| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device that can avoid a startup defect during switching control from a boosted voltage for startup to a boosted voltage for steady lighting and has higher reliability than before.SOLUTION: A discharge lamp lighting device includes: a voltage step-up conversion circuit 16 which boosts an input voltage; inverter circuits 18, 20 which step down an output voltage of the voltage setup conversion circuit 16 and convert the voltage into an AC current; lamp voltage detection means 42; setting means 52 for the boosted voltage; and means 32 for driving and controlling the voltage setup conversion circuit 16 according to a set value of the setting means. The setting means 52 includes: a first setting part 56 which sets a boosted voltage for startup; a second setting part 58 which sets a boosted voltage for steady lighting; and a set value switching part 54 which switches the boosted voltages based upon a detected value of a lamp voltage. The set value of the first setting part is used when detection means 42 detects a no-load voltage or a lamp voltage lower than a reference value for steady lighting. The set value is switched to the set value of the second setting part when no no-load voltage is detected and a lamp voltage having reaches the reference value for steady lighting is detected. |
