| 摘要 |
PURPOSE:To obtain vivid images with a nonmagnetic developer in the contact developing method by providing a control electrode member in the gap between a developing roll and a carrying roll and generating an alternating electric field between the control electrode member and the carrying roll and generating a DC electric field between the control electrode member and the developing roll and performing contact development with the nonmagnetic developer. CONSTITUTION:A control electrode 12 is provided in the gap between a developing roll 3 and a carrying roll 4 and is connected to a DC power source 13. An AC bias voltage is applied to the carrying roll 4 in a developer hopper 2 by an AC power source 11. The roll 4 carries a stuck nonmagnetic toner while controlling its layer thickness by a trimmer 6. The control electrode member 12 consisting of plural conductive wires generates the alternating electric field between the carrying roll 4 and the control electrode member 12 and prevents influences of the AC bias voltage upon the developing roll 3. The toner is electrified when passing the member and is stuck uniformly onto the developing roll 3. A bias voltage higher than the bias voltage applied to the member 12 is applied to the developing roll 3, and a latent image on a latent image carrier 1 is developed in the contact developing method. |
