| 摘要 |
PURPOSE:To obtain high-level image qualitys stably by providing a preprocessing means which is arranged at the upstream side of a development area and at the downstream side of a layer thickness control member so that it can be pressed against a developer carrier and performs the removal of an unnecessary charge on the developer carrier and the electrostatic recharging of a developer. CONSTITUTION:The preprocessing means 8 is arranged at the upstream side of the development area and at the downstream side of the layer thickness control member 6 in a developer conveyance direction so that it can be pressed against or contact the developer conveyor 1, and this preprocessing means 8 removes an unnecessary charge on the developer conveyor 1 and charges the developer again electrostatically. Thus, the unnecessary charge on the developer conveyor 1 is removed before development and the developer is charged again to discharge the surface of the developer conveyor 1 made of an insulating material which is difficult of electrostatic discharging uniformly and securely for development, and the charge of the developer is adjusted properly right before the development. Therefore, even when nonmagnetic single-component toner is used, an image defect such as stripes irregularity of discharging, charge irregularity of toner, etc., is suppressed, thereby obtaining high-level picture quality stably. |
