| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device capable of forming an image of uniform density by suppressing a change in the electrified statical charge (q/m) of toner carried on a developer carrier and suppressing an afterimage phenomenon. SOLUTION: Provided that Q1 denotes the average statical charge of the electrified toner just after passing through the counter area between a developing roller and a photoreceptor drum when a potential difference between the developing roller 402 and the surface of the photoreceptor drum 1 is 0 V, and Q2 denotes the average charge quantity of the electrified toner just after passing through the counter area between the developing roller and the photoreceptor drum in a state where a developing bias is applied to the developing roller and the potential on the photoreceptor drum surface is equal to a non image part potential, developing is performed under such a condition that the relation of |Q2|-|Q1|/|Q1|<=±0.45 is satisfied. Then, a rate of change in the charge quantity (q/m) of the electrified toner carried on the surface of the developing roller becomes <=45%, the afterimage ratio R becomes <=2%, then, the afterimage phenomenon is suppressed, and the change in the toner density of the toner image is suppressed within the allowable extent. |
