Jet drop copying apparatus and method.

摘要

A jet drop copying apparatus has a print head (18) which directs a row of jets (66) towards a print sheet (16) mounted on a rotating drum (17). The row of jets extend substantially across the full width of the print sheet and are operated under control of a printing controller (67) to print a series of tracts extending circumferentially along the sheet. The jets are shifted laterally in synchronism with the drum rotation such that each jet is moved a distance equal to the width of one printing track during one rotation of the drum. The shifting continues until a solid print has been obtained. Means (42,43,45,80, 11, 81, 13) are provided for illuminating a narrow strip extending across a document (15) to be copied and projecting an image of the illuminated strip upon a row (14) of photodetectors. Longitudinal image scanning proceeds in synchronism with the rotation of the printing drum, and there is a lateral shifting of the image in synchronism with the shifting of the jet printing tracks.