| 摘要 |
PROBLEM TO BE SOLVED: To prevent a high pressure from being applied on developer and to prevent the deterioration of the developer, irrespective of the long time use. SOLUTION: As for the developing device, a developing sleeve 11 with a built-in magnet roller 11 is arranged in the opening part of a developing unit 2a, and a developer control sleeve 30 with a built-in magnet roller 31 for controlling the layer thickness of the developer carried by the developing sleeve 11 is arranged in the developing unit 2a so as to be placed opposite to the developing sleeve 11. Among the repulsive poles N2 and N3 of the magnet roller 11 for the developing sleeve 11, a magnetic pole N11 having the same polarity as that of the repulsive poles N2 and N3 is arranged on the magnet roller 31 for the developer control sleeve 30 so as to be placed opposite to the magnetic pole N2 positioned on the downstream side in the developing sleeve 11 rotating direction. The rotating direction of the developing sleeve 11 is opposite to that of the developer control sleeve 30. |
