ELECTROPHOTOGRAPHIC DEVELOPING ROLLER AS WELL AS DEVELOPING DEVICE, DEVICE UNIT AND IMAGE FORMING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an electrophotographic developing roller which is small in the dynamic fiction coefficient of its surface and is low in hardness and is therefore small in the stress onto toners T' and has high electrostatic charge impartability to the toners, a developing device, device unit and image forming device using the same. SOLUTION: The electrophotographic developing roller for transporting nonmagnetic one-component toners by adhering these toners to its surface has a conductive arbor, an electrostatic charge impartation layer which is formed on the surface of the developing roller and ahs the electrostatic charge impartability to the nonmagnetic one- component toners, a base layer which is formed in a position nearer the conductive arbor than the electrostatic charge impartation layer and has elasticity and an elastic intermediate lawyer which is formed in the position between the base layer and the electrostatic charge impartation layer. The contact angle of a composition for forming the elastic intermediate lawyer with water is smaller than the contact angle of the composition for forming the base layer with the water. The developing device, device unit and image forming device using the developing roller.