视角扩展的头戴式超多视图三维显示

Head-Mounted Super Multi-View Three-Dimensional Display with Enlarged Field of View

近眼小孔因对入射瞳孔光束光斑尺寸的有效约束而被用于基于时序复用的超多视图显示,可以实现较大的景深,但小的尺寸也导致一个近眼小孔所能实现视角的严重受限。设计多组近眼小孔时序选通,通过同组不同近眼小孔各自对应显示区域的拼连,可以有效解决各时间点仅通过一个近眼小孔观察时所面临的视角受限问题;但各近眼小孔对应显示区域出射光通过非对应小孔出射,又引入串扰噪声这一新问题。针对头戴式显示,设计同组相邻近眼小孔具有相异正交特性的多组近眼小孔,利用各显示区域所出射正交特性光被其对应小孔的相邻小孔屏蔽的特性,解决同组相邻小孔间的串扰问题。搭建验证性头戴式超多视图显示系统,在由M个一维条状小孔构建的一个近眼小孔组中,设计相邻2个近眼小孔,分别仅允许偏振方向相互垂直的光通过;基于视觉滞留效应,利用T个近眼小孔组的时序选通,实现单眼T个视点的超多视图显示。相对于一个时间点仅一个近眼小孔选通的情况,近眼小孔组使视角得到M倍的扩展。受制于所使用的常规投影透镜,仅取M=3进行验证时,视角扩展为19.7°。

The near-eye aperture is used to realize the super multi-view display based on time multiplexing because it effectively limits the divergence angle of the light beam emitted from a display screen.Therefore,a large depth of field can be achieved.However,its small size also exerts a serious limitation on the field of view that can be obtained using only one neareye aperture.This limitation can be successfully overcome by designing timing sequentially gated multiple groups of near-eye apertures and splicing up the display regions corresponding to different apertures in the same group.However,the light emanating from each display region may pass through non-corresponding apertures,thus creating a new problem of crosstalk noise.To address these problems,mutually orthogonal characteristics are endowed to the adjacent near-eye apertures in this work,which makes the light emitted from each display region with an orthogonal characteristic be blocked by the adjacent apertures of its corresponding aperture and forms a certain range of noise-free region in the observing plane.This foundation allows for the realization of a super multi-view display with a large field of view based on near-eye apertures.In this study,a proof-of-concept head-mounted super multi-view display system is constructed and M one-dimensional strip-type apertures are composed as a group,in which two adjacent apertures,respectively,only allow light with mutually perpendicular polarizations to pass through.Based on the persistence of the vision,T groups of timing sequentially gated near-eye apertures are used to realize the super multi-view display with T viewpoints for each eye and M times larger field of view compared with the case where only one aperture opens at each time point.This work only takes M=3 for verification and gets an expanded field of view of 19.7°due to the limitations by optical performances of the used convention projection lenses.