Charging member having a foamed layer of a material with specified density and pore properties, charging device, process cartridge and image forming apparatus featuring the charging member

摘要

A charging member for charging a member to be charged includes a foamed layer; a supporting member for supporting the foamed layer, and for being supplied with a voltage; a resistance layer closer to the member to be charged than the foamed layer; wherein the foamed layer has a specific gravity not less than 0.1 (g/cm.sup.3) and not more than 0.6 (g/cm.sup.3), and wherein an average outer diameter of pores in a cross- section of said foamed layer is not less than 50 microns and not more than 1 mm.