| 摘要 |
PURPOSE:To eliminate scattering of a toner, fog, and an uneven development density by applying a voltage whose polarity is opposite to that of a transfer means, between a developer carrying body and a cylindrical elastic body, in a period in which a development is not executed. CONSTITUTION:When an electrostatic latent image which has been minus-electrified on a photosensitive drum 22 has been opposed to a developer 28 which has been plus- electrified on a developing roller 34, the developer 28 is scattered by an electrostatic force of the electrostatic latent image on the photosensitive drum 22 and can develop its latent image. After the development has been executed, the developer 28 which has adhered onto the surface of the developing roller 34 is scraped down by a fur brush 35, and also, in a period in which the development is not executed, the polarity of the second DC high voltage power source 42 is switched, and between the developing roller 34 and the fur brush 35, a voltage whose polarity is opposite to that of the time of development is applied. As for an applied voltage in this case, about 30V-250V is desirable, a surplus developer on the developing roller 34 is attracted to the fur brush 35 side by an electric field, and a development hysteresis on the developing roller 34 is erased. In this way, an image of a high quality having no ghost can be obtained. |
