Patent ID: 6185396
Filing Date: 2001-02-06
Classification: G03G

Abstract:
A color image forming apparatus comprising:a plurality of image forming units corresponding to various colors, each of said image forming units comprising a developing device;a unit retaining member for retaining said image forming units and moving said image forming units between an image forming position and a waiting position;a photosensitive drum having a surface on which various color toner images developed by said developing device are formed;an intermediate transfer unit removably attached to a machine body of the image forming apparatus, the intermediate transfer unit comprising:an intermediate transfer belt for successive transfer and superposition of toner images of various colors from said photosensitive drum so as to form a color toner image on a surface of the intermediate transfer belt;a transfer member arranged in contact with an inner surface portion of said intermediate transfer belt;a first supporting roller and a second supporting roller for supporting the inner surface portion of said intermediate transfer belt; anda secondary transfer device for transferring the color toner image on said intermediate transfer belt onto a transfer material;wherein said photosensitive drum presses against said intermediate transfer belt in a manner that the perimeter of the photosensitive drum crosses a tangent line common to said transfer member and said first supporting roller towards an inner side of said intermediate transfer belt; andwherein said intermediate transfer belt presses against said secondary transfer device in a manner that said second supporting roller opposes said secondary transfer device through said intermediate transfer belt.