| 摘要 |
PURPOSE:To facilitate developing by providing an electret having inverse polarity to toner on a supporting roller faced to a developing position in the inside of a belt photosensitive body. CONSTITUTION:The electret E having the inverse polarity to the toner is provided on the supporting roller 5a faced to a developing device 9 in the inside of the belt photosensitive body 6. The electret is the base stock of high polymer which can semipermanently maintain an electric polarization state by a high voltage. For example, even when a power source circuit which applies a bias voltage is not connected, the polarity can be maintained by the base stock itself. By providing the electret E in such a way, the toner T supplied to the latent image of the photosensitive body on a belt 4 from the developing device 9 is attracted to the latent image by attraction force by the inverse polarity. As the result the efficiency of the developing is improved and the density of the developing is enhanced. |
