Patent ID: 8358079

Claim:
A discharge lamp lighting apparatus for lighting a discharge lamp in which a pair of electrodes for main discharge face each other, comprising: a power supply circuit that supplies electric power to the discharge lamp; an electric supply control circuit that controls the power supply circuit; an inverter that is provided in a downstream side of the power supply circuit and that performs polarity reversals of voltage to be impressed to the discharge lamp; a periodic drive circuit for generating an inverter drive signal, which is a periodic signal for carrying out a periodic drive of the inverter; a transformer, which has a primary side winding and a secondary side winding; and an intermittent voltage applying unit for performing a voltage impression drive to the primary side winding, wherein the secondary side winding of the transformer is inserted in a path that connects an output of the inverter and the electrodes for main discharge of the discharge lamp to each other, so that a voltage generated in the secondary side winding can be superimposed on an output voltage of the inverter and is impressed between the electrodes of the discharge lamp, wherein in a starting sequence of the discharge lamp, while the periodic drive circuit generates the inverter drive signal so that the frequency of the inverter becomes a start-up initial frequency that is higher than stable lighting frequency, the electric supply control circuit controls the power supply circuit to output no-load opening voltage, which is voltage sufficient to maintain electric discharge of the discharge lamp, wherein the periodic drive circuit generates the inverter drive signal so that the frequency of the inverter gradually decreases until reaching a first threshold frequency from the start-up initial frequency, wherein when the frequency of the inverter reaches the first threshold frequency, the periodic drive circuit generates the inverter drive signal so that the frequency of the inverter becomes the stable lighting frequency, and wherein the electric supply control circuit controls the power supply circuit to output current, which is sufficient to maintain electric discharge of the discharge lamp.