Orientable lens for an LED fixture

[0001] This application under 35 USC §119(e) claims priority to, and benefit from, U.S. Provisional Application No. 61/061,392, filed Jun. 13, 2008, entitled “Orientable Lens for a LED Fixture,” which is currently pending, naming Jean-François Laporte as the sole inventor.

[0002] 1. Field of the Invention

[0003] The present invention is related generally to an orientable lens, and more specifically to an orientable lens for a light emitting diode fixture.

[0004] 2. Description of Related Art

[0005] Light emitting diodes, or LEDs, have been used in conjunction with various lenses that reflect light emitted by the LED. Also, various lenses have been provided for use in light fixtures utilizing a plurality of LEDs as a light source.

[0019] It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” “in communication with” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible.

[0020] Referring now in detail to FIGS. 1-10, wherein like numerals indicate like elements throughout the several views, there are shown various aspects of an orientable lens for a LED fixture. Orientable lens is usable in conjunction with a single LED and may be installed and used with a variety of LEDs. Orientable lens is preferably used as a lens for a LED with a Lambertian light distribution although it may be configured for and used as a lens for LEDs having other light distributions as well. FIG. 1 shows a LED flat board 1, on which is mounted fifty-four LEDs 4 with a Lambertian light distribution. In some embodiments of LED flat board 1, LED flat board 1 is a metallic board with advantageous heat distribution properties such as, but not limited to, aluminum. In other embodiments LED flat board 1 is a flame retardant 4 (FR-4) or other common printed circuit board. LED flat board 1 and plurality of LEDs 4 are merely exemplary of the multitude of boards, number of LEDs, and multitude of LED configurations in which a plurality of orientable lenses for a LED may be used. Design considerations such as, but not limited to, heat, desired lumen output, and desired light distribution pattern may result in a choice of differing amounts of LEDs, differing LED configurations, and/or differing materials.

[0021] Also shown in FIG. 1 are three of one embodiment of orientable lens 10, two of which are shown placed over respective LEDs 4 and mated to flat board 1 and one of which is shown exploded away from its respective LED 4. Being orientable means that each lens is individually adjustable to a given orientation about a given LED. As will become clear, when a plurality of orientable lenses 10 are used in conjunction with a plurality of LEDs, each orientable lens 10 may be individually oriented without regard to the orientation of other orientable lenses 10, such as, for example, the three orientable lenses 10 of FIG. 1 which are each oriented in a unique direction. Moreover, when a plurality of LEDs are present, as few as one LED, or as many as all LEDs in some preferred embodiments, may be provided with an individual orientable lens 10. Some or all lenses may be individually and permanently adjusted to a given orientation upon creation of the LED fixture with an orientable lens or some or all lenses may be attached to allow for adjustment in the field. Thus, complex photometric distribution patterns and a flexibility of distribution patterns may be achieved when using a plurality of orientable lenses 10 with a plurality of LEDs, such as, but not limited to, plurality of LEDs 4 on flat board 1.

[0022] Turning now to FIG. 2 and FIG. 3, an embodiment of orientable lens 10 is shown in more detail. Orientable lens 10 has a base 12 that is shown in this embodiment as having a substantially flat and substantially circular inner and outer mating surface 14 and 16, each with substantially circular inner and outer peripheries. Base 12 of FIG. 2 is also shown with a recessed portion 15 provided in between a substantial portion of inner and outer mating surfaces 14 and 16. Base 12 is provided, among other things, for attachment of orientable lens 10 to a surface on which a LED is mounted, such as, for example, attachment to flat board 1 of FIG. 1. Attachment of base 12 to a surface on which a LED is mounted and not to a LED itself reduces heat transfer from a LED to orientable lens 10. In some embodiments both inner and outer mating surface 14 and 16 mate with a surface for attachment of orientable lens 10. In some embodiments only inner mating surface 14 mates with a surface for attachment of orientable lens 10 and outer mating surface 16 interacts with a surface for alignment of orientable lens 10 about an LED. In some embodiments inner and/or outer mating surface 14 and 16 or other provided surface may be adhered to a mounting surface for attachment of orientable lens 10. In some embodiments inner and/or outer mating surface 14 and 16 or other provided surface may be snap fitted with a mounting surface for attachment of orientable lens 10. In some embodiments inner and/or outer mating surface 14 and 16 or other provided surface may be compressed against a mounting surface for attachment of orientable lens 10. Other attachment means of base 12 to a mounting surface may be provided as are generally known to those of ordinary skill in the art and as may be based on the teachings hereof.

[0023] Base 12 also has portions that may be provided for aesthetic purposes or support or attachment of other constituent parts of orientable lens 10. For example, in some preferred embodiments, at least primary reflector 24 (as shown in FIG. 6A) and reflecting prism 30 are attached to and supported by base 12. Some embodiments of orientable lens 10 may be provided with a base 12 having supports 18 or 19 that may help provide for support of reflecting prism 30 and may also be provided to fully seal orientable lens 10. Some embodiments of base 12 of orientable lens 10 may also be provided with rim portion 17 and like appendages if desired for ease in installation or other reasons. In some embodiments, when orientable lens is installed about a LED on a mounting surface, a sheet or other object may contact rim portion 17, or other portions of base 12, such as the flange portion provided around rim portion 17 and provide compressive force on orientable lens 10 in the direction of the mounting surface, thereby causing inner and/or outer mating surfaces 14 and 16 to mate with the mounting surface for attachment of orientable lens 10.

