深度线索增强的全息视网膜投影显示  

Holographic retinal projection near-eye display with enhanced depth cues

作　　者：屠科锋 孙菲 王梓 吕国强[1] 冯奇斌[1] TU Kefeng;SUN Fei;WANG Zi;LÜGuoqiang;FENG Qibin(Academy of Opto-Electric Technology,School of Instrument Science and Opto-Electronics Engineering,Hefei University of Technology,Hefei 230009,China;Anhui High-Tech Development Center(Anhui Basic Research Management Center),Hefei 230088,China)

机构地区：[1]合肥工业大学仪器科学与光电工程学院光电技术研究院,安徽合肥230009 [2]安徽省高新技术发展中心(安徽省基础研究管理中心),安徽合肥230088

出　　处：《液晶与显示》2024年第7期901-908,共8页Chinese Journal of Liquid Crystals and Displays

基　　金：国家自然科学基金(No.62275071,No.61805065)。

摘　　要：全息视网膜投影显示(retinal projection display,RPD)具有大景深的特征,是能够缓解辐辏聚焦冲突(vergence accommodation conflict,VAC)的近眼显示技术之一。但是,景深过大会导致聚焦模糊的深度线索丢失。因此,提出了一种基于带限随机相位的RPD全息图计算方法,其通过在目标图像面引入带限随机相位控制进入瞳孔的光束宽度,从而达到控制景深范围并增强深度线索的目的。计算全息图并再现过程可分为3步:首先,根据目标图像所在深度及进入瞳孔时限制的光束宽度计算得到带限随机相位。第二步,目标图像乘以球面波相位及带限随机相位后通过一步菲涅尔衍射获得全息图。最后,准直的激光光源照射于加载全息图的空间光调制器,再现的物光汇聚于人眼瞳孔处实现深度线索增强的全息RPD。实验结果表明,基于带限随机相位的全息RPD不仅具有低散斑、高再现质量等优势,而且能够灵活控制目标图像的景深,为观察者提供聚焦模糊的深度线索。Holographic retinal projection display(RPD)is one of the near eye displays that can alleviate vergence accommodation conflict(VAC)due to its large depth of field.However,an excessive depth of field(DOF)will cause a loss of depth cues whose image clarity does not vary with depth.To solve this problem,a band-limited random phase based holographic RPD is proposed by using the band-limited random phase to control the light beam width into the viewer’s pupil.And the depth of field will be limited by the controlled beam width.Thus,the depth cue of defocus can be enhanced.The process of the bandlimited random phase based RPD can be divided into three steps:Firstly,the band-limited random phase is calculated by the light beam width into the pupil and the depth of the target image.Secondly,the target image is multiplied by the spherical wave phase and the band-limited random phase.The hologram is obtained by a one-step Fresnel diffraction from the processed complex amplitude distribution in the target image plane.Lastly,the spatial light modulator loaded with the hologram is illuminated by the collimated laser light source.And the reconstructed object light converges on the pupil which achieves the depth cue enhanced RPD.The experiment verifies that the band-limited random phase based holographic RPD has the advantages of low scattering and high reproduction quality.And it can flexibly control the DOF of the target image and provide the observer with depth cues of focus blur.

关 键 词：3D显示 全息显示 视网膜投影显示 带限随机相位 

分 类 号：TN27[电子电信—物理电子学]