DISCHARGE LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce switching loss in a polarity inversion circuit portion by decreasing the number of polarity inversions, and suppress pole degradation of the discharge lamp by equalizing usage rate of a negative electrode with that of positive electrode, thereby improving life of the discharge light, in a discharge lamp lighting device in which the polarity is inversed with an input signal in synchronization with timing of light of the lamp passing through a boundary portion of each color of a color filter. SOLUTION: The number of the polarity inversions is reduced by adding a dividing circuit to the polarity inversion circuit control circuit for enabling the polarity inversion circuit to perform polarity inversion control in synchronization with the input signal which switches a voltage level with the timing when an output light of the discharge light illuminates each boundary portion of a rotary color filter. The input signal is divided for example into one polarity during a period where the output light of the discharge light illuminates one of colors of the rotary color filter, and the other polarity during a period where the output light of the discharge light illumines a plurality of colors of the rotary color filter.