Electrophotographic device

Abstract

.Iadd.Electrophotographic copying device including novel means for forming a high contrast electrostatic image on a photosensitive member, as well as means for developing said high contrast electrostatic image with toner particles, means for transferring the visualized electrostatic image to copying material and novel cleaning means for removing from the photosensitive member, residual toner particles after transfer of the image. .Iaddend.

What is claimed is: .[.1. An electrophotographic copying device which comprises: 
     
        discharger..]. .[.3.  An electrophotographic copying device as claimed in claim 1, wherein the developing means for visualizing the static latent image formed on the surface of the insulating layer of the photosensitive plate comprises a fur brush developer..]. .[.4. An electrophotographic copying device as claimed in claim 1, wherein the means for transferring the visible image formed on the surface of the insulating layer of the photosensitive plate onto the copying material comprises means for physically pressing said copying material against said insulating layer in the absence of an external electric field..]. .[.5. An electrophotographic copying device as claimed in claim 1, wherein the cleaning means for removing residual developer from the surface of said insulating layer remaining after the visible image formed on the insulating layer of the photosensitive plate is transferred onto the copying material comprises an elastic brush..]. .[.6. An electrophotographic copying device as claimed in claim 1, wherein the developing means for visualizing the static image formed on the surface of the insulating layer of the photosensitive plate comprises a magnetic brush and which utilizes a developer which comprises a carrier having an insulating resistivity of greater than 10 8   
     
     
        Ω-cm. and a toner..]. 7. An electrophotographic copying device as claimed in claim .[.3.]. .Iadd.24, .Iaddend.wherein said fur brush developing means comprising an endless belt in contact with the surface of said insulating layer, means to rotate said belt, and means for supplying 
     
     
        toner to said belt. 8. An electrophotographic copying device as claimed in claim 7, wherein said fur brush developing means additionally comprises means for applying a bias voltage to said belt at a point adjacent to the final point of contact with said layer, said voltage providing a charge of the same polarity as the polarity generated by the frictional charge 
     
     
        against the toner. 9. An electrophotographic copying device as claimed in claim 8, wherein the endless belt additionally comprises means for applying a second bias voltage for charging the belt at a point adjacent the initial point of contact with said layer, with a charge of the polarity opposite to the polarity of the charge generated by said first 
     
     
        bias voltage. 10. An electrophotographic copying device as claimed in claim .[.6.]. .Iadd.25, .Iaddend.and additionally comprising means for mixing air with said toner, said toner being attracted to said brush by a 
     
     
        frictional charge. 11. An electrophotographic copying device as claimed in claim 7, wherein said endless belt includes adjusting means to vary the 
     
     
        contact-pressure of said belt against the static image surface. 12. An electrophotographic copying device as claimed in claim .[.3.]. .Iadd.24, .Iaddend.wherein said fur brush developer comprises: a container for toner, said container having a plurality of small holes in the lower portion thereof;   a control member adjacent the lower portion of said container, said control member also having a plurality of holes therein and being mounted for movement of said holes into and out of registration with the holes in said container, whereby said toner is stirred and the amount thereof falling through said holes is controlled; and   a fur brush mounted below said container and said control member and having   
     
     
        a plurality of holes for passage of said toner. 13. An electrophotographic copying device as claimed in claim .[.5.]. .Iadd.26, .Iaddend.wherein said elastic brush cleaner includes means for charging said brush in the polarity opposite to the polarity of the residual developer remaining on 
     
     
        the surface of the insulating layer of the photosensitive plate. 14. An electrophotographic copying device as claimed in claim 13, wherein the elastic brush cleaner additionally comprises a second charging means for charging said brush in the polarity opposite to the polarity of the first 
     
     
        charging means, to remove developer adhered on said brush statically. 15. An electrophotographic copying device as claimed in claim .[.5.]. .Iadd.26, .Iaddend.wherein said cleaning means comprises an elastic cleaning roller mounted to pree-contact the surface of said insulating layer with sufficient pressure to be slightly flattened thereagainst, and means for rotating said roller slowly in the direction opposite to the 
     
     
        motion of the photosensitive plate. 16. An electrophotograhic copying device as claimed in claim 15, wherein said elastic cleaning roller has a plurality of small transverse grooves on the surface thereof wherein toner 
     
