| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device self-control toner concentration which can eliminate failures such as an abnormal image irregular density or the surface staining of the formed image being caused by dispersion in toner concentration in developer on a developer carrier. SOLUTION: This developing device is provided with a developer regulating member 12 for regulating the amount of developer fed in a state where it is carried on the outer peripheral surface of the developer carrier 6, a developer storing part 3 for storing the developer regulated by the developer regulating means, and a toner storing part 4 supplying the toner to the developer on the peripheral surface of the developer carrier through a coupling part by coupling and communicating with the upstream side position of the developer storing part through a coupling part 5 whose aperture area is narrow. In the device, the toner concentration in the developer carried by the developer carrier is held constant, by changing the contact state of the toner positioned in the coupling part with the developer on the developer carrier according to the change of the toner concentration in the developer carried by the developer carrier, and at least two electrodes 21a and 21b are arranged facing opposite each other in the coupling part, and alternating electric field is applied to the coupling part from both electrodes. |
