and 7,324,261, the disclosures of which are incorporated herein by reference, may be employed to define a unitary surface coating, such as a hydrophilic coating. Preferably, second, third and fourth surface stacks are as disclosed herein or in commonly assigned U.S. Pat. Nos. 5,818,625, 6,111,684, 6,166,848, 6,356,376, 6,441,943 and 6,700,692, the disclosure of each is incorporated in its entirety herein by reference.

[0329] FIGS. 36(D-I) depict various embodiments for configuration of the anode and cathode connections to the second and third surface conductive electrodes, respectively. Preferably, the sheet resistance of the third surface conductive electrode is less than that of the second surface conductive electrode. Therefore, the cathode contact area may be substantially less than the anode contact area. It should be understood that in certain embodiments, the anode and cathode connections may be reversed.

[0330] The configuration of FIG. 35(J) may be used to construct a no-bezel or narrow-bezel rearview mirror assembly that does not incorporate a spectral filter. If the perimeter seal and electrode contact means 3548j1, 3548j2 were both substantially moved to the mirror edge, there is not a requirement for a spectral filter material to cover the seal/contact area. When this approach to mirror element construction is used, the mirror element darkens substantially completely to the perimeter edge during glare conditions. In this approach most or all of the seal and contact area can be substantially moved from the perimeter of mirror substrate one, surface two and substrate two, surface three, to the edges of substrate one and substrate two.

[0331] In at least one embodiment, the top edge of the first substrate and the bottom edge of the second substrate were coated with a conductive epoxy to transfer electrically conductivity from the conductive electrode on each substrate to the substrate edge. The conductive epoxy is preferably formulated using: 3.36 g D.E.R. 354 epoxy resin (Dow Chemical, Midland, Mich.), 1.12 g Ancamine 2049 (Air Products and Chemicals, Reading, Pa.) and 20.5 g of silver flake with an average particle size of 7 microns tap density of 3.0-4.0 g/cc was thoroughly mixed into a uniform paste. This conductive epoxy mixture was thinned with enough toluene to produce a low viscosity conductive paint that could easily be applied to the substrate edge. The coated substrates were put in a 60° C. oven for 15 to 20 minutes to evaporate the toluene.

[0332] A uniform layer of an epoxy that was sparsely filled with conductive particles (Z-axis conductor) was applied to 0.001″ thick copper foil. The Z axis epoxy (5JS69E) was formulated as follows: 18 g of D.E.N. 438, 2 g D.E.N. 431 (Dow Chemical, Midland, Mich.), 1.6 g of US-206 fumed silica (Degussa Corporation, Dublin, Ohio), 6.86 g Ancamine 2049 and 10.0 g silver flake FS 28 (Johnson Matthey, Royston, Hertfordshire, UK) was blended into a uniform paste. The silver flake filler had a tap density of 2.3 g/cc and an average particle size of 23 microns. A cured thin film of this epoxy formulation becomes conductive in the z-axis and not in the x or y axis. This z-axis conductive epoxy was thinned with enough toluene or THF solvent to produce a viscosity suitable to spread into a thin uniform thickness onto the copper foil. The solvent was then evaporated off in a 60° C. oven for approximately 5 minutes. The epoxy remained slightly tacky after solvent evaporation. The edges of the two substrates were aligned with virtually no offset. The gap between the substrates was accurately maintained by using precision sized PMMA beads as spacers. A small piece of Kapton tape approximately 2 mm wide was used on one end extending across the edges of both substrates and the cell spacing. The Kapton tape would eventually be removed from the cell after assembly and the Kapton tape area, which was not wetted with epoxy, would be used as a fill port. The copper foil with the z-axis conductive epoxy was then applied to the peripheral edge of the part such that the epoxy wetted both substrate edges completely. The element was then cured in an oven at 200° C. for 15 minutes. After the cure, a small separation was made in the copper foil on each side to electrically isolate the copper foil on the top from the copper foil on the bottom of the part. The copper foil covering the Kapton tape and the Kapton tape were removed. The opening created by the removed Kapton tape was used to fill the part. The opening was then plugged with a UV curable adhesive. The opening on the opposite side was also plugged with a UV curable adhesive but before filling.

[0333] FIGS. 36(A-N) depict various embodiments for configuration of an electrical clip. Generally, the individual clips are depicted to define substantially a “J” shaped cross section.

[0334] The embodiment of FIG. 36(A) depicts a J-clip 3684a configured to accommodate an electrical connection post (not shown) fixed thereto. In at least one embodiment, the first and second electrical clips are configured in combination with a carrier plate (as described in detail herein with respect to FIGS. 38(A)-38(C)) to form a “plug” type electrical connector. The J-clip comprises an edge portion 3683a and an inner element portion 3682a. The inner element portion is configured to be positioned between a first and second substrate and to be in electrical contact with an electrically conductive epoxy, solder or conductive adhesive to make electrical contact with either a second or third surface stack of materials.

[0335] FIG. 36(B) depicts a series of apertures 3685b extending through an inner element portion 3682b in order to facilitate, at least in part, a mechanical and/or electrical contact with an electrically conductive material. The J-clip 3684b comprises a wire connection feature 3686b and an edge portion 3683b. The wire connection feature may be configured to either accommodate a solder or a crimp-type wire connection.

[0336] FIGS. 36(C-E) depict various J-clip configurations 3684c, 3684d, 3684e comprising an electrical connection stab 3686c, 3686d, 3686e having a friction fit hole 3687c, 3687d, 3687e. Each J-clip has an edge portion 3683c, 3683d, 3683e and an inner element portion 3682c, 3682d, 3682e. FIG. 36(C) depicts having a portion 3685c of the J-clip folded such that the J-clip is not as long and is taller than the J-clip of FIG. 36(D). FIG. 36(E) depicts a series of apertures 3681e extending through a third portion of the clip to provide a stress relief area to accommodate variations in material coefficients of expansion.

[0337] FIG. 36(F) depicts a raised portion 3685f on a J-clip 3684f along with a wire crimp 886f configured to spatially separate the wire contact area from the element. This J-clip comprises an edge portion 3683f and an inner element portion 3682f.

[0338] FIG. 36(G) depicts a J-clip 3684g comprising a wire crimp 3686g, an edge portion 3683g and an inner element portion 3682g. FIG. 36(H) depicts a J-clip 3684h comprising a wire crimp 3686h, an edge portion 3683h and an inner element portion 3682h. The inner element portion comprises a series of apertures 3681h to facilitate enhanced mechanical and/or electrical contact. FIG. 36(I) depicts a J-clip 3684i comprising a wire crimp 3686i, an edge portion 3683i and an inner element portion 3682i. FIG. 36(J) depicts a J-clip 3684j comprising a wire crimp 3686j, an edge portion 3683j and an inner element portion 3682j.

[0339] FIG. 36(K) depicts a J-clip 3684k similar to that of FIG. 36(A) except having a longer portion for adhering to a substrate. This J-clip comprises an edge portion 3683k and an inner element portion 3682k.

[0340] FIG. 36(L) depicts a J-clip 3684l having two large apertures 3686l for stress relief along with four bumps 3687l for enhancing electrical connection placement. This J-clip comprises an edge portion 3683l and an inner element portion 3682l.

[0341] FIG. 36(M) depicts a J-clip 3684m comprising a wire crimp 3686m, an edge portion 3683m and an inner element portion 3682m. FIG. 36(N) depicts a J-clip 3684n comprising a wire crimp 3686n, an edge portion 3683n and an inner element portion 3682n.

[0342] Electro-optic mirrors often incorporate a bezel that covers the edge of the mirror element and the electrical bus connections. In addition, the mirror edge and bus connection are often encapsulated in a potting material or sealant. As long as the mirror remains functional, the aesthetics of the mirror edge and bus connection are not a concern. In contrast, Electro-optic mirrors without a bezel typically have both the mirror element edge and the associated electrical bus connections exposed to the environment. The bus connection typically utilizes a metal member (the term “metal” throughout this discussion on corrosion can represent a pure metal or a metal alloy) such as a formed clip or strip. Electro-optic mirrors with bezels often have formed metallic clips or strips made of copper or copper alloy. The appearance and corrosion resistance of these formed clips or strips becomes important if good aesthetics are to be maintained over the life of the vehicle. Copper and copper alloys tend to corrode and turn green in the salty wet environments to which an EC outside mirror is exposed. This is not aesthetically acceptable. Even if the metal bus cannot be viewed directly, the formed metal clips or strips are typically made of thin material, usually less than 0.010″ thick and more typically 0.005″ or less in thickness. These thin metal pieces can corrode quickly resulting in structural failure, loss of spring electrical contact force or loss of electrical continuity. This issue can be minimized if the edge of the mirror and/or back of the mirror is covered with a paint or coating. The metal clip could also be protected from the environment with a coating such as a conformal coating, paint or varnish or metal plating or cladding. Examples of suitable conformal coatings are:

• • [0343] 1. UV curing epoxy system comprising of 354 bis F resin (Dow Chemical) with percent (by weight) of US-206 (Degussa) and 3 percent (by weight) of UVI-6992 (Union Carbide Corporation—subsidiary of Dow Chemical). 0 . . . 3 percent (by weight) of US-206 and 2 to 5 percent (by weight) of UVI-6992.
  • [0344] 2. Solvated urethane conformal coating like Humiseal 1A33 (Chase Corporation, Woodside N.Y.).
  • [0345] 3. Solvated polyisobutylene comprising of 3 parts (by weight) pentane and 1 part (by weight) Vistanex LM-MS-LC (Exxon Chemical).

[0346] Examples of protective metal platings include gold, palladium, rhodium, ruthenium, nickel and silver. In general these coatings or surface platings retard the corrosion and extend the useful life of the electrical bus; however, corrosion often eventually occurs. Another approach to extending useful bus life is to make the bus clip or strip out of a metal or metal alloy that has good corrosion resistance in salty environments. Suitable metals include the noble metals and noble metals alloys comprising gold, platinum, iridium, rhodium, ruthenium, palladium and silver as well as metals and metal alloys of titanium, nickel, chromium, molybdenum, tungsten and tantalum including stainless steel, Hastalloy C, titanium/aluminum alloys, titanium palladium alloys, titanium ruthenium alloys. Zirconium and its alloys also perform well under certain circumstances. A table ranking a number of these metals and metal alloys after the copper accelerated salt spray (CASS) testing is included herein. The rankings have the following meanings: 4—unacceptable corrosion, 3—corrosion evident but acceptable, 2—light corrosion evident, and 1—very light/no corrosion.

