ABSTRACT
Directional backlights have often been employed for generating multiple view-zones in three-dimensional (3D) display, with each backlight converging into a corresponding view-zone. By designing the view-zone interval for each pupil smaller than the pupil's diameter, super multi-view (SMV) can get implemented for a VAC-free 3D display. However, expanding the backlight from a light-source to cover the corresponding display panel often needs an extra thickness, which results in a thicker structure and is unwanted by a near-eye display. In this paper, two wave-guides are introduced into a near-eye virtual reality (NEVR) system, for sequentially guiding more than one directional backlight to each display panel for SMV display without bringing obvious extra thickness. A prototype SMV NEVR gets demonstrated, with two backlights from each wave-guide converging into two view-zones for a corresponding pupil. Although the additional configured light-sources are positioned far from the corresponding wave-guide in our proof-of-concept prototype, multiple light-sources can be attached to the corresponding wave-guide compactly if necessary. As proof, a 3D scene with defocus-blur effects gets displayed. The design range of the backlights' total reflection angles in the wave-guide is also discussed.
ABSTRACT
With strip-type timing-apertures attached to each eye of a viewer, more than one perspective views can be guided to either eye sequentially through different timing-apertures, thus implementing VAC-free (vergence-accommodation conflict-free) SMV (Super Multi-view) 3D (three-dimensional) display. To overcome the FOV (field of view) limitation problem due to small size of the timing-apertures along their arrangement direction, novel polarization architectures are designed to the timing-apertures in this paper. Correspondingly, the display screen of the proposed SMV display system is divided into M > 1 sub-screens along the arrangement direction of the timing-apertures, with adjacent sub-screens emitting light of mutually orthogonal polarization. At a time-point of each time period, a group of M timing-apertures, which correspond to the M sub-screens in a one-by-one manner along the arrangement direction, are turned on for creating an M-fold FOV, with each polarized timing-aperture of the group allowing light from the corresponding sub-screen passing through and blocking light from sub-screen(s) adjacent to the corresponding sub-screen. At 2T > 1 time-points of each time period, 2T groups of timing-apertures are turned on sequentially for presenting more than one two-dimensional images of the displayed scene to each eye, to implement SMV display based on persistence of vision. M stands for the FOV magnification number and T stands for the two-dimensional image number for each eye. As proof, a 3-fold FOV of 41° gets implemented experimentally with a currently available timing-aperture array of M = 3, accompanied by an effective noise-free region (ENFR) of 8.34 mm. Furthermore, the promising of freeing FOV from timing-aperture constraint fundamentally by larger M is described, out-of-screen blur along strip direction of the timing-apertures and the problem of limited ENFR are discussed.
