| 摘要 |
PROBLEM TO BE SOLVED: To prevent a drum fogging phenomenon and a staining phenomenon from occurring. SOLUTION: The developing roller has a conductive shaft 11a, an elastic layer 11b made of urethane rubber and a surface hardening treated layer 11c formed by performing surface treatment with isocyanate solution for the surface of the elastic layer 11b. Electronic conduction material is added to the elastic layer 11b by 0.1 to 5 pts. wt. in total amount. The resistance value of the elastic layer 11b is set in the range of 1×10<SP>3</SP>to 1×10<SP>6</SP>[Ω]. Since the elastic layer 11b whose compression set is small is formed, a nip mark is not formed even when the developing roller 11 is left for a long time in a state where it is still brought into press-contact with an image carrier and a developing blade. COPYRIGHT: (C)2005,JPO&NCIPI |
