Patent ID: 6494587
Filing Date: 2002-12-17
Classification: G09G

Abstract:
A method of backlighting a flat panel display over an expanded dimming range, the method comprising:providing a backlight including a plurality of cold cathode fluorescent lamps positionable directly behind a diffuser; providing a plurality of drive circuits, wherein each of the plurality of drive circuits is adapted to adjust arc current of at least one of the plurality of cold cathode fluorescent lamps to change an electron density in the at least one of the plurality of cold cathode fluorescent lamps and to thereby change a luminance output of the at least one of the plurality of cold cathode fluorescent lamps; and providing control signals to each of the plurality of drive circuits to separately control luminance outputs of different ones of the plurality of cold cathode fluorescent lamps such that at the same instant the different ones of the plurality of cold cathode fluorescent lamps are driven to substantially different luminance intensities, thereby reducing an overall minimum luminance provided by the backlight and expanding the dimmable range of the backlight.