LIGHTING DEVICE AND GUIDE LAMP

摘要

PROBLEM TO BE SOLVED: To provide the guide lamp which hold the prescribed lightness. SOLUTION: The guide lamp is equipped with a device main body almost in a box shape. A main lamp 11, a backup lamp 12 and the illumination device 15 are provided in the device main body. The illumination device 15 has a timer 26, a cumulative illumination time detecting circuit 27 and a switching circuit 25. The timer 26 counts the illumination time of the main lamp 11. The cumulative illumination time detecting circuit 27 detects the cumulative illumination time of the main lamp 11 reaching the prescribed time. A switching circuit 25 switching the main lamp 11 to the backup lamp 12 according to a signal from the cumulative illumination time detecting circuit 27. The backup lamp 12 is turned on before the quantity of the light from the main lamp 11 decreases below the prescribed quantity owing to deterioration after the lapse of year.