DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To prevent a developer in a developer supply chamber from becoming excess for a long period of time with a simple configuration in a developing device in which a developer storage chamber for storing a supply developer is disposed above the developer supply chamber for supplying the developer to a developer carrier.

SOLUTION: The developing device includes: the developer supply chamber 102 for supplying developer to a developing roller; the developer storage chamber 101 above the developer supply chamber; a developer supply port 111 formed in a partition member 110 between the developer supply chamber and developer storage chamber; a storage chamber screw vane member 106 for stirring and conveying developer above the partition member; and a supply chamber screw vane member 108 for stirring and conveying developer below the partition member. The partition member is provided with a return port 107 for returning the developer from the developer supply chamber to the developer storage chamber. The supply chamber screw vane member is disposed so as to pass directly below the return port. The direction of inclination of the screw vane is reversed directly below the return port so that developer is conveyed from both side in the direction of an axis toward and directly below the return port.

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