从设计、仿真与加工入手研究液晶背光模组中侧入式导光板的激光微加工技术.通过光学软件构建导光板的光学结构并采用蒙特卡洛光线追迹方法进行模拟仿真,结果表明具有渐变密度分布的微结构能够提供高均匀性的光输出.基于仿真结果,运用激光微加工技术进行验证设计.激光微加工获得的微结构在100倍光学显微镜放大测量下尺寸约为30.14 μm,接近于设计值30 μm,同时对单个微结构的3D表面形貌特征进行分析.十组采用激光微加工技术与丝网印刷技术加工的导光板分别安装至侧入式背光模组样机中进行对比.对比结果显示,激光微加工的导光板相比于传统的丝网印刷技术具有更好的光学均匀性和更低的色差,均匀性提高了6.2%,而色差下降了0.002 7.激光微加工技术快而简单,且整个加工过程是完全环保的,具备高性能、自动化生产和易于薄型化的优点.

This paper presents the design,simulation and fabrication of edge-lit Light-Guide Plates(LGPs) using laser micro-machining technique for Liquid crystal display backlights. The optical structure of the LGP is established in an optical software,and simulated by tracing rays using Monte Carlo method. The designed microstructures with gradually changing desity are proved to offer output homogeneous illuminance. Based on the simulation results,Laser Micro-machining Technique(LMT) fabrication is performed for verification. The measured size of the fabricated microstructure is approximately 30.14 μm under 100× magnification,which is close to the prescribed size of 30 μm. The 3D surface morphology of the fabricated microstructure is also available. Ten groups of edge-lit LED display backlight prototypes equipped with the LGPs fabricated by LMT and Screen Printing Technique(SPT) are developed and analyzed. Comparison results show that LGPs fabricated by LMT can provide better optical uniformity (6.2% higher) and lower color difference (0.002 7 lower) than conventional method (SPT). Besides the advantages of faster and simpler,LMT is entirely environmentally-friendly during the machining process. With the characteristics of good performance,automatic production and thinning tendency,it is reasonably believed that LMT will have bright prospect in the near future,and may be a promising alternative method for SPT in display applications.