     
        is collected. 17. An electrophotographic copying device as claimed in claim .[.6.]. .Iadd.25, .Iaddend.wherein said magnetic brush developing means comprises: a hollow, rotating, non-magnetic cylinder;   a non-rotating electromagnet mounted within said cylinder and having one pole thereof adjacent said photosensitive plate;   a developer container having an opening for feeding developer adjacent the other pole of said electromagnet; .Iadd.and.Iaddend.   .[.the polarity of said first pole being opposite to the charge on said photosensitive plate, whereby developer is magnetically attracted to said cylinder and, on rotation thereof, is repelled by said cylinder and attracted by the charge on said plate, thus visualizing the image..]. .Iadd. another magnetic pole provided opposite to said first pole sandwiching the photosensitive plate therebetween and having a polarity opposite to said first pole, whereby developer is magnetically attracted to said cylinder and, on rotation thereof, is repelled by said cylinder and attracted by the charge on said plate, thus visualizing the image.   
     
     
        .Iaddend. 18. An electrophotographic copying device as claimed in claim .[.6.]. .Iadd.25, .Iaddend.wherein said magnetic brush developing means comprises: a yoke having two, longitudinal, non-magnetic path-controlling sections defining a central open cavity;   a rotatably mounted permanent magnet within said cavity;   a container for developer mounted below said yoke;   developer in said container being attracted to said non-magnetic sections when said magnet is in a first position and repelled from said sections   
     
     
        when said magnet is rotated ninety degrees. 19. An electrophotographic copying device which comprises: a photosensitive plate, which plate comprises a base having a photoconductive layer and a translucent insulating layer overlaid thereon;   means for moving said photosensitive plate;   charging means for applying a primary charge on the surface of said photosensitive plate;   means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer;   means for forming a high contrast static image of the original image on the surface of the insulating layer comprising a light source irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer;   deveoping means for visualizing the static image with a developer;   means for laying copying material on said visible image in synchronous relation with the movement of said photosensitive plate;   means pressing the copying material onto the visible image for transferring the visible image onto the copying material;   means for peeling off the copying material from the photosensitive plate after transfer of the visible image which comprises a source of compressed air directed against the said material and a peeling-lever operated against the copying material; and cleaning means for removing residual developer remaining on the surface of said insulating layer to prepare the photosensitive plate for repeated use after the copying material is peeled   
     
     
        off. 20. An electrophotographic copying device .[.as claimed in claim 1 and additionally.]. comprising: .Iadd. charging means for applying a primary charge on the surface of a photosensitive plate, which plate comprises a base, a photoconductive layer and a translucent insulating layer overlaid thereon;   means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer;   means for forming a high contrast static image of the original image on the surface of said insulating layer by uniformly irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer;   developing means for visualizing said static latent image;   means for transferring said visualized image onto copying material;   cleaning means for removing residual developer from the surface of said insulating layer remaining after the transfer of the image, whereby the photosensitive plate is prepared for repeated use; .Iaddend.   means for moving said corona .[.discharger.]. .Iadd.discharge .Iaddend.over said photosensitive plate;   a pair of tiltable shield boards defining a central slit over said corona .[.discharger.]. .Iadd.discharge.Iaddend.; and   means for tilting said shield boards as said corona .[.discharger.]. .Iadd.discharge .Iaddend.moves over said photosensitive plate, said tilting being adapted to maintain said shield boards substantially   
     
     
        parallel with the rays of said original image. 21. A reading and electrophotographic copying device which comprises: a photosensitive plate comprising a base and a photoconductive layer and a translucent insulating layer overlaid thereon;   charging means capable of applying a primary charge to said insulating layer;   an optical system capable of projecting an original image onto said photosensitive plate;   means for applying a corona discharge to the charged surface of said insulating layer simultaneously with the projection of said original image;   reading means capable of projecting said image, said reading means comprising a semitransparent mirror located in the light path of said optical system and a screen for visualizing the image reflected by said mirror;   means comprising a light source for uniformly irradiating the whole surface of said insulating layer after projection of said original image thereon, whereby said photoconductive layer is activated and a high contrast static image is formed on said insulating layer;   developing means for visualizing the static image with a developer;   means for transferring the developed image onto copying material; and   cleaning means for removing residual developer on the surface of said insulating layer after transfer of the image to said copying material, to   
     
     
        prepare the photosensitive plate for repeated use. 22. An electrophotographic copying device .[.as claimed in claim 1,.]. 
     
