| 摘要 |
PURPOSE:To obtain high-quality image by keeping a difference between a developing bias voltage contributed to development and a residual potential on the surface of a photosensitive body equal to or more than a fixed value and making a time from exposure to development within a specified time. CONSTITUTION:A photosensitive drum 10 is electrostatically charged by an electrostatic charger 11 and toner is made to adhere to the durm 10 by a developing device 12, then a toner image on the drum is transferred to a paper by an electrostatic charger for transfer 23. Residual toner is removed by a cleaner 24 and the photosensitive drum 10 is destaticized by a lamp 25. In such a case, a difference between the residual potential of the surface of the photosensitive body and the developing bias potential is set to be at >=150V and the time from the exposure to the development to the photoensitive body is selected to be within 0.05-0.2 seconds. Since the drum is miniatur ized, an exposure time is shortened and the difference between the developing bias potential contributing to the development and the residual potential of the surface of the photosensitive body is kept equal to or more than the fixed value even when the surface potential of the photosensitive body rises, white fogging is prevented in a regular developing system and the lowering of image density is prevented in a reverse developing system, thereby obtaining the high-quality image. |
