| 摘要 |
<p>The perforations (f) of a film are arranged to pass through a detecting section of a photointerrupter (1) during film feeding to detect the presence of perforations (f) by comparing the output signal from the photointerrupter with a predetermined threshold limit value which is calculated (13) as the average of maximum and minimum values of the output signal from the photointerrupter (1), and feeding (12) of the film is controlled in response to said comparison.</p> |
