LIGHTING CONTROLLER

PROBLEM TO BE SOLVED: To light illumination only when a man's existence in a room by detecting an infrared radiation radiated from a human body with an infrared image sensor and by calculating the number of people in the room with a microcomputer according to the information. SOLUTION: An infrared radiation radiated from a person passing through an entrance 10 of a room 1 is detected by an infrared image sensor 4 in a lighting controller 3 to convert it into an infrared image. An A/D conversion part 5 converts the image information into a digital signal and sends it to a microcomputer 6. The microcomputer 6 determines the number of human bodies 2 and respective persons going in or out. If the value of a people-in- the-room counter 7 is one or more, the microcomputer 6 sends a lighting signal to a lighting drive part 8. While receiving the lighting signal, the lighting drive part 8 keeps a illumination 9 lit. Only when the human body 2 exists in the room 1, the illumination 9 can be lit.