| 摘要 |
PROBLEM TO BE SOLVED: To automatically regulate rotational phases between plate cylinders in a plurality and thereby to prevent a color shift in printing. SOLUTION: A first plate cylinder 10, a second plate cylinder 11 and an impression cylinder 12 are provided rotatably and rotational phase varying means for varying the respective rotational phases of the first and second plate cylinders 10 and 11 are provided separately, while plate cylinder rotational position detecting sensors and an impression cylinder rotational position detecting sensor which detect the respective rotational positions of the first plate cylinder 10, the second plate cylinder 11 and the impression cylinder 12 are provided separately. A phase difference computing circuit which computes a rotational phase difference between the first plate cylinder 10 and the second plate cylinder 11 from outputs of the rotational position detecting sensors is provided and the rotational phase varying means is controlled so that the phase difference computed by the phase difference computing circuit be eliminated. |
