| 摘要 |
PROBLEM TO BE SOLVED: To select electrification frequency proper for processing speed and resolution with simple constitution and to prevent a moire image from occurring by changing frequency division ratio in accordance with the change of the processing speed and the resolution and changing the electrification frequency. SOLUTION: After AC frequency generated by an oscillator 31 is frequency- divided by a frequency divider 33, it is connected to the primary side of a power source 35 for impressing electrification bias on an electryfing roller 2. A control circuit 32 switches the frequency division ratio of the frequency divider 33 simultaneously with switching the processing speed and the resolution in image forming according to a signal from a host computer. Namely, the frequency division ratio of the frequency divider 33 is changed simultaneously with the change of the processing speed and the resolution in image forming, and the AC frequency f0[Hz] from the oscillator 31 is frequency-divided to frequency fp1 or fp2 by the frequency divider 33 in accordance with the processing speed and the resolution in image forming and transmitted to the power source 35. Thus, the excellent image where moire does not occur is printed. |
