The Backlight Module Optical Design

With these advantages of Emission Low, higher sensitivity, thinner and more colorful, Liquid crystal Display (LCD) is the main equipment of flat panel display. The development trend of LCD are higher display effect, high brightness and high uniformity. Since liquid crystal does not emit light itself, LCD should equipped with an illuminator called backlight module, which is a key component to improve the optical effect. Light guide plate is an important part in backlight module, the dot pattern design is the most difficult part in light guide plate designing. Based on optical requirements, a mathematical module named"Molecular Potential Energy Method"was presented in this article. By using the model, we derived dot patterns for light guide plate, which can reduce Morie interference effect, then carve these dot patterns in the mold core, after that, we made some light guide plates by plastic injection machine. Results showed that the uniformity of our products has reached 89%.Dot patterns for light guide plate can be classified as random dot patterns and regular dot patterns, random dot patterns can re-duce Morie interference effect noticeably, so we did some research about random dot patterns. The idea is: First, generate some initial dots, then build a mathematical module (Molecular Potential Energy Method) to fine tun the initial dot patterns to improve the uniformity. Main idea of Molecular potential Energy Method is: Interaction between atoms can be divided into attractive force and repulsive force. Molecular potential energy system exerts attractive force when attractive force is larger than repulsive force, and exerts repulsive force when attractive force is smaller than repulsive force. Those interactions keep all molecular distributed near an equilibrium position. This article treat each dot on light guide plate as a molecular, molecular potential field is the viewing area, dot patterns can be fine tuned by the Molecular Potential Energy Method.In order to evaluate our work, we took our designing results to a factory which is a professional back light module company to validate if those dot patterns are suitable for backlight module. We chose a 3.2 inch (high of viewing area is 71mm, width of viewing area is 39.5mm) backlight module product for our experiment. The experimental result shows that Molecular potential Energy Method is an appropriate method for designing dot patterns.