Patent ID: 7570905
Filing Date: 2009-08-04
Classification: G03G

Abstract:
1. A developing roller having an elastic layer on the outer periphery of a mandrel and having a surface layer containing a resin and resin particles on the outer periphery thereof, wherein the surface layer has a convex portion attributable to the resin particles, and has a surface of roughness in which a distortion degree Rsk of a roughness curve is 0.15 or more and 0.70 or less, wherein the resin particles have a peak P where, “a” denotes a volume fraction of the resin particle having the particle diameter d wherein, “A”, “t” and “B” satisfy the following formulas: where, “A” denotes a blending quantity of the resin particle relative to the resin 100 parts by mass, “t” denotes the thickness of the surface layer in microns, and “B” denotes the volume fraction of the resin particle having a particle diameter not less than 1.2 times the thickness of the surface layer in the volume particle size distribution.