基于平面波导的大视场增强现实眼镜显示器

Planar waveguide based augmented reality smart glasses with large field of view

本文提出了一种用于实现大视场紧凑型的增强现实眼镜显示器的方法。采用平面波导以及嵌入的窄带负滤光膜来完成图像的传导和耦合。整个光学系统结构简单,并且具有体积小、质量轻的优点。在此方法下,通过建立光线在波导中的几何导光模型,分析了图像传导的约束条件,得到了波导结构的设计参数以及其与显示视场角之间的关系。根据计算结果,制作了一个3mm厚的波导耦合器件来进行原理验证。实验结果表明,利用设计的波导元件及搭建的增强现实眼镜显示器的光学系统可以实现虚拟图像的传导以及其与真实环境的融合,测得的显示视场角约为50°。

We present a way to achieve the compact augmented reality (AR) smart glasses with a large field of view (FOV). A planar waveguide and embedded narrow band minus filters are used for image transmission and coupling. The optical system based on the method is simple in structure and has the advantages of small size and lightweight. A geometric model for the propagation of light in the waveguide is constructed. Based on this model, the constraints of the structure and the dependence of designed parameters with viewing angles are analyzed. According to the calculations, a 3 mm thick waveguide is fabricated to investigate the feasibility of the theory. Experimental results demonstrate that the prototype can deliver a projected image and realize the fusion of the virtual image and the real scene as expected, the measured viewing FOV was about 50°.