A 30,000-cd/m2, 50-lm/W,and 92%-luminance-uniformity flat discharge fluorescent lamp for LCD backlights

Abstract— A 5.2-in.-diagonal simple-structured argon-mercury cold-cathode flat discharge fluorescent lamp has been developed for LCD backlighting. A pair of insulated electrodes is provided at the top and bottom ends of the inner surface of the front glass plate. Phosphor is deposited on both the front and rear glass plates. A luminance of 30,000 cd/m² and a luminous efficacy of 50 lm/W were obtained with a luminance uniformity of 92% without the use of a diffuser sheet. A mechanism for obtaining the high luminous efficacy is described. Luminance can be dimmed down to 4% of the peak value by extending the pulse interval and/or by reducing the pulse amplitude.