Patent ID: 7171141

Claim:
A charging roller for a contact charging assembly, said charging roller comprising: a conductive substrate; an elastic layer which covers the periphery of the conductive substrate; and a seamless tube externally so fitted as to cover the periphery of the elastic layer, wherein said charging roller has a surface of 3.0 μm or less in ten-point average roughness Rz jis 94, and 0.04 mm or more and 0.10 mm or less in roughness curve average length RSm, and wherein said seamless tube constitutes a surface layer of the charging roller, said seamless tube comprising: (A) a thermoplastic styrene elastomer; and (B) a high-impact-resistant polystyrene (HIPS) containing rubber particles, wherein a proportion of the component (A) to the composition (B) is (A)/(B) in a range of 80/20 to 40/60 in weight ratio.