| 摘要 |
PURPOSE:To enable high-quality multicolor printing and to enhance printing resistance by repeating a light shading step, a lithographic plate conveying step, a close contact step, an exposure step, and the exposed plate conveying step in at least 3 times using a red color separation filter, a green one, and a red one. CONSTITUTION:An exposure section is shaded from light with a light shading means and a lithographic plate having a panchromatic sensitive layer put in a magazine is carried to an exposure section. This plate is brought into close contact with a contact screen. The plate is exposed to a color image projected from a multicolor original continuous in gradation through a color separation filter and a lens. The exposed plate is carried to a processing bath for development, when needed, further stabilization, fixation, desensitization to fat, etc. So long as the lithographic plate has a layer sensitive to blue, green, and red lights, i.e., so-called panchromatic lights, it does not matter than the photosensitive layer is a silver salt type photographic lithographic plate or electrophotographic lithographic plate or that of other kind. |
