| 摘要 |
<p>PURPOSE:To obtain a detector not generating erroneous detection due to disturbance light and capable of being manufactured inexpensively, by providing a light blocking member to at least one of the inlet and outlet sides of a piercing hole. CONSTITUTION:A cylindrical light blocking member 32 having the same dimension as the piercing hole 28 provided to the almost central part of a package 26 is formed to the inlet side of the piercing hole 28 by the integral molding with the package 26. A detection circuit for detecting the passage of an object is received in the package 26 and has a light emitting diode 10 and a phototransistor 12 so that the light emitting part of the light emitting diode 10 and the light receiving part of the phototransistor 12 are opposed to each other across an object passage part. Since the disturbance light from an illuminator is blocked by the light blocking member 32 and not received by the phototransistor 12, no erroneous detection is generated.</p> |
