| 摘要 |
PURPOSE: To provide an electrifying member excellent in electrifying property and quietness and to provide an electrifying device using this member by control ling the electrostatic capacity and surface roughness of an electrifying member to specified values or smaller. CONSTITUTION: The electrostatic capacity of the electrifying member is controlled to <=1×10<-9> F, preferably <=8×10<-10> F, and more preferably <=6×10<-10> F. To decrease the electrostatic capacity, it is necessary to make the member to have a smaller dielectric const. or to be thin or with a small area. Namely, a material having the dielectric const. as low as possible is selected for the electrifying member and the member is made thick with a small contact area. The surface roughness, in the term of 10-point average roughness Rz according to JIS, of the electrifying member is controlled to <=20μm, preferably <=10μm, and more preferably <=6μm. Further, the electrifying member has such a structure comprising a shaft and an elastic layer around the shaft, and the elastic layer has a structure comprising at least an inner layer of a foamed material and an outer layer of an elastomer.
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