Registration System for a Reproducing Machine

FIG. 1 is a schematic representation of a reproducing apparatus employing a registration mechanism in accordance with this invention.

FIG. 2 is a side view showing the registration mechanism in greater detail with the registration gate in sheet blocking relationship.

FIG. 3 is a side view showing the registration mechanism in greater detail with the registration gate moved out of sheet blocking relationship.

Referring now to FIG. 1 there is shown by way of example an automatic xerographic reproducing machine 10 which includes a registration apparatus 11 of the present invention. The reproducing machine 10 depicted in FIG. 1 illustrates the various components utilized therein for producing copies from an original. Although the apparatus 11 of the present invention is particularly well adapted for use in an automatic xerographic reproducing machine 10, it should become evident from the following description that it is equally well suited for use in a wide variety of processing system including other electrostatographic systems and it is not necessarily limited in its application to the particular embodiment of embodiments shown herein.

The reproducing machine 10 illustrated in FIG. 1 employs an image recording drum-like member 12, the outer periphery of which is coated with a suitable photoconductive material 13. One type of suitable photoconductive material is disclosed in U.S. Pat. No. 2,970,906, issued to Bixby in 1961. The drum 12 is suitably journaled for rotation within a machine frame (not shown) by means of shaft 14 and rotates in the direction indicated by arrow 15 to bring the image-bearing surface 13 thereon past a plurality of xerographic processing stations. Suitable drive means (not shown) are provided to power and coordinate the motion of the various cooperating machine components whereby a faithful reproduction of the original input scene information is recorded upon a sheet of final support material 16 such as paper or the like.

The practice of xerography is well known in the art and is the subject of numerous patents and texts including Electrophogography by Schaffert, and Xerography and Related Processes by Dessauer and Clark, both published in 1965 by the Focal Press.

Initially, the drum 12 moves the photoconductive surface 13 through a charging station 17. In the charging station 17, an electrostatic charge is placed uniformly over the photoconductive surface 13 preparatory to imaging. The charging may be provided by a corona generating device of the type described in U.S. Pat. No. 2,836,726, issued to Vyverberg in 1958.

Thereafter, the drum 12 is rotated to exposure station 18 wherein the charged photoconductive surface 13 is exposed to a light image of the original input scene information whereby the charge is selectively dissipated in the light exposed regions to record the original input scene in the form of a latent electrostatic image. A suitable exposure system may be of a type described in U.S. Pat. No. 3,832,057, issued to Shogren in 1974. After exposure drum 12 rotates the electrostatic latent image recorded on the photoconductive surface 13 to development station 19 wherein a conventional developer mix is applied to the photoconductive surface 13 of the drum 12 rendering the latent image visible. A suitable development station is disclosed in U.S. Pat. No. 3,707,947, issued to Reichart in 1973. That patent describes a magnetic brush development system utilizing a magnetizable developer mix having coarse ferromagnetic carrier granules and toner colorant particles. The developer mix is brought through a directional flux field to form a brush thereof. The electrostatic latent image recorded on the photoconductive surface 13 is developed by bringing the brush of developer mix into contact therewith.

Sheets 16 of final support material are supported in a stack arrangement on an elevating stack support tray 20 or in an auxiliary tray 21. Sheet separators 22 and 23 selectively feed individual sheets from their respective stacks to the registration system 11 of this invention which includes rolls 24 and 25. The sheet is then forwarded to the transfer station 26 in proper registration with the image on the drum. The developed image on the photoconductive surface 13 is brought into contact with the sheet 16 of final support material within the transfer station 26 and the toner image is transferred from the photoconductive surface 13 to the contacting side of the final support sheet 16. The final support material may be paper, plastic, etc., as desired.

After the toner image has been transferred to the sheet of final support material 16 the sheet with the image thereon is advanced to a suitable fuser 27 which coalesces the transferred powder image thereto. One type of suitable fuser is described in U.S. Pat. No. 2,701,765, issued to Codichini, et al. in 1955. After the fusing process the sheet 16 is advanced selectively to a suitable output device such as tray 28 or sorter 29.

