| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deposition of a discharge product and the deterioration of a photoreceptor by lowering an inter-peak voltage of an AC voltage as low as possible in the control of setting the frequency of an AC voltage so that a moire pattern is not formed in an image. SOLUTION: In the case that the number of screen lines with black halftone images at an angle of 45° is 133 lines/inch, a charging frequency I of f2=2,200(Hz) is effective to suppress the moire pattern. If the number of screen lines is switched to 175 lines/inch, a charging frequency of f1=1400 Hz is effective to suppress the moire pattern. In the case of a frequency of 2200 Hz, the inter-peak voltage Vpp of an AC voltage of an oscillating voltage applied to a charging roller 2K is set to 1.82 kV by the control section 110. However, in the case of a charging frequency of f1=1400 Hz, the control section decreases it to 1.66 kV. COPYRIGHT: (C)2010,JPO&INPIT |
