Light barrier operating method for detecting obstacle in light path

摘要

The method involves transmitting a periodic light pulse signal over a given period duration and detecting the corresponding light pulses by a receiver (6), coupled to an evaluation circuit (9), which registers the light pulses within a reception period. This is divided into a number of time windows, with a counter indexed by each reception pulse within a time window, to provide a 'path clear' indication when a threshold count value is attained. An Independent claim is also included for a light barrier.