Fabrication of a novel integrated light guiding plate by microelectromechanical systems technique for backlight system

Abstract

A backlight panel (BLP) with a cold cathode fluorescent lamp (CCFL) light source, which is referred to as the backlight unit (BLU) is considered in the light module of a thin film transistor (TFT) LCD. A typical BLP is comprised of a light-guiding plate (LGP) and some optical components, such as reflective sheets, diffusive sheets, and prism sheets. We propose an integrated LGP that combines three functions of optical components by using microelectromechanical systems (MEMS) and hot-embossing techniques. The microprism structure, the micropyramid structure, and an aluminum thin film are used for the integrated LGP not only to eliminate the five optical components, but also to save the space and the cost of the BLU. From experimental illumination results, the maximum illumination is 426.1 lux and the minimum illumination is 370.4 lux. Thus, the integrated LGP achieves a uniformity of illumination of 86.9%. The new BLU could be simplified as only one integrated LGP and only one white LED light source without using any optical components. We anticipate that the integrated LGP could make the displays thinner and brighter for thin LCD application.