| 摘要 |
956,771. Episcopic projection in xerographic apparatus. RANK-XEROX Ltd. May 3,1960 [May 7, 1959], No. 15522/60. Headings G2H and G2J. In a xerographic process a xerographic plate is coated with developer powder either before or during exposure and the latent image formed is made visible by passing an acceptor member into contact with the plate and by establishing a suitable potential field between them thereby transferring a powder image to the acceptor member. In the apparatus shown, a rotating transparent drum 60 comprising a photo conductive layer 62 which is specular reflecting, is coated with a developing powder e.g. charcoal, by a brush 65 and is charged by a corona charging unit 20 before being exposed to a light pattern by cathode ray tube 67. The drum is then pressed against a moving web 41 which has a specular reflecting surface, and a potential difference is applied between the drum and this web (through conducting roller 40) so that a powder image of the pattern is transferred to the web. The images on the web 41 and/or drum 60 are projected on to screens 53, 78 respectively by light from lamps 50, 74 being specularly reflected by the image bearing surfaces. The images may subsequently be fixed. A positive and/or a negative image of the original may therefore be projected as required, by lamp 50 or 74, lenses 51, 54 or 75, 77, on to screen 53 or 78. |