[0347]

Corrosion Ranking Table
Material	Plating	Ranking
Olin 725 (Cu—Ni—Sn)	None	4
Olin 638 (Cu—Al—Si—Co)	None	4
Olin 194 (Cu—Fe—P—Zn)	None	4
Olin 510 Phos. Bronze (Cu—Sn—P)	None	4
Olin 713	None	4
Phos. Bronze	Tin	4
Olin 770 German Silver	None	3
(Cu—Zn—Ni)
Olin 752 (Cu—Zn—Ni)	None	3
Monel (Ni—Cu)	None	3
Brush Wellman (Cu—Be)	None	4
174-10	Palladium	3
174-10	Silver	3
174-10	Tin	4
302 Stainless Steel	None	2
302 Stainless Steel	Tin	3
302 Stainless Steel	Silver	3
302 Stainless Steel	Rhodium	2
302 Stainless Steel	Nickel Strike	1
302 Stainless Steel	Passivated Surface by JS	2
316 Stainless Steel	None	2
Tin Foil	None	3
Silver Foil	None	1
Nickel	None	1
Titanium Unalloyed (grade 1)	None	1
Titanium Unalloyed (grade 2)	None	1
Titanium Unalloyed (grade 4)	None	1
Ti-6AI-4V (grade 5)	None	1
Ti-3AI-2.5V (grade 9)	None	1
Ti-0.15-Pd (grade 11)	None	1
Ti—0.15Pd (grade 16)	None	1
Ti—0.1Ru (grade 26)	None	1
Ti-3AI-2.5V—0.1Ru (grade 28)	None	1
Ti-6Ai-4V—-0.1Ru (grade 29)	None	1
Molybdenum Foil	None	2
Gold Foil	None	1
Rhodium Foil	None	1
Lead Foil	None	3
Tungsten Foil	None	1
Palladium Foil	None	1
Cobalt Foil	None	4
Tantalum Foil	None	1
Nickel Foil	None	1
Nickel Foil	Silver	1
316 Stainless Steel	Tin	3

[0348] When the bus interconnection technique incorporates the use of two or more different metals in close contact with one another, the effects of galvanic corrosion are preferably considered. Many interconnection techniques utilize conductive adhesives. These adhesives generally are organic resins such as epoxy, urethane, phenolic, acrylic, silicone or the like that are embedded with conductive particles such as gold, palladium, nickel, silver, copper, graphite or the like. Unlike a metal solder joint, organic resins breathe. Moisture, oxygen and other gasses can diffuse through organic resins and cause corrosion. When dissimilar metals are in contact with one another, this corrosion may be accelerated by the difference in the electrochemical potential of the metals. Generally, the greater the difference in electrochemical potential between the metal, the greater the probability of galvanic corrosion. It is therefore desirable to minimize the difference in electrochemical potential between metals selected for use in a bus system, especially when a naturally non-hermetic electrically conductive adhesive is used. When one or both of the metals are plated, it is preferred that a plating material is selected that has an electrochemical potential in between the electrochemical potentials of the two metals. For office environments that are humidity and temperature controlled, the electrochemical potential differences between the metals are preferably no more than 0.5 V. For normal environments, the potential difference is preferably no more than 0.25 V. For harsh environments, the potential difference is preferably no more than 0.15 V. Many conductive adhesives use silver particulate or flake as the conductive filler. Silver represents a good compromise between cost and nobility. Silver also has excellent conductivity. As described in metals galvanic compatibility charts such as those supplied by Engineers Edge (www.engineersedge.com) and Laird Technologies (www.lairdtech.com), silver has an anodic index of 0.15 V. Tin-plated copper or copper alloy that is typically used for bus connections in bezeled mirrors has an anodic index of 0.65 V. When tin plated copper is used in contact with silver, the large 0.5 V anodic potential difference is acceptable for use in controlled office-like environments. The environment associated with outside vehicular mirrors is by no means a controlled environment. A potential difference of less than 0.45 V is desirable, a difference of less than 0.25 V is preferred and a difference of less than 0.15 V is most preferred.

[0349]

Metals Galvanic Compatibility Chart
	Anodic
Metal Surface	Index
Gold, solid and plated, gold-platinum alloy, graphite carbon	0.00
Rhodium plated on silver	0.05
Rhodium plating	0.10
Silver, solid or plated; high silver alloys, monel, high nickel-copper alloys	0.15
Nickel, solid or plated, titanium and s alloys, monel, nickel-copper alloys, titanium alloys	0.30
Copper, beryllium copper, cooper; Ni—Cr alloys; austenitic corrosion-resistant steels; most	0.35
chrome-poly steels; specialty high-temp stainless steels, solid or plated; low brasses or
bronzes; silver solder; German silvery high copper-nickel alloys
Commercial yellow brass and bronzes	0.40
High brasses and bronzes, naval brass, Muntz metal	0.45
18 percent chromium type corrosion-resistant steels, common 300 series stainless steels	0.50
Chromium plated; tin plated; 12 percent chromium type corrosion-resistant steels;	0.60
Most 400 series stainless steels
Tin-plate; tin-lead solder	0.65
Lead, solid or plated, high lead alloys	0.70
Aluminum, wrought alloys of the 2000 Series	0.75
Iron, wrought gray or malleable, plain carbon and low alloy steels; armco iron; cold-rolled	0.85
steel
Aluminum, wrought alloys other than the 2000 Series aluminum, cast alloys of the silicon	0.90
type; 6000 Series aluminum
Aluminum, cast alloys other than silicon type, cadmium, plated and chromate	0.95
Hot-dip zinc plate; galvanized steel or electro galvanized steel	1.20
Zinc, wrought; zinc-base die-casting alloys; zinc plated	1.25
Magnesium & magnesium-base alloys, cast or wrought	1.75
Beryllium	1.85
High brasses and bronzes, naval brass, Muntz metal	0.45
18 percent chromium type corrosion-resistant steels, common 300 series stainless steels	0.50

It should be noted that the potential differences between metals depends, at least in part, on the nature of the corrosive environment they are measured in. Results measured in, for example, seawater may be slightly different than for fresh water. It should also be noted that there can be large differences between passive and active surfaces of the same material. The anodic potential of a stainless steel surface may be substantially reduced by a passivation treatment using nitric acid and/or solutions of oxidizing salts. The anodic potential difference may be kept within the most preferred 0.15 V if silver is used in combination with, for example, gold, gold/platinum alloys, platinum, zirconium, carbon graphite, rhodium, nickel, nickel-copper alloys, titanium and monel. The potential difference may be kept within the preferred 0.25 V with, for example, beryllium copper, brass, bronze, silver solder, copper, copper-nickel alloys, nickel-chrome alloys, austenitic corrosion resistant steels, and most chrome-moly steel. The potential difference may be kept within the desired 0.40V by using, for example, 18-8 stainless steel or 300 series stainless steel, high brasses and bronzes, naval brass and Muntz metal. When a plating is used, it is desirable to have the plating material within these anodic potential ranges and most preferably have a potential between the two base materials in close contact with each other. For example, gold, palladium, rhodium, ruthenium, nickel or silver plating generally meets these requirements. The electrical bus is generally connected to the EC mirror drive voltage source by use of a spade connector or soldered joint. When a soldered joint or connection is used, the bus metal is preferably solderable. Platings such as gold, palladium, rhodium, ruthenium, nickel, silver and tin can enhance the solderability of the bus clip. For instance, even though tin is not a preferred plating, a tin-plated stainless steel bus clip solders easily when compared to a plain stainless steel clip. A solder-friendly, more preferred substrate/plating combination is stainless steel with palladium, silver, nickel or rhodium plating. Stainless steel with a nickel plating followed by a silver, palladium, gold, rhodium or ruthenium plating is a preferred material. Other preferred materials include metals or metal alloys comprising tantalum, zirconium, tungsten, and molybdenum with a nickel, silver, gold, palladium, rhodium and ruthenium plating. Other preferred materials are metals, or metal alloys, comprising titanium or nickel with a nickel and/or silver plating. For enhanced stability, it is desirable to passivate the surface of the base metal.
Embodiments of Mounting Elements Including Bezel and Carrier.

[0350] Turning now to FIGS. 37(A, B), a mirror element comprising a first substrate 3712b and a second substrate 3702b is depicted subsequent to being received by a carrier assembly. The carrier assembly comprises a substantially rigid portion 3701a, 3701b integrated with a pliable peripheral gripping portion 3703a, 3703b. The substantially rigid portion and the pliable peripheral gripping portion may be co-molded, individually molded and adhered to one another, designed to friction fit together, designed to interference fit together, individually molded and melted together, or a combination thereof. In any event, the pliable peripheral gripping portion 3703a, 3703b is preferably designed to result in an interface 3709 between the pliable peripheral gripping portion and the perimeter material beyond the crown 3713 such that from near the crown to near the tip 3707 there is a restraining force generated that, at least in part, retains the element proximate the carrier assembly as desired. An additional adhesion material 3705a, 3705b may be utilized to further retain the element proximate the carrier assembly. It should be understood that the perimeter portion 3703a, 3703b may be constructed, at least in part, from a material that adheres to the perimeter material 3760 such that the retentive force is also generated along the interface 3711 on the rigid portion 3701a, 3701b side of the crown 3703a, 3703b; in such a case, the perimeter portion 3703a, 3703b may extend short of the crown or just beyond the crown as depicted in FIG. 37(B). Preferably, the perimeter portion tip 907 is tapered slightly to provide a visually appealing transition to the element irrespective of whether the perimeter portion extends beyond the crown. It should be understood that the shape of the perimeter material may be altered to provide at least one edge substantially parallel to surface 3715 and the perimeter portion may be designed to impart a more pronounced transition between the crown and the interface 3709.

[0351] FIG. 37(C) depicts an element comprising a first substrate 3712c and a second substrate 3702c positioned within a carrier 3701c and perimeter portion 3703c. This configuration typically represents the as-molded condition of the pliable peripheral gripping portion. FIG. 37(B) would typically represent the installed position of the pliable peripheral gripping portion. The installed position allows the pliable peripheral gripping portion to conform to the potential irregularities of the glass profile. FIG. 37(B) is depicting a mechanical interlock between the rigid portion of the carrier and the pliable peripheral gripping portion. This is useful for materials that are not intended to be bonded together whether adhered or bonded through a molding process. The mechanical interlocks can be spaced around the perimeter of the assembly as needed. FIG. 37(C) is depicting a cross-section without a mechanical interlock. Both sections can be used as needed. Another difference between FIGS. 37(B, C) is the height of the pliable peripheral gripping portion off of the back side of the carrier. FIG. 37(B) limits the height off of the back of the carrier of the pliable peripheral gripping portion by placing some of the pliable peripheral gripping portion between the glass and carrier in place of the heater/foam assembly. This potentially eliminates clash conditions inside the housing. FIG. 37(C) can be used to allow the heater/foam assembly to be placed to the edge of the glass perimeter. This allows heating of the glass assembly all the way out to the edge. However, it could potentially create clash conditions of the mirror assembly in the mirror housing.

[0352] Turning now to FIGS. 37(D-M), various carrier plates are depicted with perimeter gripping portions. FIGS. 37(D-G) depict a carrier plate 3701d, 3701e, 3701f, 3701g having an integral perimeter gripping portion 3703d, 3703e, 3703f, 3703g. In at least one embodiment, the perimeter gripping portion comprises a “goose neck” cross-section shape and comprises a series of alternating lands 3703d1, 3703e1, 3703f1 and apertures 3703d2, 3703e2, 3703g2. The combination of the goose neck shape and the alternating lands and apertures provides hoop stress relief to account for differences in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0353] FIG. 37(H) depicts an element comprising a first substrate 3612h and a second substrate 3602h held in spaced-apart relationship with respect to one another via a primary seal material 3678h within a carrier plate 3601h and perimeter gripping portion 3603h. In this embodiment, the perimeter gripping portion comprises a compressible material that is sandwiched between the element and an outer part of the carrier plate to allow for the variations in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0354] FIG. 37(I) depicts an element comprising a first substrate 3712i and a second substrate 3702i held in spaced-apart relationship with respect to one another via a primary seal material 3778i within a carrier plate 3701i and perimeter gripping portion 3703i. In this embodiment, the perimeter gripping portion comprises a compressible material 3704i that is sandwiched between the carrier plate and the perimeter gripping portion to allow for the variations in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0355] FIG. 37(J) depicts a carrier plate 3701j having a swivel portion 3701j1 for pivotally attaching a perimeter gripping portion 3703j. The fact that the perimeter gripping portion is allowed to pivot about the swivel portion accounts for variations in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0356] FIG. 37(K) depicts a carrier plate 3701k having a perimeter gripping portion 3703k. The perimeter gripping portion is preferably molded such that it is tilted toward an associated element (not shown). A compression material 3704k is provided to account for variations in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0357] FIG. 37(L) depicts a carrier plate 3701l having a perimeter gripping portion 3703l. The perimeter gripping portion is preferably molded such that it is tilted toward an associated element (not shown). A series of vertically extending compression elements 3704l is provided to account for variations in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0358] FIG. 37(M) depicts a carrier plate 3701m having a perimeter gripping portion 3703m. The perimeter gripping portion is preferably molded such that it is tilted toward an associated element (not shown). A series of horizontally extending compression elements 3704m is provided to account for variations in expansion coefficients between the element and the carrier plate/perimeter gripping portion.

