Image formation and development

Abstract

Graphic reproductions are achieved by the image-wise modification of the triboelectric charging capability of a surface followed by the triboelectric charging of the modified surface to produce a charge pattern corresponding to an image. The charge pattern may be developed with finely divided colored electroscopic particles and the resulting colored image either fixed on the surface of the insulating member or transferred to a receiving surface and fixed thereon.

What is claimed is: 
     
       1. The method of forming a visible image comprising exposing an imaging sheet having at least a surface layer of an ultraviolet light photopolymerizable material to an imagewise exposure with ultraviolet light of sufficient intensity to cause polymerization of at least the surface of said photopolymerizable material, bringing said imagewise polymerized surface into frictional contact with a material remote in the triboelectric series from at least one of the polymerized and the unpolymerized portions of said imaging sheet so that a differential charge pattern is set up between image and non-image areas on said sheet .Iadd.as a consequence of an imagewise change in triboelectric charging susceptibility, due to said imagewise polymerization, and said contact, .Iaddend.and developing said charge surface by depositing finely divided, colored, electroscopic marking particles thereon. 
     
     
       2. The method according to claim 1 in which said photopolymerizable material is polyethylene terephthalate. 
     
     
       3. A method according to claim 1 in which said photopolymerizable material includes the cinnamate esters of polyvinyl alcohol and of cellulose. 
     
     
       4. The method according to claim 1 in which said photopolymerizable material is 1,4-bis methyl cyclohexane polyterephthalate. 
     
     
       5. The method of forming a latent electrostatic image on an imaging layer comprising increasing the molecular weight of at least a surface of said layer by subjecting it to a polymerizing influence in imagewise configuration thereby modifying the triboelectric charging susceptibility of said surface in imagewise configuration and bringing said surface into frictional contact with a material remote in the triboelectric series from at least one of the modified and the unmodified portions of said surface so that a differential charge pattern is set up between image and non-image areas on said surface .Iadd.as a consequence of said imagewise change in triboelectric susceptibility and said contact..Iaddend. 
     
     
       6. A method of forming a latent electrostatic image on an imaging layer comprising coating a surface of said layer with a contaminant comprising a material selected from the group consisting of an oil based ink and human body oils in imagewise configuration thereby modifying the triboelectric charging susceptibility of said surface in imagewise configuration and bringing said surface into frictional contact with a material remote in the triboelectric series from at least one of the modified and unmodified portions of said surface so that a differential charge pattern is set up between image and non-image areas of said surface .Iadd.as a consequence of said imagewise change in triboelectric susceptibility and said contact.Iaddend.. 
     
     
       7. The method of reproducing a page of copy formed with an oil based ink comprising placing said page of copy in face to face relationship with an imaging surface, heating at least the inked portions of said page of copy until at least a portion transfers across to said imaging surface in imagewise configuration by volatilization and condensation of at least one of the ink components which .[.is capable of modifying.]. .Iadd.modifies .Iaddend.the triboelectric charging susceptibility of said imaging surface, separating said imaging surface from said page of copy, bringing said imaging surface into frictional contact with a material remote in the triboelectric series from at least the ink coated portion of said imaging surface or the non-coated portion of said imaging surface so that a differential charge pattern is set up between image and non-image areas on said imaging surface .Iadd.as a consequence of said modified triboelectric charging susceptibility and said contact, .Iaddend.and developing said surface by depositing finely divided, colored, electroscopic marking particles thereon. 
     
     
       8. A method according to claim 7 in which said page of copy is right reading and said imaging surface is transparent whereby the mirror reversed image produced on said imaging surface may be easily read through its back. 
     
     
       9. The method of reproducing a page of copy formed with an oil based ink comprising placing said page of copy in face to face relationship with a smooth surfaced impervious master sheet, heating said page of copy and said master sheet until at least a portion of the ink from said page of copy volatilizes and recondenses on said master sheet in imagewise configuration, separating said master sheet and said page of copy, placing said master sheet in face to face relationship with an imaging surface, heating said master sheet and said imaging surface until at least a portion of the ink on said master surface volatilizes and recondenses on said imaging surface in imagewise configuration, .Iadd.said imaging surface ink portion modifying the triboelectric charging susceptibility of said surface, .Iaddend.separating said master sheet from said imaging surface, bringing said imaging surface into frictional contact with a material remote in the triboelectric series from at least one of the ink coated and the uncoated portions of said imaging surface so that a differential charge pattern is set up between image and non-image areas on said imaging surface .Iadd.as a consequence of said modified triboelectric charging susceptibility and said contact, .Iaddend.and developing said surface by depositing finely divided, colored, electroscopic marking particles thereon. 
     
     
       10. A method according to claim 9 in which said original page copy is right reading and said imaging surface is transparent whereby the mirror reversed image produced on said imaging surface may be easily read through its back. 
     
     
       11. The method of forming a reproduction of a page of copy formed with an oil based ink comprising placing said page of copy in face to face relationship with an imaging surface, pressing the two surfaces together with sufficient force to .Iadd.imagewise .Iaddend.transfer at least a portion of the ink from said page of copy to said imaging surface, .Iadd.said ink portion modifying the triboelectric charging susceptibility of said imaging surface, .Iaddend.separating said page of copy from said imaging surface, bringing said imaging surface into frictional contact with a material remote in the triboelectric series from at least one of the ink coated and the uncoated portions of said imaging surface so that a differential charge pattern is set up between image and non-image areas on said imaging surface .Iadd.as a consequence of said imagewise change in triboelectric susceptibility and said contact, .Iaddend.and developing said surface by depositing finely divided, colored, electroscopic marking particles thereon. 
     
     
       12. The method of reproducing an image on a sheet of copy formed with an oil based ink comprising placing said copy sheet in face to face relation with a smooth surfaced master sheet, applying sufficient pressure to said sheets so that at least a portion of the ink is transferred to said master, separating said master from said sheet of copy, bringing said master into face to face contact with an imaging surface, applying sufficient pressure to said master and said imaging surface so that at least a portion of said ink transferred to said master is retransferred to said imaging surface in imagewise configuration, .Iadd.said retransferred ink portion modifying the triboelectric charging susceptibility of said imaging surface, .Iaddend.separating said imaging surface from said master, bringing said imaging surface into frictional contact with a material remote in the triboelectric series from at least one of the ink coated and non-coated portions of said imaging surface so that a differential charge pattern is set up between image and non-image areas on said imaging surface .Iadd.as a consequence of said imagewise change in triboelectric susceptibility and said contact, .Iaddend.and developing said surface by depositing finely divided, colored, electroscopic marking particles thereon. .Iadd. 13. The method of forming a latent electrostatic image on an imaging layer comprising modifying the triboelectric charging susceptibility of a surface of said layer in imagewise configuration by means of imagewise contaminating said surface with human body oils and bringing said imaging surface into contact with a material remote in the triboelectric series from at least one of the modified and the unmodified portions of said imaging surface so that a differential charge pattern is set up between image and non-image areas on said imaging surface as a consequence of said imagewise change in triboelectric susceptibility and said contact..Iaddend.