| 摘要 |
PURPOSE:To easily control the magnetic force of a developing roller and to reduce the cost of the developing roller by arranging soft magnetic bodies on the side face of the magnetic pole parts of respective magnets constituting the developing roller. CONSTITUTION:The soft magnetic bodies 23 are arranged in grooves 25 on the side faces of the magnetic pole parts of respective magnets 22A-22D to be the constitutional elements of a magnetic roller 21 constituting the developing roller through non-magnetic bodies 26 in the center axial direction of the roller 21. Thereby, a part of the magnetic flux of the roller 21 is converged through the soft magnetic bodies 23 and magnetic force led from the magnetic poles to the outside is apparently reduced. Consequently, the magnetic force of the roller 21 can be changed easily and continuously. |
