Image forming apparatus for controlling a steering operation of an intermediate transfer belt

摘要

An improved image forming apparatus is described which can inhibit the quality of printed images from being degraded. A control unit performs a steering operation to shift an intermediate transfer belt toward a target belt position by controlling the inclination angle of a steering roller. Also, a memory stores the inclination angle of the steering roller in association with the operational states of rotary members facing the intermediate transfer belt. The control unit updates the values stored in the memory with an update value. When the result of detecting the belt edges indicate that the intermediate transfer belt falls in a predetermined range around the target belt position during the steering operation, the control unit determines the update value on the basis of the steering duration time and the inclination angle of the steering roller.

主权项

1. An image forming apparatus comprising:
an intermediate transfer belt wound around a plurality of rollers including a steering roller; a rotary member having switchable operational states including a pressure contact state in which the rotary member is in contact with said intermediate transfer belt under pressure, and a separate state in which the rotary member is separated from the intermediate transfer belt; a detecting unit configured to detect a position of said intermediate transfer belt in a width direction; a steering control unit configured to perform a steering operation to shift the position of said intermediate transfer belt toward a target belt position by controlling an inclination angle of said steering roller based on a detection result output from said detecting unit; a timer configured to count a duration for which said steering operation has been performed; a storing unit configured to store the inclination angle of said steering roller in association with the operational state of said rotary member; and a processing unit configured to determine an update value of the inclination angle of said steering roller, and to perform an updating process to update the inclination angle of said steering roller stored in said storing unit with the update value, wherein when it is determined based on the detection result output from said detecting unit that the position of said intermediate transfer belt falls in a predetermined range around said target belt position during said steering operation, said processing unit determines the update value based on (i) the duration for which said steering operation has been performed counted by the timer, and (ii) the inclination angle of said steering roller controlled by said steering control unit.