| 摘要 |
PROBLEM TO BE SOLVED: To make the concentration of toner and an amount of charged toner uniform in the axial direction of a developer carrier and also to make the degree of developer deterioration uniform, in a developing device of a self-supply system.SOLUTION: A developing device comprises: a circulation conveyance path that circulates and conveys two-component developer in the axial direction of a developer carrier 10 and, at the same time, supplies the developer to a periphery of the developer carrier 10; a restricting member 41 by which the amount of conveyed developer is restricted upstream of a development area in the direction of conveyance; and a toner hopper that supplies toner to a toner supply port 35a located in the axial end of the developer carrier 10 and apart from the development area and also located downstream of the restricting member 41 in the direction of conveyance. The higher the toner concentration of developer, the more the restricting member 41 restricts the developer. Toner supplied from the toner hopper is brought into contact with the developer in the toner supply port 35a and taken into the developer by the friction with carrier, is separated from the periphery of the developer carrier 10, on which magnetic force is weak, and is returned to a circulation conveyance path. |
