Seelinder: The Cylindrical Lightﬁeld Display
Tomohiro Yendo ∗Nagoya University / JST1

Naoki Kawakami †The University of Tokyo

Susumu Tachi ‡The University of TokyoIntroduction

The ideal 3D display allows multiple viewers to simultaneously
see 3D images without special glasses from a free position and aview that corresponds to there positions. Since the multiplex hologram [Cross 1977] device has these features, it is used in the display of artwork, entertainment, advertisements, and other applications. However, it can only display static images. On the otherhand, some volumetric scanning displays [Favalora et al. 1995] areused to display dynamic images that can be seen from free directions; however, their applications are limited because their images
are “phantom images,” where all objects are see-through. It is difficult to provide a multiview display that can be seen from all horizontal directions with conventional methods, such as using lenticular sheets, due to the limitations of resolution and the shape of thetwo-dimensional display devices, which include LCD panels. In
other approaches, we have proposed a ray-based cylindrical display[Endo et al. 2000] that allows multiple viewers to see 3D images
from a 360◦ horizontal arc. This technique uses a cylindrical parallax barrier and a one-dimensional light source array constructedfrom such semiconductor light sources as LEDs aligned in a verticalline. The light source array rotates along the inside of the cylindrical parallax barrier, and the intensity of each light is synchronously
modulated with the rotation. A prototype display is also demonstrated at Emerging technologies in SIGGRAPH2001 [Endo 2001].
It showed adequate images of each viewer corresponding to his position and movement that smoothly brought changes into view; theimages have high presence. But it displayed only monochrome binary still images generated from 3D models.

1-D light source array (LED Array)(Slow rotation

Cylindrical parallax barrier(Fast rotation)

Figure 1: Schematic diagram of basic structure

Now we extend a previous ray-based cylindrical displaying methodand develop a new display that can show dynamic colored images.
Moreover, we developed a ray control method to display actual objects whose source is a set of photos taken from around an object.
In this paper, for the first time we describe the design’s details andcreate image data of the new display.

2Principles

The basic structure of the proposed display is shown in Figure 2. It
has two spinning cylinders, one inside the other. The outer cylinder
is a parallax barrier that has a series of vertical slits spinning rapidly
while the inner cylinder spins slower in the opposite direction witha series of one-dimensional LED arrays on its surface. If the slit
width of the outer cylinder is sufficiently small, the light throughthe slit becomes a thin flux, whose direction is scanned rapidly by
the spinning of the outer cylinder. In this paper we call this angularscanning. By synchronously changing the intensity of each LED in
the arrays to the spinning, rays of different direction have different
colors with time-multiplexing. Moreover, the inner cylinder also
rotates slower, and the LED array’s position is a little different when
the next slit comes, and so rays are shot to each direction from eachposition. In this way, a cylindrical light field display is realized.
∗ e-mail:yendo@nuee.nagoya-u.ac.jp† e-mail:kawakami@star.t.u-tokyo.ac.jp‡ e-mail:tachi@star.t.u-tokyo.ac.jp

Figure 2: Photograph of Seelinder

References
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E NDO , T., K AJIKI , Y., H ONDA , T., AND S ATO , M. 2000. Cylindrical 3-d video display observable from all directions. In Proceedings of Pacific Graphics 2000, 300–306.
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