Abstract: The low noise light receiver comprises a light sensor for generating a sensor signal, the sensor signal comprising a wanted signal resulting from a light source and an interfering signal resulting from interfering light; an optical filter apparatus for reducing the interfering light; an electric filter apparatus connected to the light sensor for filtering out the interfering signal and for generating a correction signal that substantially compensates for the interfering signal; and a processing apparatus connected to the light sensor and the electric filter apparatus for processing the wanted signal in order to generate an output signal (Vout).
Abstract: Photoelectric proximity switch for detecting the presence of an object in a monitored area. A light pulse transmitter emits transmitting light pulses into the monitored area. The pulses are triggered by an output signal of a random signal generator or a pseudo-random signal generator and are emitted with a time interval between them. A light receiver is arranged in relation to the light pulse transmitter and to the monitored area such that in the absence of an object to be detected in the monitored area, the receiver receives essentially no light from the light pulse transmitter, but in the presence of an object to be detected in the monitored area, it receives such light from the light pulse transmitter due to reflection that a receiving signal evaluating device connected to the light receiver and to random signal generator or the pseudo-random signal generator delivers an object detection signal.