| 摘要 |
PURPOSE:To enhance gradation using one component toner, and to perform development with high edge effect, by coating the surface of a developing roller with a resistor layer, such as silicone rubber, and using a plurality of electrodes adjacent to each other as charging means. CONSTITUTION:Conductive substrate 7 of developing roller 9 is coated with resistor layer 8, and bias voltage same in polarity to a static latent image is applied to substrate 7 with voltage source 16. First and second electrodes 12, 13 arranged at the outlet of toner hopper 10 are also used for doctors for regulating toner layer thickness on roller 9. Since voltage is applied between electrodes 12, 13 from power source 15, current flows from electrode 13 through the toner to electrode 12, resulting in charging the toner positively. This structure permits high edge effect development to be carried out using one component toner, gradation to be enhanced, and excellent copy quality to be obtained. |
