Working principle of elevator light curtain

There are several infrared transmitting tubes in the transmitting end of the elevator light curtain. Under the control of the microcontroller unit, the transmitting and receiving tubes are turned on in sequence, and the light emitted by one transmitting head is received by multiple receiving heads in sequence, forming a multi-channel scan. By continuously scanning the car door area from top to bottom, a dense infrared protection light curtain is formed. When any beam of light is blocked, since the back-end circuit of the receiving head cannot realize photoelectric conversion, the light curtain determines that there is an obstruction, so it outputs an interrupt signal to the door machine. This interrupt signal can be a switch signal or a high or low level signal. After the elevator door machine receives the signal from the light curtain, it immediately outputs a door opening signal, and the car door stops closing and reverses to open until the passenger or obstacle leaves the warning area. The elevator door can be closed normally, thereby achieving the purpose of safety protection and avoiding the occurrence of elevator pinching accidents.