| 摘要 |
PURPOSE:To provide a photointerruptor which can prevent the production of noise due to disturbance light, by a method wherein a light is emitted and received via photofibers whose and surfaces are positioned facing and opposite to each other, and a light-receiving angle to a light-receiving fiber for external light is limited to a given extent. CONSTITUTION:Support members 12 and 13 support a light-receiving photofiber 14 and a light-transferring photofiber 15, respectively, which are located photo- coaxially, so that end surfaces of the photofibers are positioned facing and opposite to each other. The interruption of light generates a detection signal of a member 9 to be detected. The shape of the member 13 is formed such that an angle thetan of a straight line l2, connecting together the outer edge of the member 13 and end surface edge of the fiber 15, to a photoaxis l1, is larger than a light-receiving angle which the fiber 14 can transmit in a whole reflection manner. Thus, exteral light except light transmitted from the end surface of the photofiber 15 does not propagate through the fiber 14 to produce a photointerruptor which can check the production of noise due to disturbance light. |
