| 摘要 |
An image forming apparatus comprising a cleaning unit (45) wherein a storage (104) is defined in a cleaning housing (101) to store therein toner to be discarded which is collected from the surface of a photoconductive drum (42) after image transfer. The aforesaid storage (104) has a capacity exceeding the maximum volume of toner to be used under normal conditions within the service life of the photoconductive drum (42). A cumulative number of produced copies is found from a signal from a paper discharge detecting sensor (140), so that with the number reaching a certain value, it is judged that the life of the photoconductive drum (42) has expired. If a reed switch (130) detects the fullness of toner waste before the expiry of the life of the photoconductive drum, it is judged to be abnormal, and a display unit (10) is caused to indicate abnormality. Concurrent execution of exchange of photoconductive drums and disposal of toner waste is assured, and if this is not accomplished, warning for trouble shooting is provided. <IMAGE> |
