Patent ID: 7109666

Claim:
A lighting device for a dielectric barrier discharge lamp comprising: a pulse number judging circuit to which a dimming control signal is supplied as an input signal designating a dimming ratio of the dielectric barrier discharge lamp using a rare gas, for judging a number of pulses of drive signals per unit time corresponding to the dimming ratio from the dimming control signal, and for outputting a result as a pulse number setting signal; a drive signal generating circuit to which the pulse number setting signal outputted from the pulse number judging circuit is supplied, for outputting the drive signal pulses having a number of pulses per unit time designated by the pulse number setting signal; and an inverter circuit which generates an HF pulse voltage for driving the dielectric barrier discharge lamp, wherein the unit time is equal to a period T of a repetition cycle of the dimming control signal, wherein the drive signals are a pair of pulse signals each having substantially an equal repetition cycle and each having a different phase from each other by substantially 180°, and wherein a fluctuation of a start timing of a first pulse of the drive signals in a repetition period T of the dimming control signal for a repetition period t of the drive pulse signals confined in a range from −½×t to +½×t.