Patent ID: 8200133

Claim:
A tandem-type image forming apparatus including a photoreceptor for black which is rotatable, a plurality of photoreceptors for colors which is rotatable, an intermediate transfer member or a transfer belt, the intermediate transfer member which is an endless belt shape and transfers a toner image formed on the photoreceptors, the transfer belt which is an endless belt shape and carries a printing medium to transfer the toner image, and a motor which drives the intermediate transfer member or the transfer belt, in which the photoreceptor for black and the plurality of the photoreceptors for colors are controlled to be contacted to the intermediate transfer member or the transfer belt in a case of forming a color image, and in which the photoreceptor for black is controlled to be contacted to the intermediate transfer member or the transfer belt and the plurality of the photoreceptors for colors are controlled to be separated from the intermediate transfer member or the transfer belt in a case of forming a black and white image, said tandem-type image forming apparatus comprising: a current control part configured to control so that in the case of forming the black and white image, when the intermediate transfer member or the transfer belt is driven, a value of a current flowing to the motor is equal to the value of the current in the case of forming the color image, wherein the current control part controls the value of the current by controlling a rotational velocity of the photoreceptor for black.