     
       .Iadd.comprising: charging means for applying a primary charge on the surface of a photosensitive plate, which plate comprises a base, a photoconductive layer and a translucent insulating layer overlaid thereon;   means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer;   means for forming a high contrast static image of the original image on the surface of said insulating layer by uniformly irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer;   developing means for visualizing said static latent image;   means for transferring said visualized image onto copying material;   cleaning means for removing residual developer from the surface of said insulating layer remaining after the transfer of the image, whereby the photosensitive plate is prepared for repeated use; and .Iaddend.   wherein the means for transferring powder image onto the copying material comprises means for forming an electrostatic image on the insulating layer of the photosensitive plate, laying the said translucent insulating layer onto the photoconductive layer, means for visualizing said image with a colored toner charged in a polarity opposite to the polarity of said image, means for charging said insulating layer inclusive of said powder image to an optional polarity and transferring the image onto the copying   
     
     
        material overlaid thereon. 23. An electrophotographic copying device .[.as claimed in claim 1,.]. .Iadd.comprising: charging means for applying a primary charge on the surface of a photosensitive plate, which plate comprises a base, a photoconductive layer and a translucent insulating layer overlaid thereon;   means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer;   means for forming a high contrast static image on the original image on the surface of said insulating layer by uniformly irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer;   developing means for visualizing said static latent image;   means for transferring said visualized image onto copying material;   cleaning means for removing residual developer from the surface of said insulating layer remaining after the transfer of the image, whereby the photosensitive plate is prepared for repeated use; and .Iaddend.   wherein means for irradiating corona discharge has the optically opened upper portion and is so arranged that the charge width and the slit   
     
