摘要 |
A photoelectric sensor unit comprises a light emitting section for emitting light to a detection area, a light receiving section for receiving light from the detection area, and a signal processing section for amplifying and processing an electric signal corresponding to the light reception amount output from the light receiving section. A four-element, high-brightness type LED is used as a light emitting element forming a part of the light emitting section and a drive circuit comprises an automatic control circuit for reducing fluctuation in the light emission amount relative to change in the ambient temperature of the LED.
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