| 摘要 |
<p>PROBLEM TO BE SOLVED: To cancel, with high accuracy, variation in torque of an image carrier due to an impact or the like, of which the occurrence cannot be predicted or which cannot be predicted with high accuracy, even in the case of the image carrier being a belt member, while suppressing the increase of energy consumption.SOLUTION: An auxiliary motor 209 is provided for a driven roller 201 existing nearer to an intermediate transfer belt 6 on a drive transmission path to the intermediate transfer belt 6 than gear reduction mechanisms 204 and 205 which give the weakest spring characteristics being spring characteristics exerting the largest influence on a drive transmission system, out of drive transmission members provided on the drive transmission path. An estimation parameter for estimating a variation of drive load torque of an intermediate transfer body, which is varied by entrance of a transfer paper into a transfer nip, is continuously sampled to estimate disturbanceτr, and a signal obtained by shifting a control signal for canceling the estimated disturbanceτr, by a half period, is used to control a driving force given by the auxiliary motor.</p> |
