| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing roller capable of highly achieving both of suppression of fusion due to long-term use and suppression of initial filming, and capable of obtaining images of uniform density from the beginning of use to the end of long-term use, and an image forming apparatus and a process cartridge using the same. SOLUTION: The developing roller 4 comprises a conductive shaft and an elastic layer and a surface layer sequentially disposed on the conductive shaft, wherein the surface layer contains at least a urethane resin and carbon black, wherein a content of the carbon black is 15.0-25.0 parts by mass based on 100.0 parts by mass of the urethane resin, an arithmetic average of area-equivalent diameters of the carbon black is 21.0-27.0 nm, and a degree of skew in the distribution of the area-equivalent diameters of the carbon black is 0.25-0.63. COPYRIGHT: (C)2008,JPO&INPIT |
