| 摘要 |
PURPOSE:To enable image control in accordance with an operator, by incorporating a voltage controller in a charger voltage circuit to control charging of a photoreceptor by regulation of discharge voltge in a copying machine provided with an automatic bias voltage developing unit. CONSTITUTION:Five output taps for taking out 5 steps of voltages are connected to the secondary coil of an iron core resonance transformer 19 using a commercial alternating current as a primary input, and fixed contacts 11-15 of rotary switch RS of a voltage controller are connected to these taps. Rotary contact piece 16 of switch RS is connected to high voltage resistant all wave rectification bridge 20, and high voltage resistant smoothing capacitor 21 is connected to the DC output terminal of bridge 20. The smoothing output of capacitor 21 is applied to the discharging wire of main charger 3 through current limiting resistor 22. The rotary shaft of switch RS is connected to image control knob 18, with insulator 17 interposed, protruding out of the outer case of a copier. An operator can obtain copies of desired image density by manual operation of knob 18 in accordance with the image quality of an original. |
