Patent ID: 7800317

Claim:
A discharge lamp lighting apparatus for converting a direct current into an alternating current and supplying power to a discharge lamp, comprising: a resonant circuit including a transformer, a capacitor connected to at least one of primary and secondary windings of the transformer, and an output end connected to the discharge lamp; a plurality of switching elements connected to both ends of a direct-current power source and configured to pass a current through the primary winding and capacitor of the resonant circuit; an oscillator configured to generate a triangular signal; an error amplifier configured to amplify an error voltage between a reference voltage and a voltage corresponding to a current passed through the discharge lamp and receive a burst dimming signal that is a pulse signal to intermittently supply power to the discharge lamp; comparators configured to generate PWM control signals to turn on/off the switching elements, respectively, according to the error voltage from the error amplifier and the triangular signal from the oscillator; a first clamp circuit configured to clamp an output from the error amplifier so that the output from the error amplifier may not drop below a lower limit value of the triangular signal during an OFF period of the burst dimming signal; and breaking circuits configured to block the PWM control signals provided by the comparators during the OFF period of the burst dimming signal.