| 摘要 |
PROBLEM TO BE SOLVED: To prevent layer thickness from being faultily regulated because developer amount in a developing container gets too small with simple constitution. SOLUTION: When toner concentration obtained by detecting two-component developer in the developing container V gets high, the developer amount in the container gets large, so that the developer accumulated in a state where a developer discharge port 7 is covered with the developer is reduced by making the carrying speed of a discharged developer carrying member R5 high. Since the developer amount discharged from the port 7 gets large, the developer amount in the container is prevented from getting large. When the toner concentration gets low, the developer amount in the container gets small, so that the developer accumulated in the state where the port 7 is covered therewith is increased by making the carrying speed of the member R5 low. Therefore, since the developer amount discharged from the port 7 gets small, the developer amount in the container is prevented from getting small. |
