Reflection light barrier, has receiver comprising optical device that is provided for distributing light in plane of receivers, where amplification of signals of one of receivers is smaller than amplification of signals of another receiver

摘要

The barrier has an emitter (1) i.e. LED, for emitting light, and two receivers (5, 6) for light reflected from a reflector (4). The receivers have polarization filters (7, 8) and an optical device e.g. lenticular lens (9) or beam splitter. The optical device distributes light in a plane of the receivers, and signals of the receivers are differentially amplified. Amplification of the signals of one of the receivers is smaller than amplification of signals of the other receiver. A difference between the amplification of the signals is formed from values of the signals.