Patent ID: 8116648

Claim:
An image forming apparatus comprising a transfer unit for transferring to a recording medium a toner image developed on a photoreceptor, the transfer unit having a transfer belt conveying the recording medium, and the image forming apparatus comprising: a cleaning section for cleaning a surface of the transfer belt by coming into contact therewith; and a control section for controlling a running speed of the transfer belt based on a change in frictional force due to abrasions at a contact portion between the transfer belt and the cleaning section, wherein the control section: stores a decrease of a running speed of the transfer belt due to an increase of frictional force between the transfer belt and the cleaning blade caused by a decrease of a surface roughness of the transfer belt, as a correlation with a predetermined cumulative number of printed copies or a running distance of the transfer belt; controls a driving roller of the transfer belt so that its revolving speed becomes a predetermined speed according to a cumulative number of printed copies and a running distance; and controls the transfer belt so that its running speed becomes equal to a circumferential speed of the photoreceptor.