Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Performance Evaluation of 2-Dimensional Light Source using Mercury-free Flat Fluorescent Lamps for LCD Backlight Applications

  • Park, Joung-Hu (Dept. of Electrical Eng. and Comp. Sci., Seoul National University) ;
  • Cho, Bo-Hyung (Dept. of Electrical Eng. and Comp. Sci., Seoul National University) ;
  • Lee, Ju-Kwang (Dept. of Electrical Eng. and Comp. Sci., Seoul National University) ;
  • Whang, Ki-Woong (Dept. of Electrical Eng. and Comp. Sci., Seoul National University)
  • Published : 2009.03.20
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Abstract

Recently, 2-dimensional flat light sources have been attracting much attention for its use in LCD backlight applications because of its high luminous efficiency and uniformity. A long-gap discharge, mercury-tree flat fluorescent lamp has been developed, which shows a high brightness ($>5000\;cd/m^2$) and high luminous efficacy (60 lm/W). Additionally, it has a wide operating margin and stable driving condition with the aid of an auxiliary electrode. For driving the lamp, a narrow pulse power to maintain the glow discharge state is required. Since there has been no research for this kind of lamp driving, this paper proposes a newly developed short-pulse, high-voltage lamp-driving scheme. The proposed lamp system uses a ballast with a coupled-inductor in order to raise the short pulse voltage up to the lamp ignition level and to obtain energy-recovery action during the glow discharge mode. The operation principles are presented and also the system performances such as the lighting efficiency, spatial and angular uniformities are evaluated by hardware experiments. The results show that the proposed lighting system is a good candidate for the next-generation of LCD backlight systems.

Keywords

References

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