Digital plate maker system and method

摘要

Graphics and text data are combined selectively to discharge incremental areas of a charged electrophotographic member to form thereon a latent text and/or graphics image represented by the graphics and text data, the imaged member thereafter being toned and output from the system so that the toned image may be fused on the member and the member may be used as a printing plate in an offset lithographic printing press. The apparatus includes an optical system that may form a maximum of 22 individual rays which are deflected twice through a field flattening lens and then onto the charged member. The optical system further includes an optical scale or grating which provides electrical signals indicating the precise location of the individual rays along scan lines on the member. The apparatus further includes an electronic system which generates electrical signals from the graphics and text data to form the 22 individual rays. The text data is used to modulate signals produced by the graphics data, the result of the modulation being beam control signals used to form the 22 individual rays. The apparatus further includes a toning system that provides a vertical meniscus of toning fluid, the meniscus being essentially stationary with the electrophotographic member as the electrophotographic member is rotated past the toning station.