LED Backlight Modular Design

Nowadays, there is a rapid development in the trade of LED, and its application throughout the field of lighting, display, cars' lamp and backlight. In this paper, we focus on the design of lightguide as it is the key part of the backlight modular. The main topic is how to transform the point source to the surface in the meanwhile achieving the high light efficiency. We are interested in the integration of BEF, diffuser, even reflective film with lightguide. It means a lot especially in large LCD.In this paper, we make use of the lighting software to simulate the backlight modular and brought up with the plan relatively. We make a design of edge-lit one to thinner the backlight. Then we take the advantage of reasonable design of micro-structure on the lightguide together with the Bezier and polynomial polyfit to get good uniform luminance and high light efficiency. Image processing has been employed here to deal with the area division, threshold is set after iterative optimization to make sure the division random and reasonable. The r-cut method is then introduced to insure the light distribution. Finally to polyfit the radii of the dots and the results show a uniform luminance of 90%.For the large size of backlight modular, we put up with a new method that make the V-cut on both sides of the lightguide witch is equal to the effect with BEF, i.e. integrating the BEF (Brightness Enhancement Film) with the lightguide. Then by coating on the non-inlet surface, the optical efficiency has been highly improved to 65%, and with a luminance uniformity of 88%.