[0359] Turning now to FIGS. 38(A-C), an element 3812a is depicted proximate an alignment plate 3801a, 3801b and an electrical circuit board 3820a, 3820b. In at least one embodiment, an electrical clip 3884a, 3884b having a contact post 3886a, 3886c is connected to an element electrical connection 3885a, 3885b. The element electrical connection may be via an electrically conductive epoxy, solder, conductive adhesive or an edge spring clip. When the element is engaged with the electrical circuit board, the contact post is received through a hole 3821a, 3821c in the electrical circuit board and is slidingly engaged with friction fit contacts 3822a, 3822c, 3823a, 3823c. FIG. 38(C) depicts an enlarged view of the corresponding area 3827b of FIG. 38(B). In at least one embodiment, the alignment plate comprises apertures 3803a, 3804a for alignment with apertures 3824b, 3825b, respectively, of the electrical circuit board. Preferably, alignment pins (not shown) are provided elsewhere in the associated mirror assembly, such as, in the housing or bezel to accurately position the individual components within the assembly. In at least one embodiment, the alignment plate comprises an aperture 3802a through which the contact post is received for alignment with the corresponding hole in the circuit board. In at least one embodiment, the alignment plate comprises features 3805a, 3805b, 3806a, 3806b for accurately securing the components within a complete assembly. It should be understood that the electrical circuit board may comprise components such as a microprocessor and/or other electrical components, such as a display driver, a compass sensor, a temperature sensor, a moisture detection system, an exterior light control system and operator interfaces that are at least partially shared with at least one mirror element dimming circuitry.

Considerations of Aesthetic Appearance and Styling.

[0360] The aesthetics of the rearview mirror assembly is not a tangible concept and is generally guided by customer preference. Addressing the aesthetics concerns, however, is not a trivial task that often involves balancing of design and functionality of the resulting embodiments.

[0361] The styling and appearance of a bezel of an embodiment of the invention may be improved using various techniques. FIG. 39, for example, illustrates the use of a bezel 3944, which has at least one metallic surface, e.g., a portion of the bezel made of chromium or plastic or other material that is chromium-plated. Thus, at least a portion of the front surface of the bezel 3944 would not have a black color, but rather would be reflective similar to the appearance of the mirror itself and thus be difficult to distinguish from the remainder of the mirror subassembly. Bezel 3944 may engage a carrier plate 3945 in any conventional manner.

[0362] Another reason why the bezels typically are fairly wide is to accommodate the difference in the coefficient of thermal expansion of the material from which the bezel is made relative to the materials used to form the electrochromic element. Conventional bezels are made out of strong and fairly rigid engineering plastics such as polypropylene, ABS/PC, ASA, and have thermal expansion coefficients that are much larger than glass mirrors. This expansion difference can create tremendous hoop stress as the strong rigid bezel shrinks around the mirror at cold temperatures. As a result, conventional bezels may have ribs or defined voids for accommodating the thermal expansion difference between the element and rigid bezel. A solution in this regard is illustrated in FIG. 40 in which the bezel 4044a is formed of an elastomeric material which stretches and contracts with the thermal expansion/contraction of the electrochromic element.

[0363] The elastomeric material could be injected or resin transfer molded directly around the mirror element such as with injection molded PVC or polyurethane Reactive Injection Molding (RIM). The elastomeric bezel could be injection molded separately out of elastomeric materials known as Thermoplastic Elastomers (TPE) such as thermoplastic polyurethane (TPU), thermal plastic polyolefin (TPO, TPV), Styrenic Thermoplastic Elastomer (TPS), Polyester Thermoplastic Elastomer (TPC), Nylon or Polyamide Thermoplastic Elastomer (TPA) or a vulcanized or polymerized rubber, polyurethane, silicone or fluoroelastomer and then applied to the mirror element. One approach would be to injection mold the elastomeric bezel in a “C” or “U” shape that is the mirror shape and size or preferably that is slightly smaller than the mirror shape and size and then stretch and “snap” the bezel onto the mirror. Bezels made in such a fashion fit snugly on the mirror and survive thermal shock and thermal cycling very well. One benefit of “C” or “U” shaped bezels is if they are made symmetrical from front to back, a bezel that is made for the drivers side of the vehicle, if rotated 180 degrees, will generally also fit the passenger side of the vehicle because the two mirrors are usually mirror images of one another. Since the bezels are flexible, another benefit is that a bezel made for a flat mirror will also conform to a convex or aspheric mirror shape. Only one bezel needs to be tooled to fit the left and right side flat, convex and aspheric mirrors resulting in major cost, time and inventory savings. It may be desirable to fix or fasten the bezel to the mirror or mirror back with adhesive or mechanically to avoid the bezel dislodging from the mirror if the mirror is scraped with an ice scraper. The adhesive could be a single component system such as a moisture cure silicone or urethane that is applied either around the edge on the glass or inside the “C” or “U” shaped bezel or both. The bezel could then be applied and the adhesive would cure with time. A two component or solvent-based adhesive could also be used in this manner. A hot melt adhesive could also be applied to the perimeter of the mirror or inside the “C” or “U” of the bezel or both. The bezel could then be applied to the mirror while the adhesive was still hot or the bezel/mirror assembly could be re-heated to melt the hot melt and bond the bezel to the mirror. A mechanical means to trap or engage the elastomeric bezel in place could also be used. The bezel could be made with holes or grooves in the back or side to engage with a more rigid back member. The elastomeric bezel could also be co-injected with a more rigid material that would form an elastomeric portion around the perimeter and a more rigid section around the back of the mirror to hold the elastomeric section in place. This rigid section could cover most of the back of the mirror and engage with the power pack or adjustable mirror support that holds the mirror in place in the mirror housing shell. The mirror in this arrangement could be attached to the rigid back portion with adhesive or double sided adhesive tape. The rigid portion could also only cover the perimeter of the mirror back and attach to a carrier that engages with the power pack or adjustable mirror support. In any case, the rigid portion of the mirror back would mechanically hold the elastomeric portion of the mirror back and bezel in place. An adhesive could also be used to bond the elastomeric portion of the bezel or mirror back to the more rigid portion of the mirror back to hold it in place.

[0364] FIG. 41 plots Force vs. Displacement for short sections cut from a typical bezel made from different materials. The short sections were fixtured in a Chatillon (Greensboro, N.C.) device and pulled. The force vs. displacement plots show that with rigid materials typically used to make prior art bezels (Geloy, ASA/PC) the force increases rapidly with a small change in displacement when compared to bezels made from elastomers or rubbers (950 U, DP7 1050, RPT). Consequently, bezels made of these elastomeric materials that snugly fit the glass mirror at room temperature do not generate high values of hoop stress as the bezel contracts around the glass at low temperatures. By contrast, a bezel made of a rigid material like ASA/PC that fit snugly at room temperature would generate high values of hoop stress as the bezel contracts around the glass at low temperatures. The elastomeric bezel 4044a is preferably disposed around the periphery of at least the front element 612. Due to its elastic nature, the elastomeric bezel has a smaller perimeter than that of at least the front element so that the elastomeric bezel fits snugly around the mirror element.

[0365] Some of the physical properties of rigid and elastomeric bezel materials are shown below in Table 5. The tensile modulus of some prior art rigid plastic material range for a low of 72,000 psi to a high of just over 350,000 psi. By contrast, the preferred elastomeric bezel materials have a tensile modulus of from about 100 psi to 3,000 psi. Thus, the inventive elastomeric bezel materials have a tensile modulus of less than about 72,000 psi, and may have a tensile modulus less than about 3,000 psi. The lower the tensile modulus of the bezel material, the lower the hoop stress value will be in the thermal coefficient mismatched system of a glass mirror surrounded by a plastic bezel.

[0366]

TABLE 5
		Tensile
	Tensile Modulus	Elongation,	Tensile Elongation,	Tensile Strength,	Glass Transition	Shore Hardness
polymer	(100% Secant) psi	break (%)	yield (%)	yield (psi)	Temperature (° F.)	(R = Rockwell R)
Bayer T84 PC/ABS	336000	75	4	8000	N/A	119R
GE LG9000 PC/ABS	352000	75	N/A	7900	N/A	118R
GE Geloy PC/ASA	324000	25	4-5**	8600	N/A	114R
Huntsman AP 6112-HS PP	72500-1100000	120*	6	3550	N/A	98R
Bayer Makrolon 3258 PC	348000	125	6	9100	N/A	~115R***
Texin DP7-1050 polyether	1100 (100%)	450	N/A	5000	−47	90A
Texin 950 U polyether	2000 (100%)	400	N/A	6000	−17	50D
						(~93A)
Multibase Inc. Multi-Flex A 3810	170 (100%)	N/A	700	725	N/A	45A
TPE
Multibase Inc. Multi-Flex A 4001	120 (100%)	600	N/A	800	N/A	33A
LC TPE
Multibase Inc. Multi-Flex A	175 (100%)	700	N/A	750	N/A	49A
4710 S TPE
DSM Sarlink 4139D TPE	1550 (100%)	588	N/A	2340	N/A	39D
						(~88A)
*Value taken from “Machinery's Handbook 25”
**Data taken from www.matweb.com
***Data taken from Hardness Comparison Chart

[0367] Methods for connecting electrodes of an electrochromic medium to a heater circuit or a flexible circuit board are disclosed in commonly assigned U.S. Pat. No. 6,657,767, the entire disclosure of which is incorporated herein by reference. Specifically, part of the flexible circuit board on which the heater circuit is provided may extend beyond the edges of element 614 and wrap upwardly so as to make contact with conductive material on the edge of the electrochromic device.

[0368] Another option for providing electrical contact in an embodiment (not shown) including both a conductive material 852 in the seal region and a bezel such as the bezel 3944, 4044a embracing an edge portion of the embodiment would be to dispose a conductive layer or other material on the inner surface of the bezel 3944, 4044a, in which case pressure exerted by the bezel would create the contact force between the connector and either the electrode layers themselves or the conductive portion 852 of the seal.

[0369] As apparent from the foregoing embodiments, portions of the seal may be configured to function as an electrical bus. The seal may be electrically conductive either across a portion of its width, a portion of its height, or a portion of its length. A seal may be formed of a conductive ink or epoxy and may be filled with metal flakes, fibers, particles, or other conductive materials as described above.

[0370] It should be noted that the zero offset mirror with either the majority of the seal between the substrates or on the edge of the substrates presents a very sleek profile as compared to a typical electrochromic mirror with an offset and may require no substantial bezel at all. For example, with a black or tinted seal between the substrates an aesthetically pleasing mirror can be made by just rolling black or tinted paint over the edges of the mirror. The bezel would then consist of just a thin layer coating of paint or other material on the perimeter of the mirror that would look like a bezel. Likewise, this thin coating can be applied to wrap over the edge and cover a portion, or all, of the region between the substrate seal. This process would also apply to mirrors where the majority of the seal is on the edge of the glass. A thin coating of paint or other material could be applied to the edge of the mirror to present an edge that is aesthetically pleasing and uniform in appearance. Further, by providing a wider and more uniform seal, the need to obscure the seal may be eliminated.

[0371] With respect to various embodiments discussed above, as will be apparent to those skilled in the art, each of the embodiments is advantageous in that the vertical positional offset between the front and rear elements 612 and 614 may be reduced or eliminated thereby reducing any corresponding portion of the width of the bezel (if provided). Other aspects of the invention can otherwise be used to obscure the view of the seal or provide unique bezels. It will be appreciated, however, that the various aspects may be used separately regardless of implementation of any of the other aspects, or may be used in various combinations.

