Abstract: Electrophotographic medium which comprises a multilayer structure of materials for imaging radiant energy patterns at high speed and with high sensitivity of a degree capable of meeting and exceeding the sensitivity of silver halide film, with greater resolution than that of silver halide film of the high speed type.A method of using electrophotographic film to achieve high sensitivities and speeds.The medium 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 intimately bonded to the surface of the photoconductive coating and a conductive electrode in intimate contact with the dielectric layer.The use of the electrophotographic medium does not require initial charging; hence no means for effecting this are required.

Abstract: Electrophotographic medium which comprises a multilayer structure of materials for imaging radiant energy patterns at high speed comprising a transparent substrate, ohmic layer and coating of photoconductive material, which form a modulating structure for the radiant energy projected through the substrate; a dielectric layer intimately bonded to the surface of the photoconductive coating and a conductive electrode in intimate contact with the dielectric layer. The dielectric layer constitutes the storage medium for the image which is produced in electrostatic charge form and, the medium is capable of retaining latent images for a very substantial length of time.The use of the electrophotographic medium does not require initial charging; hence no means for effecting this are required. Further, the speed of the medium is so high compared with all other media that extremely low energy levels can provide sufficient contrast to produce images.The structure as described is used by connecting a d.c.