BILDERZEUGUNGSVORRICHTUNG

A toner image which is carried by a photosensitive endless belt is pressed against a printing paper by a transfer opposed roller provided inside the photosensitive belt to transfer the toner image onto the printing paper, and the image transferred onto the printing paper is fixed. The position of the transfer roller which is moved inside the photosensitive belt is detected by a detector. When the detected position agrees with a predetermined position, the moving direction is reversed by a control unit and the moving distance of the transfer roller is varied in accordance with the size of the image and, further, the contamination of the backside of the printing paper is avoided.