| 摘要 |
PURPOSE:To correctly detect notches even if the notches are different from each other in depth by successively measuring the width of a film and judging a part changed by a fixed value or more to be a notch part. CONSTITUTION:Light from light source 2 is detected with a group of light detecting elements 4 through diffusion plate 3. By the number of elements 4 which have detected the light the width of film 1 is measured. When the number is changed by a fixed value or more from a predetermined value, the changed part is judged to be a notch part. |
