| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device by which high quality image is formed by forming a uniform thin layer of electrified toner onto a developer carrier without a layer regulating blade. SOLUTION: The developing device 10 includes a developing roller 1 which holds toner 8 and conveys it to a developing area opposite a photoreceptor drum 7 during a developing operation, and an electrifying roller 5 to which a DC voltage and an AC voltage are applied during the developing operation. The electrifying roller 5 is freely rotatably disposed upstream of the developing area in the direction of the rotation of the developing roller 1 with a predetermined gap of not less than 40μm but not more than 250μm left from the developing roller 1. The developing roller forms a thin layer of toner 8 with uniform thickness onto the developing roller 1, and uniformly electrifies the toner 8 present between the developing roller 1 and the electrifying roller 5 itself. COPYRIGHT: (C)2005,JPO&NCIPI |
