Patent ID: 7733029
Filing Date: 2010-06-08
Classification: H05B,Y02B

Abstract:
1. A high pressure discharge lamp lighting device for supplying an AC lamp current to light up a high pressure discharge lamp, comprising: a lamp current former that forms a lamp current having a waveform in which one cycle of a standard period current with a polarity inversion of a predetermined standard period and one cycle of a short period current with a polarity inversion of a period shorter than the predetermined standard period appear alternately, and in which a duty ratio before the polarity inversion for at least one of the standard period current and the short period current is different than a duty ratio after the polarity inversion, wherein the lamp current former has a current controller that sets at least one of a current value before the polarity inversion for the short period current and a current value after the polarity inversion for the short period current to be higher than a current value of the standard period current.