Novel integrated light-guide plates for liquid crystal display backlight

Abstract

A conventional LCD backlight system is composed of light sources, a light-guide plate (LGP) and optical sheets, such as reflection sheets, diffusion sheets and prism sheets, etc. In order to make the backlight system thinner and brighter, we propose a novel integrated LGP based on micro-prism structures by using traditional transparent polymethyl methacrylate (PMMA) material, which can be designed to control the illumination angle, and to get high uniformity of intensity. So the backlight system will be simplified to use only one LGP and to require no other optical sheets. By using the Monte Carlo ray tracing method, the light scattering phenomenon inside the LGP is analysed. The illumination angle with forward directivity and sufficient intensity uniformity are optimized with the simulation program. Design results reveal that our LGPs can achieve a uniformity of intensity better than 86%, and get a peak illumination angle from +40? to ?20?, without using any optical sheets. Design examples, including 1.8?inch LGPs and 14.1?inch LGPs, are also performed.