Elevator light curtain is a kind of elevator door safety protection device made by using the principle of photoelectric induction, applicable to all elevators, to protect the safety of passengers entering and leaving the elevator. Elevator light curtain is composed of three main parts: infrared transmitter and receiver installed on both sides of the elevator car door and special flexible cable. For environmental protection and energy saving needs, more and more elevators have omitted the power box. Some brands of light curtains also have to be sure to use the power box due to poor resistance to electromagnetic interference. But with the popularization of the concept of green elevator, power box-free light curtain is a trend. Because 220V to 24V process is bound to lose a lot of energy.

Light curtain transmitter inside a number of infrared transmitter tube, under the control of the MCU, the transmitter-receiver tube is opened in turn, a transmitter head emitted light is received by a number of receiver head, forming a multi-channel scanning. Through this top-down continuous scanning of the car door area, forming a dense infrared protective light curtain. When any of these beams of light is blocked, the light curtain determines that there is an obstruction due to the inability to realize photoelectric conversion, and therefore outputs an interrupt signal. This interrupt signal can be a switching signal or a high and low level signal. The control system receives the signal given by the light curtain, immediately output the open signal, the car door that stops closing and reversing open, until the passengers or blocking objects out of the warning area before the elevator door can be closed normally, so as to achieve the purpose of safety protection, so as to avoid the elevator clamping accidents.