Patent ID: 8311421

Claim:
An image forming apparatus comprising: a conveyer-member control device that controls a conveying speed of a conveyer member; and an image forming unit that forms an image on the conveyer member, wherein the conveyer-member control device includes a detecting unit that detects a conveying speed of the conveyer member, a driving unit that drives the conveyer member, a first control unit that performs a first feedback control of the conveying speed based on the detected conveying speed and a predetermined target conveying speed, a second control unit that detects a rotation speed of the driving unit and performs a second feedback control of the rotation speed based on the detected rotation speed and a predetermined target rotation speed, a determining unit that determines whether the detecting unit is anomalous based on the detected conveying speed while the first feedback control is performed, and a switching unit that switches, when the determining unit determines that the detecting unit is anomalous, from the first feedback control to the second feedback control, the image forming apparatus further comprising an operation display unit that displays thereon either one of the first feedback control and the second feedback control which is currently performed, and receives an instruction from a user for switching the feedback control from the first feedback control to the second feedback control, wherein when the instruction is received by the operation display unit, the switching unit switches from the first feedback control to the second feedback control.