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Adaptive Parallax Autostereoscopic LED Display
Kouta Minamizawa

Keitaro Shimizu

Masahiko Inami

Keio University
Yokohama, Japankouta@tachilab.org

Keio University
Yokohama Japan
k-taro@kmd.keio.ac.jp

Keio University
Yokohama, Japaninami@kmd.keio.ac.jp

Susumu Tachi

Shigeto Yoshida

Noriaki Yamaguchi

Keio University
Yokohama, Japantachi@tachilab.org

Sharp Corporation
Osaka, Japan
yoshida.shigeto@sharp.co.jp

Sharp Corporation
Osaka, Japan
yamaguchi.noriaki@sharp.co.jp

Naohisa Ohta

Keio University
Yokohama, Japannaohisa@kmd.keio.ac.jp

Shigeki Imai

Sharp Corporation
Osaka, Japan
imai.shigeki@sharp.co.jp!

Figure 1. The 38-inch adaptive parallax
autostereoscopic LED display!

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Single-viewer mode
Multi-viewers mode
Figure 2. Reconstruction method of the 3D image.
(Left) In single-viewer mode, the light fields are gathered around the viewer’s head.
(Right) In multi-viewers mode, the light fields are distributed in front of the display.

Introduction

Autostereoscopic 3D displays using static parallax barrier or
lenticular lens are commercially available in these days. In thesemethods, however, the number of viewpoints is fixed at the timeof manufacturing. Active parallax barrier [Perlin, 2000] anddynamic parallax barrier [Peterka, 2008] have been proposed toimprove the resolution and number of viewpoints by moving theposition of the parallax barriers. To implement an
autostereoscopic display, with dynamic parallax barriers, duallayered LCD panel is a common approach as is mentioned by[Hirsch, 2010]. And a method of optimizing the parallax barriers[Lanman, 2010] has been proposed to represent more
perceptually-acceptable imagery. Remaining limitations of thedual-layered LCD method are the refresh rate and brightness of
the LCD panel. Commonly used high-speed LCD has 120Hz inrefresh rate and around 500cd/m2 in brightness so thatconventional systems did not have enough quality to be used inpublic. To solve this problem, we propose an adaptive parallax
autostereoscopic display composed of a high-density/highfrequency LED panel and a high-speed/high-contrast LCD panel.

Implementation!!We implemented a novel 38inch high-density LED panel that has
240Hz refresh rate and 1500cd/m2 brightness. More than 160,000
full-color LEDs are arranged on the panel with 1.5mm pitch. A
moving image rendered on the basis of a particular parallax
barrier pattern is displayed on the LED display, and a 240Hz VA
type LCD panel with HD resolution, which works as dynamicparallax barrier, is placed in front of the LED panel. The distance
between the LED panel and LCD panel is 45mm and both theimages on the LED and the LCD panels are displayed
synchronously. Consequently, appropriate rays of light aredelivered to each viewpoint as shown in Figure 2. As the barrier
pattern can be varies arbitrarily, the number and direction ofmotion parallax can be flexibly controlled according to theviewer’s condition.
Copyright is held by the author / owner(s).
SIGGRAPH Asia 2011, Hong Kong, China, December 12 – 15, 2011.
ISBN 978-1-4503-0807-6/11/0012

Figure 3. (Left) Construction of the 3D display using a LED
panel as light source and a LCD panel as dynamic parallax
barrier. (Right) Our developed high-density LED module
When a viewer stands in front of the display, the system
recognizes the rough position of the viewer’s head by a camera,
and then the viewpoints are densely arranged around the viewer’s
head so as to maximize the range of the horizontal motion
parallax. When the viewer lies down in front of the display, theparallax would automatically changed to vertical. Further, when
there are multiple users in front of the display, the number andangle of horizontal parallax would be changed according to thedistribution of the people. This proposed system enhances theviewing style of 3DTV from individual use as gaming to public
use as digital signage.

References
Perlin, K., Paxia, S. and Kollin, J. 2000. An Autostereoscopic
Display. In Proc. of ACM SIGGRAPH 2000, pp. 319-326.
Peterka, T., Kooima, R. L., Sandin, D. J., Johnson, A., Leigh, J.,
DeFanti, T. A., 2008. IEEE Trans. on Visualization andComputer Graphics, Vol. 14, No. 3, pp. 487-499.
Hirsch, M. and Lanman, D., 2010. Build your own 3D display, In
Proc. of ACM SIGGRAPH ASIA 2010 Courses, Article 16.
Lanman, D., Hirsch, M., Kim, Y., and Raskar, R., 2010. ContentAdaptive Parallax Barriers: Optimizing Dual-Layer 3D
Displays using Low-Rank Light Field Factorization, ACM
Transactions on Graphics, Vol. 29, Issue 6, Article 163.