Patent ID: 7075246

Claim:
A discharge lamp illumination circuit comprising: a DC-AC conversion circuit which effects AC conversion and boosting upon receipt of a DC input, a starter circuit for supplying a start-up signal to a discharge lamp, and control means for controlling illumination of the discharge lamp by means of controlling power output from the DC-AC conversion circuit, wherein the DC-AC conversion circuit comprises an AC transformer that includes a primary circuit and a secondary circuit, which are insulated from each other, wherein the start-up signal boosted by said AC transformer is superposed on an AC-converted output, and a resultant signal is supplied to the discharge lamp, and wherein the DC-AC conversion circuit further comprises a plurality of switching elements and a resonance capacitor, and said switching elements are activated by the control means to affect serial resonance between said resonance capacitor and either an inductance component of said AC transformer or an inductance component connected to said resonance capacitor wherein one end of the resonance capacitor is connected to a node between the switching elements and the other end thereof is connected to the inductance component.