公开(公告)号：WO1980002466A1

公开(公告)日：1980-11-13

申请号：PCT/US1980000361

申请日：1980-04-09

Applicant: ELTRA CORP

Inventor： ELTRA CORP ,  KLEPPER H ,  KAUFMAN A ,  GALBRAITH W

IPC: G03G15/10

CPC classification number: G03G15/10 ,  G03G15/28

Abstract: Electrophotographic apparatus for producing high quality, toned, first-generation images on a suitable flexible record or image receiving medium such as paper. Because of its unique characteristics, however, electrophotography cannot be readily adapted to provide a dry output from a typesetter. The first problem is the quality of the output. Normal copier quality is far below the standards used in the graphic arts industry. A second problem concerns the dark decay rate of a photoconductor. In typesetter applications where exposure of the photoconductor is carried out letter by letter or computed raster line by raster line, the time between charging and toning may be as long as ten to twenty minutes as compared to, say, ten seconds or less for a typical office copier. Therefore, if electrophotography is to be used to produce dry developed output from a typesetter, the photoconductor must exhibit an extremely low dark decay rate. Therefore, a principal object of the present invention is to provide electrophotographic apparatus for producing high quality, toned, first generation images. A further object of the present invention is to provide electrophotographic apparatus for use with a typesetter which meets the various requirements set forth above. These objects, are achieved, according to the present invention, by providing a particular configuration of elements, for charging, exposing and developing images on a flexible substrate, such as paper, coated with a layer of photoconductive material, such as zinc oxide. In particular, the apparatus includes: (a) a transporting device, such as a drum (74), for supporting and transporting an image receiving medium (14 or 60), such as ZnO-coated paper; (b) a charging device (22 or 80), such as scorotron, disposed adjacent to the transporting device (74), for applying a uniform charge on the photoconductive surface of the image receiving medium; (c) an exposing device (24 or 82) such as an illuminated character mask (30) or laser scanner (94, 98, 100, 104), for directing radiation onto the photoconductive surface after charging at the areas where toned images are to appear, thereby to discharge the surface at these areas; and (d) a developing device (42 or 86) disposed adjacent to the transporting device, for applying liquid toner to the discharge areas on the photoconductive surface after exposing.