[0372] As noted above, FIGS. 34-42 are enlarged fragmentary cross sectional views of the edge of eleven additional mirror constructions, each having a bezel aesthetically covering an outboard edge of an electrochromic mirror element, the bezels in FIG. 34-36B being bonded to an edge of a carrier of the mirror subassembly, and the bezels in FIGS. 37-42 being mechanically interlockingly engaged (and also potentially bonded) with an edge of a carrier in FIGS. 37-42.

[0373] In the FIGS. 34-49, similar and identical components are referred to using the same numbers, but with the addition of a letter (e.g. “A”, “B”, etc.). This is done to reduce redundant discussion.

[0374] More specifically, in FIGS. 34-42, the electrochromic mirror subassembly 4210 includes front and rear glass mirror elements 4212 and 4214 defining a cavity 4225 therebetween filled with electrochromic material 4226. Electrodes, clips, a seal, a reflective layer, and other structure are included as described above and as shown in previously described Figures. The illustrated elements 4212 and 4214 have edges that preferably have a “zero offset” (i.e. the edges are on average about 1-mm or less from perfect alignment, or more preferably are about 0.5-mm or less from perfect alignment, or most preferably are about 0.2-mm or less from perfect alignment). It is noted that illustrated mirrors have a zero offset that extends completely around their periphery, however, it is conceivable that some bezels could function where the zero offset extends along only part of the edges of the front and rear element assemblies.

[0375] The mirror assembly 4208 (FIG. 42) includes a carrier 4260 with a substantially flat front surface 4261, and further includes a substantially flat thin heater element 4262 and double-sticky-sided foam tape 4263 that adheringly bond the electrochromic mirror subassembly 4210 to the front surface 4261 in a laminar well-supported arrangement. The front surface 4261 of the carrier 4260 is made to be as flat as possible so that the front and rear elements 4212 and 4214 do not undergo localized deformation that would unacceptably distort reflected images. Depending on the flatness of the front surface 4261, the front and rear elements 4212 and 4214 are made thicker or thinner. It is contemplated that the carrier 4260 may be a molded plastic component, or may be a metal or other material. If the reader desires additional information on such systems, the reader's attention is directed to U.S. Pat. Nos. 6,195,194 and 7,287,868, the entire contents of both of which are incorporated herein in their entirety.

[0376] A bezel 4244 (FIG. 42) is attached to the mirror assembly 4208. The bezel 4244 has a C-shaped cross section, and forms a continuous loop that extends around a perimeter of the mirror subassembly 4210 in a fashion similar to bezels 544 of FIG. 5. The bezel 4244 (FIG. 42) includes a forwardly-extending leg 4265, a front lip 4266 that extends onto an outer marginal portion of the front surface 4212a of the front element 4212, and a rear lip 4267 that extends onto an outer marginal portion of the rear surface 4268 of the carrier 4260. As illustrated in FIG. 42, an edge flange 4269 on the carrier 4260 forms a rear-facing recess 4270 that receives the rear lip 4267. The inner surface of the leg 4265 closely engages the edges of the front and rear elements 4212 and 4214, and the inner surface of the lips 4266 and 4267 closely engage the front surface 4212a of front element 4212 and the rear surface 4268 of the carrier 4260, respectively. In a preferred embodiment, the bezel 4244 is insert molded onto the carrier 4260, with the rear lip 4267 being bonded to the rear surface 4268 of the carrier 4260 as part of the molding process. Alternatively, the rear lip 4267 can be adhered or bonded as a secondary assembly process. It is contemplated that the front lip 4266 can also be bonded to the front surface 4212a of the front element 4212. The leg 4265 could also be bonded to an edge of the front and rear elements 4212 and 4214, although this is not a required or condition. Alternatively, it is contemplated that the front lip 4266 can be formed with an “over-bent” condition so that the innermost tip 4266′ of the front lip 4266 resiliently engages the front surface 4212a with a bias, and is not held away by engagement of an outboard portion of the front lip 4266. By this arrangement, the bezel 4244 is an integral part of the mirror assembly 4208, and both helps retain the assembly together, and also seals an outer edge of the electrochromic mirror subassembly 4210.

[0377] The bezel 4244 has an exceptionally thin profile dimension 4271. This is a desirable condition which original equipment manufacturers are looking for, in order to allow a smaller dimension 4272 to the inner surface 4283 of the outside rearview mirror housing 4273. This is an important characteristic to original equipment manufacturers of vehicles, since larger mirror subassemblies 4210 allow greater fields of vision in a rearward direction, and smaller exterior mirror housings 4273 allow greater field of vision in a forward direction (i.e. past the mirror toward a front of the vehicle). It is contemplated that the material of bezel 4244 can be elastomer or a more rigid thermoplastic or metal material, as described above in regard to bezel 4044a (FIG. 40). It is contemplated that the front lip 4266 will be about 2-mm wide or less, and will cover a continuous perimeter strip on the front surface 4212a that is about 2-mm or less wide. However, it is contemplated that the lip 4266 can cover a strip on the front surface that is as low as about 1-mm or less wide; or can be made to extend onto the front surface 4212a only in certain areas (such as top and bottom edges and not onto the right and left sides of the face surface 4212a); or can be made to not extend onto the front surface 4212a at all. Where the bezel does not cover any of the elements 4212 and 4214, the entire front surface of the front element 4212 can be used (i.e. 100% of the front surface can be used for showing a reflected image). This is believed to be novel and non-obvious for modern mirrors with electronic options, especially electrochromic mirrors. (See, e.g., embodiments of FIGS. 6(A), 8(D), 12, 14-16, 24, 25, 27-29, 30B-34, 49 and 57.)

[0378] Bezel 4244A (FIG. 43) is similar to the bezel 4244 (FIG. 42), except that the recess 4270A is formed on a front surface of the carrier 4260A, and the rear lip 4267A is positioned in and bonded to the front surface of the carrier 4260A. As a result, the rear lip 4267A is positioned in a space 4263A′ located between the edge of the carrier 4260A and the edge of the rear element 4214. The rear lip 4267A terminates outboard of an outer edge of the heater 4262 and the foam tape 4263.

[0379] Bezel 4244A′ (FIG. 43A) is similar to bezel 4244A, except in bezel 4244A′, the carrier 4260A′ has a forwardly extending lip 4260A1 that engages a mating recess 4260A2 in a rear of the bezel's rear lip 4267A′. Also, the carrier 4260A′ is modified to include an aperture 4260A3 permitting wire 4260A4 to pass through and connect to the electrical conductor or clip 4260A5 for operating the electrochromic material 4226A.

[0380] Bezel 4244B (FIG. 44) is similar to the bezel 4244A (FIG. 43), with the recess 4270B being formed on a front surface of the carrier 4260B. However, the front surface of the rear lip 4267B of bezel 4244B is coplanar with the front surface of the carrier 4260B, and the outer edge of the foam tape 4263 (and also the heater 4262) extends onto the rear lip 4267B.

[0381] Bezel 4244C (FIG. 37) is similar to the bezel 4244 (FIG. 34) except that the carrier 4260C includes a trapezoidally-shaped keyhole 4275C, and the bezel 4244C includes a key 4276C that engages the keyhole 4275C to positively mechanically retain the bezel 4244C to the mirror assembly 4208. It is contemplated that the key 4276C is molded as part of the insert molding process of molding the bezel 4244C onto the mirror assembly 4208. However, the keyed arrangement can also be made by heat staking, or by sonic or mechanical methods of forming a protrusion into the shape of a key or rivet-like connection.

[0382] Bezel 4244D (FIG. 46) is similar to the bezel 4244C (FIG. 45), except that the keyhole 4275D faces an opposite direction (i.e. a large end opens rearwardly), and the key 4276D extends into the keyhole 4275D from a front location.

[0383] Bezel 4244E (FIG. 47) is similar to the bezel 4244D, with the key 4276E extending rearwardly. In bezel 4244E, the tape 4263 extends onto the rear lip 4267E. However, the key 4276E is preferably located at or outboard of an outboard edge of the foam tape 4263, to minimize a possibility of the key 4276E disrupting the surface that the tape 4263 is bonded to; however, this is not required.

[0384] Bezel 4244F (FIG. 48) is similar to the bezel 4244C (FIG. 45), except that bezel 4244F of FIG. 48 includes a large radius 4277F on an inside corner of defined by the joint of leg 4265F and front lip 4266F. The larger radius 4277F forms a cavity that better assures that the inside corner does not engage an edge of the front element 4212 in a manner causing the front lip 4266F to stand away from the front surface 4212a. The radius 4277F also causes a thinned section on a front portion 4278F of leg 4265F that both acts as a resilient hinge point and prevents bending in other undesirable areas along leg 4265F.

[0385] Bezel 4244G (FIG. 49) is similar to bezel 4244F of FIG. 48, except that bezel 4244G includes a second large radius 4279G at the corner formed by the leg 4265G and the rear lip 4267G. This allows the leg 4265G (and front lip 4266G) to adjust to any undulations along the edge of the mirror assembly 4208G, such as may occur along a clip positioned on the edge of the mirror subassembly 4210G.

[0386] Bezel 4244H (FIG. 50) is similar to the bezel 4244G (FIG. 449), except that the front-located radius 4277H is made larger than front radius 4277G. Further, the radius 4277H is also shifted so that, instead of being at the corner, the radius 4277H is located on the underside of the front lip 366H.

[0387] As noted above, the FIGS. 51-54 are enlarged fragmentary cross sectional views of the edge of four additional mirror constructions, each having a bezel aesthetically covering a front edge of an electrochromic mirror element, the bezels in FIGS. 51-52 also covering an entire side of the edge, but the bezels in FIGS. 53-54 only partially covering a side of the edge.

[0388] More specifically, the bezel 4244I (FIG. 51) is L-shaped and includes a leg 4265I and front lip 4266I, but does not include a rear lip 4267. The leg 4265I is spaced slightly away from the edge of the front and rear elements 4212 and 4214, creating a gap 4279I. Preferably, the front lip 4266I is insert molded onto and bonded to the front surface 4212a. The gap 4279I prevents any irregularity along the edge of the front and rear elements 4212 and 4214 from deforming the leg 4265I of the bezel 4244I in a manner that reads through onto the front lip 4266I. Also, the gap 4279I allows the leg 4265I to flex and move when the elements 4212/4214 and the bezel 4244I undergo different thermal expansions/contractions. Bezel 4244J (FIG. 52) is similar to bezel 4244I (FIG. 51), except that bezel 4244J does not include any gap (4279I) between leg 4265J and the edges of the front and rear elements 4212 and 4214. If desired, leg 4265J is bonded to the side edges of the elements 4212 and 4214.

[0389] Bezel 4244K (FIG. 53) is similar to bezel 4244I (FIG. 41), except that the leg 4265K is shortened, such that it extends only slightly past the cavity 4225. Further, the end 4280K of the leg 4265K is tapered toward the rear element 4214. The bezel 4244L (FIG. 54) is similar to bezel 4244J (FIG. 52), but bezel 4244L (FIG. 54) includes an end 4280L that terminates short of the cavity 4225, and that is relatively blunt rather than being tapered. Specifically, the end 4280L terminates on an edge of the front element 4212. The end 4280L can be bonded to a side edge of the element 4212 as part of an insert molding operation, for example.

[0390] FIGS. 55-57 are enlarged fragmentary cross sectional views of the edge of three additional mirror constructions, each having an edge of an electrochromic mirror element coated by a strip of material. These arrangements are described as bezels since they provide a similar appearance, including a thin profile around a perimeter of the mirror subassembly 4210.

[0391] Bezel 4244M (FIG. 55) is similar to bezel 4244J, in that it includes an L-shaped strip of material with a front lip 4266M extending on the front surface and a leg 4265M extending across side edges of the front and rear elements 4212 and 4214. The material of bezel 4244M and examples of the process of applying the bezel 4244M are described above in regard to FIGS. 14-16(B). (For example, see coating 1676, FIG. 16(A), and see non-conductive material 1262, FIG. 12., and see elastomeric material 4044a, FIG. 40.)

