Patent ID: 7656102
Filing Date: 2010-02-02
Classification: H02M,H05B,Y02B

Abstract:
1. A discharge lamp lighting circuit for supplying, to a discharge lamp, an AC power to turn ON the discharge lamp, the lighting circuit comprising: a power supplying circuitry having a series resonant circuit including a plurality of switching units, at least one of an inductor or a transformer, and a capacitor, and a driving portion to drive the switching units and to convert a DC power and to supply the AC power to the discharge lamp; a control circuitry to generate a control signal to control a driving frequency of the driving portion; and a starting circuitry to apply a high voltage pulse to the discharge lamp to promote lighting, the control circuitry having: wherein the lighting circuit is operable so that: the control signal from the first circuit portion is selected after a first time that the high voltage pulse is applied, the control signal from the third circuit portion is selected after a third time when a driving frequency based on the control signal from the third circuit portion exceeds a driving frequency based on the control signal from the second circuit portion, and the control signal from the second circuit portion is selected during a period from a second time, which is between the first time and the third time, to the third time.