Method and apparatus for maintaining registration when making a printing plate

摘要

A printing plate making apparatus for color printing is provided with a depicting section for recording an image on the surface of a printing plate, a processing section for processing the printing plate, with a processing solution, while conveying the printing plate, and a punching section for punching notches for positioning and winding the printing plate around a plate cylinder of a rotary press, the depicting and punching sections are provided with a first reference pin for abutting against a side edge of the printing plate being moved in a first direction to position the printing plate in the first direction, and a second reference pin for abutting against a side edge of the printing plate being moved in a second direction to position the printing plate in the second direction. The positional relation between the first and second reference pins in the depicting section and the positional relation between the first and second reference pins in the punching section are set identically. Therefore, positioning notches for the rotary press can be punched after the printing plate has been processed.