Patent ID: 6997108

Claim:
A plate-making type printing press for supplying dampening water and ink to a printing plate and printing on a medium, comprising: a rotating printing cylinder on which said printing plate is formed; a supply apparatus for supplying said dampening water and said ink to said printing cylinder; a blanket cylinder onto which the image of said printing plate on said printing cylinder is transferred; a pressing cylinder for pressing said medium against said blanket cylinder and printing said medium with said image on said blanket cylinder; an adjustment mechanism for adjusting the positions of said printing cylinder and said blanket cylinder in accordance with the thickness and printing position of said medium; a plate-making mechanism which has a writing device for writing the image that is to be printed on said printing cylinder, and for making said printing plate; a target that is disposed on said printing cylinder; a detection mechanism for detecting said target; and a control device for controlling the writing operation of said writing device to said rotating printing cylinder in accordance with an encoder output of a driving system for driving said printing cylinder, and for correcting a zero point of an encoder of said printing cylinder driving system with respect to the phase of the printing cylinder in accordance with the output of said detection mechanism.