Light-emitting diode cover lens design for large-scale liquid crystal device television backlight

We present a high-performance cover lens for light-emitting diode (LED) light sources to be applied to large-scale liquid crystal device television (LCD-TV) backlight modules. The cover lens with simple structure can redistribute light rays emitted from an LED light source to make the light distribution more extended so that the luminance uniformity of the backlight module can be increased. To gain a better performance, the parameters of the lens structure are optimized using a genetic algorithm. The simulation result shows that using the cover lens can achieve a luminance uniformity of 94.75% and an optical efficiency of 72.29% for a 46-in LCD-TV backlight module. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3421791]