摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing roller for an electrophotographic apparatus that has excellent toner conveyability and suppresses adhesion of toner after enduring high-number of conveyance to have excellent durability. <P>SOLUTION: A developing roller for an electrophotographic apparatus includes a rubber elastic layer 14 on an outer periphery of a shaft body 12, and the rubber elastic layer 14 has recesses and protrusions on the surface thereof. The arithmetic average roughness Ra of the surface of the rubber elastic layer 14 is set to 0.8 to 2.0 μm; the ten-point average roughness Rz is set to 15 to 40 μm; and the surface area ratio S/S0 of the rubber elastic layer 14 is set to 4.0 or more. Note that S is the actually-measured surface area of the rubber elastic layer 14, and S0 is the theoretical surface area provided that the surface of the rubber elastic layer 14 is a flat surface. <P>COPYRIGHT: (C)2013,JPO&INPIT |