Patent ID: 6996357
Filing Date: 2006-02-07
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an endless belt passed over a plurality of rotary support bodies; a drive source for outputting drive torque that drives said belt; rotation sensing means mounted on a shaft of, among the plurality of rotary support bodies, a driven rotary support body not contributing to transfer of the drive torque; a reference mark provided on said belt; mark sensing means for sensing said reference mark; and storing means for storing, when said drive source is driven at a preselected angular velocity for a test, information produced from an output of said rotation sensing means on the basis of reference mark sense information output from said mark sensing means; wherein rotation of said drive source is so controlled as to cancel a variation of rotation of said driven rotary support body on the basis of the reference mark sense information output from said mark sensing means and the information stored in said storing means.