| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device capable of stably discharging a proper amount of a developer without forming an aggregate even when a developer decreases in flowability.SOLUTION: A projection part 307 when provided downstream in a rotating direction of a collar part 304 is provided within 90 degrees from a starting phase of a third spiral part 303. The projection part 307 when provided upstream in the rotating direction of the collar part 304 is provided within 30 degrees from the starting phase of the third spiral part 303. Thus, the projection part 307 is provided downstream in the rotating direction of the collar part 304 within a range of 90 degrees from the starting phase of the third spiral part 303 and upstream in the rotating direction of the collar part 304 within a range of 30 degrees, and a developer conveyed in a circumferential direction at the collar part 304 by the projection part 307 and falling to the side of the third spiral part 303 can be scooped and conveyed by a third conveyance blade 303a without fail before falling into a gap part. Consequently, the developer can be prevented from staying at the gap part and thereby stably discharged.SELECTED DRAWING: Figure 6 |
