Discharge lamp lighting apparatus

A discharge lamp lighting apparatus comprising:

• an inverter circuit that includes a high-side switching device and a low-side switching device and that generates an AC voltage supplied to a discharge lamp;
• an inverter control circuit that performs driving control of the inverter circuit;
• and
• a resonant circuit that includes a resonant inductor and a resonant capacitor, that is provided in a stage subsequent to the inverter circuit, and that increases, at a start-up time of the discharge lamp, a supply voltage supplied to the discharge lamp through a voltage step-up action accompanying a resonance phenomenon;
• wherein
• the inverter control circuit includes:
• a driving frequency control circuit that drives the inverter circuit by using a first frequency including a resonant frequency of the resonant circuit during a first period which is a period in which breakdown and a glow discharge subsequent to initiation of a start-up process of the discharge lamp are generated, that drives the inverter circuit by using a second frequency including a resonant frequency of the resonant circuit, the second frequency being lower than the first frequency, during a second period which is a period in which an arc discharge of the discharge lamp is generated, and that drives the inverter circuit by using a third frequency lower than the second frequency, during a third period subsequent to the second period;
• and
• a dead time control circuit that sets a dead time in which both of the high-side switching device and the low-side switching device of the inverter circuit are turned off so that the dead time is longer in the second period than in the first period and the third period.