Patent ID: 9274453
Filing Date: 2016-03-01
CPC Classification: G03G

Claim Text:
1. A developing roller comprising: a roller main body disposed to face, without contact, an outer circumferential surface of an image carrier, wherein in the roller main body, a boehmite layer of 0.2 to 1.0 μm in thickness has been formed on an outer circumferential surface of a base body that is made of a metal including aluminum, by a surface treatment by a boehmite method, and a resin coat layer of 5.3 to 6.1 μm in thickness has been formed on a surface of the boehmite layer, the resin coat layer being made of a resin material having electric conductivity, a product of resistance component Rs [Ω] and electrostatic capacitance component Cs [F] in AC impedance Z of the roller main body is in a range from 8.0×10 the resin coat layer is formed from nylon resin which contains 50 to 125 parts by weight of titanium oxide in a dispersed state, and surface roughness Ra of the resin coat layer of the roller main body is in a range from 0.21 to 0.26 μm.