| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device in which the surface of a developer carrier, located especially downstream in a developer conveyance path, can be stably coated with a uniform thin layer of developer even when one-component magnetic toner is used. SOLUTION: The developing device includes the first and second developer carriers 3a and 3b having magnetic members 30a and 30b respectively. The magnetic field generating means 30a and 30b have the first magnetic pole of the first developer carrier 3a, disposed near a photoreceptor drum 1, and the second magnetic pole of the first developer carrier 3a and the third magnetic pole of the second developer carrier 3b, disposed near the area where the first and second developer carriers 3a and 3b are near to each other. The magnetic field generating means 30a and 30b have the fourth magnetic pole disposed between and adjacent to the first and second magnetic poles. The means 30a and 30b also have the fifth magnetic pole disposed downstream of the second magnetic pole in the rotating direction of the first developer carrier 3a and adjacent to the second magnetic pole. The polarities of the first magnetic pole and fourth magnetic pole are different. The polarities of the second magnetic pole and fourth magnetic pole are different. The polarities of the second magnetic pole and third magnetic pole are different. The polarities of the second magnetic pole and fifth magnetic pole are the same. COPYRIGHT: (C)2007,JPO&INPIT |
