Image forming apparatus that includes a transfer member that can be separated from an inner circumferential surface of a transfer belt when belt is rotating

摘要

An image forming apparatus includes a transfer roller that can be separated from an intermediate transfer belt. When an operational mode is switched from a multicolor mode to a mono-color mode, the image forming apparatus changes a rotational speed of the intermediate transfer belt to a level slower than a rotational speed of the intermediate transfer belt to be set in the multicolor mode to transfer a toner image to the intermediate transfer belt, then separates a first transfer member from the intermediate transfer belt, and after the first transfer member is separated from the intermediate transfer belt, the image forming apparatus increases the rotational speed of the intermediate transfer belt to a rotational speed to be set in the mono-color mode to transfer the toner image to the intermediate transfer belt.