| 摘要 |
PURPOSE:To enable toner density to be controlled in high sensitivity and high precision, by transducing toner concentration change into changes of inductance and electrostatic capacity and detecting two values using two detecting means to detect toner concentration change. CONSTITUTION:Developer 13 is conveyed with rotation of rotary sleeve 11, and develops and visualizes the static latent image of static recorder 10, then passes through electrode plates 15, and returns to the bottom of container 12. Capacity obtained by plates 15 and inductance obtained by coil 16 are connected with a lead in series, a.c. current is fed to the lead by oscillator 25, and the oscillation frequency of oscillator, the capacity of plates 15, and the inductance of coil 16 are set so that the series circuit of the capacity and the inductance operates like resonance when toner concentration is optimum. The concentration is kept optimum by providing a signal in accordance with the concentration to control circuit 27 and operating feed valve 17 by drive of motor 28 etc.. |
