Patent ID: 8314573

Claim:
A discharge lamp lighting circuit comprising: a driving voltage generating portion arranged to supply an AC driving voltage to a discharge lamp to be a driving target; and an auxiliary lighting circuit on a terminal side of the discharge lamp, wherein the auxiliary lighting circuit includes: a capacitor, a switch unit and a resistance element in series between the terminal side of the discharge lamp and a fixed voltage terminal; a control portion for controlling a conducting state of the switch unit; and a diode having an anode disposed on the fixed voltage terminal side in parallel with the switch unit; wherein the control portion is arranged to turn ON the switch unit when a lamp voltage to be applied to the terminal of the discharge lamp is higher than a predetermined threshold voltage, and to turn OFF the switch unit when the lamp voltage is lower than the threshold voltage, and wherein the control portion controls the switch unit to turn on after the discharge lamp lighting circuit is turned on, but before the discharge lamp turns on, and wherein the control portion controls the switch unit to turn off after the discharge the discharge lamp turns on.