| 摘要 |
PROBLEM TO BE SOLVED: To detect rotational phase of a developer conveying part and an image holding body without providing detection means such as a sensor on the developer conveying part such as a developing roll and on the image holding body such as a photoreceptor drum.SOLUTION: A filter 21 removes noise of a high frequency component from an AC component waveform in a power source of a developing bias applying device 40. A rotational phase detection unit 22 detects rotational phase of a developing roll 157K from the AC component waveform in the power source of the developing bias applying device 40 after passage of the filter 21. A density correction unit 23 corrects density variation caused by rotation of the developing roll 157K on the basis of the rotational phase of the developing roll 157K detected by the rotational phase detection unit 22.SELECTED DRAWING: Figure 2 |
