| 摘要 |
PURPOSE:To reduce the handling time of an operator and simultaneously, to prevent the forgetting of setting by detecting the magnetic permeability of a developer when a correct value detected at the time of warming up just after the attachment of a developing tank is detected is a limited one set in advance or above, and setting the detected value as reference magnetic permeability. CONSTITUTION:When the power source switch of a copying machine main body is turned on, warming up is started. When the attachment/detachment of the developing tank 1 is carried out, the current value ID of the developer is read out by a current value detecting circuit 8. When this value exceeds the reference current value, it is judged that the replacing of the developer is carried out. When the replacement of the developer is decided, the magnetic permeability detected by a toner concentration sensor 7 is read out and stores it as the reference magnetic permeability in a memorial area M1, while a toner empty lamp is turned on, and the acceptance of a key operation, etc., is refused. Thus, it is unnecessary that the reference magnetic permeability is manually set, and the operating load of the operator can be reduced. |
