To prevent the electrostatic charge quantity of a photoreceptor drum from being change due to the change of resistance value of an electrifying roller caused by environmental change, especially, humidity change, and to set an electrifying roller resistance to an arbitrary value.
The electrifying roller 11 is constituted of a conductive shaft 21, an intermediate layer 22 consisting of an ionic conductive semiconductive material covering the conductive shaft 21, and an electron conductive protective layer 23 where carbon and filler are dispersed. Since the protective layer 23 of the electrifying roller 11 composed of an electron conductive material, the resistance of the electrifying roller 11 does not change even if there is an environmental change during electrification, and the electrostatic charge quantity on the photoreceptor drum is not largely changed. It is easy to set a resistance of the electrifying roller 11.
| JP3950524 | ELECTROPHOTOGRAPHIC DEVICE AND PROCESS CARTRIDGE |
| JP4807973 | Image forming device |
| JPS6085 | CORONA DISCHARGER |
ANDO KOICHI
MIZUTANI TAKAO
ISODA MASAO
Next Patent: ROLLER FOR ELECTROPHOTOGRAPHIC SYSTEM