CONTROLLER FOR DISCHARGE LAMP AND LIGHT SOURCE DEVICE

摘要

A control circuit for discharge lamp which can enhance the lighting properties of a discharge lamp while reducing power consumption. A light source device is also provided. Resistance of variable resistors (RC1, RC2) is not switched to a low resistance (R02) during steady discharge at the fourth time t4, but switched to the low resistance (R02) at the fifth time t5 after power supply to a filament is lowered. Since variation in lamp impedance is absorbed sufficiently by the variable resistors when power supply to a filament is lowered, instability of discharge is suppressed and lighting properties are enhanced.