Patent ID: 6877428
Filing Date: 2005-04-12
Classification: B41C,B41F,B41N,B41P,G03F

Abstract:
1. A regenerative off-press plate making and printing process using a laser plate making and regenerating apparatus (I) including a plate fixing drum, a plate material-feeding mechanism, an exposure mechanism, a plate-treating agent-feeding mechanism and a plate material-removing mechanism, and a printing machine (II), the process comprising the steps of: (A) supplying a photosensitive plate material onto a substrate fixed on the plate fixing drum from the plate material-feeding mechanism to prepare a photosensitive lithographic plate; (B) exposing the thus prepared photosensitive lithographic plate to image light by the exposure mechanism; (C) supplying an alkali development solution onto the thus image-exposed photosensitive lithographic plate from the plate-treating-agent-feeding mechanism, followed by, if required, applying physical stimulus thereto, to obtain a lithographic plate having images thereon wherein conditions of the images formed on the photosensitive layer of the photosensitive lithographic plate are detected to control developing conditions on the basis of detected data, the data detected and used for controlling the developing conditions being those satisfying such a condition that a value obtained by dividing a reflection absorbance A by a reflection absorbance B is not less than 0.5, wherein A represents a reflection absorbance obtained by subtracting a reflection absorbance of the substrate from the reflection absorbance of the image portions; and B represents a reflection absorbance obtained by subtracting the reflection absorbance of the substrate from the reflection absorbance of the non-image portions; (D) after removing the lithographic plate from the plate fixing drum, fitting the lithographic plate on the printing machine to conduct printing; and (E) after removing the lithographic plate used for printing from the printing machine and then fitting the lithographic printing plate on the plate fixing drum again, removing image portions formed on the lithographic plate by the plate material-removing mechanism using an aqueous alkali solution as a release agent, to regenerate the substrate.