| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing roller which can uniformly disperse spherical particles on a surface layer, enhance mechanical strength of the spherical particles, and prevent damage to a member contacted with a surface of the developing roller compared with the configuration described in the patent document 1; a developing device, an image forming apparatus and a process cartridge which are provided with the developing roller; and an image formation method using the developing roller. <P>SOLUTION: A spherical particle 500 which is contained in a surface layer 51c of a developing roller 51 has a three-layer structure consisting of a substrate 501 composed of a spherical-shaped resin particle, an inorganic fine particle-containing layer 502 which coats the substrate 501 and contains inorganic fine particles 502a having a higher hardness than that of the substrate 501, and a resin layer 503 which coats the inorganic fine particle-containing layer 502 and has a lower hardness than that of the inorganic fine particles 502a. <P>COPYRIGHT: (C)2012,JPO&INPIT |
