DISCHARGE LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To detect the end of the life of a discharge lamp and to announce it at the end of the life before the discharge lamp turns off. SOLUTION: For the lamp voltage of a discharge lamp La, an allowable range specified by an upper limit value Up and a lower limit value Lw is set, and when the voltage deviates from the allowable range, a display device 3 announces the possibility that the lamp may come to its end. When the state in which the voltage deviates from the allowable range has continued for a certain time or more that is set by a timer 27, the discharge lamp La is turned off and the end of its life is announced by means of the display device 3.