Electrophotographic copying apparatus of slit exposure type

Abstract

An electrophotographic copying apparatus of slit exposure type comprises a sheet original conveyor mechanism provided on top of the machine housing, and an original carriage having a transparent sheet of glass or the like provided contiguously with the frame of the conveyor mechanism. When a sheet original is to be copied, such original is transported by the sheet original conveyor mechanism for a through-slit exposure. When a thick original such as book or the like is to be copied, the original carriage with the thick original thereon is forced to move with the conveyor mechanism to disconnect the mechanism from its drive system but connect the drive system to the original carriage, whereafter the carriage is moved for the thick original thereon to be subjected to a through-slit exposure.

We claim: 
     
       1. A photographic copying machine of the through-slit exposure type comprising: a housing;   a through-slit exposure device mounted in said housing;   sheet original conveyor means having a sheet passage for transporting a sheet original through said passage and past said through-slit exposure device to form the image of said sheet original on a photosensitive medium;   an original carriage mounted for reciprocal movement on said housing and having a transparent plate fixed thereto for supporting a thick original for a movement past said through-slit exposure device to form the image of said thick original on the photosensitive medium;   means integrally mounting said conveyor means on said carriage wherein said conveyor means is fixed against movement with respect to said carriage;   photographic copy processing means for operation to produce copies of said sheet original and thick original images on said photosensitive medium when one of said originals is moved past said exposure device; and   drive system means releasably coupled to said conveyor means for operation to activate said conveyor means to transport said sheet original past said through-slit exposure device while maintaining said carriage in a predetermined stationary position when a sheet original is being copied, and means for decoupling said drive system means from said conveyor means when said carriage is reciprocated to move said thick original past said through-slit exposure device.   
     
     
       2. A photographic copying machine according to claim 1, wherein said original carriage has driven means, and further comprising means for coupling said driven means to said drive system means for moving said original carriage when said thick original is being copied. 
     
     
       3. A photograhic copying machine according to claim 1, further comprising control means for synchronizing the movement of said sheet and thick originals past said through-slit exposure device with the movement of said photosensitive medium, said control means including a first actuator member operated by said sheet original and a second actuator member operated by a cam formed in said original carriage. 
     
     
       4. Photocopying apparatus according to claim 1, wherein said transparent .Iadd.plate .Iaddend.is disposed to provide a guide member for said sheet original. 
     
