Patent ID: 11156935

Abstract:
The developing member includes a substrate having an electroconductive outer surface; an insulating resin layer on the outer surface of the substrate; and electrically insulating domains on an outer surface of insulating resin layer, and has an outer surface including a surface of the insulating resin layer and surfaces of the domains, wherein a potential decay time constant of each of the surfaces of the domains is ≥60.0 seconds, and a potential decay time constant of the surface of the electrically insulating resin layer is <6.0 seconds, and assuming that the electrically insulating domains are orthographically projected onto the outer surface of the substrate, to obtain projection images of the respective domains, each of areas of the projection images is defined as S, and each of areas of convex envelopes of the projection images is defined as H, at least one of the domains satisfies 0.05≤S/H≤0.80.