Patent ID: 8112021

Claim:
An image forming apparatus comprising: a first image bearing member and a second image bearing member, toner images being formed on the first and second image bearing members; a belt member capable of contacting the first and second image bearing members; a moving member configured to move a surface of the belt member to produce a first state, in which the belt member contacts the first and second image bearing members, and a second state, in which the belt member contacts the second image bearing member and separates from the first image bearing member; a supporting roller rotatably contacting the belt member, an area of contact of the supporting roller and the belt member being changed by the movement of the moving member; and a supporting roller inclination device configured to incline the supporting roller to move the belt member in a rotational axis direction of the supporting roller, wherein an inclination angle of the supporting roller with respect to a predetermined belt position while the area of contact of the supporting roller and the belt member is small is larger than an inclination angle of the supporting roller with respect to the predetermined belt position while the area of contact of the supporting roller and the belt member is large.