Research On The Methods Of Improving Uniformity And Brightness Of The Backlight System

Compared with Cathode Ray Tube (CRT), Plasma Display Panel (PDP) and Digital Light Processing (DLP), Liquid Crystal Display (LCD) has the advantages of flatter, higher sensitivity, thinner and more colorful, which make it the main equipment of flat panel display. To make sure its expanding future, it is necessary to improve its display quality, especially the brightness and uniformity. Since LCD itself is not luminiferous, the design of Backlight System, which is valuable in both theory and application, becomes the focus of the research in display and imaging domain.Currently, the main problems that LCD industry is faced with are light guiding and brightness improvement. The paper analyzed several reasons of light energy attenuation while traveling in the LCD Backlight System. Feasible approaches of improving effective light energy ratio are demonstrated, such as: introducing Enhanced Specular Reflector(ESR), reusing polarization light, adding Brightness Enhancement Film(BEF), Light Guide Plate(LGP) and so on.On the basis of LCD product in China, this paper designed experimental optical system by reusing polarization light in the light source, calculated the light energy usage ratio and analyzed the error. Our design is for large size display equipment. It enhances the light energy usage ratio, minimizes the attenuation of polarization, and decreases the usage of lens and electricity consumption. The design is simple and achievable.This paper built the 3D model of Backlight System using LightTools, simulated the whole optical system by Monte Carlo ray trace techniques, and viewed the output of illuminance and intensity in a wide variety formats, making it easy for further debug and perfect.In this paper, the ray trace program was improved to work with interactive solid-modeling using .txt file as interface. Besides, the integrated LGP with BEF was discussed to make display equipment having smaller size and better quality.