| 摘要 |
PROBLEM TO BE SOLVED: To prevent the formation of an image due to improper processing, in control involved in the detection of the film thickness of a photoreceptor in particular. SOLUTION: The film thickness is detected in a short time, during a pre- rotation before the image is formed. When the value of the difference between the value of the detection and a detection signal in the last γ-table switching which is stored in advance is lower than a prescribed threshold and further, the number of copies is >=500, the film thickness is detected during a post- rotation after the image is formed. Switching to a γ-table corresponding to the value at this time is attained. On the other hand, when the value is higher than the prescribed threshold, shifting to a pre-rotation detecting mode is executed to detect the film thickness of the photoreceptor and switching to the γ-table corresponding to the value at this time is attained. |
