Reproduction apparatus incorporating alternate redevelopment and reimaging cycles for multiple copies

Abstract

A continuously operating transfer reproduction apparatus includes a cyclic control unit which automatically effects alternate redevelopment and reimaging cycles when reproducing multiple copies of the same master. An electrophotographic plate travels in a closed loop past a moving optical system which images the plate with a light image of the master creating a latent electrostatic image on the plate. The latent image is developed at a developing station and transferred to a substrate at a transfer station as the plate travels therepast. Increased throughput speed is achieved by effecting a fixed number of redevelopment cycles while the moving optical system is resetting. Thus, the plate continues its travel past the resetting optical system to the developing station where the latent image is redeveloped and thence to the transfer station for transfer of the developed image to a second substrate. The plate is then cleaned and charged prior to being reimaged with the light image of the same master, and the process continues until the requisite number of copies have been reproduced. In one embodiment, multiple imaging areas, preferably an odd number thereof, are located on the plate facilitating rapid alternate imaging and redevelopment cycles.

What is claimed is: 
     
       1. An electrostatic transfer reproduction apparatus incorporating an electrophotographic plate having at least one image area thereon which travels in a first direction in a closed loop past a plurality of processing stations comprising: mounting means for mounting a master for optical projection;   an imaging .[.processing.]. station for projecting a light image of said mounted master onto said image area of said plate as said image area travels therepast creating a latent image on said image area, said imaging .[.processing.]. station including;   an actuable moving optical projecting system for projecting said light image while moving in said first direction from a home position;   actuable drive means for moving said optical projection system in said first direction from said home position and for returning said optical projection system to said home position;   a developer .[.processing.]. station for applying electrostatically charged developer material onto said image area thereby developing said latent image whenever said image area travels therepast;   
     
     
       a transfer .[.processing.]. station for transferring each developed image from said image area onto a substrate when said image area travels therepast; an actuable .[.processing.]. station actuable for removing a latent image on said image area as said image area travels therepast;   position sensing means for sensing the position of said at least one image area with respect to said processing stations;   cycle control means responsive to said sensing means for actuating said optical projection system and said drive means when said image area travels past said imaging .[.processing.]. station on a first pass thereby creating a latent image of the mounted master on said image area, for deactuating said actuable .[.processing.]. station and said optical projection system when said image area travels past said actuable .[.processing.]. station and said image .[.processing.]. station on at least one next subsequent pass following said first pass thereby retaining said latent image created during said first pass and for actuating said actuable .[.processing.]. station and said optical projecting system and drive means when said image area travels past said actuable .[.processing.]. station and said imaging .[.processing.]. station following said at least one next subsequent pass thereby creating a further latent image of said mounted master on said image area, the latent image on said at least one image area being developed at said developer .[.processing.]. station and transferred at said transfer .[.processing.]. station at least two times before removal thereof at said actuable .[.processing.]. station.   
     
     
       2. The electrostatic transfer reproduction apparatus set forth in claim 1 wherein said electrophotographic plate having an odd number of image areas thereon and wherein said cycle control means alternately actuates and deactuates said actuable .[.processing.]. station and said optical projection system when an image area travels past said actuable .[.processing.]. station and said imaging .[.processing.]. station. 
     
     
       3. The electrophotographic transfer reproduction apparatus set forth in claim 2 wherein said electrostatic plate having an odd plural number of image areas thereon. 
     
     
       4. The electrostatic transfer reproduction apparatus set forth in claim 1 wherein said actuable .[.processing.]. station includes: an actuable charging station for charging said image area of said electrophotographic plate when said image area travels therepast, said charging station being located prior to said imaging station in said first direction of plate travel;   said cycle control means actuating and deactuating said charging station in the same actuation-deactuation sequence applied to said optical projection system when the image area travels past said charging station.   
     
     
       5. The electrostatic transfer reproduction apparatus set forth in claim 1 wherein said actuable processing station includes: an actuable cleaning station for cleaning residual developer material from said image area of said plate when said image area travels therepast, said cleaning station being located prior to said imaging station in said first direction of plate travel;   said cycle control means actuating and deactuating said cleaning station in the same actuation-deactuation sequence applied to said optical projection system when the image area travels past said cleaning station.   
     
     
       6. The electrostatic transfer reproduction apparatus set forth in claim 1 wherein said drive means moves said optical projection system in a second direction opposite said first direction when return said optical projection system to said home position: at least one of said at least one image areas travelling past said imaging .[.processing.]. station during the movement of said optical projection system in said second direction.   
     
     
       7. The electrostatic transfer reproduction apparatus set forth in claim 6 wherein said electrophotographic plate having an odd number of image areas thereon and wherein said cycle control means alternately actuates and deactuates said actuable .[.processing.]. station and said optical projection system when an image area travels past said imaging .[.processing.]. station. 
     
