| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optimum image by performing waveform shaping by restraining the overshoot and the undershoot of the rectangular wave of developing bias in accordance with the individual dispersion of a developing device. SOLUTION: An AC load current is converted into voltage and detected by a current detecting bypass capacitor (C11) 71 and a detection resistance (R11) 72, and converted into DC by a rectifier diode (D11) 73 and a smoothing electrolytic capacitor (C12) 74. A resistance (R12) 75 and a resistance (R13) 76 change the voltage converted into DC to a processable voltage level and input it in a control part. The control part variably controls the frequency of the AC rectangular wave of the developing bias in accordance with the detected load current value. |