[0392] Bezel 4244N (FIG. 56) is similar to bezel 4244M (and bezel 4244L) in that the bezel 4244N includes a front lip 4266N and leg 4265N. However, the leg 4265N is shortened such that it extends short of the cavity 4225.

[0393] Bezel 4244P (FIG. 57) is similar to the bezels 4244M and 4244N, in that it includes a painted strip of material located along a marginal edge of the front element 4212. However, bezel 4244P is applied to the second surface of the front element 4212 (i.e. in the cavity 4225) and does not extend onto side edges of the front or rear elements 4212 and 4214. Visually, the appearance is not unlike the bezel 4244M (FIG. 55) and bezel 4244N (FIG. 56). The material of bezel 4244P can be opaque, translucent, light-absorbing, or reflective, and dark or light color.

[0394] FIGS. 58-59 are enlarged fragmentary cross sectional views of bezels having a C-shaped cross section that covers a side edge of the electrochromic mirror element and that wraps onto the first and fourth surfaces of the electrochromic mirror element subassembly. However, the bezels further include a resiliently flexible fin that extends laterally away from the electrochromic mirror element into wiping contact with a mirror housing.

[0395] More specifically, the bezel 4244Q (FIG. 59) is C-shaped, and is not unlike the bezel 544 (FIG. 5), or bezel 4044a (FIG. 40) or bezel 4244 (FIG. 42). The bezel 4244Q includes a leg 4265Q creating a gap 4279Q to an edge of the front and rear elements 4212 and 4214, and further includes a front lip 4266Q that extends onto the front surface 4212a of the front element 4221, and a rear lip 4267Q that extends onto a rear surface 4214b of the rear element 4214. A flexible resilient fin 4282Q extends in a outboard direction from a midpoint on the leg 4265Q. The illustrated fin 4282Q becomes thinner and thinner as it extends to its tip, although it is contemplated that the fin can have different shapes. The mirror housing 4273 includes an inner surface 4283Q that is engaged by the fin 4282Q. It is preferable that the fin 4282Q only lightly engage the inner surface 4283Q so that minimal frictional drag is created as the mirror assembly 4208 is angularly adjusted within the mirror housing 4273. Thus, the power pack that is connected to the carrier 4260Q and that angularly adjusts the mirror assembly maintains its low energy requirement for adjustment. It is noted that the fin 4282Q can be designed to allow a small gap to occur between the fin 4282Q and the inner surface 4283Q, especially at extreme angular positions of the mirror assembly if desired. The fin 4282Q allows the vertical and horizontal dimensions of the mirror subassembly 4210 to be maximized relative to the opening 4284Q defined by the housing 4273. This is an important characteristic to original equipment manufacturers of vehicles, since larger mirror subassemblies 4210 allow greater fields of vision in a rearward direction, and smaller exterior mirror housings 4273 allow greater field of vision in a forward direction.

[0396] Bezel 4244R (FIG. 59) is similar to bezel 4244Q, except bezel 4244R includes a foreshortened leg 4265R and a front lip 4266R similar to the bezel 4244L (FIG. 54). A resilient fin 4282R extends laterally from the leg 4265R in an outboard direction, into light sliding contact with the inner surface 4283R of the housing 4273.

[0397] It is contemplated that the bezels 4244-4244R can be extruded onto or molded onto or adhering applied to the front surface 4212a of a front element 4212; and/or extruded or molded or applied onto the front and side surfaces of the mirror subassembly 4210 (which includes elements 4212 and 4214); and/or extruded/molded/applied onto the mirror subassembly 4210 (which includes elements 4212, 4214, carrier 4260, heater 4262, and foam tape 4263); and/or extruded/molded/applied to the carrier 4260; and/or extruded/molded/applied to the side edges of one or both of the elements 4212, 4214. For example, technology is available to extrude polymer directly onto a window glass. See Osanami U.S. Pat. No. 5,158,638, issued Oct. 27, 1992, entitled METHOD OF MAKING WINDOW GLASS WITH A GASKET, the entire contents of which are incorporated herein by reference for the purpose of teaching such a method of direct application/extruding onto a glass element.

Exemplary Embodiments Including a Light Source and Other Optical Elements.

[0398] Turning now to FIGS. 60-61, a carrier 4260 with an integral bezel 4266 on only the “inboard edge” is depicted. This carrier with integral bezel is preferred for use with elements as described with regard to FIGS. 6(B), 21(A) and 21(B). A related assembly method is to provide a double sided adhesive layer, such as a tape or foam, and adhere an element to the carrier with integral bezel such that the related contacts to the associated electrically conductive layers are disposed within the bezel receptacle 4266a. Most preferably, the bezel is positioned on an edge of the element to be located closest to the associated vehicle (i.e. the inboard edge).

[0399] It is contemplated that the present inventive concepts can be used in combination with mirrors (interior and/or exterior) having many different options to create synergistic and non-obvious combinations that provide surprising and unexpected benefits not previously possible. For example, turning now to FIG. 61, an interior mirror assembly 6200 includes a bezel 6255 (similar to any of bezels 544 of FIG. 5 and/or 4244-4244R in FIGS. 42-59) and a case 6256. The bezel and the case combine to define a mirror housing for incorporation of features in addition to a reflective element and information displays. Commonly assigned U.S. Pat. Nos. 6,102,546; D 410,607; 6,407,468; 6,420,800; and U.S. patent application Ser. No. 09/687,743, the disclosures of which are incorporated in their entireties herein by reference, describe various bezels, cases, and associated button constructions for use with the present invention.

[0400] With further reference to FIG. 62, mirror assembly 6200 includes first and second illumination assemblies 6267, 6271. Various illumination assemblies and illuminators for use with the present invention are described in commonly assigned U.S. Pat. Nos. 5,803,579, 6,335,548, and 6,521,916, the disclosures of which are incorporated in their entireties herein by reference. As further depicted in FIG. 64, each illumination assembly preferably comprises a reflector, a lens, and an illuminator (not shown). Most preferably there are two illumination assemblies with one generally positioned to illuminate a front passenger seat area and the second generally positioned to illuminate a driver seat area. There may be only one or may be additional illuminator assemblies such as one to illuminate a center console area, overhead console area, or an area between the front seats.

[0401] With further reference to FIG. 62, mirror assembly 6200 includes first and second switches 6275, 6277. Suitable switches for use with the present invention are described in detail in commonly assigned U.S. Pat. Nos. 6,407,468 and 6,420,800, 6,471,362, 6,614,579, the disclosures of which are incorporated in their entireties herein by reference. These switches may be incorporated to control the illumination assemblies, the displays, the mirror reflectivity, a voice-activated system, a compass system, a telephone system, a highway toll booth interface, a telemetry system, a headlight controller, a rain sensor, etc. Any other display or system described herein or within the reference incorporated by reference may be incorporated in any location within the associated vehicle and may be controlled using the switches.

[0402] With further reference to FIG. 62, mirror assembly 6200 includes indicators 6283. Various indicators for use with the present invention are described in commonly assigned U.S. Pat. Nos. 5,803,579, 6,335,548, and 6,521,916, the disclosures of which are incorporated in their entireties herein by reference. These indicators may indicate the status of the displays, the mirror reflectivity, a voice-activated system, a compass system, a telephone system, a highway toll booth interface, a telemetry system, a headlight controller, a rain sensor, etc. Any other display or system described herein or within the references incorporated by reference may be incorporated in any location within the associated vehicle and may have a status depicted by the indicators.

[0403] With further reference to FIG. 61, mirror assembly 6200 includes first and second light sensors 6286, 6288. Preferred light sensors for use within the present invention are described in detail in commonly assigned U.S. Pat. Nos. 5,923,027 and 6,313,457, the disclosures of which are incorporated in their entireties herein by reference. The glare sensor and/or ambient sensor automatically control the reflectivity of a self-dimming reflective element as well as the intensity of information displays and/or backlighting. The glare sensor is used to sense headlights of trailing vehicles and the ambient sensor is used to detect the ambient lighting conditions that the system is operating within. In another embodiment, a sky sensor may be incorporated positioned to detect light levels generally above and in front of an associated vehicle, the sky sensor may be used to automatically control the reflectivity of a self-dimming element, the exterior lights of a controlled vehicle and/or the intensity of information displays.

[0404] With further reference to FIG. 61, mirror assembly 6200 includes first, second, third, and fourth operator interfaces 6290, 6291, 6292, 6293 located in mirror bezel 6255. Each operator interface is shown to comprise a backlit information display “A”, “AB”, “A1” and “12”. It should be understood that these operator interfaces can be incorporated anywhere in the associated vehicle, for example, in the mirror case, accessory module, instrument panel, overhead console, dashboard, seats, center console, etc. Suitable switch construction is described in detail in commonly assigned U.S. Pat. Nos. 6,407,468, 6,420,800, 6,471,362, and 6,614,579, the disclosures of which are incorporated in their entireties herein by reference. These operator interfaces may control the illumination assemblies, the displays, the mirror reflectivity, a voice-activated system, a compass system, a telephone system, a highway toll booth interface, a telemetry system, a headlight controller, a rain sensor, etc. Any other display or system described herein or within the references incorporated by reference may be incorporated in any location within the associated vehicle and may be controlled using an operator interface or interfaces. For example, a user may program a display or displays to depict predetermined information or may program a display or displays to scroll through a series of information, or may enter set points associated with certain operating equipment with associated sensor inputs to display certain information upon the occurrence of a given event. In one embodiment, for example, a given display may be in a non-illuminated state until the engine temperature is above a threshold, the display then automatically is set to display the engine temperature. Another example is that proximity sensors located on the rear of a vehicle may be connected to a controller and combined with a display in a rearview mirror to indicate to a driver the distance to an object; the display may be configured as a bar that has a length proportional to the given distance. In addition to or instead of the above-mentioned devices, fewer or more individual devices may be incorporated in any location within the associated vehicle and as described within the references incorporated herein.

[0405] Turning now to FIG. 63, there is shown a section view of the mirror assembly 6300 that includes the embodiment 6200 of FIG. 62, with a reflective electrochromic mirror subassembly 6305 affixed to an internal plate frame 6321 with double-sided adhesive foam tape 622. An attachment component 6334 is screwed to (or integrally formed from) plate frame 6321 and defines a ball section 6324 that engages a crown section 6372 in the two-ball mount 6357 with tube assembly 6357′. The depicted sections of FIG. 63 are taken along a cut line VI-VI of FIG. 62. FIG. 63 shows a preferred positional relationship of information displays 6326 and/or backlighting (not specifically shown located at a bottom of the mirror subassembly 6325) with respect to reflective element 6305 within a housing defined by case 6356 and bezel 6255. In further reference to FIGS. 62 and 63, the mirror assembly 6300 is also shown to comprise a microphone 6259; first operator interface 6290 along with circuit board 6395; mirror mount 6357 and accessory module 6358. The mirror mount 6357 and/or an accessory module 6358 may comprise compass sensors, a camera, a headlight control, an additional microprocessor, a rain sensor, additional information displays, additional operator interfaces, etc.

[0406] Turning now to FIG. 64, there is shown an exploded view 6400 of the mirror assembly 6300. FIG. 64 provides additional details with regard to one preferred positional relationship of individual components, as well as providing additional structural detail of a mirror assembly. As shown, the mirror assembly comprises a reflective element 6405 within a bezel 6455 and a mirror case 6456. Bezel 6455 can be adapted to be like any of bezels 1944 and 4244-4244R previously described. A mirror mount 6457 is included for mounting the mirror assembly within a vehicle. It is noted that a person skilled in the art of vehicle mirror design can re-design the bezel 6455, mirror case 6456, and tube mount 6457 to be replaced with the bezel 4244 (-4244R), mirror housing 4273, and carrier 4260 previously described in this application. It should be understood that a host of accessories may be incorporated into the mount 6457 and/or onto the plate frame carrier 6321 in addition to a power pack adjuster, such as a rain sensor, a camera, a headlight control, an additional microprocessor, additional information displays, compass sensors, etc. These systems may be integrated, at least in part, in a common control with information displays and/or may share components with the information displays. In addition, the status of these systems and/or the devices controlled thereby may be displayed on the associated information displays.

