用于2D/3D兼容显示的电致形变凝胶可调焦柱透镜阵列的研究

2D display has the merits of wide viewing angle, high contrast ratio, full resolution; 3D display can show natural, emotional, vivid images, a switchable 2D/3D display based on a lenticular microlens array has gained much attention gradually. Liquid crystal lenticular microlens array relys on polarizer, more than 50% light has been lost, and the cost is very high; Liquid lenticular microlens array is in the preliminary stage of research, its driving apparatus is bulk, the gravity effect is serious, and the liquid optical axis is unstable; this project put forward a new intelligent material, electro-deformation and transparent polyvinyl chloride (PVC) gels, to prepare adaptive focus tunable lenticular microlens array, which can be used to convert 2D display and 3D display. The objective of this project is focusing on the charge transfer mechanism and the structure dynamics of PVC gels, the study of maching problems and key technology of PVC gels lenticular microlens array with 2D display. By controlling the type and content of the plasticizer, doping transparent liquid with high dielectric constant, ionic liquid, stabilizers, experimently analysis the change of dielectric constant, space charge distribution, charge transfer speed, Young’s modulus, electrostatic force of the PVC gels, to provide theoretical basis for obtaining large electro-deformation, low power consumption and stable PVC gels. Meanwhile, through numerical modeling and graphic electrode structure designing, to improve the matching of PVC gel lenticular lens array and 2D display, and to recude the crosstalk. By the research of this project, a PVC gel lenticular lens array with low driving voltage, fast response, high transmittance, low cost, no gravity effect and a 2D/3D convertible display with wide viewing angle, small crosstalk can be ontained.

2D显示清晰度高，3D显示栩栩如生，柱透镜光栅式2D/3D可切换显示备受人们青睐。液晶柱透镜依赖偏振片，光损失超过50%，且成本较高；液体柱透镜驱动装置笨重，重力效应严重，且光轴不稳定；本项目提出使用新型电致形变聚氯乙烯（PVC）凝胶制备可调焦柱透镜阵列实现2D/3D显示的可切换，拟针对PVC凝胶的电荷传输机理、结构动力学变化及PVC凝胶柱透镜阵列与2D显示屏匹配性的关键技术问题展开研究。通过调控增塑剂种类和含量、掺杂高介电透明液体、离子液体、稳定剂，分析PVC凝胶的介电常数、空间电荷分布、电荷传输速度、杨氏模量、静电力的变化，为获得大电致形变、低功耗、稳定的PVC凝胶提供理论依据。同时通过数值模拟和图案化电极设计，增加PVC凝胶柱透镜阵列和2D显示屏的匹配性，提高清晰度，减小串扰。预计可获得低压快响应、高透过率的PVC凝胶柱透镜阵列及高清晰度、低串扰的2D/3D可切换显示效果。

聚氯乙烯凝胶是一种高度透明、可电致变形的智能材料。在图案化电极表面旋涂聚氯乙烯凝胶，经直流电场作用，聚氯乙烯凝胶中的电负性增塑剂分子向阳极迁移并在阳极表面积累，从而发生蠕变变形。聚氯乙烯凝胶的形貌与电极结构相对应，通过改变电极结构，可以制备不同形状、不同尺寸、不同填充率的微透镜阵列。本项目围绕如何降低驱动电压和如何提高聚氯乙烯凝胶微透镜阵列的响应速度展开研究。首先，利用CYTOP疏水层修饰图案化电极基板，可以降低聚氯乙烯凝胶与基板表面的摩擦力，使得响应速度从120 s提高到240 ms。其次，使用离子液体改性聚氯乙烯凝胶，能够将驱动电压从160V降低到5V，不仅降低了功耗，还可保证聚氯乙烯凝胶微透镜可在安全电压下使用。而且透过率、成像效果、聚焦能力均保持良好状态。研究过程中发现聚氯乙烯/增塑剂在溶液状态下也能够被直流电场驱动，由此可以利用电场诱导聚氯乙烯/增塑剂溶液发生形变，待溶剂挥发定型后获得具有初始焦距的聚氯乙烯凝胶微透镜阵列。研究过程中还发现纯增塑剂由于其独特的电负性是制备电控变焦液体透镜的极佳材料。经项目组的努力，低电压快响应的聚氯乙烯凝胶微透镜的技术已见雏形，能够为聚氯乙烯凝胶柱透镜在2D/3D可切换显示中的应用起到积极的促进作用。项目组发表SCI论文14篇，申请发明专利13项；培养硕士研究生8人，其中2人顺利毕业。