Patent ID: 7589311

Claim:
An optoelectronic sensor for detecting objects comprising at least one light source, at least one light receiver, and a light retroreflector between them arranged for transmitting light from the source to the detector along a light transmission path from the source to the retroreflector and back to the detector along a light reflection path that substantially corresponds to the transmission path, one of a single lens and a pair of adjacent lenses for shaping respective light beams from both light emitted by the source and light reflected by the retroreflector in accordance with one of the auto collimation principle and the double-eye principle, respectively, a polarizer and a beam splitter in the light transmission path for light from the source, a polarization filter in the light reflection path arranged so that light reflected by the retroreflector passes through the beam splitter and the polarization filter, and a control unit configured to recognize an interruption of at least one of the light beams as a detection of an object, the beam splitter comprising a dielectricum which has differing transmission and reflection characteristics for p-polarized light and s-polarized light.