Analysis of Color Gamut of LCD System Based on LED Backlight with Area-Controlling Technique
LI Fu-wen1, JIN Wei-qi1*, SHAO Xi-bin2, ZHANG Li-lei2, WAN Li-fang2
1. School of Optoelectronics, Beijing Institute of Technology, Beijing 100081, China 2. Central Research Institute, BOE Technology Group Co. Ltd., Beijing 100016, China
Abstract：Color gamut as a significant performance index for display system describes the color reproduction ability IN real scenes. liquid crystal display (LCD) is the most popular technology in flat panel display. However, conventional cold cathode fluorescent lamp (CCFL) backlight of LCD can not behave high color gamut compared with cathode ray tube (CRT). The common used method of color gamut measuring for LCD system is introduced at the beginning. According to the inner structure and display principle of LCD system, there are three major factors deciding LCD’s color gamut: spectral properties of backlight, transmittance properties of color filters and performance of liquid crystal panel. Instead of conventional backlight CCFL，RGB-LED backlight is used for improving color reproduction of LCD display system. Due to the imperfect match between RGB-LED’s spectra and color filter’s transmittance, the color filter would reduce the color gamut of LCD system more or less. Therefore, LCD system based on LED backlight with area-control technique is introduced which modifies backlight control signal according to the input signal. After analyzing and calculating the spectra of LED backlight which passes through the color filters using method of colorimetry, the area sizes of color gamut triangles of RGB-LED backlight with area-control and RGB-LED backlight without area-control LCD systems are compared and the relationship between color gamut and varying contrast of liquid crystal panel is analyzed. It is indicated that LED backlight with area-control technique can avoid color saturation dropping and have little effects on the contrast variation of liquid crystal panel. In other words, LED backlight with area-control technique relaxes the requirements of both color filter performance and liquid crystal panel. Thus, it is of importance to improve the color gamut of the current LCD system with area-control LED backlight.
李福文1，金伟其1*，邵喜斌2，张丽蕾2，万丽芳2 . 基于LED背光源区域控制的LCD系统色域分析[J]. 光谱学与光谱分析, 2010, 30(05): 1371-1375.
LI Fu-wen1, JIN Wei-qi1*, SHAO Xi-bin2, ZHANG Li-lei2, WAN Li-fang2 . Analysis of Color Gamut of LCD System Based on LED Backlight with Area-Controlling Technique . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(05): 1371-1375.
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