| 摘要 |
PROBLEM TO BE SOLVED: To surely remove faultily electrified developer and to excellently form an image by controlling so that a potential difference between surface potential at the time of forming an image and bias voltage on a developer carrier may be a potential difference in accordance with the characteristic of the faultily electrified developer and recovering the faultily electrified developer on an electrostatic image carrier. SOLUTION: The rising of the bias voltage to a developing roller is started from the point of time B when time (T1+T2) elapses after the point of time A when the rising of the surface potential Vo of a photoreceptor is started. At the point of time B, a fogging potential difference is -2.50 V and reversely electrified toner adheres to the photoreceptor and carrier does not adhere to it. Hereafter, the normally electrified toner is made to adhere to the photoreceptor till the point of time C when the fogging potential difference reaches -20 V. Thereafter, the fogging potential difference of -20 V is maintained till the point of time D when the bias voltage reaches -400 V, while the toner not electrified yet adheres to the photoreceptor. Then, the faultily electrified toner is made to adhere to the photoreceptor and is forcibly discharged to the outside of a developing device before development. |
