PURPOSE: To obtain an instrument lighting apparatus for a vehicle, which sets the instrument light at a night mode when the amount of light detected with an optical sensor is less than a specified amount and a tail lamp is turned ON and can perform the switching of the day and night modes reflecting driver' s will.
CONSTITUTION: When a vehicle is running in a day mode, a mode switching means 58 judges that the outside of the vehicle becomes dark based on the signal from an optical sensor and sets a night mode for an instrument light at a night mode when ON of a tail lamp sensor 54 is detected. When the fact that the outside of the vehicle is bright based on the signal from the optical sensor 52 is judged or the tail lamp sensor 54 is turned ON, whether the signal from the optical sensor 52 is in the 'L' state or not is judged. When the signal from the optical sensor 52 is in the 'L' state after the elapse of one second, the mode of the instrument light is set in the night mode. The reason of the one-second waiting is to prevent the occurrence of the passing phenomenon of the day, night and day modes based on the judgment that the outside of the vehicle becomes dark when the vehicle passes the road under a bridge and the like.
IMAIZUMI MOTOMU
UCHIDA TOMOHIRO
