Research Of Dynamic LED Backlight Algorithm For Large-scale LCD

Liquid crystal display (LCD) is very popular in the flat panel display market for its advantages of big size, slight thickness, clear image quality, low electric power consumption, and long service life. It has become the consumers’most favorite flat panel display device. With the help of LED backlight system, which is the mainstream of the LCD market, LCD has improved the problems of those old products with CCFL backlight system effectively, such as low contrast, narrow color gamut, mercury pollution, and so on. How to determine the brightness of the backlight quickly and accurately is the key step of the dynamic backlight control system. Thus, the research of dynamic backlight algorithm is of great practical value and market benefit.This paper points out the flaws of the traditional backlight algorithms and the difficulty of the research field of dynamic backlight algorithm through studying existing algorithms, and works for improving the backlight algorithm to get better backlight signals. Firstly, this paper introduces the concept of local image quality, which improves the objective assessment of image quality effectively. Then a novel dynamic backlight algorithm, based on distortion threshold of local image (DT-LI), is proposed. This algorithm is indicated the validity and superiority by large numbers of simulation experiments. Finally, this paper combines DT-LI algorithm with RGB-LED system successfully, and is demonstrated the feasibility of this method by experiments.Firstly, this paper expatiates the advantages of dynamic LED backlight system, and introduces the theory and method of dynamic backlight control technology. After analysis and comparison, dynamic backlight algorithm is established as the core of the dynamic backlight control system and the main research object of this paper. Secondly, some traditional algorithms are introduced. In order to solve the problems existing in traditional algorithms, the concept of local image quality is introduced to improve the objective assessment of image quality, and a novel dynamic backlight algorithm, DT-LI, is proposed, which is indicated the validity and superiority by experiments. Finally, DT-LI algorithm is successfully combined with RGB-LED system and gets better image quality and lower backlight luminance.