| 摘要 |
PURPOSE: To provide a developing device capable of always and stably obtaining an excellent image, without increasing torque, even if a long-term copying operation of 500,000 sheets is executed by preventing a blotch phenomenon without increasing the advancing quantity of a closed-cell foam roller toward a sleeve and the circumferential speed of the closed-cell foam roller with respect to the sleeve, even if <=6μm fine grain toner is used. CONSTITUTION: A magnetic pole N1 is arranged at a position nearly facing a magnetic blade 5 and a magnetic pole N3 having the same polarity as that of the magnetic pole N1 is provided in adjacent to the pole N1 between a proximity part to the magnetic blade 5 and the approaching/contacting part of the closed-cell foam roller 6 with the developing sleeve 3, to form a repulsive magnetic field with the pole N1. |
