摘要
微结构光学元件(导光板、扩散板)是液晶显示器(LCD)背光模组里的核心组件,其主要作用是引导光的散射方向,用来提高亮度和控制亮度的均匀性。导光板或扩散板上的微结构的形状和排布形式是决定射出光源的辉度、分布均匀性及出光效率等光学性能的主要因素。为了实现光源在通过导光板(扩散板)转向到所需的工作面时衰减最小化,行之有效途径之一是通过对其底面上微结构外型设计及其排布方式最优化来实现。
本文借助光学模拟软件Lighttools,基于蒙特卡洛光线追迹原理,重点研究了导光板和扩散板上微结构外型及其排布方式。为了提高背光模组的透光率及光线均匀性,本文通过Lighttools软件模拟的方法分析导光板(扩散板)底面上的半球型、V-cut微结构各个参数对背光系统的导光性能的影响程度,并对模拟结果进行对比分析,得出较佳的导光板(扩散板)结构。
本文详细介绍了自己设计的均匀度及扩散性能测试实验台的原理,并详细介绍了扩散板的导光性能测试方法。对已加工出的四种扩散板进行透光率、均匀度及扩散性能测试,发现三角锥微结构对光线的散射效果最好,而V型槽微结构对光线的均匀性最好。并借助Lighttools光学软件进行相应模拟,然后将实验结果与模拟结果进行对比验证。
The optical components (light guide plate or diffuser plate) are the key component of the backlight module in Liquid Crystal Display (LCD). They can soften the light distribution, and reduce the difference between brightness and darkness to make the light distribution more uniform. The diffusivity, lminance and transmittance depend mainly on the geometry and placement of micro-structures. Therefore, optimum design of the geometry and placement of the micro-structures not only improves the lminance and the emitting transmittance, but also decreases the processing cost. The optimization and design of the micro-structures on the surface of the plate are the critical factors in manufacturing optical plate of good optical properties.
The size and arrangement of micro-structures are simulated using Lighttools software Lighttools based on a Monte Carlo ray tracing. The influence of the magnitude and arrangement of semispheres or V-Cut on the optical properties of the optical plate is analyzed by using this method. By analyzing the simulation results, we got the light guide plate with better optical properties.
This paper introduces the principle of the test equipment of uniformity and diffusion capacity, and also the optical properties testing method. By this method, we test the transmittance, uniformity and diffusion capacity of the fabricated diffuser plates. Analyzing the simulation results, we find the diffusion capacity of diffuser with quadrihedrons is the best and the uniformity of the diffuser with V-cut is the best.Finally, we simulate the four diffusers by optical software and contrast the simulation and equipment results.
引文
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