| 摘要 |
PURPOSE:To prevent an apparent volume change of a developer due to the rise of temperature from being detected erroneously as an actual volume change, by providing a volume detector which detects the volume of the developer on the basis of the change of an inductance and changing the volume detection level in accordance with the state of the developer or environments around the developer. CONSTITUTION:The output of an oscillating circuit 1 is inputted to the input side of a rectifying and detecting circuit 4 through a resistance R together with the output from a volume detector 2. The volume detector 2 forms a coil, and an inductance L of this coil has a large value if the developer including a carrier exists near the coil. The output of the rectifying and detecting circuit 4 is compared with a reference voltage (level) in a level comparator 5, and this comparison signal is sent as a driving command signal to a driving motor 7 of a toner automatic supply device. Thus, since the volume detection level is changed when the apparent volume of the developer is changed by the rise of temperture, the volume of the developer is detected accuracy without the influence of the the variance of temperture. |
