| 摘要 |
PURPOSE:To detect the accurate winding position of a photosensitive paper without changing the photosensitive characteristic of the photosensitive paper by detecting the change of electrostatic capacity between an electrode and a drum. CONSTITUTION:An exposing drum 8 is made of iron or aluminum having conductivity in order to uniformly electrostatically charge the photosensitive paper 1 and connected to earth, then the electrode 101 is arranged to be opposed to the drum 8 and forms a capacitor with the drum 8. When the photosensitive paper 1 is fed and reaches the position of the electrode 101, the photosensitive paper 1 is inserted inside the capacitor constituted of the electrode 101 and the drum 8, so that the electrostatic capacity of the capacitor is changed. Since a capacity measuring circuit is connected to the electrode 101, it detects that the electrostatic capacity of the capacitor is changed and transmits it to a controller. Thus, the controller recognizes a position where the leading edge of the photosensitive paper 1 is wound round the drum 8. |
