为了实现液晶显示器的轻薄高亮化, 进一步减小背光模组的厚度和成本, 光学膜片的复合化已成为各大光学膜片厂商研究开发的重点。本文对背光模组的结构以及液晶显示用光学膜片的光学效能做了描述, 利用light tools软件对光学膜片复合化过程中的关键影响因子做出了研究, 探讨了棱镜顶角角度、棱镜周期(Pitch)与棱峰刺入深度(D)对复合结构光学膜片的影响机制; 并对2张膜片的复合结构以及3张膜片的复合结构进行了建模仿真, 模拟其光学效果, 分别从中心亮度、均匀度、可视角角度做出评估分析, 得到不同组合架构的光学复合结构对于显示画面的改善特点, 并通过实验对仿真进行了验证。通过仿真与实验, 探究得到了棱镜的顶角角度90°, 棱镜的周期为24～54 μm, 刺入深度为1～3 μm时, 复合光学膜片的辉度均匀度可达到80%以上, 该研究对于实际的复合光学膜片的应用开发具有一定的指导意义, 将有助于加快背光模组的开发进度, 减少背光模组的厚度和成本。

In order to realize the lightness of the LCD(liquid crystal display)and further reduce the thinness and the cost of backlight module, composite optical films have become the focus of research and development of most optical films manufacturers. In this paper, the structure of the backlight module and the optical performance of the optical film for liquid crystal display are described and optical efficiency of optical films for LCD are described. The pivotal factors in the process of optical films recombination are studied by using light tools software. The influenced mechanism of prism angle, prism pitch and prism peak penetration depth (D) are evaluated. Two types of composite optical films structure are separately discussed and simulated, one is two-in-one structure; another one is three-in-one structure include. Through using the light tools simulation, the optical effects are evaluated and analyzed from the point of view of center brightness, uniformity and visual angle. Via the phenomenon of stimulating, the improvement characteristics of optical composite structure with two different combination structures for display picture are obtained. Through simulation and experiment, it is found that when the top angle of prism is 90°, the pitch of prism is from 24 μm to 54 μm, and the penetration depth (D) is 1～3 μm, the brightness uniformity of composite optical diaphragm can reach more than 81%. This research has certain guiding significance for practical application and development about composite optical films, which will help to speed up the development progress of backlight module and reduce the thickness and cost of backlight module.