A lighting method for a high pressure discharge lamp in which a high-pressure
pulse
is applied to cause a dielectric breakdown, and then in step S1, it is judged
whether the lamp voltage is higher than 25 volts as the current switching voltage.
If it is judged negatively in step S1, the control circuit (304)
performs a constant current control with the current limiting level set to 6 amperes
(step S2). If it is judged that the lamp voltage is higher than 25 in step
S1, the control circuit (304) performs a constant current control
with the current limiting level set to 4 amperes (step S3). When the lamp
voltage rises and reaches 50 volts, the control circuit (304) performs a
constant power control so that the lamp power remains to be 200 W.