| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the breakdown of a master, such as a break or a tear thereof, is caused by a bending force given as four corner parts of the front and rear end parts of printing paper and the master come into pressure contact with each other and this causes, in its turn, staining of printed matter or a pressing means (impression cylinder or a press roller) with ink. SOLUTION: Based on a signal from a paper size detecting sensor group 120, a control means 90 controls a cam driving motor 14 of a throw-on/off time varying means 12 so that the outer peripheral surface of the impression cylinder 8 may press the printing paper P on the master 3 already subjected to plate making and set on a plate cylinder 1 between a paper front end position and a printing start position along the direction A of rotation of the plate cylinder 1 in the printing paper P, and controls the cam driving motor 14 so that the outer peripheral surface of the impression cylinder 8 may detach from the plate cylinder 1 between a printing end position and a paper rear end position along the direction A of rotation of the plate cylinder 1 in the printing paper P. |
