| 摘要 |
PROBLEM TO BE SOLVED: To simply and accurately control a toner concentration of the developer stored in a developing unit.SOLUTION: A developing device estimates an amount of carriers in a developing unit on the basis of a discharge amount accumulated value of carriers in the developer discharged from a discharge port of the developing unit and a supply amount accumulated value of the carriers calculated by taking account of the content of carriers changed according to a toner residual amount in a toner cartridge that is included in toner per unit flow rate supplied from the toner cartridge to the developing unit, estimates a developer storage amount in the developer unit on the basis of the estimated amount of carriers and a toner concentration of the developer in the developing unit, calculates an output target value of the sensor changing an output value according to the toner concentration in the developer on the basis of the estimated developer storage amount in the developer unit, and controls a toner supply amount to the developing unit so that the sensor output value matches the output target value.SELECTED DRAWING: Figure 3 |
