Sanyo Electric Co., Ltd.

Akihiko Fujio

Hiroshi Iwaki

Kunio Tsuboi

Akihiko Sutoh

A developing apparatus comprises a container in which a developer composed of a mixture of carrier and toner is stored and a screw conveyor for transferring and stirring the developer is disposed. The screw conveyor has a stirring blade formed in a spiral shape, and the stirring blade is cut out at nearly the center of the screw conveyor so that stagnation of the developer takes place at that interrupted portion thereof. A level sensor is disposed so as to be able to detect the level of the developer at that interrupted portion. In the interrupted portion, since stagnation of the developer takes place, pulsation of the developer produced in the case of the screw conveyor having a continuous stirring blade is suppressed, and thereby a level of the developer can be detected more accurately. This means that when toner density is increased, fluidity of the developer is reduced, and in the interrupted portion, the level of the developer rises by an amount larger than an increment of volume of the developer due to a relative increase in toner to carrier. In reverse, when the toner density is reduced, the fluidity of the developer is increased, and in the interrupted portion, the level of the developer falls by an amount larger than a decrement of volume of the developer due to a relative decrease in toner to carrier.

Growing community of inventors

Hyogo, Japan

Akihiko Fujio