| 摘要 |
Electric discharge between a photosensitive member and a charge retaining medium is ON/OFF controlled by changing either the gap or the gas pressure between these two members, so that it is possible to effect image recording in a state where a DC voltage is being 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. Further, the conductive layer and/or surface of at least either the photosensitive member or the charge retaining medium is provided with dimple patterns, thereby dimply changing the voltage that is applied across the gap between them and modulating the discharge pattern in accordance with the dimple patterns, and thus enabling recording of a halftone dot image simultaneously with the exposure. It is therefore unnecessary to effect a special electrical processing for the formation of halftone dots and hence possible to record a halftone dot image at a reduced cost and with ease. Further, an electric charge which is opposite in 42 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. 43 |
