Patent ID: 8513903
Filing Date: 2013-08-20
Classification: H05B,Y02B

Abstract:
1. A discharge lamp lighting device comprising: a DC power circuit for regulating an input voltage matching a tube voltage of a discharge lamp; an inverter for converting a DC output from said DC power circuit into an AC power to supply a current to said discharge lamp; a control circuit for controlling said DC power circuit and said inverter; and an inductor connected with an output of said inverter to apply a high-voltage pulse across electrodes of said discharge lamp at the start-up of said discharge lamp, wherein said inverter comprises: a first set of switching elements for switching an output voltage of said inverter to a voltage with one polarity; and a second set of switching elements for switching said output voltage to a voltage with the other polarity, wherein each of said switching elements is allowed to perform switching operations at the start-up of said discharge lamp in such a pattern that after turning on and off said first set of switching elements more than once, said second set of switching elements is allowed to turn on and off more than once, wherein a timing to turn on one set of said switching elements other than the other set of said switching elements turned on last is set in a range of 0 to 180 degrees in a period of a resonant frequency determined by a component of said inductor connected with the output of said inverter, a component determined by capacitances of a diode included in each of said switching elements and its peripheral circuit and an input voltage of said inverter, with a time at which all of said switching elements begin to turn off last defined as 0 degree, and wherein a timing to turn on again the set of said switching elements equal to the other set of said switching elements turned on last is set in a range of 180 to 360 degrees in the period of said resonant frequency, with a time at which all of said switching elements begin to turn off last defined as 0 degree.