| 摘要 |
PROBLEM TO BE SOLVED: To prevent the problem in, wherein when the operation of switching between the contact and the separation of each developer carrier and a corresponding image carrier and the operation of switching between transmission through a drive transmission path to the developer carrier and its cancellation are optimized at a prescribed processing speed (1/1 speed) and even at other processing speeds (1/2 speed and 1/3 speed), the surface layer of the image carrier wears due to the friction between the image carrier and the developer carrier, with the result that cartridge lifetime decreases and the amount of operation of the developer carrier increases, which lead to damage to developer and stabilization of the charges of the developer and result in image defects, such as fogging. SOLUTION: The image forming apparatus includes a contact and separation mechanism for bringing the image carrier 1 and the corresponding developer carrier 40 into contact with each other or separating them; and one drive source 70, acting on the contact and separation mechanism, in order to perform the operation of switching between the contact and separation of all the image carriers and all the corresponding developer carriers and the operation of switching between transmission through the drive transmission path to the developer carrier and its cancellation. According to prescribed printing conditions, the time for start the drive source and time for stopping it are altered. COPYRIGHT: (C)2006,JPO&NCIPI |