     
        exposure width are equal. .Iadd. 24.  In an electrophotographic copying device which includes charging means for applying a primary charge on the surface of a photosensitive plate, which plate comprises a base, a photoconductive layer and a translucent insulating layer overlaid thereon, means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer, means for forming a high contrast static latent image of the original image on the surface of said insulating layer by uniformly irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer, developing means for visualizing said static latent image, means for transferring said visualized image onto copying material, and cleaning means for removing residual developer from the surface of said insulating layer remaining after the transfer of the visualized image, whereby the photosensitive plate is prepared for repeated use, the improvement wherein said developing means for visualizing said static latent image comprises a fur brush developer. .Iaddend..Iadd. 25. In an electrophotographic copying device which includes charging means for applying a primary charge on the surface of a photosensitive plate, which plate comprises a base, a photoconductive layer and a translucent insulating layer overlaid thereon, means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer, means for forming a high contrast static latent image of the original image on the surface of said insulating layer by uniformly irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer, developing means for visualizing said static latent image, means for transferring said visualized image onto copying material, and cleaning means for removing residual developer from the surface of said insulating layer remaining after the transfer of the visualized image, whereby the photosensitive plate is prepared for repeated use, the improvement wherein said developing means for visualizing said static latent image comprises a magnetic brush developer and utilizes a developer comprising a carrier having an insulating resistivity of greater than 10 8  Ω-cm. and a toner. .Iaddend. .Iadd. 26. In an electrophotographic copying device which includes charging means for applying a primary charge on the surface of a photosensitive plate, which plate comprises a base, a photoconductive layer and a translucent insulating layer overlaid thereon, means for simultaneously exposing an original image and for applying a corona discharge onto the surface of said charged insulating layer, means for forming a high contrast static latent image of the original image on the surface of said insulating layer by uniformly irradiating the whole surface of said insulating layer, thereby activating the photoconductive layer, developing means for visualizing said static latent image, means for transferring said visualized image onto said copying material, and cleaning means for removing residual developer from the surface of said insulating layer remaining after the transfer of the visualized image, whereby the photosensitive plate is prepared for repeated use, the improvement wherein said cleaning means for removing residual developer comprises an elastic brush. .Iaddend. .Iadd. 27. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement comprising a resilient scraping blade having a substantially angular engaging edge and being elongated along the width of said photosensitive member, holder means for holding said resilient scraping blade and maintaining its engaging edge in contact with the surface of said photosensitive member for scraping off residual toner particles and means for recovering said scraped off residual toner particles. .Iaddend..Iadd. 28. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement comprising a scraping blade positioned in contact with the surface of said photosensitive member for scraping off residual toner particles, means for recovering said scraped off residual toner particles, means for applying to said scraping blade a charge of the same polarity as the polarity of said residual toner particles for repulsing the collected residual toner particles and means for suctioning said collected residual toner particles for recovering the same. .Iaddend. .Iadd. 29. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement comprising a scraping blade positioned in contact with the surface of said photosensitive member for scraping off residual toner particles, means for recovering said scraped off residual toner particles, means for applying to said scraping blade a first charge of a polarity opposite to the residual toner particles for attracting said residual toner particles to said blade, and means for thereafter applying a charge of opposite polarity to said first charge for repulsing the collected residual toner particles for recovering the same. .Iaddend..Iadd. 30. A cleaning apparatus for removing electrostatically adhering toner particles from an electrostatic recording surface comprising a scraping blade arranged for engaging along an edge thereof said electrostatic recording surface, said edge being axially coextensive with said electrostatic recording surface and adapted to scrape toner particles contacted during relative movement between said scraping blade and said electrostatic recording surface, means for applying to said scraping blade a charge of the opposite polarity as the polarity of the electrostatic adhering toner particles to attract the toner particles being scraped from said photosensitive plate. .Iaddend. .Iadd. 31. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement for removing residual toner particles from said photosensitive member after the transfer of said toner image comprising a scraping blade having a substantially angular edge positioned to contact the surface of said photosensitive member to remove residual toner particles therefrom by scraping said surface and further comprising means mounting said scraping blade for movement out of contact with the surface of said photosensitive member. .Iaddend. .Iadd. 32. An electrophotographic copying device as in claim 31, further comprising a second scraping blade fixed to said mounting means for selective movement into contact with and away from said surface of said photosensitive member. .Iaddend. .Iadd. 33. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement for removing residual toner particles from said photosensitive member after the transfer of said toner image comprising a resilient scraping blade having a substantially angular engaging edge and being elongated along the width of said photosensitive member and holder means for holding said resilient scraping blade and maintaining its engaging edge in contact with the surface of said photosensitive member to remove residual toner particles therefrom by scraping said surface, said resilient scraping blade being made of hard rubber elastic material. .Iaddend. .Iadd. 34. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement for removing residual toner particles from said photosensitive member after the transfer of said toner image comprising a resilient scraping blade having a substantially angular engaging edge and being elongated along the width of said photosensitive member and holder means for holding said resilient scraping blade and maintaining its engaging edge in contact with the surface of said photosensitive member to remove residual toner particles therefrom by scraping said surface, said resilient scraping blade being made of a conductive elastic material. .Iaddend..Iadd. 35. A cleaning apparatus for removing electrostatically adhering toner particles remaining on an electrostatic recording surface after transfer of a toner particle image to copy material comprising a resilient scraping blade arranged for engaging along an edge thereof said electrostatic recording surface, said edge extending along the width of said electrostatic recording surface, holder means for holding said resilient scraping blade and maintaining its engaging edge in contact with the surface of said electrostatic recording member to scrape toner particles, means for establishing relative movement between said electrostatic recording surface and said resilient scraping blade, and means for removing toner particles scraped up by said scraping blade to a collection source whereby said toner particles can be reused. .Iaddend..Iadd. 36. In an electrophotographic copying device wherein an electrostatic latent image formed on the surface of a photosensitive member is moved past a series of processing stations including a development station at which the latent image is developed with toner particles to form a toner image and a transfer station at which the toner image is transferred to copying material, an improvement for removing residual toner particles from said photosensitive member after the transfer of said toner image comprising a resilient scraping blade having a substantially angular engaging edge and being elongated along the width of said photosensitive member, holder means for holding said resilient scraping blade and maintaining its engaging edge in contact with the surface of said photosensitive member to remove residual toner particles therefrom by scraping said surface, and collecting means for receiving said residual toner particles scraped from said surface. .Iaddend. .Iadd. 37. An electrophotographic copying device as in claim 36, further comprising means for transporting said residual toner particles from said collecting means to said development station for reuse. .Iaddend.