Printing unit of a sheet-fed printing press

摘要

A printing unit of a sheet-fed printing press for printing on sheets includes a plate cylinder having a circumference, on which a recess is formed; a feed reel mounted within the recess for feeding a printing film onto the circumference of the plate cylinder so as to introduce an image forming region for each printing operation; an image forming device for forming an image on the image forming region of the printing film fed on the circumference of the plate cylinder with the first edge of the image forming region positioned at an edge of the recess closer to the rewind reel; a rewind reel mounted within the recess for rewinding the printing film from the circumference of the plate cylinder; and a control unit for controlling the length of the printing film to be fed from the feed reel onto the circumference of the plate cylinder, based upon the length of sheets to be printed for each printing operation.