Optical barrier light interference protector - has luminous source and light reflector having number of sun-shades with variable orientation w.r.t. to light source

摘要

The barrier system comprises a luminous source with a reflector placed at a distance to reflect the beam to a detector. The problems at sunrise and sunset are avoided by a sunshade to protect the reflector. The barrier also has an optical emitter and receiver assembly in which a luminous beam of modulated intensity is generated. A vertical sweep is generated, which is detected at the receiver after reflection by a reflector. The reflector comprises a row of catadioptric elements with small sunshade slots which are directed towards the luminous source. These may be lowered by several degrees and directed towards the luminous source to prevent saturation of the detector by the parasitic light.