In an electrophotographic apparatus wherein the images of successive portions of an original to be copied are formed into electrostatic latent images which in turn are visualized by means of liquid developer to provide a copy image, the latent images are formed in predetermined spaced-apart relationship...http://www.google.de/patents/US3981576?utm_source=gb-gplus-sharePatent US3981576 - Multicolor electrophotographic copier with liquid developing