[0407] The mirror assembly is shown in FIG. 64 to further comprise third information display 6426 with third information display backlighting 6437, 6438, 6439; first and second microphones 6460, 6461; and includes other known options such as a first reflector with a first lens; a second reflector with a second lens; a glare sensor; an ambient light sensor; first, second, third, and fourth operator interfaces 6490, 6491, 6492, 6493 with first, second, third, and fourth operator interface backlighting 6490a, 6491a, 6492a, 6493a; a circuit board 6495 having a compass sensor module 6499; and a daughter board 6498 with an input/output bus interface 6497.

[0408] Preferably, the illumination assemblies with associated light source are constructed in accordance with the teachings of commonly assigned U.S. Pat. Nos. 5,803,579 and 6,335,548, as well as U.S. patent application Ser. No. 09/835,278, the disclosures of which are incorporated in their entireties herein by reference.

[0409] Preferably, the glare light sensor and the ambient light sensor are active light sensors as described in commonly assigned U.S. Pat. Nos. 6,359,274 and 6,402,328, the disclosures of which are incorporated in their entireties herein by reference. The electrical output signal from either or both of the sensors may be used as inputs to a controller on the circuit board 6440 or 6495 to control the reflectivity of reflective element 6405 and/or the intensity of third information display backlighting. The details of various control circuits for use herewith are described in commonly assigned U.S. Pat. Nos. 5,956,012; 6,084,700; 6,222,177; 6,224,716; 6,247,819; 6,249,369; 6,392,783; and 6,402,328, the disclosures of which are incorporated in their entireties herein by reference. These systems may be integrated, at least in part, in a common control with information displays and/or may share components with the information displays. In addition, the status of these systems and/or the devices controlled thereby may be displayed on the associated information displays.

[0410] Although the compass sensor module 6499 is shown to be mounted circuit board 6495 in FIG. 64, it should be understood that the sensor module may be located within mount 6457, an accessory module 6458 positioned proximate mirror assembly 6400 or at any location within an associated vehicle such as under a dashboard, in an overhead console, a center console, a trunk, an engine compartment, etc. Commonly assigned U.S. Pat. Nos. 6,023,229, 6,140,933, and 6,968,273 as well as commonly assigned U.S. Patent Application 60/360,723, the disclosures of which are incorporated in their entireties herein by reference, described in detail various compass systems for use with the present invention. These systems may be integrated, at least in part, in a common control with information displays and/or may share components with the information displays. In addition, the status of these systems and/or the devices controlled thereby may be displayed on the associated information displays.

[0411] Daughter board 6498 is in operational communication with circuit board 6495. Circuit board 6495 may comprise a controller 6496, such as a microprocessor, and daughter board 6498 may comprise an information display. The microprocessor may, for example, receive signal(s) from the compass sensor module 6499 and process the signal(s) and transmit signal(s) to the daughter board to control a display to indicate the corresponding vehicle heading. As described herein and within the references incorporated by reference herein, the controller may receive signal(s) from light sensor(s), rains sensor(s) (not shown), automatic vehicle exterior light controller(s) (not shown), microphone(s), global positioning systems (not shown), telecommunication systems (not shown), operator interface(s), and a host of other devices, and control the information display(s) to provide appropriate visual indications.

[0412] Controller 6496 (or controllers) may, at least in part, control the mirror reflectivity, exterior lights, rain sensor, compass, information displays, windshield wipers, heater, defroster, defogger, air conditioning, telemetry systems, voice recognition systems such as digital signal processor-based voice-actuation systems, and vehicle speed. The controller 6496 (or controllers) may receive signals from switches and/or sensors associated with any of the devices described herein and in the references incorporated by reference herein to automatically manipulate any other device described herein or described in the references included by reference. The controller 6496 may be, at least in part, located outside the mirror assembly, or may comprise a second controller elsewhere in the vehicle or additional controllers throughout the vehicle. The individual processors may be configured to communicate serially, in parallel, via Bluetooth protocol, wireless communication, over the vehicle bus, over a CAN bus or any other suitable communication.

[0413] Exterior light control systems as described in commonly assigned U.S. Pat. Nos. 5,990,469; 6,008,486; 6,130,421; 6,130,448; 6,255,639; 6,049,171; 5,837,994; 6,403,942; 6,281,632; 6,291,812; 6,469,739; 6,399,049; 6,465,963; 6,587,573; 6,429,594; 6,379,013; 6,871,809; 6,774,988 and U.S. patent application Ser. Nos. 09/847,197; and 60/404,879, the disclosures of which are incorporated in their entireties herein by reference, may be incorporated in accordance with the present invention. These systems may be integrated, at least in part, in a common control with information displays and/or may share components with the information displays. In addition, the status of these systems and/or the devices controlled thereby may be displayed on the associated information displays.

[0414] Moisture sensors and windshield fog detector systems are described in commonly assigned U.S. Pat. Nos. 5,923,027 and 6,313,457, the disclosures of which are incorporated in their entireties herein by reference. These systems may be integrated, at least in part, in a common control with information displays and/or may share components with the information displays. In addition, the status of these systems and/or the devices controlled thereby may be displayed on the associated information displays.

[0415] Commonly assigned U.S. Pat. No. 6,262,831, the disclosure of which is incorporated herein by reference in its entirety, describes power supplies for use with the present invention. These systems may be integrated, at least in part, in a common control with information displays and/or may share components with the information displays. In addition, the status of these systems and/or the devices controlled thereby may be displayed on the associated information displays.

[0416] It is contemplated that the present invention would be useful in inside or outside rearview mirrors having electro-optic mirror elements, convex mirror elements, aspheric mirror elements, planar mirror elements, non-planar mirror elements, hydrophilic mirror elements, hydrophobic mirror elements, and mirror elements having third surface and fourth surface reflectors. It is further contemplated that the present invention will be useful on mirrors that are transflective, or that have a third or fourth surface mirror element with patterns of lines (sometimes referred to as “jail bars”) thereon to optimize the effect of visible light. Further, the present invention is useful with mirrors having first surface or fourth surface heaters, anti-scratch layers, and circuit boards including flexible circuit boards, and circuit board and heater combinations, such as heaters having embedded or integrated non-heater functions such as signal ellipses and signal diffusants, locating holes or windows for light pass-through. The present invention is also useful with potted or snap-attached or elastomeric bezels, and useful with carriers having an ultra-flat front surface. Also, additional options can be integrated into the mirrors including signal lighting, key lights, radar distance detectors, puddle lights, information displays, light sensors and indicator and warning lighting, retainers with living hinges, and integrated housings for receiving and supporting said components. Still further, it is conceived that the present mirror can include a manually folding or power folding mirrors, extendable mirrors, and mirrors with a wide field of view, and with information on the mirror such as “object in mirror is closer than may appear” or other indicia, such as “heated” or “auto-dim”. Still further, the present invention is useful with a blue glass mirror or “blue chemical” darkening mirror. Still further, efficiencies can be had by incorporating the present concepts with mirrors having an electrochromic mirror subassembly with front and rear glass mirror elements with edges having a “zero offset” (i.e. less than an average of about 1-mm, or more preferably, less than about 0.5-mm difference between perfect alignment of edges of the mirror elements), an edge seal, including clear reflective or opaque edge seals, and/or second surface chrome or a chrome bezel.

[0417] Although the present invention has been generally described as being used in connection with electrochromic devices, such as mirrors and architectural windows, those skilled in the art will understand that various aspects of the present invention may be employed in the construction of other electro-optic devices.

[0418] Turning now to FIG. 65, there is shown an exploded view of an exterior rearview mirror assembly 6505 having a housing 6510 connected to an attachment member 6515 via a telescoping extension 6520. In at least one embodiment, the telescoping extension 6520 comprises a single arm having a linear actuator for extending and retracting the telescoping extension from within the associated vehicle. The telescoping extension 6520 may comprise a rack and pinion type linear actuator, an electrical solenoid type linear actuator, a pneumatic piston or a hydraulic actuator. The housing 6510 may be configured such that the housing axially pivots about the telescoping extension. Additionally, the telescoping extension may be configured such that the housing may be folded inward toward the associated vehicle and outward away from the associated vehicle. The attachment member 6515 is configured to be received by a vehicle mount 6525. The vehicle mount may be fixed to a door panel, an A-pillar, a front fender, a window assembly, or any other position where a driver can view the scene generally rearward of the associated vehicle. It should be understood that the telescoping extension may comprise two or more arms and that the housing may be configured to pivot and fold irrespective of the number of arms employed. It should also be understood that the housing may be connected to a non-telescoping extension at a location shown as reference number 6520a such that the housing pivots about the connection 6520a such that the mirror may be positioned closer or farther from the vehicle as desired; this feature may be accompanied by a power positioning mechanism such that actuation may be performed inside the vehicle. It should be understood that the mirror housing, extension and attachment member may be configured such that the telescoping, pivoting and folding requires a manual operation.

[0419] A wiring harness 6530 with a connector 6535 is provided to interface the exterior mirror with associated apparatus located inside the associated vehicle. The wiring harness may be configured to provide extension, folding and pivoting of the housing and may also be configured to provide reflective element control, electrical power, turn signal actuation, mirror heater control, mirror element positioning, light sensor interface, exterior mirror circuit board interface, transceiver interface, information display interface, antenna interface, light source power and control, emergency flasher interface, and all other electrical features as described herein. It should be understood that operator interfaces are provided within the vehicle for each of these features where appropriate.

[0420] A mirror element positioner 6540 is provided for aligning the associated reflective element within the housing from the interior of the associated vehicle. It should be understood that a corresponding operator interface is provided within the vehicle for positioning of the reflective element.

[0421] The positioner 6540 is mechanically connected to a carrier for providing a secure structure for supporting and moving of the associated reflective element. Examples of suitable carriers are described in U.S. Pat. Nos. 6,195,194 and 6,239,899, the disclosures of which are incorporated herein in their entireties by reference.

[0422] In at least one embodiment, a double sided adhesive foam 6550 is employed to attach the reflective element to the carrier. In certain instances, apertures 6551 may be provided in the double sided adhesive foam for accommodating positioning of various components.

[0423] In at least one embodiment, an electrical circuit board 6555 is provided in the rearview mirror assembly. The electrical circuit board may comprise a light source such as a turn signal light, a keyhole illuminator, or an outside door area illuminator, as taught in U.S. Pat. No. 6,441,943, the entire disclosure of which is incorporated in its entirety herein by reference, an information display, an antenna, a transceiver, a reflective element control, an outside mirror communication system, a remote keyless entry system, proximity sensors, and interfaces for other apparatus described herein. U.S. Pat. Nos. 6,244,716, 6,523,976, 6,521,916, 6,441,943, 6,335,548, 6,132,072, 5,803,579, 6,229,435, 6,504,142, 6,402,328, 6,379,013, and 6,359,274 disclose various electrical components and electrical circuit boards that may be employed in one or more embodiments, the disclosures of each of each of these U.S. patents are incorporated herein in their entireties by reference.

[0424] In at least one embodiment, a rearview mirror assembly is provided with a heater 6560 for improving the operation of the device and for melting frozen precipitation that may be present. Examples of various heaters are disclosed in U.S. Pat. Nos. 5,151,824, 6,244,716, 6,426,485, 6,441,943 and 6,356,376, the disclosures of each of these patents are incorporated in their entireties herein by reference.

