| 摘要 |
PROBLEM TO BE SOLVED: To prevent the rotational irregulality of an image carrier of a transfer belt system and abuttment irregularities in a primary transfer part and a secondary transfer part, to avoid the occurrences of image irregularities, color slippage or the like, and to maintain satisfactory image quality by subjecting the image carrier of the transfer belt system to deformation-removal rotation with specific timing when image formation is not carried out (except the timing of image formation and that of transfer). SOLUTION: During an initial sequence until image formation is allowed after a power source is turned on, an intermediate transfer belt 9 is subjected to deformation-removal rotation. Because the belt is stopped for a long time before the power source is turned on, the probability of a deformation of the belt is high right after the power source is turned on. By the deformation- removal rotation, the deformed portion of the belt is curved and stretched each time it passes rollers and other composing members which abut on the intermediate transfer belt 9, so that the deformation is removed. Also, an environment sensor 24 is incorporated in the device, information detected by it is sent to a controller 23, and the controller 23 controls a motor 22 based on the information so as to alter an amount of deformation-removal rotation. |
