| 摘要 |
PURPOSE:To prevent scatter of toner during, before and after transfer, formation of a filming layer on the surface of a transfer belt, contamination inside a device, and soiling of the heat roller and backup roller of a fixing device, in an image forming device employing a belt transfer system. CONSTITUTION:The lower roller 7b of a pair of regist rollers is made of metal, the rotary shaft of the roller is grounded, the roller is driven following the other to carry paper 6, after passing the regist rollers, to the transfer belt 8 while preventing the electrification of the rear surface of the paper 6. A control circuit 15 receives a signal from a paper-thickness sensor 16. When the paper 6 is thick, it transmits control signals to the drive power source 22 of an exposure device 3 and the operation circuit 14 of a developing device 4, thereby reducing exposure intensity, a development bias voltage, and the circumferential speed of a developing roll, and controlling an amount of development toner. |
