Patent ID: 8222830

Claim:
A discharge lamp lighting device comprising: DC power supply circuit that outputs DC power; an inverter circuit that includes a resonance circuit having at least one capacitor and at least one inductor, and converts a DC voltage, which is output by the DC power supply circuit, into an AC voltage, the AC voltage being applied to a discharge lamp; a start detection circuit that detects starting of a discharge in the discharge lamp; and a control circuit that controls the inverter circuit, wherein the control circuit includes: a no-load mode in which a voltage for starting a glow discharge is applied to the discharge lamp by setting a frequency of an output of the inverter circuit at approximately a resonance frequency of the resonance circuit included in the inverter circuit; a lighting mode in which the arc discharge is maintained by lowering the frequency of the output of the inverter circuit to be lower than the resonance frequency of the resonance circuit; and a starting improvement mode in which the frequency of the output of the inverter circuit is higher than the frequency of the output of the inverter circuit in the lighting mode, and at a time of starting of the discharge lamp, the control circuit first operates in the no-load mode, shifts to the starting improvement mode, in which the glow discharge in the discharge lamp is shifted to an arc discharge, when starting of the discharge in the discharge lamp is detected by the start detection circuit during the no-load mode, and shifts to the lighting mode, after the starting improvement mode is continued for a predetermined time.