To securely ensure accuracy of parallelism between an axial line of a press roller and a drum axial line of a drum unit without requiring difficult adjustment work, and prevent decline in image quality such as skew of printing images caused by deviation of the parallelism over printing time.
When no printing pressure is applied, each bearing portion 7 of the press roller 66 and each guide part 6a, 6b are not brought into contact with each other. When printing pressure is applied by a printing pressure application means of a displacement means which is not shown in the figure, as shown in Figs.2(c) and 2(d), the press roller 66 moves upwards to occupy a printing position. At the same time, each guide portion 6a, 6b on the drum unit 1 side guides each bearing portion 7 of the press roller 66, so as to achieve a state where the parallelism between the drum axis 2a of the drum unit 1 and the axis 67a of the press roller 66 is securely ensured.
Toru Kabayama
Shuichi Kudo