Patent ID: 8254813

Claim:
A multicolor imaging system comprising: a plurality of photoreceptors on which electrostatic latent images are generated; a plurality of develop units generating toner images based on the electrostatic latent images on the photoreceptors, respectively; a transfer unit comprising a no-end belt element onto which the toner images are transferred sequentially while rotated, and a belt drive element which rotates the belt element; a drive unit controlling the transfer unit via the belt drive element based on a fluctuation in a rotary velocity of the belt element so that the belt element rotates at a constant velocity, and driving one of the plurality of photoreceptors together with the belt element; a toner pattern detector which detects a toner pattern on the belt element; an arithmetic unit which calculates a periodic fluctuation in each of the photoreceptors from information detected by the toner pattern detector; a rotary position detector which detects rotary positions of the photoreceptors; a controller which adjusts a phase difference in rotations of the photoreceptors based on information detected by the rotary position detector; a drive gear system for the one photoreceptor, comprised of a gear and the belt drive element; and a gear system for the photoreceptors other than the one photoreceptor, comprised of a gear and at least one phase adjusting gear having a same rotary cycle as that of the gear of the drive gear system to adjust the rotary velocity of the photoreceptors other than the one photoreceptor to fluctuate in a same cycle as that of the one photoreceptor.