| 摘要 |
PROBLEM TO BE SOLVED: To improve calculation precision of a speed variation quantity of an intermediate transfer belt than ever before. SOLUTION: A speed variation ratio in first and second conditions is obtained based on: a result obtained by detecting, by a patch detection sensor 206, a plurality of toner patches formed at predetermined intervals over a peripheral direction of the intermediate transfer belt 25 under the first condition for maintaining an angular velocity of a driving roller 27a that drives the intermediate transfer belt 25; and a result obtained by detecting, by the patch detection sensor 206, the plurality of toner patches formed at predetermined intervals over the peripheral direction of the intermediate transfer belt 25 under the second condition for maintaining an angular velocity of a driven roller 27c with the movement of the intermediate transfer belt 25. Thereafter, based on the obtained speed variation ratio, a ratio between a pitch-line distance variation quantity-effective coefficientκ1 on the driving roller 27a of the belt and a pitch-line distance variation quantity-effective coefficientκ2 on the driven roller 27c is calculated, thereby a driving motor 201 is controlled based on the resultant ratio. COPYRIGHT: (C)2010,JPO&INPIT |
