| 摘要 |
PURPOSE:To enable normal copying operation even after an overflow occurs by inhibiting toner from being supplied by giving a signal from a toner overflow detection sensor priority to a signal from a toner concentration detection sensor even when a decrease in the toner concentration in a developer storage case is detected. CONSTITUTION:The toner overflow detection sensor 42 composed of, for example, a photocoupler is provided outside the upper recessed part 41 of a waste toner tank 10. This overflow detection sensor 42 detects an overflow state by detecting waste toner 39 in the waste toner tank 10 increasing up to the inside of the recessed part 41, thereby outputting a specific signal. This signal is given priority to the signal from the toner concentration detection sensor 36. When waste toner 29 overflows, a specific signal is outputted from the toner overflow detection sensor 42 and this signal has the priority to the signal from the toner concentration detection sensor 36, so a motor 30 is never turned on. |
