| 摘要 |
PURPOSE:To prevent damage of a photosensitive body by receiving the irradiated light to the surface of the photosensitive body from a light emitting element, whose light emission timing is controlled, by a photodetector to detect whether the form brought into contact with the photosensitive body is peeled or not. CONSTITUTION:A terminal 23 is connected to a driving motor; and while the driving motor is driven, the output high level of a NAND gate 24 turns on a transistor TR25 by the driving signal to light a light emitting element 21. If a form exists on a photosensitive body 3, a strong reflected light is made incident on a photodetector 22, and a comparator 26 to which the output of the detector 22 and a reference voltage are inputted goes to the high level. Meanwhile, the output of the gate 24 is inputted to a NAND gate 27, and the output of the comparator 26 is inputted to the gate 27 also, and therefore, the gate 27 goes to the low level if the form exists on the photosensitive body 3. A microcomputer detects existence of the unpeeled form on the photosensitive body to stop the copying operation and indicates paper jam and prevents damage of the photosensitive body. |
