Patent ID: 8515311

Claim:
An image forming apparatus comprising: a toner image forming portion for forming a toner image; a rotatable belt member which bears a toner image formed by the toner image forming portion; a transfer portion for forming a transfer nip portion which transfers the toner image on the belt member on to a recording material; an adjustment roller that is located next to the transfer portion at an upstream side of the transfer portion and at a downstream side of the toner image forming portion, in a belt moving direction of the belt member, and sets up the belt member by coming into contact with an inside surface of the belt member; a moving unit for moving the adjustment roller so that an advancing angle of the belt member advancing into the transfer nip portion changes; a guide member, which is arranged at an upstream side of the transfer nip portion in a recording material conveying direction and adapted to come in contact with a face of a recording material opposite to a face to which the toner image is transferred from the belt member, to guide the recording material to the transfer nip portion; and a controller for controlling the moving unit so that a belt face advancing into the transfer nip portion when a recording material having a first thickness is conveyed to the transfer nip portion is at a position farther from the guide member than the belt face advancing into the transfer nip portion when a recording material having a second thickness, smaller than the first thickness, is conveyed to the transfer nip portion.