Reflection light barrier has receiver that is provided with near and remote elements, such that evaluation unit outputs switching signal whose status depends on which element reception light beams strike

摘要

A transmitter (3) emits transmission light beams (2) to a reflector (8) from which reception light beams (4) are received by a receiver (5). Polarization filters (14,15) are individually arranged before the transmitter and receiver. An evaluation unit (6) generates a switching signal whose status depends on whether the reception light beams strike the near (9) or remote (10) element in the receiver.