Patent ID: 8853612

Claim:
A light barrier, comprising: a housing; a first and second limb connected to said housing wherein a spacing between said first limb and said second limb is variable, said first limb forming a first side of said light barrier and said second limb forming a second side of said light barrier, wherein said first side and said second side define a region to be monitored therebetween; at least one transmitter; at least one receiver, wherein said at least en one transmitter and said at least one receiver are located at said first side of said light barrier; and an optical system located at said second side of said light barrier, wherein at least one primary light beam is transmitted from said at least one transmitter to said optical system, and said optical system deflects said at least one primary light beam and returns at least one secondary light beam separate from the at least one primary light beam by a distance from the at least one primary light beam to said at least one receiver, wherein the at least one primary light beam includes at least two primary light beams and the at least one secondary light beam includes only one secondary light beam, and wherein the optical system is arranged for receiving said at least two primary light beams and for combining the at least two primary light beams to form said only one secondary light beam.