| 摘要 |
PURPOSE:To improve the sensitivity in detecting the failure in sepn. of transfer paper by providing a sensor for surface potential which detects the failure in sepn. of transfer paper in accordance with the surface potential of a photoreceptor changing according to the presence or absence of the transfer paper after the end of transferring and separating stages. CONSTITUTION:A sensor 11 for surface potential facing a photosensitive drum 1 is provided between a separating and conveying belt 6 and a cleaning unit 7. When the failure in sepn. wherein transfer paper 9 which is transferred with images fails to be separated from the drum 1 despite passing through the belt 6 arises, the surface potential of the drum is detected while the paper 9 is held wrapped thereon, and the detected surface potential differs from the surface potential of the drum 1 in a normal time and is lower than the same; therefore, said potential is judged as failure in sepn. by a CPU control part 18. Since the influence of the surface, etc. of the photoreceptor is not received, the sensitivity in detecting the failure in sepn. of the transfer paper is improved. |