[0425] In at least one embodiment, the reflective element is has variable reflectance feature. The variable reflectance reflective element may comprise a first substrate 6565 and a second substrate 6570 secured in a spaced apart relationship by a seal 6575 to define a chamber therebetween. The reflective element may be configured to define a convex element, an aspheric element, a planar element, a non-planar element, a wide field of view element, or a combination of these various configurations in different areas to define a complex mirror element shape. The first surface of the first substrate may comprise a hydrophilic or hydrophobic coating to improve the operation. The reflective element may comprise transflective properties such that a light source, or information display, may be positioned behind the element and project light rays therethrough. The reflective element may comprise an anti-scratch layer, or layers, on the exposed surfaces of the first and, or, second substrates. The reflective element may comprise area(s) that are devoid of reflective material, such as etched in bars or words, to define information display area(s). Examples of various reflective elements are described in U.S. Pat. Nos. 5,682,267, 5,689,370, 6,064,509, 6,062,920, 6,268,950, 6,195,194, 5,940,201, 6,246,507, 6,057,956, 6,512,624, 6356,376, 6,166,848, 6,111,684, 6,193,378, 6,239,898, 6,441,943, 6,037,471, 6,020,987, 5,825,527 6,111,684 and 5,998,617, the disclosures of each of these patents are incorporated in their entireties herein by reference.

Modifications, Auxiliary and Alternative Embodiments.

[0426] As discussed above in reference to FIGS. 1 through 65, an embodiment of a rearview mirror system employing an EC-element and a source of light behind the EC-element preferably includes a ring of an optical thin-film spectral filter material that is circumferentially disposed in a peripheral area, next to a corresponding perimeter-defining edge, of either the first or the second surface of the system. It is recognized that the use of the peripheral ring is partly directed to configuring an overall mirror system in such a fashion as to make the system as aesthetically appealing to the user as possible. For example, one purpose of this thin-film ring is to hide the seal, the plug material, and, possibly, the electrical connectors of the EC-element from being visually discernable by the user through the first substrate. As such, this peripheral ring of material is usually opaque in at least a portion of visible spectrum of electromagnetic radiation and may be sufficiently wide, up to 6.5 mm. It has also been discussed in this application that such a peripheral ring must facilitate matching of spectral characteristics of ambient light reflected from the periphery of the mirror system that includes such a ring with those of ambient light reflected from a central area inside the periphery of the mirror system where the ring is not present. The better the spectral matching, e.g., matching of reflectance and color gamut, the less discernable is the area of the peripheral ring to the viewer when the EC-element is switched “off” and the rearview assembly of the invention operates purely as a mirror. Solutions to achieving various degrees of spectral matching between the ring-portion of the mirror and the central, transflective portion of the mirror have already been discussed in this application and included judicious thin-film designs of the peripheral ring with the use of such materials as chromium, nickel, stainless steel, molybdenum, silicon, platinum group metals, aluminum, silver, copper, gold or various alloys of these metals.

[0427] Also discussed was another, more tangible purpose of utilizing a peripherally deposited thin-film ring—to reduce exposure of the seal, disposed between the substrates forming an EC-cavity, to UV light that causes degradation of the seal. Clearly, then, such UV-protection measure is of particular importance in an outside rearview assembly (see, e.g., FIGS. 3 and 5) that is fully exposed to sunlight, while requirements to UV-properties of a ring of an EC-element employed within an inside rearview assembly (see, e.g., FIGS. 4 and 5) may be not as stringent.

[0428] It is recognized that the use of a peripheral ring entails certain shortcomings. For example, it must be realized that, in operation, the peripheral area of a mirror system of the assembly containing the peripheral ring does not darken, unlike the central portion of the mirror, when the voltage is applied to the electrodes of the EC-element (or other electrically darkening technology) in order to reduce the light-glare blinding the user. As a result, the difference in appearances of the peripheral ring and the central portion of the mirror when the EC-element is “on” may be quite significant, in particular in inside rearview assemblies that typically employ higher reflectance levels. Consequently, not only the size of the central portion of the mirror is accordingly reduced, as compared to the overall front surface of the mirror element, by a width of the peripheral ring but the peripheral ring continues producing the undesired glare even when the EC-element is “on”. Another problem arises from the fact that a typical mirror system of an inside rearview assembly contains an eye-hole (such as the elements 497 and 515 of FIGS. 4 and 5) behind which corresponding sensors (such as the sensor 396 of FIG. 3) may be positioned. When the eyehole is used in combination with a peripheral ring, appropriate positioning of the eye-hole may not be straightforward. For example, if the eye-hole is formed by creating an opening in a coating stack of the third surface, then locating such an opening within the peripheral area of the mirror element will disrupt the visual continuity of the mirror and will be perceived as aesthetically unpleasing, particularly in an embodiment where the height of the mirror is not significant. It is appreciated that, although in description of the embodiments below mounting elements (e.g., carrier, bezel, and housing elements) as well as electrical connectors are omitted, all of these elements are implied and the described alternative and modified embodiments may be used with any combination of the mounting and electrical elements discussed in this application.

Eye-Hole Openings.

[0429] Common embodiments of automotive electrochromic mirrors generally include light sensors for measuring glare and ambient light levels. In certain embodiments the glare sensor is positioned behind the EC mirror element and views glare light levels through an aperture in the reflective coating. Prior art embodiments of eyehole openings for light sensors comprise single continuous openings. These openings in the reflective layer may comprise a TCO or a transflective metal layer for conductivity. In general, these openings can be several millimeters wide and are often round or elliptical in shape. The aperture must be large enough to allow glare light entering the vehicle to adequately illuminate the glare sensor for accurate light level measurement. A single, hard edged eyehole might be considered aesthetically less than optimum by certain observers. Some prior art embodiments utilize a transflective opening that is effectively stealthy and non-obvious to an observer. For certain other embodiments discussed herein, the use of a cluster of multiple, smaller openings instead one large opening may have aesthetic and/or manufacturing advantages. Non-limiting embodiments of multi-opening eyeholes are shown in FIGS. 66(A-E). These examples comprise reflective regions 6620 (reflective material present) and areas 6610 that are patterned to be essentially devoid of reflective material. As shown in FIGS. 66(A-E), these patterns may be essentially circular, rectangular or line-like and may have a regular or irregular spacing. In general, an optimized pattern of reflective and essentially non-reflective regions within the geometric boundaries of an eyehole can be less noticeable and therefore less aesthetically objectionable. The size and spacing of the openings, as they contribute to percent open area in the eyehole region, determine the transmittance of light to the glare sensor. Because the eyehole is part of the EC element, it darkens when the element is energized resulting in a change of light intensity measured by the glare sensor. It is preferable that the eyehole clear as quickly as the rest of the EC mirror element so that the measured light intensity is accurately indicative of the glare observed by the driver. If the eyehole clears slower than the rest of the mirror element then it is possible that the EC mirror will not respond to changing glare situations as intended.

[0430] There can be negative impacts on EC mirror element aesthetics and function caused by essentially non-conductive regions of the electrode. In the currently described electrochromic (EC) cell embodiments, the EC fluid comprises two primary coloring compounds, an anodic material, which is bleached in its normal state and becomes oxidized at the anode when the cell is energized, and a cathodic material, which is bleached in its normal state and becomes reduced at the cathode when the cell is energized. In one embodiment the anodic material is yellow/green in its colored state and the cathodic material is violet in its colored state. Because these two EC materials are dissolved in the EC fluid, they are free to diffuse through the cell. Therefore, when the operating potential is applied between the anode and cathode, the two EC active compounds proximate to the proper electrode surface are converted to their colored states. The colored state compounds diffuse away from the electrode surfaces where they were created and are replaced by more bleached state compounds which are subsequently colored. When a molecule of oxidized (colored) anodic material diffuses proximate to a molecule of reduced (colored) cathodic material, there is some probability that a charge transfer reaction will occur, converting both molecules back into their bleached state. A second potential route to bleaching of a colored state molecule is diffusion to the opposite electrode from which it was created. A molecule of anodic material that has been oxidized at the anode has some probability of diffusing proximate to the cathode surface. Once this occurs it is likely that the anodic material will be reduced back to its bleached state. Likewise, the same effect can apply to reduced cathodic material that diffuses to the anode. In this way, some time after the initial activation of the EC cell, steady state equilibrium is reached between the creation of colored state compounds and the bleaching of colored state compounds by intermolecular charge exchange and diffusion to the opposite electrode. In the equilibrium state, colored EC molecules have the highest probability of bleaching through intermolecular charge transfer with the opposite species in a depletion zone between the two electrodes where the concentration of colored species approaches zero. As described elsewhere, in a standard EC mirror cell design, surface 2 of the EC element comprises a transparent electrode which is commonly configured as the anode. Surface 3 of the EC element comprises a conductive, reflective layer which is commonly configured as the cathode. Considering the equilibrium described above, if one considers the EC cell in cross-section, there will be a somewhat higher concentration of colored anodic material proximate the anode surface and a somewhat higher concentration of colored cathodic material proximate the cathode surface. Nearer the center of the cell (in cross-section), the concentrations of the colored anodic and cathodic materials will be more similar until the concentrations fall to near zero in the depletion zone. To an observer viewing the reflective element from a position normal to its first surface, the stratification of the colored species is not apparent since the layered colors are blended by the path the light takes to the observer. Consequently, if there is a gap in one of the conductive layers generating a non-conductive or significantly less conductive region (for example, an area 6610), a localized imbalance can be caused in the equilibrium. The side of the cell still having a functional electrode will generate colored material as described above. The side of the cell with the compromised electrode will not generate colored material or will do so at a significantly reduced rate. Therefore if there is a gap in the cathode of the above described embodiment, yellow/green material will be produced at the anode without commensurate violet material being product at the opposing cathode location. This imbalance can lead to a net yellow/green appearance at the location of the compromised cathode. This color imbalance is here and elsewhere (U.S. Pat. Nos. 4,902,108 and 5,679,283 herein incorporated by reference in their entirety) referred to as segregation. This effect can lead to less than optimum aesthetics when the mirror element has been in the dark state for several minutes. The size or area of the compromised zone of the electrode affects the degree of segregation due to its effect on the diffusion length required to reach the other electrode. For example, in a non-compromised system with two parallel electrodes separated by 140 microns, the shortest diffusion path length at any position in the system must be less than or equal to 140 microns. If a segment of an electrode 500 microns wide is removed then the shortest diffusion path length can be as high as 287 microns in the compromised segment, describing the hypotenuse of the triangle running from the center of the compromised segment to its edge then across to the other electrode of the EC cell. Increasing the shortest path length will increase the effects of segregation. These effects are illustrated in FIG. 66F.

[0431] A common method of clearing the EC element involves removal of the driving potential and electrical shorting of the anode to the cathode. At this point no new EC molecules are being converted to their colored states and diffusion takes over. The high concentration of oxidized anodic species proximate the anode and reduced cathodic species proximate the cathode result in a chemical potential similar to a battery. Shorting the electrodes allows the species proximate to the electrode surfaces to rapidly return to their bleached state. Diffusion across the cell allows the remaining oxidized anodic molecules to bleach through charge transfer reactions with reduced cathodic molecules. Again, as described above, a non- or partially-conductive area of one of the electrodes means that the bleaching of one of the EC species cannot occur at the compromised electrode surface resulting in diffusion being the only route to bleaching. If only one electrode, cathode or anode, is compromised then one species may bleach more quickly than the other resulting in a color imbalance and slower than normal clearing of that species which is herein also considered a form of segregation. The sum effect of one electrode having a non- or partially-conductive region is that in the driven (darkened) state, one colored EC species increases in concentration in the compromised zone, due to lack of depletion by the opposite EC species, until it dominates the color. This dominate color persists for some time after clearing of the EC element by the method described above due to diffusion being the only route to bleaching in the compromised region. Depending on the size and shape of the compromised zone, it is possible, due to the chemical potential present during clearing, to see a small amount of the violet color, for the above described embodiment, proximate the perimeter of the compromised zone during clearing. As described above, the colored EC species persisting in the eyehole zone longer than the clearing time for the rest of the element may lead to less than optimum performance of the glare sensor.

