| 摘要 |
PURPOSE:To obtain an image forming device having a simultaneous developing- and-cleaning system where the miniaturization of the device, reduction in weight and, in addition, reduction in cost can be achieved, toner replenishment is only required and the need for the disposal of recovered toner is eliminated, and maintenance is grealy improved. CONSTITUTION:The condition for transferring toner 28 to a photosensitive body exposure part 27a from a developing roller 21 by bringing a developing roller 21 into contact with a photosensitive body 27 is >=150V development potential. The condition for transferring residual toner 34 on a photosensitive body unexposure part 27a to the developing roller 21 is >=300V cleaning potential. In addition, the length of time when a bias is applied to the developing roller 21 is defined from the time when the formation of a latent image on the photosensitive body 27 is started after the actuation of an exposure device to the time when the transfer of a toner image on the photosensitive body 27 to a transfer sheet 12 by the use of a transfer charger 13 is finished. At the time of rotating the photosensitive body 27 and the developing roller 21 other than that time, only an electrifier 30 is operated. Thus, cleaning performance is remarkably improved. |
