| 摘要 |
PROBLEM TO BE SOLVED: To reduce variance in the electric resistance of a conductive elastic layer in a circumference direction by providing specified electric resistance between a rotary shaft and the outer peripheral part of the conductive elastic layer and setting a ratio between the maximum and minimum values of electric resistance in the circumferential direction equal to a fixed value or lower. SOLUTION: Electric resistance between the rotary shaft 12 of a conductive roller 10 and the outer peripheral surface 11 of a conductive elastic layer is regulated to 10<3> to 10<9>Ωcm. This range varies depending on a place for using the conductive roller 10 or the like, but when this is set lower than 10<3>Ωcm, if a large current is supplied to the rotary shaft 12 because of an accident or the like, electricity is passed through the conductive elastic layer to an outer surface to cause an image failure or damage part items, and on the other hand, if electric resistance exceeds 10<9>Ωcm, static electricity generated by friction with an opposite member is charged to the surface of the conductive roller to cause an image failure. Further, by setting a ratio between the maximum and minimum values of electric resistance in a circumferential direction equal to 10 or lower, an image having no uneven gradation is stably provided. |
