Patent ID: 7019465
Filing Date: 2006-03-28
Classification: H05B,Y10S

Abstract:
1. A discharge lamp illumination circuit comprising: a DC-AC conversion circuit which effects AC conversion and boosting upon receipt of a DC input; and a starter circuit for supplying a start-up signal to a discharge lamp, the discharge lamp illumination circuit being used for illumination control using control means for controlling a power output from the DC-AC conversion circuit, wherein the DC-AC conversion circuit comprises an AC transformer; a plurality of switching elements; and a resonance capacitor, wherein the switching elements are activated by the control means, to induce series resonance between the resonance capacitor and an inductance component of the AC transformer, or between the resonance capacitor and an inductance element connected to the resonance capacitor; and in relation to the operating frequency of the switching elements, a first frequency value and a second frequency are substantially the same, wherein the first frequency value corresponds to a period before the discharge lamp is illuminated, and the second frequency value corresponds to a period from illumination of the discharge lamp by the starter circuit until elapse of a predetermined time period or a time period specified in accordance with an illumination state.