Reflection light barrier with adjacent transmission and reception optics - contains retroreflector and polarising elements in transmission and reception light paths

摘要

The light barrier arrangement contains a retroreflector (16) and polarising elements in the transmission and reception light paths. A polariser (17) is arranged in front of the retroreflector, and a polarising beam divider (15) is arranged behind a beam divider (15) in the reflection direction. One light receiver (12) receives the light of corresp. polarisation passing the beam divider, and another (13) receives the light reflected by the beam divider and with a polarisation direction rotated through 90 deg. The difference between the signal amplitudes generated in the two light receivers is used as the output signal. USE/ADVANTAGE - Reliable detection of objects with reflective and/or depolarising characteristics.