Nakamura Toshiteru, Takashima Yuzuru
Opt Express. 2018 Oct 1;26(20):26520-26533. doi: 10.1364/OE.26.026520.
For the see-through and near-to-eye displays, light throughput and uniformity of luminance over the field of view are improved by employing an optical image guide with discretely depth-varying surface relief holographic gratings. In the design process, a newly developed mathematical model, in conjunction with rigorous coupled wave analysis of diffraction efficiency, eliminates massive and time consuming iteration of non-sequential ray tracing but rapidly identifies the depth-varying structure and optimum optical performance. The depth-varying grating based approach achieved a 1.37x improvement in light throughput compared to the conventional depth un-varying design, 315 cd/m/lm, along with improved uniformity over the field of view of 35 (H) x 20 (V) degrees with an eye box size of 17 (H) x 14 (V) mm.
对于透视式近眼显示器，通过采用具有随深度离散变化的表面浮雕全息光栅的光学图像导光板，可提高光通量和视场亮度均匀性。在设计过程中，一种新开发的数学模型与严格的衍射效率耦合波分析相结合，消除了非序列光线追迹的大量耗时迭代，而是快速确定随深度变化的结构和最佳光学性能。与传统的深度不变设计相比，基于随深度变化光栅的方法实现了1.37倍的光通量提升，达到315 cd/m/lm，同时在35（水平）×20（垂直）度的视场范围内实现了更好的均匀性，眼框尺寸为17（水平）×14（垂直）毫米。
