Patent ID: 7239090

Claim:
A discharge lamp lighting apparatus for lighting a discharge lamp including a pair of main-discharge electrodes disposed so as to face each other, the discharge lamp lighting apparatus comprising: a power supply circuit for supplying electrical power to the discharge lamp; an inverter disposed at a stage following the power supply circuit and serving to invert the polarity of a voltage applied to the discharge lamp; a resonant transformer having a primary winding and a secondary winding, a resonant capacitor, and a periodic voltage applying section, wherein the secondary winding of the resonant transformer is disposed in a path connecting an output of the inverter to the main-discharge electrodes of the discharge lamp, the resonant capacitor being connected in parallel to the primary winding of the resonant transformer so as to form a parallel resonant circuit, the periodic voltage applying section being connected to the parallel resonant circuit, and the periodic voltage applying section being operated in a starting period of the discharge lamp at a frequency capable of causing resonance in the parallel resonant circuit.