Patent ID: 9026016
Filing Date: 2015-05-05
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a plurality of photosensitive drums configured to bear a toner image; a rotatable endless belt provided so that its outer peripheral surface opposes said photosensitive drums; a plurality of rigid transfer rollers, provided at positions corresponding to the photosensitive drums, respectively, so as to contact an inner peripheral surface of said belt, configured to transfer the toner image from said photosensitive drum onto said belt or a recording material conveyed by said belt by being supplied with a transfer bias, wherein a coefficient of static friction of a surface of said transfer roller contacting the inner peripheral surface of said belt is smaller than a coefficient of static friction of the inner peripheral surface of said belt; a cleaning roller, provided adjacent to and downstream of a downstream-most photosensitive drum of said photosensitive drums with respect to a rotational direction of said belt so as to contact the inner peripheral surface of said belt to clean said belt, wherein a coefficient of static friction of a surface of said cleaning roller contacting the inner peripheral surface of said belt is larger than the coefficient of static friction of the inner peripheral surface of said belt; a cleaning member configured to clean the surface of said cleaning roller; and a movement control portion configured to control movement of said belt in a widthwise direction so that a reciprocating movement time of said belt with respect to the widthwise direction during non-image formation is shorter than that during image formation.