Patent ID: 7639959

Claim:
An image forming apparatus comprising: an image bearing member: a toner image forming device configured to form a toner image on the image bearing member; a belt unit including: a belt member configured to bear the toner image transferred from the image bearing member; and a supporting member that supports the belt member, wherein the belt unit is movable between a first position where the belt member is in contact with the image bearing member and the toner image is formed on the belt member and a second position where the belt member is apart from the image bearing member; a detecting member configured to detect the toner image on the belt member positioned at the first position; a control device that controls conditions of toner image formation of the toner image forming device on the basis of detection results of the detecting member; and a moving device that moves the detecting member so that a distance between the detecting member and the belt member is greater at the second position than at the first position, in conjunction with an operation to move the belt unit from the first position to the second position.