Lysføler med baggrundsundertrykkelse realiseret ved anvendelse af kvotientfremgangsmåden

The sensor has a light source providing a light beam reflected from the surface of an object to allow a reflected light signal to be received by a pair of adjacent photodetectors (9, 10). The light source and the photodetectors are placed at a given angle to one another, for allowing the distance of the object to be determined via a triangulation method. The signals from both the photodetectors are fed to a divider (15), providing a value of less than 1 when the detected object is at a relatively distance spacing, a value of 1 when the object is at a given spacing and a value of greater than 1 when the object is at a relatively close spacing.