Patent ID: 8606153

Claim:
An image forming apparatus comprising: a rotatable belt member; an image forming station configured to form an image on said belt member or a recording material carried on said belt member in a region opposing said belt member; a first and a second detecting member configured to detect position of said belt member with respect to a widthwise direction of said belt member; a first and a second steering roller configured to correct the position of said belt member with respect to the widthwise direction by inclination; a control portion configured to control an inclination of said first steering roller and said second steering roller on the basis of an output of at least one of said first detecting member and said second detecting member; a first executing portion configured to execute, in a period other than an image formation period, an operation in a correction mode in which, in a state that said first steering roller is maintained at a first reference inclination, said control portion controls said second steering roller to correct a second reference inclination of said second steering roller; and a second executing portion configured to execute, in a period other than a period of the correction mode operation, an operation in a control mode in which said first steering roller is controlled on the basis of the first reference inclination, and said second steering roller is controlled on the basis of the second reference inclination.