| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a shaft part is worn when using a shaft integrated type magnet roller, consequently, a developing sleeve becomes eccentric to cause an image defect. SOLUTION: By regulating the outside diameter of the shaft part of the magnet roller and the length in a shaft direction of a bearing, the shaft part is prevented from being worn, and the eccentricity of the developing roller is prevented, whereby the image defect is eliminated. The developing roller is equipped with at least the shaft part integrated type magnet roller obtained by a manufacture method including a stage in which melted mixture containing ferromagnetic powder and resin binder is molded by the application of magnetic field, a sleeve, a flange and the bearing, and the dimension A of the maximum outside diameter of the shaft part of the magnet roller and the length B in the shaft direction of the bearing satisfy relation; B≥0.8×A. Then, the material of the bearing contains a sliding resin. COPYRIGHT: (C)2008,JPO&INPIT |
