One of the key issues in conventional stereoscopic displays is the well-known vergence-accommodation conflict problem due to the lack of the ability to render correct focus cues for 3D scenes. Recently several light field display methods have been explored to reconstruct a true 3D scene by sampling either the projections of the 3D scene at different depths or the directions of the light rays apparently emitted by the 3D scene and viewed from different eye positions. These methods are potentially capable of rendering correct or nearly correct focus cues and addressing the vergence-accommodation conflict problem. In this paper, we describe a generalized framework to model the image formation process of the existing light-field display methods and present a systematic method to simulate and characterize the retinal image and the accommodation response rendered by a light field display. We further employ this framework to investigate the trade-offs and guidelines for an optimal 3D light field display design. Our method is based on quantitatively evaluating the modulation transfer functions of the perceived retinal image of a light field display by accounting for the ocular factors of the human visual system.

Abstract:A new integral-imaging-based light field augmented-reality display is proposed and implemented for the first time, to our best knowledge, to achieve a wide see-through view and high image quality over a large depth range. By using custom-designed freeform optics and incorporating a tunable lens and an aperture array, we demonstrated a compact design of a light field head-mounted-display that offers a true 3D display view of 30° by 18°, maintains a spatial resolution of 3 arc minutes across a depth range of over 3 diopters, and provides a see-through field of view of 65° by 40°.

A 3D light field display typically reconstructs a 3D scene by sampling either the projections of the 3D scene at different depths or the directions of the light rays apparently emitted by the 3D scene and viewed from different eye positions. These light field display methods are potentially capable of rendering correct or nearly correct focus cues and therefore addressing the well-known vergence-accommodation conflict problem plaguing the conventional stereoscopic displays. However, very limited efforts have been made to investigate the effects of light ray sampling on the quality of the rendered focus cues and thus the visual responses of a viewer in light field displays. In this paper, by accounting for both the specifications of a light field display system and the ocular factors of the human visual system, we systematically model and analyze the ray position sampling issue in the reconstruction of the light field and characterize its effect on the quality of the rendered retinal image and on the accommodative response in viewing a 3D light field display. Using a recently developed 3D light field display prototype, we further experimentally validated the effects of ray position sampling on the resolution and accommodative response of a light field display, of which the result matches with theoretical characterization.

A head‐mounted light field display based on integral imaging is considered as one of the promising methods that can render correct or nearly correct focus cues and address the well‐known vergence‐accommodation conflict problem in head‐mounted displays. Despite its great potential, it still suffers some of the same limitations of conventional integral imaging‐based displays such as low spatial resolution and crosstalk. In this paper, we present a prototype design using tunable lens and aperture array to render 3D scenes over a large depth range while maintaining high image quality and minimizing crosstalk. Experimental results verify and show that the proposed design could significantly improve the viewing experience.