Image forming apparatus

Abstract

A developing apparatus is provided in which the concentration of a toner in a developer material and the amount of developer material is kept constant by the use of simple mechanical parts so as not to deteriorate the electrification performance of the developer material. In the image forming apparatus of the present invention, a pocket 25 of a discharged developer material weighing part 20 receives a discharged developer material discharged from a developer material discharge port 14. Each time the accumulated weight thereof reaches a prescribed weight, the discharged developer material thus received is discharged into a discharged developer material receiving part 30, and this discharge is detected by a sensor 27. An unillustrated control unit counts this detection and calculates an amount of carrier decreased. Based on this result, a carrier supply roller 13 of the replenishment device is driven to replenish the carrier. On the other hand, the consumption of the toner is detected by a toner concentration sensor, and the control unit replenishes the toner by means of a replenishment device 10. The mixing ratio by weight of the toner and the carrier in the developer material and the amount of the developer material held in each of developer material supply, path sections 5, 6 are kept constant under the control operation of this control unit. As a result, the formation of excellent images can be continued for an extended period of time.

Dependencies are inferred from the claim text.