[0024] In other embodiments base 12 may take on different shapes and forms so long as it enables orientable lens 10 to be appropriately used with a given LED and be installable at any orientation around an LED light output axis, the LED light output axis being an axis emanating from the center of the light emitting portion of any given LED and oriented away from the LED mounting surface. For example, base 12 may be provided in some embodiments without recessed portion 15 and with only one distinct mating surface, as opposed to inner and outer mating surfaces 14 and 16 shown in. Also, for example, base 12 may be provided with inner and/or outer peripheries that have a shape other than circular. Also, for example, base 12 may be provided with other configurations for attachment to and/or support of constituent parts of orientable lens 10, such as primary reflector 24 and reflecting prism 30. Other variations on base 12 will be apparent to one skilled in the art.

[0025] Also shown in FIG. 2 are portions of a refracting lens 22, primary reflector 24, a surface 26, a reflecting portion 28, and reflecting prism 30. When orientable lens 10 is placed about an LED and base 12 is affixed to a surface, such as LED 9 and surface 5 of FIG. 4A, FIG. 5A, FIG. 5B, and FIG. 6A, refracting lens 22 and primary reflector 24 are proximal LED 9. In particular, primary reflector 24 is positioned such that it partially surrounds the light emitting portion of LED 9 and refracting lens 22 is positioned such that it intersects the LED light output axis of LED 9 and is partially surrounded by primary reflector 24. In some embodiments primary reflector 24 is a parabolic reflector. Refracting lens 22 and primary reflector 24 are positioned so that a majority of light emitted from LED 9 will collectively be incident upon one of the two. In some embodiments, primary reflector 24 may be provided such that it completely surrounds the light emitting portion of LED 9. In some embodiments, such as those shown in the figures, primary reflector 24 only partially surrounds the light emitting portion of LED 9 and reflecting portion 28 is provided on one side of the light emitting portion of LED 9 positioned adjacent primary reflector 24 and surface 26 is provided on a substantially opposite side of the light emitting portion of LED 9 and also positioned adjacent primary reflector 24.

[0026] In some additional embodiments refracting lens 22 is positioned at the base of sidewall 23 and sidewall 23 substantially surrounds the light emitting portion of LED 9. A majority of rays emanating from LED 9 and incident upon refracting lens 22 will be refracted such that they are directed towards a reflective surface 32 of reflecting prism 30. In some embodiments, refracting lens 22 is configured such that it refracts rays so they are substantially collimated towards reflective surface 32, such as the exemplary rays shown in FIG. 5A.

[0027] In other embodiments, other rays emanating from LED 9 will be incident upon sidewall 23 proximal primary reflector 24, pass therethrough at an altered angle and will be incident upon primary reflector 24. A majority of rays incident upon primary reflector 24 are reflected and directed towards reflective surface 32 of reflecting prism 30, such as the exemplary rays shown in FIG. 6A which are directed towards portions of reflective surface 32 not shown in the figure, but evident from reference to other figures. In some embodiments of orientable lens 10, primary reflector 24 has a composition and orientation such that a majority of rays incident upon it are internally reflected and directed towards reflective surface 32. In other embodiments, primary reflector 24 is composed of a reflective material.

[0028] In additional embodiments, other rays emanating from LED 9 will be incident upon sidewall 23 proximal reflecting portion 28, pass therethrough at an altered angle and will be incident upon reflecting portion 28. A majority of rays incident upon reflecting portion 28 are reflected and directed towards reflective surface 32 of reflecting prism 30, such as the exemplary rays shown incident upon reflecting portion 28 and directed towards reflective surface 32 in FIG. 5B. In some embodiments reflecting portion 28 is positioned and configured to direct light rays in a unique direction from those rays directed by primary reflector 24 and refracting lens 22 such that they also exit orientable lens 10 in a unique direction. In embodiments of orientable lens 10 reflecting portion 28 has a composition and orientation such that a majority of rays incident upon it are internally reflected and directed towards reflective surface 32. In other embodiments, reflecting portion 28 is composed of a reflective material.

[0029] In some embodiments, other rays emanating from LED 9 will be incident upon sidewall 23 proximal surface 26, pass therethrough at an altered angle and will be directed towards an optical lens 34 of reflecting prism 30, such as the exemplary rays shown in FIG. 5B. A majority of these rays will pass through optical lens 34 and many of the rays will also pass through support 18 as shown in FIG. 5B. Also, as shown in FIG. 5B, some light rays may also be incident upon surface 26 and reflected and directed towards lens 34 and potentially support 18. One skilled in the art will recognize that varying configurations of orientable lens 10 may call for varying configurations of any or all of refracting lens 22, sidewall 23, primary reflector 24, surface 26, and reflecting portion 28 in order to achieve desired light distribution characteristics.

