| 摘要 |
PURPOSE:To detect a film without contact and to prevent the failure of motor windings, brushes, etc. occurring in the overloading when the perforations of the film are ruptured or the film winding is stopped, by detecting the perforations photoelectrically with photosensors and stopping the drivng of a motor so as to stop the film in a prescribed position. CONSTITUTION:Perforations 7 disposed at a specified interval to determine the feed rate of a film 4 are formed on said film and a photoreflector 1 is disposed in the position facing the same. In the stage of feeding the film, the perforation 7 is detected with the photoreflector 1, and a winding motor for the film is stopped, by which the film can be fed by 1 pitch P between the perforations. Since the perforations are detected photoelectrically without contact, the rupture of the film is prevented and since the supply of the power source the motor is interrupted after said detection, the motor is kept free from overloading and hence troubles. |
