| 摘要 |
PURPOSE:To improve the unit formation, the reliability and the maintainability by varying directly a vibration amplitude of a vibrator by a detecting signal by a density detector, and making a mixing ratio of a toner and a carrier constant. CONSTITUTION:A density detector 13 is connected to an amplifier 14, and by this amplifier 14, an output signal of the density detector 13 is amplified. When the quantity of a toner in a developer container 2 decreases, the density of a carrier becomes high and a signal from the density detector 13 is outputted in a high level, therefore, a level from a power amplifier 18 also becomes high and a vibration amplitude by a vibrator 19 becomes large, and the quantity of the toner which drops down from a toner hopper 3 increases. Also, on the contrary, in case the quantity of the toner in the developer container 2 is more than a reference, an output waveform from the power amplifier 18 becomes a low amplitude, the vibration amplitude by the vibrator 19 also becomes a low amplitude, and the quantity of the toner which drops down from the toner hopper 3 also decreases. |
