Reflection light barrier for detecting objects in monitoring region

摘要

The reflection barrier has a receiver (3) and a transmitter (2). The light beam (5) emitted from the transmitter is reflected back from a reflector (12) and is received by the receiver. The receiver signal is compared with a second threshold value (S2) lying above a first threshold value (S1). The receiver signal with a free beam course lies between the two values. The receiver signal lies above the second threshold value, in the event of an object encroachment or a disturbing influence in the monitoring region. In comparison to the receiver signal with a free beam course, with an increased amount of light then impinging on the receiver (3).