| 摘要 |
PROBLEM TO BE SOLVED: To simplify the constitution of a toner recovering device and to secure toner conveyance while optimizing the size of a device main body and satisfying the quality, performance, and function of a cleaning means by controlling the driving of a screw pump according to the detection result of a toner replenishment quantity detecting means. SOLUTION: The driving of the screw pump is controlled according to the detection result of the toner replenishment quantity detecting means. The toner recovering device is placed in operation by sending signals to a driving motor 542 and an air pump 532 fitted to a powder pump unit 520 of the toner recovering device when the amount of toner that a developing means is replenished with reaches a certain value. In this case, when the powder pump unit 520 begins to be operated, only the air pump 532 is operated precedently to discharge recovered toner left in a pipe 400 for recovered toner conveyance only with air or only the air pump 532 is operated after the pump unit 520 stops operating to nearly empty the recovered toner conveyance pipe. |
