ELECTRIFYING ROLLER, ELECTRIFYING DEVICE, IMAGE FORMING DEVICE AND PROCESS CARTRIDGE

PROBLEM TO BE SOLVED: To improve electrifying uniformity in DC electrification, especially, unevenness in a horizontal stripe state by simple means constitution having no destaticizing means 12 such as a pre-exposure device in a roller electrifying system + DC electrifying system, and to secure uniform electrifying property having no unevenness at the time of outputting a halftone image even under low-temperature and low-humidity environment with simple constitution where the destaticizing means 12 such as the pre-exposure device is omitted in an image forming device adopting the roller electrifying system + DC electrifying system. SOLUTION: The electrifying roller set so that the correlation coefficient R of V-I characteristic measured by a specified V-I characteristic measuring method is >=0.95 and =0.4×10 and 1.5×10 (A/V).