P‐36: LCD Planar Backlight Employing the External Electrode Fluorescent Lamps Driven by Square Pulses from Switching Inverter

Abstract

The planar luminaries with the external electrode fluorescent lamps arrayed on a flat panel for the LCD-backlight have been improved by driving with the square pulses from a single switching inverter. With the square pulses of the driving frequency about 30 kHz, the high efficiency up to 40-70 lm/W and high brightness up to 30,000 cd/m 2 along with the luminance uniformity 90% in the 15-inch, 18-inch, 21-inch diagonal panels, respectively, could be obtained.

40.4: Capacity Coupled Electrodeless Discharge Backlight Driven by Switching Inverter for 17″ and 20.1″ LCD TVs

“…Since the discharge current in EEFLs is self-restricted by wall charge accumulated on the dielectric material around the electrode, the multi-EEFLs connected in parallel can be driven by a single driving system. Particularly, the brightness is no different among lamps so that a good luminance uniformity has been simply achieved in the backlight arraying with EEFLs [1][2][3]. Practically, the inverters should be small enough to fit the LCD modules.…”

“…Capacity coupled electric discharge backlights arraying the external electrode fluorescent lamps(EEFLs) [1][2][3] have been introduced by a single inverter, and they have had a relatively long life times because of use of external electrodes. In the flat panel employing the EEFLs, the luminance efficiency of 20 lm/W with the brightness of 10,000 cd/m 2 has been reported in Ref.…”

“…The high luminance and the high efficiency have been shown by operating with a square pulse of low frequency less than 100 kHz from switching inverter in Refs. [2,3]. So far it has taken some times for the backlight to be commercialized since the inverter has not been well designed in size for the backlight to fit the LCD modules.…”

49.4: High Power Dimming Control for a Large Area LCD Backlight

“…LCD has been developed from battery-powered notebook to the monitor and TV. For the backlight of a large area panel, direct lighting backlight with the multi-lamps operated by a single inverter system has been introduced [1][2][3][4][5][6][7][8][9][10]. As the panel size increases, the backlight needs a high power resulting in difficulties in adjusting the brightness of backlight with a conventional dimming method.…”

P‐38 Discharge Characteristics of External Electrode Fluorescent Lamps (EEFLs) for LCD Backlighting Application

“…The most conventional light sources include CCFL. Recently, the EEFL, a fluorescent lamps without cold cathode, was introduced as a new light source for LCD backlighting [1,2]. The electrode structures of the CCFL and EEFL are shown in Fig.…”