| 摘要 |
<P>PROBLEM TO BE SOLVED: To make the enhancement in the uniformity of electrification compatible with the prolongation of the life of a photoreceptor drum (ORG) in an image forming apparatus having a contact type electrifying device. <P>SOLUTION: Primary electrifying bias is varied to enhance potential convergence as the service of a body to be electrified progresses (DC→AC+DC, making an AC current high). The service state is judged based on the revolving speed of the drum, the total number of image forming sheets, an inflow current from an electrifying member, the film thickness of a photosensitive layer, and potential fluctuation at the time of rotating the drum or the like. It is also good to vary control according to an image forming mode (characters and photographs or the like, or resolution, printer and Fax mode or the like). <P>COPYRIGHT: (C)2003,JPO |
