Patent ID: 7580655

Claim:
A charging roller comprising: a support; an elastic layer that is provided on the outer peripheral surface of the support, the elastic layer having a ground-finished outer peripheral surface; and a surface layer that is formed to cover the outer peripheral surface of the elastic layer and that has a thickness of about 2 μm to about 10 μm from the outer peripheral surface of the elastic layer, and a proportion of water absorbed in the total of the elastic layer and the surface layer, after storage for 48 hours in an environment having a temperature of 10° C. and a humidity of 15% RH, being about 2% to about 8% by weight, and a proportion of water absorbed in the total of the elastic layer and the surface layer, after storage for 48 hours in an environment having a temperature of 28° C. and a humidity of 85% RH, being about 2% to about 8% by weight.