聚合物稳定液晶/向列相液晶复合微透镜阵列的结构设计及其裸眼3D显示

Nowadays, the naked-eye 3D display is the next generation of display technology. It is the new priority-development high technology around the world. In order to realize this new type of display technology, some optical elements with an important feature of tunable focal length are urgently needed. Liquid crystal microlens array (LCMLA) is a kind of the optical element with electrically tunable focal length. And the LCMLA has greatly potential in naked-eye 3D display. However, the problems of the LCMLA such as polarization and disclination line will seriously affect its imaging performances. Those problems are the main bottlenecks in 3D display and could also restrict its application in 3D display. In this project, the method of utilizing polymer stabilized liquid crystal (PSLC) and nematic LC is proposed to solve the above problems. The structure of the LCMLA will be studied in details. Firstly, the interaction between UV photosensitive monomers and nematic LC molecules will be studied. The mechanism of phase-separation and phase-shift will be found out in the PSLC layer. While the coupling effect between the internal materials and the external factors happens, the electrically tunable adaptive phase-shift feature in the nematic LC layer will be revealed. With some experimental instruments, the microscopic phase behaviors affecting LC alignment inside the LCMLA will be carefully explored. Secondly, the two dimensional LC directors distribution in the LCMLA will be calculated. That distribution result is got under the structure of a Thin-Film-Transistor electrode structure with a high impedance of medium layer. The structural parameters of the LCMLA will be further optimized. With the new structure of the LCMLA, the relationship among the structural parameters of the LCMLA, polarization, and disclination line will be evaluated. Finally, the optical properties of the proposed LCMLA will be measured. And the imaging features of the LCMLA will be quantitatively analyzed by some experiments. Based on this LCMLA, a naked-eye 3D display with integrated imaging will realize. The purpose of this project is to reveal the method to avoid the problems of the proposed LCMLA such as the polarization and disclination line. In this way, the theoretical and technical basics for developing the naked-eye 3D display and a new type of LCMLA will establish.

裸眼3D显示是世界各国争先发展的下一代显示技术，焦距可电调的液晶微透镜阵列是实现该技术的关键元件。然而，偏振和向错线会严重影响液晶微透镜阵列的成像性能，是制约该器件在3D显示应用的主要瓶颈。本项目以聚合物稳定液晶薄膜为研究对象，对液晶微透镜阵列的结构设计开展研究，具体包括：在聚合物稳定液晶层中，研究紫外光敏单体与向列相液晶分子相互作用，发生相分离、相移的规律；在器件内部材料与外界因素协同耦合作用下，揭示向列相液晶层电控自适应相移的规律，探究影响器件内表面液晶分子取向的微观相行为；设计含高阻抗介质层的薄膜晶体管式电极结构，计算器件内液晶指向矢的分布规律，阐明器件结构参数与偏振、向错线之间的关系，并优化器件结构参数；定量分析液晶微透镜阵列光学成像特性，实现集成成像裸眼3D显示。本项目旨在揭示液晶微透镜阵列偏振及向错线的消除方法，为发展裸眼3D显示和研制新型液晶微透镜阵列奠定理论和技术基础。

项目以向列相液晶E7、紫外光敏单体NOA65为研究对象，探究了薄膜厚度、紫外光的曝光时间、强度、聚合温度、外加电压、电极图案尺寸以及掩模版图形等因素，对液晶、聚合物相分离的影响。通过实验发现，使用较低强度的紫外光，较长时间照射，可有效促使液晶与单体发生较为完全的相分离；所分离出液晶的液滴体积，较传统方法要大。基于此，制备了电控可调谐的二元相位菲涅尔透镜；并进一步探索了在掺杂手性分子条件下，所制备光栅器件的偏振无关性。利用液晶弹性连续体理论，计算得到液晶二维自由能密度的表达式，获得了液晶微透镜阵列内液晶指向矢的二维数值分布情况；并经过理论分析，发现液晶器件内向错线产生的根源主要在于液晶分子在反倾区域产生转向不一致，即电场边缘处电场线变化较为剧烈、易造成液晶分子无法在弛豫时间内顺利完成旋转。针对液晶器件向错线产生原因，提出了使用纳米碳管掺杂向列相液晶的思路。为了最大化利用掺杂纳米粒子特性来提升液晶透镜的性能，在所设计的液晶透镜器件结构中加入了PEDOT：PSS高电阻层；并引入相衬显微镜成像概念，借助相位调制理论解释了掺杂纳米粒子提升成像对比度的原因，获得了器件结构参数与器件成像质量之间的关系，尤其是与向错线之间的关系。基于所提出的液晶微透镜阵列与CCD构成了3D成像系统，并进行了相关的3D成像测试；以相分离方法，制备了可用于3D显示的聚合物薄膜。基于所研究的聚合物薄膜、液晶微透镜阵列，提出了一种软硬件一体化的高分辨率裸眼3D显示的方法，该方法是在传统二维液晶显示器基础上改造获得。所提出的方法算法核心为：在频率域中，通过对微透镜阵列成像获得的图像阵列进行平移；再将平移后的结果与原始结果进行融合，利用时分复用并借助人眼暂存效应获得了高分辨率裸眼3D显示结果。本项目较为详尽研究了液晶器件中偏振、向错线的消除方法，提出了一种软硬件一体化的思路，为发展裸眼3D显示和研制新型液晶光电器件奠定了理论和技术基础。