Patent ID: 7011928
Filing Date: 2006-03-14
Classification: G03F,Y10S

Abstract:
1. A method of forming an image on a light sensitive planographic printing plate material comprising a hydrophilic support and provided thereon, a light sensitive layer containing an addition polymerizable ethylenically unsaturated monomer, a photopolymerization initiator, a polymer binder, and a sensitizing dye having an absorption maximum in the wavelength regions of from 390 to 430 nm, the minimum laser exposure amount necessary to form an image on the material being from 1.0 to 100 μJ/cm 2 , the method comprising the step of: imagewise exposing the light sensitive planographic printing plate material to laser under a non-yellow safelight to form an image, the non-yellow safelight having an optical filter cutting out light only with a wavelength of less than 440 nm, and emitting a light-yellow light, and satisfying the following expression: wherein I