| 摘要 |
PURPOSE:To reduce not only the number of connection wirings but also the number of assembling processes and to miniaturize machinery, by also using a power supply wire as a detection output signal wire and utilizing common earth as a power return path in each optical object detection apparatus. CONSTITUTION:When an object 3 moves to generate such a state that a light sufficiently passes between a light emitter 21 and a light receiver 22, the impedance of a phototransistor 25 lowers and an Ip component flowing through a route of power source resistor 26 phototransistor 25 base of transistor 24 earth increases and the collector current of the transistor 24 begins to flow. When this current exceeds a threshold value by the increase in receiving quantity of light, the current Id flowing through a light emitting diode 27 does not pass through a constant voltage diode 28 but passes through the transistor 24 and begins to increase and positive feedback is brought about to perfectly bring the transistor 24 to a continuity and saturation state and detection signal voltage Vi is amplified by a Schmidt trigger element 29 to be outputted.
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