| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device capable of obtaining an image of high quality without a ghost and with equal or smaller amount of fog for instance, as in the case where a contact type toner supplying roller is used even if a noncontact type toner supplying roller is used and remarkably prolonging the lives of toner, a developing sleeve and the supplying roller as well. SOLUTION: Since the noncontact toner supplying roller is used, a blank pulse is applied to the developing sleeve between it and a photoreceptor drum, as a developing bias, to improve capacity to scrape and supply the toner onto the developing sleeve. When the whole of a section (amplitude part) D where AC and DC voltages are superimposed and applied and a section (blank part) E which is continuous to the section D and to which only the DC voltage is applied is set as one cycle, the blank pulse is of a bias for repeating this cycle. |
