IMAGE-FORMING DEVICE AND CONTROL METHOD THEREOF

PROBLEM TO BE SOLVED: To provide an image-forming device which synchronizes rotational phases of a plurality of image carriers without severely damaging the image carries and an intermediate transfer belt and without significantly changing the load of their respective driving sources. SOLUTION: The drive of the intermediate transfer belt 8 is controlled by a CPU 201, while photosensitive drums 2a-2d are separated from the intermediate transfer belt 8, to control the rotational speed and rotation phase of the intermediate transfer belt 8 with respect to the photosensitive drums 2a-2d (Steps S101, S102). By this control, the circumferential speed of the intermediate transfer belt 8 reaches a speed Vt, and the circumferential speeds of the photosensitive drums 2a-2d reach the speed Vt, and consequently the rotational phases of the photosensitive drums 2a-2d are synchronized (a driving state C). Then, the photosensitive drums 2a-2d are brought into contact with the intermediate transfer belt 8 (Step S104). COPYRIGHT: (C)2009,JPO&INPIT