Patent ID: 7176637

Claim:
A rare gas fluorescent lamp apparatus, comprising: an outer enclosure in which electric discharge is generated; a rare gas fluorescent lamp using excimer light generated by the electric discharge, in which at least one of electrodes is disposed on an outer surface of the outer enclosure, and a fluorescent material layer is formed on an inner side of the outer enclosure; and a power supply unit, which supplies high frequency wave voltage between the electrodes of the rare gas fluorescent lamp, wherein the power supply unit has an inverter unit and a control unit, the control unit has a detecting unit which detects lamp voltage or lamp current and converts the lamp voltage or the lamp current into a predetermined voltage signal, a reference voltage source unit, and an error amplifier which compares the voltage signal detected by the detecting unit with a reference voltage of the reference voltage source unit so as to carry out negative feedback control to the inverter unit, and a time constant control unit is provided in the reference voltage source unit or the detecting unit, in which the reference voltage of the reference voltage source unit or the voltage signal detected by the detecting unit is controlled with passage of time from initiation of a lamp lighting operation by the time constant control unit.