| 摘要 |
PURPOSE:To detect a service life of a process kit at the time point when there is no toner in a developing device and to eliminate the waste of a replenished toner by providing a counter which can read and write on a process kit which can replenish the toner and detecting the service life of the process kit by counting the number of times of replenishment of the toner. CONSTITUTION:A control part 8 increases the number of times of replenishment of a counter by '1' whenever a toner is replenished to a developing device 2, and at the time point when a toner remaining quantity sensor 4 has outputted a fact that there is no toner in the developing device 2, when the number of times of replenishment of the toner exceeds some prescribed number of times, it is decided that a process kit 7 has reached its service life. In this regard, the number of times of replenishment of the toner which is allowed against the process kit 7 is selected so as to satisfy the service life of a photosensitive body 1 and the developing device 2 and the toner collection capacity of a cleaning device 3. In such a way, it is prevented that the replenished toner becomes waste. |
