| 摘要 |
PROBLEM TO BE SOLVED: To provide a tandem type image forming apparatus capable of eliminating the difference of final image density by toner in a 1st image forming station on the most upstream side caused between the moment of forming a monochrome image and the moment of forming a full color image. SOLUTION: In this image forming apparatus equipped with 1st to 4th image forming stations equipped with a photoreceptor drum 3 and a transfer transport belt for transporting a recording medium, only the 1st image forming station on the most upstream side is used in forming the monochrome image, and the transfer transport belt is retreated with respect to the photoreceptor drums of the other 2nd to 4th image forming stations. In the image forming station on the most upstream side, conical rollers 91 and 91 inserted between the photoreceptor drum and a development roller are retreated in forming the full color image so as to change the development gap between the photoreceptor drum and the development roller 52 to be smaller than in forming the monochrome image, while the conical rollers are advanced in forming the monochrome image so as to change the development gap to be larger than in forming the full color image. |
