| 摘要 |
<p>PURPOSE:To obtain a device which is inexpensive and whose constitution is simple, and which can accurately detect the abnormality of the winding state of a photosensitive paper, especially, in a non-contact state without radiating light by comparing the calculated rate of change of an electrostatic capacitance with a value stored in a storage means. CONSTITUTION:An electrode 19 constitutes a capacitor with an exposing drum, and the electrostatic capacitance of the capacitor formed of the electrode 19 and the exposing drum is nearly primarily increased when the photosensitive paper is normally inserted in the gap of the capacitor. The rate of change at this time, that is, inclination in a graph is calculated by a change rate calculation circuit 27 based on the measured result by a capacitance measurement circuit 26. A CPU 20 compares the rate of change previously stored in a storage circuit 28 with the calculated result by the circuit 27 so as to recognize that the winding state of the photosensitive paper is normal. When the CPU 20 detects that abnormality occurs in the winding state, the photosensitive paper is peeled from an exposing drum in a state where the image is not formed on the photosensitive paper and ejected to a paper ejection tray by a paper ejection belt.</p> |