[0030] In some embodiments, sidewall 23 is provided for provision of refracting lens 22 and many rays pass through sidewall 23 prior to being incident upon primary reflector 24 and potentially reflecting portion 28 and surface 26. In some embodiments sidewall 23 alters the travel path of rays passing therethrough. In some embodiments the height of sidewall 23 is shortened near its connection with reflecting portion 28. In other embodiments refracting lens 22 is positioned using thin supports attached to the inner surface of primary reflector 24 or otherwise and sidewall 23 is not provided. Also, in some embodiments, such as shown in the figures, sidewall 23 is provided and orientable lens 10 is formed from an integral molded solid unit of an appropriate medium. In these embodiments where orientable lens 10 forms an integral molded solid unit, once light rays emitted from LED enter orientable lens 10, they travel through the appropriate medium until they exit orientable lens 10. In some embodiments the medium is optical grade acrylic and all reflections occurring within orientable lens 10 are the result of internal reflection.

[0031] Reflective surface 32 of reflecting prism 30 may have a composition and orientation such that rays that have been collimated by refracting lens 22 or reflected by primary reflector 24 or reflecting portion 28 and directed towards reflective surface 32 are reflected off reflective surface 32 and directed towards optical lens 34, such as those rays shown in FIGS. 5A and 5B. Preferably the rays are internally reflected off reflective surface 32, although reflective surface 32 could also be formed of a reflective material. Most rays incident upon optical lens 34 pass through optical lens 34, potentially at an altered angle in some embodiments. Preferably, the direction of rays passing through optical lens 34 is only slightly altered. In embodiments where constituent parts of orientable lens 10 form an integral molded solid unit, reflective surface 32 internally reflects any rays incident upon it and rays that emanate from an LED and enter orientable lens 10 travel through the medium of orientable lens 10 until they exit orientable lens 10 through optical lens 34 or otherwise.

[0032] Reflective surface 32 of reflecting prism 30 need not be a flat surface. In some embodiments, such as those shown in the figures, reflective surface 32 actually comprises two faces at slightly different angles in order to allow more accurate control of light reflected from reflective surface 32 and to allow for a narrower range of light rays to be emitted by orientable lens 10. In other embodiments a reflective surface may be provided that is curved, concave, convex, or provided with more than two faces. Similarly, optical lens 34 may take on varying embodiments to allow more accurate control of light reflected from reflective surface 32 and/or to allow for a narrower range of light rays to be emitted by orientable lens 10.

[0033] Through use of orientable lens 10, the light emitted from a given LED is able to be redirected from the LED light output axis at angle from the LED light output axis. Since orientable lens 10 is installable at any orientation around an LED light output axis, this light can likewise be distributed at any orientation around an LED light output axis. Dependent on the configuration of a given orientable lens 10 and its constituent parts, the angle at which light emitted from an LED is redirected off its light output axis can vary. Moreover, the spread of the light beam that is redirected can likewise vary. When a plurality of orientable lenses 10 are used on a plurality of LEDS mounted on a surface, such as flat board 1 and plurality of LEDs 4, each orientable lens 10 can be installed at any given orientation around an LED axis without complicating the mounting surface. Moreover, complex photometric distribution patterns and a flexibility of light distributions can be achieved with a plurality of LEDs mounted on a surface, such as flat board 1 and plurality of LEDs 4.

[0034] FIG. 7 shows a polar distribution in the vertical plane, scaled in candela, of a single LED with a Lambertian light distribution and without an orientable lens. FIG. 9 shows a polar distribution in the horizontal plane, scaled in candela, of the same led of FIG. 7. FIG. 8 shows a polar distribution in the vertical plane, scaled in candela, of the same LED of FIG. 7 with the embodiment of orientable lens showed in the figures in use. FIG. 10 shows a polar distribution in the horizontal plane, scaled in candela, of the same LED of FIG. 7 with the same orientable lens of FIG. 8 in use.

[0035] As can be seen from FIG. 8 and FIG. 10 orientable lens 10 directs a majority of light outputted by a LED with a Lambertian light distribution off a LED light output axis. In the vertical plane, shown in FIG. 8, a majority of the light is directed within a range from approximately 50° to 75° off the light output axis. In the horizontal plane, shown in FIG. 10, a majority of the light is directed within a 40° range away from the light output axis. Approximately 90% of light outputted by a LED with a Lambertian light distribution having the embodiment of orientable lens of FIG. 8 and FIG. 10 in use is distributed off the light output axis. FIG. 7-FIG. 10 are provided for purposes of illustration of an embodiment of orientable lens. Of course, other embodiments of orientable lens may be provided that produce differing polar distributions that direct light in a differing range off of and away from the light output axis. Thus, in the vertical plane of other embodiments light may be mainly directed in wider or narrower ranges and at a variety of angles away from the light output axis. In the horizontal plane of other embodiments light may likewise be directed in wider or narrower ranges.

[0036] The foregoing description has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is understood that while certain forms of the orientable lens for a led fixture have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.