The safety light curtain is a safety device for anti-intrusion detection. It is commonly used in industrial automated production and safety manufacturing, and it is also useful in some special environments in life. For example, elevators, but the safety light curtains generally used in elevators are all common types of light curtains, while the safety light curtains with a certain safety level are mostly used in the industry. The safety light curtain uses the principle of photoelectric induction to work, and usually consists of multiple pairs of infrared sensors with transmitting and receiving functions to form the physical part of its detection.

Generally, there are more than 30 pairs of infrared transmitting and receiving tubes in the elevator safety light curtain, and they are respectively located on both sides of the elevator car door. When working, the beams emitted by these infrared sensors will form a densely interlaced "protection net" in the height range of 20mm~1806mm. When there are no obstacles to enter the space, all the beams emitted can reach the receiving tube normally. Therefore, the elevator's The control part will not get the "intrusion" detection signal.

Once an object blocks any of the light, it will cause the "abnormal" output of the corresponding infrared receiver, which will be detected by the circuit and control the elevator to reopen the car door. It can be closed normally until passengers or obstructions leave the alert area, avoiding accidents and safety accidents.