     
       8. The electrostatic transfer reproduction apparatus set forth in claim 7 wherein said electrophotographic plate having an odd plural number of image areas thereon. 
     
     
       9. The electrostatic transfer reproduction apparatus set forth in claim 6 wherein said mounting means retains said master in a stationary position and wherein said optical projection system includes a movable carriage for scanning said mounted master. .Iadd.10. In electrostatic transfer reproduction incorporating an electrophotographic surface which travels cyclically around a closed loop past an imaging station where the image of a master document is projected onto said electrophotographic surface, past a developing station for developing said projected images with electrostatically charged developer material, past a transfer station for transferring the developed image from the electrophotographic surface to a substrate, past a cleaning station for cleaning developer material from the electrophotographic surface, and past a charging station for charging the electrophotographic surface to a predetermined charge in preparation for the imaging station, apparatus for hiding flyback time occurring at the imaging station comprising: means for sensing the position of frame on the electrophotographic surface relative to said stations;   means responsive to said sensing means for indicating cycles of the electrophotographic surface about the closed loop;   optical projection means mounted with relative movement between said projection means and the master document, said optical projection means responsive to said position sensing means and said cycle indicating means for projecting at the image station an image of the master document on frames separated by at least one frame to allow said optical projection means time to fly back so that in a given cycle of the electrophotographic surface around the closed loop imaged frames are followed by at least one non-imaged frame;   said developing and transferring stations responsive to said position sensing means and said cycle indicating means for developing and transferring the image from each imaged frame and each non-imaged frame carrying a latent image from a previous cycle of the electrophotographic surface;   said cleaning and charging stations responsive to said position sensing means and said cycle indicating means for cleaning and charging the non-imaged frames carrying a latent image during the cycle of the electrophotographic surface in which the latent image is developed and transferred for the last time before the frame is again imaged on the next cycle whereby a frame on the electrophotographic surface is imaged in one cycle, and is passed over by the flyback of the projection means in another succeeding cycle. .Iaddend..Iadd.11. The apparatus of claim 10 wherein said electrophotographic surface contains an odd number of frames in the closed loop and each frame becomes an imaged frame and a non-imaged frame in alternate cycles of said electrophotographic surface around the closed loop. .Iaddend. .Iadd.12. Method for hiding the flyback time of an optical system used in an electrostatic transfer reproduction apparatus wherein said apparatus has a charging station, an imaging station, a developing station, a developed image transfer station, and a cleaning station past which an electrophotographic surface moves cyclically in a closed loop, said electrophotographic surface being of a predetermined size having an odd numer of image frames consuming substantially all of the electrophotographic surface except for small interframe gaps to separate the frames, and said optical system and a master document to be projected mounted with relative movement therebetween, the method comprising the steps of:   sensing the cylindrical position of the frames relative to each of said stations;   actuating the optical system at the imaging station to image the master document on a first frame and every other frame thereafter and to fly back during an immediately succeeding frame and every other frame thereafter;   developing and transferring a developed image from said first frame and every other frame thereafter during the first electrophotographic-surface cycle and from each frame during each cycle after the first cycle of the electrophotographic surface through the closed loop;   cleaning and recharging a frame in the electrophotographic-surface cycle during which the frame was not imaged whereby each frame is imaged once and developed and transferred twice during two cycles of the electrophotographic surface through the closed loop and each frame is moved past the image station during optic system flyback time, cleaned and recharged once during two cycles of the electrophotographic surface in the closed loop. .Iaddend. .Iadd.13. Method for hiding flyback time of an optical system used in an electrostatic transfer reproduction apparatus wherein said apparatus has a charging station, an imaging station, a developing station, a developed image transfer station, and a cleaning station past which an electrophotographic surface moves cyclically in a closed loop, said electrophotographic surface being of a predetermined size having an even number of image frames consuming substantially all of the electrophotographic surface except for small interframe gaps to separate the frames, and said optical system and a master document to be projected mounted with relative movement therebetween, the method comprising the steps of:   sensing the cyclical position of the frames relative to each of said stations;   actuating the optical system at the imaging station to image the master document on a first frame and every third frame thereafter and to fly back during at least one frame intermediate the imaged frames;   developing and transferring a developed image from each frame during the first cycle of the electrophotographic surface around the closed loop in which said frame is imaged and thereafter in each successive cycle;   cleaning and recharging a frame in the second electrophotographic-surface cycle during which the frame was not imaged whereby each frame is imaged once and developed and transferred three times during three cycles of the electrophotographic surface through the closed loop and each frame is moved past the image station twice without being imaged, cleaned and recharged once during three cycles of the electrophotographic surface in the closed loop. .Iaddend.