[0432] As alluded to above, one route to minimizing the segregation effects is to compromise both the anode and cathode electrodes. So if the intent is to create openings or essentially non-conductive zones in the third surface reflector layer to enhance transmission or create a conductance break, creating an essentially equivalent opening or essentially non-conductive zone in the opposing region of the second surface conductive layer will have roughly equivalent, offsetting effects, resulting in less segregation effects. This is due to the effect that both electrodes are compromised meaning that neither EC material effectively dominates in the compromised zone. This may significantly reduce the color bias in the activated (dark) state as well as during clearing. This may also reduce the lag in clearing time but will not necessarily eliminate it.

[0433] Examples: EC-mirror elements were fabricated with nominal cell spacing of approximately 140 microns. The eyeholes in these devices were configured by patterning the third surface metal reflector (cathode) with vertical lines created by laser ablation in a fashion similar to that of FIG. 66C. The perimeter of the ablated area approximated an oval with a length of about 5 mm and a width of about 7 mm. The width of the remaining metal traces and the width of the ablated openings in the eyehole area are shown in Table 6. Each of the samples was activated (darkened) for 10 minutes and then shorted (cleared). During the coloring and clearing phases the eyehole region was observed by transmittance spectroscopy to track the change in transmittance versus time. Examples A1-L1 represent openings in the surface 3 reflective layer without a corresponding “opening” in the surface 2 TCO. Examples A2-L2 represent openings in surface 2 plus corresponding essentially equivalent “openings” in the surface 2 TCO. FIG. 66G demonstrates the change in transmittance at the eyehole during coloring and clearing for both an element showing segregation effects and an element not showing segregation. As can be seen from FIG. 66G, a non-compromised EC element shows relatively monotonic change between the bright and dark states while an EC element with a compromised electrode in the region of the eyehole shows a non-monotonic change both for coloring and clearing. The secondary, slow change identified as segregation in FIG. 66G is due to the slow diffusion of colored state EC molecules into and out of the compromised zone/s of the eyehole. A time measure, t₁, was assigned for the time at which the primary rapid clearing step transitioned to the slow segregation clearing step. A second time measure, t₂, was assigned to the point at which the clearing reached essentially a steady state transmittance. The difference between t₂ and t₁ was defined as the Clearing Time Delay, Delta-t. The transmittance at time t₁ was defined as % T₁. Similarly the transmittance at time t₂ was defined as % T₂. The value of % T₂ represents the transmittance of the eyehole in its essentially fully clear state. The attenuation of light at time t₁ relative to t₂ was defined as Delta-% I which represents the loss of light intensity reaching the glare sensor at time t₁ relative to the intensity of light reaching the glare sensor in the fully clear state; in other words, the attenuation of the glare sensor response due to segregation. Table 6 lists the properties of the example surface 3 eyehole ablations including whether surface 2 was also ablated, the width of the metal traces, the width of the ablated spaces, the clear state transmittance, the dark state transmittance and the variables listed above. To minimize the effects of segregation on the performance of the glare sensor it is preferable to minimize either the clearing time delay, Delta-t, or the attenuation of the glare sensor, Delta-% I. Minimizing both measures will result in a preferable embodiment however; the minimization of either measure reduces the impact of the other measure.

[0434]

TABLE 6
	Surf2	Traces	Ablations			Darkened	t1	t2				Delta-
Label	Ablation	(um)	(um)	% Open	% T	% T	sec	sec	Delta-t	% T1	% T2	% T	Delta-% I
A1	N	54	50	48	22.1	4.7	17	113	96	20.7	22.1	1.4	6.4
B1	N	123	50	29	14.1	2.7	13	68	55	13.6	14.1	0.5	3.9
C1	N	210	50	19	9.2	1.8	16	42	26	9.1	9.2	0.1	0.8
D1	N	81	75	48	23.6	7.5	20	130	110	21.2	23.6	2.4	10.2
E1	N	185	75	29	13.8	4.4	13	72	59	13.1	13.8	0.7	5.2
F1	N	315	75	19	10.1	3.4	16	50	34	9.8	10.1	0.3	2.8
J1	N	217	200	48	25.4	16.5	2	265	263	18.8	25.3	6.5	25.6
K1	N	490	200	29	16.1	10.5	3	164	161	12.2	16.0	3.8	23.6
L1	N	853	200	19	9.4	6.1	3	97	94	7.1	9.4	2.3	24.5
A2	Y	54	50	48	21.3	4.1	17	62	45	20.7	21.3	0.6	2.7
B2	Y	123	50	29	13.6	2.4	20	42	22	13.5	13.6	0.1	0.9
C2	Y	210	50	19	9.0	1.7	23	28	5	8.9	9.0	0.1	0.6
D2	Y	81	75	48	23.8	6.2	20	70	50	23.3	23.8	0.5	2.3
E2	Y	185	75	29	13.6	4.2	20	42	22	13.6	13.6	0.0	0.3
F2	Y	315	75	19	9.6	3.1	18	22	4	9.6	9.6	0.0	0.4
G2	Y	69	251	78	40.6	29.8	9	229	220	36.6	40.5	3.9	9.6
H2	Y	158	481	75	38.9	25.0	4	324	320	26.6	38.9	12.3	31.6
J2	Y	217	200	48	25.6	16.9	7	109	102	22.3	25.6	3.3	12.9
K2	Y	490	200	29	15.8	11.2	9	109	100	14.3	15.7	1.4	8.9
L2	Y	853	200	19	11.1	7.8	10	109	99	10.1	11.1	1.0	9.0

[0435] Another approach to quantifying the effects of segregation on the glare sensor response is to consider the lag between initiation of clearing the EC element and the time at which the eyehole transmittance reaches a predetermined value. For this purpose it is convenient to consider a normalized Percent Full Scale (% FS) transmittance scale for the eyehole. The actual transmittance of the eyehole at any time t is normalized and scaled such that the minimum transmittance of the eyehole in the fully darkened state becomes 0% FS and the maximum transmittance of the eyehole in the fully cleared state becomes 100% FS. The behavior of this measure for the clearing of selected examples is given in FIG. 66H. This normalized scale is convenient because it more accurately describes the effects of the segregation on the actual response range of the glare sensor. It is preferable that the eyehole reach a % FS value of greater than 75% within 20 seconds of the initiation of clearing. It is more preferable that the eyehole reach a % FS value of greater than 80% within 20 seconds of the initiation of clearing. It is most preferable that the eyehole reach a % FS value of greater than 90% within 20 seconds of the initiation of clearing. The Percent Full Scale transmittance data for the examples described above is given in Table 7. Tuning of the clearing speed and optical properties of the eyehole, as described above, is controlled by the conductivity of the surface 2 and surface 3 electrodes as well as the fraction open area in the surface 3 electrode within the boundaries of the eyehole zone and the selection of a metal trace (area 6620 of FIGS. 66A through 66 E) and open area (area 6610 of FIGS. 66A through 66E) dimensions and geometry. It is therefore preferable that the fraction of open area in the eyehole zone be between 5 and 75 percent. It is more preferable that the fraction of open area in the eyehole zone be between 10 and 60 percent. It is most preferable that the fraction of open area in the eyehole zone be between 15 and 50 percent. It is preferable that the minimum dimension of the metal traces be between 1 and 1000 microns. It is more preferable that the minimum dimension of the metal traces be between 10 and 500 microns. It is most preferable that the minimum dimension of the metal traces be between 20 and 250 microns. It is preferable that the maximum dimension of the openings be between 1 and 1000 microns. It is more preferable that the maximum dimension of the openings be between 10 and 500 microns. It is most preferable that the maximum dimension of the openings be between 20 and 250 microns.

[0436] It is appreciated that the dimension of the remaining metal traces (areas 6620) in the eyehole zone may affect the performance of the glare sensor. If the traces are not small compared to the dimensions of the glare sensor, or its optics, then the shadowing of the sensor by the metal traces might result in the response of the glare sensor being non-uniform with respect to the angle of incidence of the light. For this reason the dimension and spacing of the metal traces may require optimization beyond the requirements of the segregation effects described above. Eyeholes comprising multiple smaller apertures may be considered less obtrusive and therefore more aesthetically pleasing than larger, single aperture eyeholes. The use of laser ablation to form the above described apertures/ablations is one example of a potential manufacturing advantage over common methods used to generate conductive, single aperture eyeholes in a reflective conductive layer stack.

[0437]

TABLE 7
Percent of Full Scale Transmittance.
	Time (sec)
	% Tmin	% Tmax	0	1	2	3	4	5	6	7	8	9	10	15	20	25	30
A1	4.7	22.1	0	0.5	3.6	11.0	20.7	44.7	57.7	70.4	81.9	89.1	89.8	89.6	89.7	89.9	90.3
B1	2.7	14.1	0	0.8	5.3	12.4	21.3	42.6	54.0	65.4	76.1	85.8	93.0	95.1	95.4	96.1	96.7
C1	1.8	9.2	0	1.0	5.9	13.5	22.9	44.6	56.0	66.9	76.9	85.6	92.8	98.3	98.7	99.1	99.4
D1	7.5	23.6	0	1.2	7.4	16.7	27.7	52.1	64.3	75.5	82.9	85.8	85.9	85.3	85.3	85.4	85.7
E1	4.4	13.8	0	1.6	7.9	17.1	27.8	50.7	62.2	72.9	82.1	88.5	91.5	92.0	92.2	92.8	93.4
F1	3.4	10.1	0	1.1	7.3	17.3	29.0	53.6	65.2	75.9	84.9	91.0	94.3	96.2	96.9	97.6	98.4
J1	16.6	25.4	0	10.3	19.9	24.2	26.6	28.5	30.2	31.5	32.7	33.9	34.8	38.3	40.5	41.8	42.8
K1	10.5	16.1	0	12.6	23.4	28.6	32.3	34.8	37.2	39.3	41.2	43.0	44.7	51.1	55.7	59.2	61.9
L1	6.1	9.4	0	12.7	23.5	29.4	33.5	36.7	39.4	42.0	44.4	47.3	49.2	57.5	64.0	69.2	74.0
A2	4.1	21.3	0	0.2	4.0	11.1	20.2	43.7	53.5	64.7	75.1	84.1	91.3	96.6	97.1	97.7	98.1
B2	2.4	13.6	0	0.3	3.2	8.9	16.3	34.5	44.5	54.6	64.2	73.1	80.9	98.9	99.3	99.6	99.8
C2	1.7	9.0	0	0.5	3.7	9.8	17.7	36.9	47.1	56.9	66.3	74.7	81.9	99.6	99.9	99.9	100.0
D2	6.2	23.8	0	0.6	4.3	10.5	18.2	35.5	44.7	53.9	62.8	71.2	78.9	97.0	97.2	97.6	98.0
E2	4.2	13.6	0	1.4	6.8	14.9	24.4	44.5	54.3	63.4	71.8	79.4	85.7	99.1	99.3	99.5	99.6
F2	3.1	9.6	0	1.2	6.1	14.1	23.6	44.1	54.0	63.5	71.9	79.5	85.7	99.0	99.6	99.6	99.9
G2	30.0	40.6	0	5.8	15.4	26.3	37.5	45.6	51.9	57.0	60.8	62.2	62.7	65.0	67.2	69.0	70.9
H2	25.1	38.9	0	3.3	6.3	8.5	10.2	11.4	12.7	14.0	15.4	16.7	18.1	25.4	33.2	41.1	49.0
J2	16.9	25.6	0	13.0	25.8	37.0	45.9	51.9	56.4	59.6	62.3	64.5	66.7	75.1	80.7	84.9	88.0
K2	11.2	15.8	0	7.0	17.4	28.6	39.2	46.7	53.7	59.4	64.0	67.3	69.1	74.3	78.2	81.6	84.1
L2	7.8	11.1	0	5.7	15.4	26.4	37.6	45.6	52.6	58.4	63.0	66.1	68.6	74.0	77.9	81.1	84.1