| 摘要 |
PURPOSE:To prevent the occurrence of the explosive scatter of toner without intensifying transfer bias at the second time of image formation, regarding an image forming device where an image is twice formed on the same transfer material. CONSTITUTION:A photosensitive drum is charged to dark section potential VD (-600V in the graphs (a) and (b)) at both of the first and second times of image formation, and an image is exposed to keep an image section at light section potential VL (-150V). Development bias is kept at -450V during the first image forming process and at -400V during the second image forming process. Development contrast VC at the second process (or absolute value of (¦VDC2-VL¦) is thereby kept lower than at the first process by 50V. As a result, an amount of toner T adhering to the light section of photosensitive drum surface is reduced. At the same time, the explosive scatter of the toner is reduced. |
