Belt drive control device and image forming apparatus including the same

摘要

A belt drive control device constructed to sense the angular displacement or the angular velocity of a driven roller. The belt drive control device separates, from a sensed angular displacement or the angular velocity, an AC component having a frequency that corresponds to the periodic thickness variation of an endless belt in the circumferential direction, and then controls the rotation of a drive roller in accordance with the amplitude and phase of the AC component.