PURPOSE: To obviate the problem that the quality of a printed surface is poor only at an area corresponding to a slippage, by rotating a plate cylinder at such as predetermined rate of change in the circumferential velocity that the circumferential velocity is asynchronous with the feeding velocity of a web, and making a printing plate so that the hardness of the plate is 50W70° (Shore A).
CONSTITUTION: The circumferential velocity of a plate cylinder 42 and the velocity of a web 10 being fed are ordinarily asynchronous due to slipping. When the velocity of the web 10 is greater than the circumferential velocity of the plate cylinder, a printed pattern P is extended in the circumferential direction in printing as compared with a pattern P2 engraved in a printing plate 44, whereas when the velocity of the web 10 is lower than the circumferential velocity of the cylinder 42, the printed pattern P is contracted in the circumferential direction as compared with the pattern P2. A velocity signal of the web 10 obtained by a velocity sensor 36 is transmitted to a controlling unit 60, and a value obtained by multiplying this signal by the rate of change in the circumferential velocity relative to the velocity of the web is transmitted as a control signal, whereby the plate cylinder 42 is driven by a motor 62 at the rate of change in the circumferential velocity. In addition, the hardness of the printing plate is set to be 50W70° (Shore A). With this arrangement, a slippage can be reduced to a practically negligible level.
YOSHIMATSU TATSUHIKO
TSUCHIMOTO HIDEYUKI
HIWATARI KATSUMI
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