Patent ID: 8008869

Claim:
A discharge lamp lighting device comprising: a power control circuit that outputs a DC current; an AC converter circuit to which the DC current is inputted, the AC conversion circuit inverting polarity of the DC current between first polarity and second polarity in predetermined timing, and thereby generates and outputs an AC current for discharge lamp driving; and a control unit that carries out AC conversion control, current control and repair control, the AC conversion control processing to the AC converter circuit to control polarity inversion timing of the AC current for discharge lamp driving, the current control processing to the power control circuit to control a current value of the DC current, the repair control changing, in a first cyclical pattern, cumulative energy supplied to each electrode of a discharge lamp during one cycle of the AC current for discharge lamp driving, in predetermined timing, the first cyclical pattern including plural sectional periods in which the cumulative energy is maintained at the same value over plural cycles of the AC current for discharge lamp driving, and the cumulative energy differs between at least two of the sectional periods.