| 摘要 |
PURPOSE:To detect the end face of a transparent moving object stably at a high accuracy by fully reflecting a light flux on the end face to vary the state of receiving the flux on a light receiving surface. CONSTITUTION:A laser beam 2 forms a beam waist 2a with a convergence lens 3 and then, received with a photoelectric converter 4 provided with a light receiving surface 5. When a transparent film sheet 1 moves until the end face 1a thereof reaches the waist 2a, the beam 2 fails to be received by the surface 5 as fully reflected on the end face 1a. Thus, the state of receiving the light flux changes rapidly thereby enabling the detection of the end face of a transparent moving object stably at a high accuracy. |
