| 摘要 |
PURPOSE:To prevent the malfunction that a separation failure is detected though a transfer paper is separated, by utilizing a ratio of the quantity of reflected light of the surface of a photosensitive drum to that of the transfer paper to detect the separation failure of the transfer paper during the copy operation. CONSTITUTION:A reflected light quantity detector 11 is arranged to face a photosensitive drum 1 in a transfer paper separating part; and if the separation failure occurs, an output voltage V1 of a phototransistor 11b is higher than the hold voltage of a capacitor 23c when the front end part of the transfer paper is detected by the detector 11, and consequently, the output of a comparator 25 becomes H, and a transistor 26 is turned on, and a lamp 27 indicates the occurrence of the separation failure. In this case, the amplification factor of a non- inverting amplifier 22 is set to a value lower than the ratio of the quantity of reflected light of the surface of a photosensitive drum 1 to that of the transfer paper and is set to a value larger than the variation rate of the quantity of reflected light of the photosensitive drum 1, thereby detecting surely the separation failure of the transfer paper. |
