基于微结构导光板的增强现实裸眼3D显示系统及其虚实遮挡问题研究

Recently, augmented reality (AR) display has become a hot field for research and application. In head-mounted AR three-dimensional (3D) display, there exists severe problems such as visual fatigue, vertigo and discomfort. Thus, it is significant to research on naked-eye AR-3D display without visual fatigue. In this project, an optical see-through naked-eye AR-3D display system based on integral imaging is proposed. We are aimed at research of 3D display performance enhancement based on microstructured light guide plate, and building correct occlusion relationships between real scene and virtual objects. The specific contents include: modeling point light source output of microstructured light guide plate, and researching the influences of microstructure profile parameters on the optical performance of point light source, to provide theoretical basis for enhancement of brightness, uniformity of brightness, image crosstalk and other display performance parameters; Obtaining light field data of real scene for depth modeling based on integral imaging, and researching free viewpoint characterization of occlusion effect; Building light field control system based on 4D light field theory, and researching digital recovery of occluded light rays, to build correct occlusion effect and to recover depth cues. This research can obtain naked-eye AR-3D display system with high realism, practicality and comfort, having wide prospect and social value.

近年来，增强现实（AR）显示逐渐成为研究和应用热点。头戴式AR三维（3D）显示存在视疲劳、眩晕、佩戴不适等技术瓶颈问题，研究无视疲劳的裸眼AR-3D显示具有重要意义。本项目提出一种基于集成成像原理的光学透视裸眼AR-3D显示系统，研究基于微结构导光板的3D显示性能增强，构建该系统中真实场景和虚拟物体间的正确遮挡关系。具体内容包括：建立微结构导光板的点光源阵列光场输出理论模型，研究微结构三维形貌参数对点光源光学性能的影响机制，为亮度、亮度均匀度、图像串扰等关键3D显示性能增强提供理论依据；基于集成成像原理获取真实场景的光场数据进行深度建模，研究虚实遮挡关系的自由视点表征；基于四维光场理论构建真实场景光场遮挡调控系统，对被遮挡的有效光线进行数字恢复研究，构建正确虚实遮挡关系，恢复正确的深度线索。研究成果可实现高真实度、高实用性、高舒适度的裸眼AR-3D显示系统，具有广阔应用前景和重要社会价值。

本项目对增强现实(AR)3D显示开展了较为丰富的理论和实验研究，理论设计了高性能的微结构导光板用于透明3D背光，实现了裸眼AR-3D显示的虚实遮挡，提升了光场全息的显示质量，探索了头戴式增强现实全息近眼显示的新方法，取得了如下重要成果：1.理论设计了数量渐变式散射网点及倒圆台微结构，实现高亮度、均匀的透明导光板3D背光。2.开发了多平面高速投影的压缩光场3D显示系统，提出透明帧方法实现了光学透视，并提出光场掩膜方法实现虚实遮挡。3.提出掩膜阵列方法实现了导光板3D显示的虚实遮挡。4. 借鉴导光板点光源阵列模型，提出了点光源式光场编码计算全息图及其他高性能光场计算全息方法，实现了快速计算、分辨率提升及信息量压缩。5.探索了新型全息视网膜投影（RPD）增强现实近眼显示方法，提出了景深拓展方法，实现了无透镜的单SLM彩色动态全息RPD显示，并通过编码共轭光波实现了全息RPD的出瞳拓展。本项目的开展为增强现实3D显示的发展提供了新思路。项目组发表相关SCI论文18篇，申请发明专利9项，授权5项。培养研究生5人。. AR显示被认为是“下一代计算平台”。本项目针对AR显示中的虚实遮挡、全息计算、RPD出瞳拓展等关键问题，探索了新的解决方案，为我国AR显示领域的基础研究提供有益参考。