| 摘要 |
PURPOSE:To perform registering even before printing in addition to registering after printing by disposing mark sensors at the front and rear of a slave unit. CONSTITUTION:A distance l1 from the detecting position of a first mark sensor 52 to a printing point is always constant. A distance from a mark 43 on a plate cylinder 42 to the printing point is always constant and it is so rotated as to become the same as the l1. The distance from a position sensor 56 to the printing point is substantially the same as the l1, and the difference is corrected. A time from when a registor mark is detected by the sensor 52 to when the mark 43 is detected by the sensor 56 or the running distance of a web 12 during the time is measured, and is compared with a correction value l2. If an error is generated from the value l2, the cylinder 42 is accelerated or decelerated that much to be corrected. An error between it and the register mark of printed one is detected by a mark sensor 54, an arithmetic average value or a moving average value of several sheets is calculated, and if an average error is generated, a motor 48 is fed back to be controlled at its rotation. |
