PURPOSE: To print patterns different in a repeated length on a web without changing the diameter of a plate cylinder, by rotating the plate cylinder at a definite change rate so that the peripheral speed of the plate cylinder becomes non-synchronous to the running speed of the web.
CONSTITUTION: The running speed signal of a web 10 obtained from a speed sensor 36 is transmitted to a control unit 60 being a control means and the value calculated by multiplying the running speed of the web 10 by the change rate of the peripheral speed of a plate cylinder is transmitted to the first electromotor 62 being a drive means as a control signal. Said change rate is constant during the use of the same printing plate and does not depend on a printing speed, that is, the running speed of the web 10 but the peripheral speed of the plate cylinder increases when the running speed of the web 10 increases and decreases when said running speed decreases. Further, the change rate of the peripheral speed is substantially equal to the rate (R/R2) of the repeated length R of a printing pattern P to the dimension R2 of the plate cylinder 44 in the peripheral direction thereof. As a result, the repeated length can be different without changing the diameter of the plate cylinder.
YOSHIMATSU TATSUHIKO
TSUCHIMOTO HIDEYUKI
HIWATARI KATSUMI
