A digital color copying machine comprising a memory for storing a multi-level image signal or a binary image signal is disclosed. In a superimpose mode of the copying machine, after an image signal of a first document image stored in the memory is read out, the first document image is superimposed on...http://www.google.fr/patents/US5165071?utm_source=gb-gplus-shareBrevet US5165071 - Digital color copying machine
