| 摘要 |
PROBLEM TO BE SOLVED: To prevent saturation of an inductor of a step-down converter without delaying rising of light flux after lighting start of a discharge lamp, in a discharge lamp lighting device having the step-down converter.SOLUTION: A discharge lamp lighting device (1) comprises: a step-down converter (4) that has an inductor (42) and a switching element (41), switches a DC voltage inputted from a DC power supply circuit (3) to the inductor by means of the switching element to supply a restricted output current to a discharge lamp (9); and a control circuit (8) that can drive the switching element at a variable drive frequency, and is configured to drive the switching element at a first frequency (f1) higher than a second frequency (f2) applied at stable lighting in a predetermined time period from the lighting start of the discharge lamp to stable lighting arrival. |
