| 摘要 |
PURPOSE:To recover a residual toner existing on a sleeve, to simplify a device, and to obtain it at a low cost by switching the polarity of a bias voltage of a developing sleeve, and executing an inversion development and a cleaning by the same device. CONSTITUTION:A developing and cleaning device 39 is constituted of a developing sleeve 51, a bias applying means 52 and a destaticizing lamp 53, and the same device is provided at every color. In case of the development, for instance, with repsect to a drum 33 charged electrostatically to +800V, +700V of the same polarity is applied to the sleeve 51 from a terminal 1, a toner 55 of possitive charge is transferred by a potential difference of 600V, and an inversion development is executed. In the cleaning process, destaticization is executed by lighting the destaticizing lamp 53, -700V of the opposite polarity is applied to the sleeve 51, and a residual toner is recovered by generating a potential difference of 780V to the surface of a photosensitive body. Therefore, the device is simplified, and it is obtained at a low cost. |
