[Paper] A Full-HD Super-Multiview Display Based on Adaptive Time-Division Multiplexing Parallax Barrier

In the conventional stereoscopy, two different images with binocular parallax are shown to each eye, where binocular vergence is induced in front of or behind the screen, while focal accommodation is always adjusted to the screen. This vergence-accommodation conflict often causes eye fatigue of the viewer. Super-multiview displays have been proposed as one of the solutions to this problem 1)-4). Super-multiview displays project multiple light rays to the pupil. When two or more rays are projected onto the retina, focal accommodation is induced to the stereo image so that the image on the retina may not be a double image. To realize a practical super-multiview display, a huge number of views are required to be displayed to cover a wide viewing zone. To overcome this problem, Takaki et al. have proposed a system to generate light field only around the tracked eye positions 5). However, the resolution of the presented image decreases because it is based on spatial multiplexing using a lenticular lens. Recently, several autostereoscopic displays that attain full resolution of the display panel have been proposed. One solution is time-division multiplexing parallax barrier 6)-7), where half of the resolution of each view is shown in one frame, while the other half is shown in the other frame by shifting the phase of the barrier and the image pattern. To suppress perceived flickers, 120 Hz refresh rate is necessary to ensure that each eye sees the full resolution image at 60 Hz. In addition, headtracking technology solves the problem of limited viewing zone 8)-11). By monitoring the position of the observer, the image or the barrier pattern is adjusted accordingly to move the viewing zone so that it may always follow the position of the observer to maintain autostereoscopy. To reduce crosstalk, Zhang et al. have proposed timedivision quadruplexing parallax barrier 12)-15). In this system the same image is delivered to two of the four viewpoints, which suppresses emergence of crosstalk when each of the viewer's eyes is positioned between the two viewpoints corresponding the same image. In this paper we propose a full-HD super-multiview display based on adaptive time-division parallax barrier and report the results of experiments to measure the focusing of human eyes to the time-multiplexing supermultiview display. Abstract This paper proposes a super-multiview autostereoscopic display with a full HD resolution. A supermultiview display, where multiple views are generated around the eyes to stimulate focal accommodation, requires generation of images for many viewpoints. When we apply time-division multiplexing, the number of views can be increased without losing spatial resolutions, while flickers stand out as the number of time-division increases. To attain more views with the same refresh rate, we set two LCD panels so that they may face the opposite directions. In this way, the order of color filter is reversed and the light rays of different colors are directed to different orientations. Each color creates a different directional light to achieve three fold views. To extend the viewing zone in the depth direction, we introduce adaptive time-division, where quadruplexing is applied when the viewer is farthest, quintuplexing is applied when the viewer is in the middle, and sextuplexing is applied when the viewer is nearest. Expansion of viewing zone and the effect of focal induction are confirmed by the experiments using a prototype system based on the proposed method.