| 摘要 |
PURPOSE:To obtain a vivid image stably, by making the charge quantity of a nonmagnetic one-component developer uniform in a developing device where plural grid members parallel with one another are provided between an electrostatic latent image carrier and a developing member. CONSTITUTION:A counter electrode 12 is provided to face to a developing roller 4 between a developer supply part and a grid wire 6, and a DC power source 13 which outputs the same voltage as a DC bias power source 11 whose voltage is applied to the developing roller 4 is connected to this counter electrode 12. In the place where the developing roller 4 and the counter electrode 12 face to each other, the same DC voltage is applied to the developing roller 4 and the counter electrode 12, and an AC voltage is applied to the developing roller 4, and therefore, an AC voltage difference due to an AC power source 10 is generated in this place. Consequently, a toner (d) is reciprocated between the developing roller 4 and the counter electrode 12 in accordance with this AC voltage and is charged frictionally up to a potential suitable for contactless development. |
