TWISTER: A Media Booth
Kenji Tanaka
Junya Hayashi
Yutaka Kunita
Masahiko Inami
Taro Maeda
Susumu Tachi
Graduate School of Information Science and Technology, The University of Tokyoe-mail: twister@star.t.u-tokyo.ac.jp
http://www.star.t.u-tokyo.ac.jp/projects/mutel/

TWISTER (Telexistence Wide-angle Immersive STEReoscope) is an immersive full-color autostereoscopic display,designed for a face-to-face telecommunication system called“mutual telexistence”, where people in distant locations cancommunicate as if they were in the same virtual three dimensional space.
The basic idea of mutual telexistence is the projection ofhuman beings into a virtual environment in real time[Tachiet al. 1996][Kunita et al. 1999]. Each human user resides inside a booth, which displays a live full-color panoramic andautostereoscopic images to the user, and at the same time,
captures images of the user from every angle. Autostereoscopic here means there are no obstacles to hide the user’s
face, and therefore, the face of the observer can be clearly
seen. With multiple booths, people at remote locations canmeet together as if they were close at hand.
TWISTER has rotating display units surrounding the observer. One unit consists of two LED (Light-Emitting Diode)arrays and a parallax barrier. Each LED array consistsof pairs of red, green, and blue LED’s, and displays timevarying patterns so that the observer can perceive an image.
Due to the use of LED, TWISTER can be used as a displayof high intensity full-color images for use in a bright room.
The rotation of the display unit makes it a wide angle display. In fact, the angle of view as a normal display is 360
degrees.
The key device for autostereopsis is the rotating parallax barrier. One of the LED arrays is for the left eye, andthe other is for the right eye. Because the parallax barrier
obscures the opposite side LED emission, diﬀerent images
are shown to the left and right eyes. The angle of view asa stereoscopic display depends on the direction and the position of the observer. If the head of the observer is ﬁxed,
it exceeds 120 degrees. Thus, the observer can experience
panoramic and autostereoscopic images without bothersome
eyewear.

Figure 2: A user stands inside a booth (left) and sees theﬁgure of other person (right).
(a)

(b)

Figure 3: (a)The displayed full-color natural images.
(b)TWISTER provides separate light sources to the left andright eyes.

rotateLED arrayfor left eye

Acknowledgments This research has been conducted as apart of the CREST Telexistence Communication Systems
Project supported by JST (Japan Science and TechnologyCorporation)

LED arrayfor right eye

NL

References

RKunita, Y., Inami, M., Maeda, T., and Tachi, S. 1999.
Prototype system of mutual tele-existence. In ACM SIGGRAPH ’99 Conference Abstracts and Applications, 267.

Bparallax barrier

Tachi, S., Maeda, T., Yanagida, Y., Koyanagi, M., andYokoyama, H. 1996. A method of mutual tele-existence
in a virtual environment. In Proceedings of the ICAT’96,9–18.

observerFigure 1: The principle of the rotating parallax barrier. In
areas L and R, only images for the left and right eye can beseen, respectively. In area B, both images can be seen, while
in area N no image can be seen.

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