LED LIGHTING DEVICE

PROBLEM TO BE SOLVED: To provide an LED lighting device that also works as an emergency light. SOLUTION: The LED lighting device 10 includes: an illuminance sensor 57a for detecting the illuminance around the LED lighting device 10; a microcomputer unit 51 for determining whether or not the detected illuminance is equal to or lower than a reference illuminance; a voltage sensor 57b for determining whether or not the LED lighting device 10 receives electric power; and a battery unit 58 and a current switching control unit 52 that supply auxiliary electric power equivalent to the electric power to an LED unit 27c. If it is determined that the detected illuminance is equal to or lower than the reference illuminance by the illuminance determination process by the microcomputer unit 51 and it is determined by the voltage determination means that the LED lighting device does not receive electric power from a lamp line PL, the current switching control unit 52 supplies a driving current to one of the LED unit 27c out of the LED units 27a to 27h from the battery unit 58 by an emergency partial lighting process. COPYRIGHT: (C)2011,JPO&INPIT