A multi-beam infrared safety device spanning the door opening that detects obstructions and triggers door reversal.
Full Definition
The elevator infrared curtain (light curtain) consists of an emitter unit projecting multiple parallel infrared beams across the door opening and a receiver unit on the opposite door edge. Interruption of any beam by a passenger, luggage, or other obstruction during a closing cycle instantly signals the door operator to reverse. Modern curtains use 40–80 or more beam channels spaced 25–50 mm apart, providing detection from floor level to door header height. They offer superior coverage compared to single-beam photocells or contact safety edges. The curtain must be certified to EN 81-20 and include self-monitoring (broken beam = fault = door held open). IP54 or higher rated housings are required for dusty or wet environments. Alignment between emitter and receiver is set during commissioning using indicator LEDs; periodic cleaning of optic windows maintains beam integrity.
