Patent ID: 6476568
Filing Date: 2002-11-05
Classification: H05B,Y02B,Y10S

Abstract:
A gas discharge lamp lighting device for lighting a gas discharge lamp having a pair of electrodes, the device comprising:electric power adjusting means for adjusting electric power supplied from a power supply to generate and output a DC voltage; gas discharge lamp driving means electrically connected to said electric power adjusting means, for converting the DC voltage from said electric power adjusting means to an AC voltage to be supplied to a gas discharge lamp; and control means for bringing the gas discharge lamp to an electrode heating state in which both electrodes of the gas discharge lamp are heated after supplying the AC voltage to the gas discharge lamp, for controlling energy supplied to the gas discharge lamp in an electrode heating state according to a voltage across the gas discharge lamp, and for bringing the gas discharge lamp to an AC discharging state in which an AC current flows through the gas discharge lamp after the energy has been supplied to the gas discharge lamp, wherein said gas discharge lamp driving means comprises a first output terminal connected to a first electrode of the gas discharge lamp, a second output terminal coupled to a second electrode of the gas discharge lamp, a first capacitor connected between the first output terminal of the said gas discharge lamp driving means and the first electrode of the gas discharge lamp; and a switching element connected in parallel with said first capacitor, turned on or turned off under control of said control means, said control means turning on said switching element and supplying a controlled amount of energy to the gas discharge lamp, and, subsequently, turning off said switching element to charge said first capacitor and bring the gas discharge lamp to the AC discharging state when a voltage across said first capacitor reaches a threshold voltage, thereby controlling the energy supplied to the gas discharge lamp in the electrode heating state.