| 摘要 |
<p>PURPOSE:To count marks securely even if a back lash or oscillation occurs, by providing the 1st and the 2nd detectors parallel to the feeding direction of a beltlike body and setting or resetting a flip-flop according to their outputs. CONSTITUTION:The mark detecting elements 4 and 5 are arranged parallel to the film feeding direction and when a film is fed lengthwise, marks are detected successively. When the detecting element 4 detects a mark and the detecting elements 5 detects no mark, the flip-flop 12 is set to output a mark detection signal through a differentiating circuit 13 and when the detecting element 5 does not detect any mark, the flip-flop 12 is reset.</p> |
