Patent ID: 8417165

Claim:
An image forming apparatus in which a toner image primarily transferred from an image bearing member to an intermediate transfer belt is secondarily transferred from the intermediate transfer belt to a recording material, comprising: a movable endless intermediate transfer belt; a rotatable first image bearing member; a first developing member which develops a toner image on the first image bearing member, and is contactable to and separable from the first image bearing member; a rotatable second image bearing member which is contactable to and separable from the intermediate transfer belt; a second developing member which develops a toner image on the second image bearing member, and is contactable to and separable from the second image bearing member; a stretching member configured to stretch the intermediate transfer belt; and a secondary transfer member opposed to the stretching member through the intermediate transfer belt in contact with an outer peripheral surface of the intermediate transfer belt, the secondary transfer member forming a secondary transfer portion together with the stretching member through the intermediate transfer belt, and the secondary transfer member transferring a toner image to a recording material proceeding into the secondary transfer portion, wherein the image forming apparatus is operable in a multiple color mode of transferring toner images from the first image bearing member and the second image bearing member to the intermediate transfer belt in a state in which the first image bearing member and the second image bearing member are in contact with the intermediate transfer belt, and in a single color mode of transferring the toner image from only the first image bearing member to the intermediate transfer belt in a state in which at least the first image bearing member is in contact with the intermediate transfer belt, and wherein in the single color mode, the toner image is transferred from the first image bearing member to the intermediate transfer belt when the recording material proceeds to the secondary transfer portion, the single color mode is further switchable to a plurality of modes, and one of the plurality of modes is a first mode of transferring the toner image from only the first image bearing member to the intermediate transfer belt in a state in which the first image bearing member is in contact with the first developing member and the intermediate transfer belt and in which the second image bearing member is separated from the second developing member and in contact with the intermediate transfer belt.