| 摘要 |
PURPOSE:To form sharp images by providing a control electrode member between a developing roll and a carrying roll and electrifying a nonmagnetic developer with an AC electric field while oscillating it and electrifying the developer uniformly with one polarity by a DC electric field. CONSTITUTION:A control electrode 12 consisting of conductive wires or the like which is connected to a DC power source 13 is provided in a prescribed gap between a developing roll 3 and a carrying roll 4, and an insulating nonmagnetic developer 5 is electrified by the AC magnetic field due to an AC bias voltage applied to the roll 4 from an AC power source 11 while being oscillated, and therefore, the developer is not flocculated. Meanwhile, the developer 5 electrified with a prescribed polarity by the DC electric field between the roll 3 to which a DC bias voltage is applied from a DC power source and the electrode 12 which intercepts the AC electric field is electrified uniformly when passing the electrode 12, and a uniform developer layer is formed on the roll 3. The developer which is not flocculated and has the prescribed polarity and a uniform electrification quantity is flied to a latent image carrier to form a vivid image. |
