Process for preparing a masked color separation positive utilizing an electrophotographic photoconductive copysheet

Claim 1

A PROCESS FOR PREPARING A MASKED COLOR SEPARATION POSITIVE FROM A COLOR NEGATIVE SUITABLE FOR USE IN CONJUNCTION WITH A PRINTING PROCESS USING PRINTING INKS OF PRIMARY COLORS X AND Y, SAID MASKED COLOR SEPARATION POSITIVE TO CONSTITUTE A BLACK-AND-WHITE RECORD FOR PRIMARY COLOR X, WHICH COMPRISES: (1) EXPOSING AN ELECTROPHOTOGRAPHIC PHOTOCONDUCTIVE COPYSHEET SENSITIVE TO COLOR COMPLEMENTS OF X AND Y THROUGH SAID COLOR NEGATIVE TO LIGHT OF THE COLOR COMPLEMENT OF Y THEREBY FORMING A DIFFERENTIAL CONDUCTIVITY PATTERN IN SAID COPYSHEET, AND ELECTRODEVELOPING SAID COPYSHEET TO PROVIDE DYE OF COLOR X SELECTIVELY ON THE LIGHT EXPOSED AREAS OF THE COPYSHEET IN AN AMOUNT SUFFICIENT TO COMPENSATE FOR THE X COMPONENT OF THE Y COLORED PRINTING INK, (2) REMOVING SAID DIFFERENTIAL CONDUCTIVITY PATTERN IN SAID COPYSHEET AND RESTORING SAID COPYSHEET TO A UNIFORM PHOTOSENSITIVITY, (3) EXPOSING SAID COPYSHEET THROUGH SAID COLOR NEGATIVE TO LIGHT OF THE COLOR COMPLEMENT OF X, THEREBY FORMING A SECOND DIFFERENTIAL CONDUCTIVITY PATTERN IN SAID COPYSHEET, AND ELECTRODEVELOPING SAID COPYSHEET TO PROVIDE SELECTIVELY ON ITS LIGHT EXPOSED AREAS A COLORED MATERIAL OF A COLOR WHICH IS CAPABLE OF ABSORBING LIGHT FREELY TRANSMITTED BY SAID DYE OF COLOR X, AND (4) PHOTOGRAPHING SAID COPYSHEET IN LIGHT OF A COLOR WHICH IS FREELY TRANSMITTED BY SAID DYE OF COLOR X AND WHICH IS ABSORBED BY THE AFORESAID COLORED MATERIAL AND PRODUCING A BLACK-AND-WHITE POSITIVE SEPARATION RECORD FOR COLOR X.