Patent ID: 8824939

Claim:
An image forming apparatus comprising: a plurality of image bearing members; a rotatable belt member configured to carry a toner image transferred from said image bearing members or configured to carry a recording material carrying a toner image transferred from said image bearing members; a plurality of rotatable supporting rollers, configured to stretch said belt member, and one of the plurality of rotatable supporting rollers includes a steering roller which moves said belt member in a widthwise direction by an inclining operation; a detecting unit configured to detect a position of said belt member with respect to the widthwise direction; a first control portion configured to correct the position of said belt member with a first predetermined amount of an inclination of said steering roller; a second control portion configured to correct the position of said belt member with a second predetermined amount of an inclination of said steering roller in response to a positional change, having a predetermined frequency, of said belt member; and a controller configured to control the position of said belt member based on an output of said detecting unit and configured to form a feed-back loop in which the first control portion and the second control portion are connected in parallel.