| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in which, in a contact system where toner is developed by the contact of a photoreceptor drum and a developing roller, the developing roller of an electrophotographic image forming apparatus comes into contact with a developing blade, a toner supply roller, etc., in addition to the photoreceptor drum, in the case of which, if the surface of the developing roller is hard, the pressure of the developing roller on the members which are in contact with it increases, with the result that the toner on the developing roller may deteriorate and fuse (cause filming) on the surface of the developing roller. SOLUTION: When the JIS-A hardness of the elastic layer 6b of the developing roller 6 is H<SB>A</SB>[degrees], and the dynamic hardness of the surface layer 6c of the developing roller 6 is H<SB>S</SB>[mN/μm<SP>2</SP>], a relation between them satisfies H<SB>A</SB>×H<SB>S</SB><15. This relation restrains filming. COPYRIGHT: (C)2006,JPO&NCIPI |
