Abstract: A method of preparing a lithographic printing plate, and the resulting printing plate, by applying an acidified oxidizing agent such as aqueous potassium permanganate solution to the toned electrostatic latent image on the photoconductive layer of an electrophotographic member to define water-receptive non-printing areas. The thus treated surface may be washed or further treated with conventional ferrocyanide ion containing fountain solutions or gum arabic, but only if desired.

Abstract: A device for use in developing a latent electrostatic image formed on the image bearing surface of an electrophotographic belt as the belt is moving through an arcuate path includes a container having a quantity of liquid toner. The container includes a top wall that has a centrally located slot and that is shaped to conform to the shape of the top wall. A development electrode is located on the top surface of the top wall. A feed roller is rotatably mounted in the container and positioned so as to project out slightly from the slot in the top wall. In use, the container is positioned with the top wall close to and parallel to the arcuate path of travel of the belt and the feed roller close to but not touching the belt. As the feed roller rotates, liquid toner is brought up close to the belt at which location the toner particles dispersed in the liquid toner are electrically attracted to and deposit on the charged portions of the belt.

Abstract: An endless belt or cylinder in which the base or substrate is a conductive member and there is a coating of a wholly inorganic, microcrystalline, high quantum yield, electronically anisotropic photoconductive material on the substrate. The coating is capable of being charged and thereafter exposed to radiant energy from an object such as a scene or pattern for selectively discharging the coating and providing a latent image of the object on the coating. The latent image can thereafter be developed by toner and transferred to a receptor such as a sheet of paper, cloth and the like.The belt may be formed of highly flexible synthetic organic resin such as polyester or the like and in such case the coating will be deposited onto an intervening thin layer of an ohmic material.The cylinder may be a relatively rigid one of metal.The coating may be cadmium sulfide.The method of making the cylinder or belt comprises forming the cylinder or belt and placing same in a sputtering apparatus and r.f.

Abstract: Apparatus for detecting and providing a signal from detection indicia that is applied to a substrate such as a controlled document for the purpose of determining the character of the document, the substrate comprising individual substrate members or an elongate relatively continuous substrate member passing through the apparatus at high speed. Speeds of between 10 to 15 linear meters per second are the order of speeds which are contemplated by the invention.The detection indicia on the controlled document comprises an area or areas which are deliberately applied to the document in a manner which renders the detection indicia substantially more conductive than the substrate.

Abstract: A flexible metal printing cylinder having a coating of a crystalline photoconductive material thereon. The cylinder is an electrodeposited sleeve of nickel or similar material that is a fraction of a millimeter in thickness which is adapted to be mounted in a printing press in order to enable the press to print electrostatically. The coating is applied by r.f. sputtering and comprises a thin film layer of the order of about 2000 to 6000 Angstroms thick of a wholly inorganic, electronically anisotropic, crystalline, flexible, high gain photoconductive material, as for example ultrapure cadmium sulfide. The cylinder may have an image adhered to its surface which is of dry insulating toner.

Abstract: A method for obtaining multiple copies from apparatus including an electrophotographic member of the type in which the latent image is represented by charge not removed when toner is applied and thereafter transferred. The electrophotographic member with its latent image is repeatedly subjected to toning and transfer to respective multiple receptors without intervening charge and exposure. This may be done until the desired number of copies is made or until the image quality deteriorates by reason of dark decay. If additional copies are desired the electrophotographic member is again charged and exposed and thereafter toned and the image transferred repeatedly without intervening additional charge and exposure.Apparatus for effecting the method above and providing structure for carrying out the described steps include other functions such as automatically sensing quality and responding to a condition which requires a new cycle of charge and expose.

Abstract: An electrophotographic copy machine formed as an assembly of three removably mounted self-contained operational modules. A mechanical assembly module includes the platen for supporting the original document, a paper supply and feed mechanism and an electrophotographic imaging apparatus. The electrophotographic imaging apparatus includes an endless electrophotographic belt operative through a charging station, an imaging station, a toning station and an image transfer station. The second module contains all but the toning station which comprises the third self-contained module. A cabinet assembly for receiving and holding the three modules in assembly is provided and further mounts the miscellaneous switches, controls and associated electronics of the system copying machine.

Abstract: A system for impressing images on electrophotographic film provides for the charging of each film frame rapidly to a peak voltage determined by the prevailing light conditions of the image to be produced or recorded. After charging the film frame is immediately exposed to an image. In the preferred method, the time of exposure is predetermined and fixed. Next, toner is applied immediately to the charged frame in the presence of a bias field which propels the toner particles toward the film. Thereafter excess toner is removed or leaves the film frame and the remaining toner is fused to the surface of the film to form a permanent visible image on the film frame. An alternate form transfers the toned image to an acceptor member where it is fixed.The various processing steps are all carried out at points on the dark decay portion of the characteristic discharge curve for the particular film so that the resultant image has high resolution and optimum contrast.

Abstract: A flexible offset printing plate is formed from a directly imaged electrophotographic member comprising an inorganic coating of a photoconductive material on a polyester substrate. The photoconductive material is an oriented crystalline deposit about 3000 Angstroms thick which has been directly sputtered with radiofrequency energy in a process using a Langmuir sheath to produce a light sensitive, readily imaged abrasion-resistant, transparent coating. It is deposited on a sheet of dimensionally stable, transparent polyester film having a thickness of about 0.005 inch with an intervening sandwiched layer of ohmic material such as indium-tin oxide about 300 Angstroms thick. The transparency of the ohmic layer and the photoconductive coating on a transparent substrate result in a transparent plate.The electrophotographic member is imaged by charging, exposure and toning with a suitable toner.

Abstract: Electrophotographic medium which comprises a transparent substrate, ohmic layer and coating of photoconductive material, all of which form a modulating structure for the radiant energy that is adapted to be projected through the substrate; a dielectric layer (storage medium) intimately bonded to the surface of the photoconductive coating and a conductive electrode in intimate contact with the dielectric layer. The structure is used by connecting a d.c. voltage across the outer electrode and the ohmic layer and projecting the image onto the electrophotographic medium from the bottom surface of the substrate. The charge image appears on the dielectric layer. The charge image is read out with an electronic beam or toned and fixed or transferred. During use the electrode is brought into intimate contact with the dielectric layer and removed after forming the charge image in order to enable the medium to be processed further without the electrode.

Abstract: A method of toning the latent image carried by the photoconductive surface of an electrophotographic film in which a liquid suspension of toner particles is flowed or streamed substantially simultaneously uniformly against said surface over all said surface in a direction normal thereto from a source spaced from the surface and the excess or remanent toner suspension is removed from the surface thereafter without displacing said source or moving the film.The toner particles are biased with a d.c. bias voltage of a polarity the same as the electrophoretic surface charge of the toner particles to enhance particle movement toward the photoconductive surface.