     
       5. Photocopying apparatus according to claim .[.5.]. .Iadd.1.Iaddend., further comprising locking means for maintaining said carriage in said predetermined stationary position wherein said locking means comprises a projecting member provided on said carriage and resilient holding means mounted on said housing for releasably grasping said projecting member. .Iadd. 6. Electrophotographic copying apparatus selectively operable in a first mode for copying relatively thick originals and in a second mode for copying sheet originals comprising an exposure station through which an original to be copied is to be moved, an imaging station, an optical system for projecting an image of an original moving through said exposure station to said imaging station, means for moving an electrically photosensitive member through said imaging station for the formation of an electrostatic latent image of said original thereon, means for transferring images from said photosensitive member to copy material, an original support carriage capable of supporting relatively thick originals, means for moving said original support carriage along a path to carry such originals through said exposure station when the apparatus is operated in said first mode, a sheet conveyor integrally mounted on said carriage and operable to transport sheet originals through said exposure station, and releasable means for maintaining said carriage stationary when the apparatus is operated in said second mode. .Iaddend..Iadd. 7. Apparatus according to claim 6, wherein said carriage is arranged to be movable to a first position for selecting said first mode of operation and a second position for selecting said second mode of operation. .Iaddend..Iadd. 8. Apparatus according to claim 6, including a surface associated with said sheet conveyor for exposing sheet originals to be copied, and a surface associated with said original support carriage for exposing thick originals to be copied, said surfaces being substantially coplanar to form a substantially linear sheet original transport path on the sheet original exposing surface. .Iaddend. .Iadd. 9. Apparatus according to claim 7, further comprising means for activating said means for moving said original support carriage when said carriage is disposed in said first position. .Iaddend..Iadd. 10. Apparatus according to claim 6, including means for developing the electrostatic latent images formed on said photosensitive member prior to operation of said transfer means. .Iaddend..Iadd. 11. Apparatus according to claim 10, including cleaning means for cleaning said photosensitive member after transfer therefrom of a developed image. .Iaddend..Iadd. 12. Apparatus according to claim 6, wherein the photosensitive member includes a photoconductive layer and an insulating layer, and includes means for applying a primary charge to said insulating layer in advance of said image projection and applying a secondary charge to the insulating layer simultaneously with the image projection, said secondary charge being with an A.C. corona device or a charge of polarity opposite to the primary charge, thereby forming said electrostatic latent image. .Iaddend..Iadd. 13. Apparatus according to claim 6, wherein said conveyor and said carriage are driven by a common drive mechanism, said conveyor being engaged with or disengaged from said drive mechanism according to whether said carriage is disengaged from or engaged with said drive mechanism. .Iaddend. .Iadd. 14. Apparatus according to claim 6, further comprising a drive gear mounted on said apparatus, and a driven gear mounted on said sheet conveyor for engagement with said drive gear when said apparatus is operated in said second mode, wherein said gears disengage when said apparatus is operated in said first mode. .Iaddend..Iadd. 15. Apparatus according to claim 6, wherein said carriage carries a rack which engages a drive gear when the apparatus is operated in the first mode but which is disengaged therefrom when the apparatus is operated in the second mode. .Iaddend..Iadd. 16. Apparatus according to claim 6, including clutch means operable for stopping transport of the original, following initial movement thereof, and for re-starting said transport in synchronism with movement of the photosensitive member. .Iaddend..Iadd. 17. Apparatus according to claim 6, including separator means and means for creating electrostatic forces to attract copy material from the photosensitive member to the separator means to effect separation of the copy material from the photosensitive member. .Iaddend..Iadd. 18. Apparatus according to claim 17, wherein said separator means is a roller. .Iaddend..Iadd. 19. Apparatus according to claim 18, wherein said electrostatic force producing means comprises first electrode means on the surface of said roller, second electrode means inside the roller and separated from the first electrode means by dielectric material, and means for applying voltage between said first and second electrode means. .Iaddend. .Iadd. 20. Photocopying apparatus selectively operable in a first mode for copying relatively thick originals and in a second mode for copying sheet originals comprising an exposure station through which an original to be copied is to be moved, an optical system for projecting an image of an original moving through said exposure station to an imaging station, means for moving a photosensitive member through said imaging station for the formation of an image of said original thereon, an original support carriage capable of supporting relatively thick originals, means for moving said original support carriage along a path to carry such originals through said exposure station when the apparatus is operated in the first mode, sheet conveyor means operable to transport sheet originals through said exposure station while said carriage is stationary when the apparatus is operated in the second mode, means integrally mounting said sheet conveyor means on said support carriage wherein said conveyor means is fixed against movement with respect to said carriage, and means for shifting the position of said original support carriage in response to operation of the apparatus in said first mode, and said second mode, said carriage being arranged to be movable to a first position for selecting said first mode of operation and a second position for selecting the second mode of operation. .Iaddend. .Iadd. 21. Apparatus according to claim 20, including a surface associated with said sheet conveyor means for exposing sheet originals to be copied, and a surface associated with said original support carriage for exposing thick originals to be copied, said surfaces being substantially coplanar to form a substantially linear sheet original transport path on the sheet original exposing surface. .Iaddend. .Iadd. 22. Apparatus according to claim 20, wherein the photosensitive member includes a photoconductive layer and an insulating layer, and includes means for applying a primary charge to said insulating layer in advance of said image projection and applying a secondary charge to the insulating layer simultaneously with the image projection, said secondary charge being with an A.C. corona device or a charge of polarity opposite to the primary charge, thereby forming said electrostatic latent image. .Iaddend..Iadd. 23. Apparatus according to claim 20, wherein said conveyor means and said carriage are driven by a common drive mechanism, said conveyor means being engaged with or disengaged from said drive mechanism according to whether said carriage is disengaged from or engaged with said drive mechanism. .Iaddend..Iadd. 24. Apparatus according to claim 20, further comprising a drive gear mounted on said apparatus, and a driven gear mounted on said sheet conveyor means for engagement with said drive gear when said apparatus is operated in said second mode, wherein said gears disengage when said apparatus is operated in said first mode. .Iaddend..Iadd. 25. Apparatus according to claim 20, wherein said carriage carries a rack which engages a drive gear when the apparatus is operated in the first mode but which is disengaged therefrom when the apparatus is operated in the second mode. .Iaddend..Iadd. 26. Apparatus according to claim 20, including clutch means operable for stopping transport of the original, following initial movement thereof, and for re-starting said transport in synchronism with movement of the photosensitive member. .Iaddend.