| 摘要 |
PURPOSE: To make possible the stabilization of the application of a charge to magnetic toner by arranging magnetic poles in a developing sleeve and a developer regulator, so as to obtain desired magnetic force. CONSTITUTION: The developer regulator 6a is arranged to be rotatable in the direction of the allow, that is, in the same direction as the rotational direction of the developing sleeve 1a in the vicinity of it. On the other hand, a permanent magnet 6b is provided with at least two or more magnetic poles and disposed in a part nearer to the downstream side than a position where the magnetic pole S61 in the permanent magnet 6b is magnetically balanced with the magnetic pole N11 in the developing sleeve 1a, in the rotational direction of the developing sleeve 1a and to the upstream side than a closest line P that links the centers of the developing sleeve 1a and the developer regulator 6a. Thus, a magnetic flux density in a developer regulating part is higher than that in the vicinity of the developer regulator 6a, so that the rate of change of the square of the magnetic flux density in the normal direction of a developer carrier is positive, that is, work in a direction where the toner is brought back in the developing unit is obtained. |
