AMBIENT LIGHT AND ELECTROMAGNETIC NOIXE REDUCTION CIRCUIT

摘要

The circuit comprises at leat one light emitting device(40) and the photodector(42) arranged in pairs, the switching means(48) for successively coupling the outputs of the photodetector(42) to the photodetector output circuit(46), the electromagnetic noise compensation pickup circuit(62, 63) extending coextensively with the photodetector output circuit(46) and the circuit means(56) including combining means for differentially combining the outputs from the photodetector output circuit and the electromagnetic noise compensation pickup circuit to substantially eliminate electromagnetic noise components.