| 摘要 |
PROBLEM TO BE SOLVED: To put respective color photoreceptor drums of an image forming apparatus in phase with one another in a short time. SOLUTION: The device has an intermediate transfer belt 8 which can abut against the photoreceptor drums 1 where electrostatic latent images corresponding to respective color toner images are formed and to which the color toner images developed on the photoreceptor drums 1 are put one over another and transferred, a photoreceptor body driving gear which rotates the photoreceptor drums 1, a cam 15 which has 1st cam projections 15a and 2nd cam projections 15b in mutually different shapes and rotates together with the photoreceptor drums 1 and the photoreceptor body driving gear, a subordinate part 17 which is cyclically displaced by the rotation of the cam 15, and a sensor 18 which detects the displacement position of the subordinate part 17, and puts the photoreceptor drums in phase with one another by using 1st pulses a1 and b1 and 2nd pulse a2 and b2 which are generated by the 1st cam projections 15a and 2nd cam projections 15b detected by the sensor 18 via the subordinate part 17 and differ in width from each other. |
