Dai Nippon Printing Co., Ltd.

Kohji Ichimura

Hiroyuki Obata

Minoru Utsumi

Masayuki Iijima

Takashi Aono

A photosensitive member which has an electrode provided on the front side and a photoconductive layer stacked on the electrode, the photosensitive member being disposed face-to-face with an electrostatic information recording medium that includes a charge retaining layer having an electrode provided on the rear side, either in or out of contact with each other, to carry out exposure with a voltage being applied between the two electrodes, thereby forming an electrostatic charge pattern on the electrostatic information recording medium in accordance with an exposure light pattern. The layer arrangements of the photosensitive member and the photoconductive layer as well as the method of forming the photoconductive layer are improved so that electrostatic information can be recorded on the electrostatic information recording medium with high sensitivity and it is also possible to improve the contrast ratio of the information charge at the exposed region to that at the unexposed region.

Photosensitive member and electrostatic information recording method

Electric discharge between a photosensitive member and a charge retaining medium is ON/OFF controlled by changing the gas pressure between these two members, so that it is possible to effect image recording in a state where a DC voltage is applied. An electric charge which is opposite in polarity to an image forming charge is uniformly formed on the charge retaining medium in advance of the image exposure, and thereafter image exposure is carried out, thereby reducing the background potential at the unexposed region and increasing the contrast potential of the electrostatic latent image formed on the charge retaining medium. In addition, it is possible to increase the voltage distribution to the photosensitive member. As a result, it is possible to improve the photosensitivity of image exposure.

Image recording method

Electric discharge between a photosensitive member and a charge retaining medium is ON/OFF controlled by changing the gas pressure between these two members, so that it is possible to effect image recording in a state where a DC voltage is applied. Accordingly, it is possible to effect image recording on the charge retaining medium without the need for precise control for obtaining a high-voltage pulse and without employing an optical shutter. In addition, an electric charge that is emitted by a field is attracted to the charge retaining medium and accumulated on the surface thereof, thereby forming an electrostatic latent image, and thus making it possible to attain image recording of extremely high resolution.

Process for recording images on an electrostatic information recording

The a-selenium-tellurium photosensitive member according to the present invention comprises an electric charge injection preventive layer, an a-selenium-tellurium mixed vacuum evaporation layer of 0.03-0.2 .mu.m thick having tellurium concentration within the range of 20-50 wt % with uniform concentration on the deposited surface, and an electric charge transport layer, and these three layers are sequentially laminated on a transparent electrode layer. Thus, a-selenium-tellurium layer is formed in thin film, and thermal excitation carrier and injection carrier can be reduced to very low level even when tellurium concentration is increased. The increase of dark current is not very high. Panchromatic property can be provided in visible light region, and the sensitivity can be improved even in short wavelength region.

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Tokyo, Japan

Kohji Ichimura