| 摘要 |
PROBLEM TO BE SOLVED: To realize proper transfer in an electrophotographic image-forming device, having plural image forming processing speeds and capable of forming an image on both sides of a sheet of paper. SOLUTION: A transfer device 17 is provided with plural transfer rollers A to D, formed to have resistance values respectively adaptable to the selection of the processing speed and the selection of one side/both-side image forming, and any one of the transfer rollers is used selectively, by rotating a pair of disks 72 for supporting rotary shafts A1 to D1 about a shaft 71. Therefore, the fluctuation of the electrical resistance value of the sheet is compensated by the electrical resistance values of the respective transfer rollers. Even in the case of constant current by making transfer voltage applied between a photoreceptor drum 13 and the transfer roller constant, appropriate transfer voltage is applied to the paper, so that proper transfer is realized. Since complicated current and voltage control is not required, the device can be realized with inexpensive constitution, and since no change is required on the drum 13 side, the device can be applied easily also to an existent device. |
