| 摘要 |
<p>PURPOSE:To make a light receiving section to receive the light of a light emitting section so that an electrical position detecting signal can be obtained by forming a slit between the edge section of an object to be detected and the edge section of a shielding section when the object to be detected moves to a detecting position. CONSTITUTION:A photoreflector 4 detects the position of a nonreflective black piece 3 to be inspected mounted on a shutter blade. The reflector 4 is fitted to the rear side of a fitting section 6 having a rectangular opening 8. A reflecting plate 9 is provided at a position opposite to a light emitting and receiving sections 7 and 10 at intervals which allow the piece 3 to move between the sections 7 and 10 and plate 9. Then the piece 3 blocking the opening 8 moves toward the opening from a blocking section 14 and a slit S is detected between the edge section 15 of the piece 3 and edge section 13 of the section 14, When the slit S is detected, the section 10 receives the light of the section 7 reflected by the plate 9 and obtains an electric signal.</p> |
