Patent ID: 7332874
Filing Date: 2008-02-19
Classification: H05B

Abstract:
1. A discharge lamp ignition device for lighting a discharge lamp having a pair of facing electrodes as main electrodes, comprising: a feeder circuit for feeding power to the discharge lamp, an inverter located at a stage following the feeder circuit that inverts the polarity of a voltage impressed on the discharge lamp, a transformer with a primary winding and a secondary winding, a capacitor connected to the transformer, and an intermittent voltage impression means for drive impression of voltage on the primary winding of the transformer; wherein the secondary winding of the transformer is constituted such that the voltage generated in the secondary winding is impressible overlapping the output voltage of said inverter between the electrodes of the discharge lamp by means of interposing it in a path connecting the output of the inverter and the electrodes for the main discharge of the discharge lamp; wherein the capacitor has a capacitance with a value such that a free oscillation frequency of the voltage generated in the secondary winding does not exceed 3 MHz; wherein, during startup of the discharge lamp, the intermittent voltage impression means drives voltage impression at an average frequency of at least 8,000 repetitions per second and the voltage impression drive continues for a period after discharge begins in the discharge lamp.