| 摘要 |
PROBLEM TO BE SOLVED: To provide a development device for image formation which will not deteriorate the charging properties of toner by preventing field concentration due to surface roughness, is free from filming phenomenon on the surface of a toner bearing member even on a long-term basis, excels in toner transport property, as well as in image uniformity, and can suppress voltage drop on the surface of a developing roller. SOLUTION: The development device for image formation is a developing device for color image formation comprising the toner bearing member, wherein the toner bearing member comprises a core to which voltage can be applied, the core having a surface roughened so as to have ruggedness; and a ceramic covering layer, having high dielectric property or high resistance disposed on a roughened surface of the core, wherein the thickness (t<SB>1</SB>) of the ceramic covering layer on convex portions in the core surface is made larger than the thickness (t<SB>2</SB>) of the ceramic-covering layer on concave portions. COPYRIGHT: (C)2007,JPO&INPIT |
