| 摘要 |
PURPOSE:To make it possible to detect a variation of the quantity of a developer swiftly and exactly, by providing a piezoelectric magnetic vibrator at the angle by which a developer does not stay on the vibrating surface, at the regular position of the developer containing case, making it operate depending upon the existence of the developer, and forming it so that the annunciator can be controlled by the timer circuit in accordance with said output. CONSTITUTION:The piezoelectric magnetic vibrator 13 is provided to the slanting surface near the toner make-up roller of the toner containing case so that the toner does not stay on the vibrating surface, its vibrator 13 operates depending upon the existence of the toner, and its output to the amplifier 20. Its square wave output is clamped by the DC regenerating circuit 26, and is input to the AND circuit 38 through the inverter 30, the integral network 31, and the inverting circuit 39. An output of the timer circuit 37 is provided to the other terminal of the AND circuit 38, and the annunciator 41 is turned on by the driving circuit 40 in accordance with said signal. Accordingly, a variation of the developer in the containing case can be detected swiftly and exactly. |
