| 摘要 |
PROBLEM TO BE SOLVED: To downsize a developing device and improve the developing performance by providing magnetic poles, which extends in parallel to the axis, in such a state as arranging the N, S alternatively in the circumferential direction on a permanent magnet member formed into a cylindrical shape and providing, at least, a resin layer of a specific thickness containing conductive particles around the circumferential face. SOLUTION: A permanent magnet member 4 is formed of a semiconducting or insulating, for example, isotropic ferrite magnet, and a plurality of magnet poles extending axially are provided around the outer circumferential face, formed into a cylindrical shape, and rotatably provided in the bottom of a developer tank 1. A resin layer containing conductive particles is coveringly stuck on the surface of this permanent magnet member 4. Namely, the magnetic poles extending in parallel to the axis are provided with their N, S arranged alternately on the permanent magnet member 4, which is fanned into a cylindrical shape, and, at least, the resin layer of 10-1000μm in thickness and containing the conductive particles is coveringly stuck to the circumferential face. This constitution can provide an image without any fogging, dust, fine line, and density ununiformity even in using a small-size developer support means having a structure of no sleeve. |
