| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device which suppresses a damage which may be caused to toner in the contact nip region between a development roller and a photosensitive drum, while maintaining a sharp and clear image with sufficient image density and substantially free from production of fog, thereby accomplishing long term usability. SOLUTION: A peripheral speed of the development roller 11 is not less than 1.05 times and not more than 1.20 times a peripheral speed of the photosensitive drum 2, and an arithmetic average roughness Ra of the surface of the development roller 11 is not less than 0.20 times and not more than 0.33 times a volume average particle size of the toner. A potential applied to a supply roller 13 is on the toner's normal charge polarity side of a potential applied to the development roller 11. COPYRIGHT: (C)2007,JPO&INPIT |
