| 摘要 |
PURPOSE:To discriminate the film transporting direction for a film transporting detector, by arranging two detection elements with different relations to the perforations of the film. CONSTITUTION:The perforation detecting means 5A and 5B using the combination of a light emitting element and a photodetector are arranged with a shift of DELTAl(<a/2) or DELTAl+na (n: natural number) secured in the lengthwise direction of a film. The output of the light emitting element and the photodetector vary with detection of the perforation. Thus these variations are supplied to a flip-flop, etc. to compare the lengths of high and low levels. In such way, the film transporting direction is detected, and a counter is actuated in both the film winding and film rewinding modes. As a result, the film can be advanced by a prescribed extent. |
