PURPOSE: To prevent the fluctuation in the activity of an etching liquid from significantly affecting a finish and from affecting the reproducibility of an original picture image and to effectively prevent the generation of the undesirable states occurring in etching defects, such as generation of the unequalness in dot reproduction and inking in non-image parts.
CONSTITUTION: Plural etching treatment stages A, B are prepd. in the method for forming toner images by an electrophotographic system on the photosensitive planographic printing original plate provided with a photoconductive layer on a conductive base, then removing the photoconductive layer of the non-image parts. The etching treatments are executed by supplying the substantially unused etching liquid in the preceding etching treatment stage A and supplying the recycled etching liquid in the succeeding etching treatment stage B.
GOTO SEI
KOJIMA YASUO
SUZUKI TOSHITSUGU
