| 摘要 |
PROBLEM TO BE SOLVED: To rapidly reflect toner concentration detected by a magnetic sensor in supplied toner and to perform accurate and stable toner concentration control by providing a means for allowing a toner supply device to intermittently execute toner supply operation. SOLUTION: The toner supplied from a toner supply part is stirred by a stirring screw, and it is mixed with the developer while it is stirred and carried together with the developer. Then, a control part 18 intermittently tunrs on/off a toner supply clutch 21 at the time of making the toner supply device 20 supply the toner based on an output value from the magnetic sensor 16 so that the toner may be supplied succeedingly by choosing the time when the toner supplied previous time does not remain in the toner supply part by finely supplying the toner from the toner supply part plural times. Thus, the time required for uniformly mixing the toner with the developer in a developing device 19 is shotened. |
