| 摘要 |
PURPOSE:To prevent the wearing of a cleaning blade and deterioration of a photoreceptor by allowing the cleaning blade to come into contact with the surface of the photoreceptor only when the specific conditions are satisfied. CONSTITUTION:Timing that the cleaning blade 22 of a cleaning device 20 comes into contact with the photoreceptor 4, is set in accordance with a quantity of black picture element parts or white parts in image information read from an original in each original. For instance, when a black picture element value exceeds a prescribed reference value, the blade 22 is controlled to press against the photoreceptor 4 and remove residual toner. On the other hand, when the black image element value does not reach the prescribed value, the cleaning blade 22 is controlled to stay away from the photoreceptor 4. Then, the toner scraped by the cleaning blade 22 is carried to a toner recovering device outside the cleaning device by a toner carrying screw 23. Thus, the surface of the photoreceptor drum 4 becomes a state where the toner is not present, to obtain the next image forming process again. |
