HIGH SPEED ELECTROPHOTOGRAPHIC MEDIUM AND METHOD

摘要

An 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. The interface between the dielectric layer and electrode preferably is liquid, at least when originally formed, and may comprise a conductive fluid or an organic or inorganic material or a low melting point metal that is easily stripped off the dielectric surface. Imaging apparatus incorporating,and a method of using,said medium also is described.