Although a preponderance of the toner powder is transferred to the final support material 16, invariably some residual toner remains on the photoconductive surface 13 after the transfer of the toner powder image to the final support material. The residual toner particles remaining on the photoconductive surface 13 after the transfer operation are removed from the drum 12 as it moves through a cleaning station 30. The toner particles may be mechanically cleaned from the photoconductive surface 13 by any conventional means as, for example, the use of a blade as set forth in U.S. Pat. No. 3,740,789, issued to Ticknor in 1973.

If desired, a document handling system 31 can be used to advance documents on and off a viewing platen 32.

It is believed that the foregoing description is sufficient for purposes of the present application to illustrate the general operation of an automatic xerographic copier 10 which can embody the apparatus 11 in accordance with the present invention.

A detailed description of a suitable registration mechanism for use in accordance with the present invention can be found by reference to the above-noted Taylor, et al. patent. The present invention relates to an improvement particularly adapted for use with the Taylor, et al. registration apparatus.

Referring now to FIG. 2, it has been found that the width of the gap or the throat 33 defined between the registration gate 34 and the guide member 35 adjacent thereto at the point of registration in the Taylor, et al. apparatus was sufficiently wide to allow some variability in the exact position of the edge of the sheet intercepted by the gate. Further, depending upon where the edge of the sheet intercepted the gate, nicking of the sheet edge or other comparable damage could occur.

In order to eliminate this variability and lead edge nicking a means 36 is provided in accordance with the present invention to restrict the throat 33 opening adjacent the registration gate 34 so that each succeeding sheet 16 intercepts the registration gate at essentially the same point on the stop face 37. This is accomplished by providing a resilient member 36, such as a Mylar strip which is adhesively mounted to the chute portion 38 registration gate 34. The resilient member 36 is arranged to overly the lower guide chute or member 35. It is secured to the registration gate 34 so as to extend out toward the stop face 37 of the gate in a cantilevered fashion. The stiffness of the Mylar member 36 and its cantilevered mounting result in its acting like a spring which is biased against the lower guide chute 35 at the registration portion. This restricts the throat 33 of the sheet path at the registration gate 35.

When a sheet 16 is fed to the registration gate 34 the Mylar strip 36 is lifted off of the lower chute 35, and operates upon the sheet to urge it against the lower chute. Therefore, the sheet 16 engages the gate at a position consistently defined by the lower chute 35.

After the registration sequence has been completed and the registration gate 34 moves out of its sheet blocking position, as in FIG. 3, the cantilever mounting of the Mylar strip 36 causes the free end of the strip adjacent the stop face 37 to move away from the stop face and thereby aid in stripping the sheet from the stop face as it is fed into the transfer station 26. The registration gate 34 has been designed as in the Taylor, et al. patent so that the sheet 16 strips from the stop face 37 as the gate pivots about shaft 39 in coordination with the movement of the sheet, namely, in the direction of sheet movement, to deliver the sheet into the nip of the registration rolls 24 and 25.

The throat control member 36 in accordance with this invention provides a dual function. It aids in stripping a sheet from the gate 34 thereby preventing a sheet from hanging up on the stop face 37 and jamming in the machine. It also restricts the throat 33 or opening in the sheet path at the registration position.

In the embodiment which has been shown, the Mylar strip 36 extends completely across the registration gate 34 from side-to-side thereof. It comprises a unitary spring-like member having a plurality of fingers extending out in cantilevered fashion in correspondence with the fingers of the registration gate 34 of Taylor, et al.. If desired, however, the stripper assist and throat control means 36 in accordance with this invention can comprise a plurality of spring-like members attached to the registration gate in spaced apart fashion. The specific shape of the stripper assist and throat control means of this invention may be selected as desired.

While the invention has been described with reference to an embodiment wherein the registration gate 34 and stripper assist and throat control means 36 are supported above the sheet path, if desired, they could be supported below the sheet path and the sheet urged against an upper chute or guide member 35.

The stripper assist and throat control means 36 also operates to decelerate the sheet 16 as it approaches the stop face 37 thereby reducing the occurrence of lead edge nicking of the sheet.

The patents and texts referred to specifically in detailed description of this application are intended to be incorporated by reference into the description.

It is apparent that there has been provided in accordance with this invention a registration system for a reproducing machine which fully satisfies the objects, means and advantages set forth hereinbefore. While the invention has been described in conjunction with specific embodiments therefor, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.