| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing roller improved in fog during long-term printing and to provide an electrophotographic process cartridge and an image forming apparatus equipped with the roller. SOLUTION: The developing roller comprises a conductive shaft body and at least one layer of elastic layer provided around the conductive shaft body, and is characterized in that: the outermost surface layer of the developing roller contains biconvex lens-like particles; and the biconvex lens-like particles satisfy following formulae (a) to (f) relating to the film thickness Tμm of the outermost surface layer and an average major diameter Xμm and an average minor diameter Yμm of the biconvex lens-like particles. (a):0.5≤T/Y≤2.0, (b):4μm≤T≤14μm, (c):2μm≤Y≤7μm, (d):1.5≤X/Y≤2.0, (e):(average distance between particles)≤30μm, and (f):orientation degree (θ)≤30 degrees. COPYRIGHT: (C)2009,JPO&INPIT |
