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emerging technologies


A new-generation head-mounted projective display system. Using retro-reflective material as a projection screen, the system projects stereoscopic color images with high contrast and brightness. By using an all-reflective micro mirror to reflect projection images, it delivers an open field of view.

Art and Science

Because head-mounted displays (even the see-through variety) are primarily designed to explore the pure "computer world," they provide a quite limited view of the real world. And because the displays cover the wearer's eyes, they hinder delicate facial communication between users in the real world.

In contrast, X'talVisor obtains a virtual field of view without limiting the view of the real world, and the wearer's face is not covered by the display. These characteristics are essential for wearable displays that can be used in daily life, just like ordinary eyeglasses. X'talVisor's compact design and extended field of view will make stereoscopic head-mounted displays viable tools for a broad range of applications in collaborative environments, where they have been considered too inhibiting or uncomfortable.


To enable mutual communication between people in remote sites with a high sense of presence. This requires display of a high-quality image with natural stereoscopic viewing, a large real field of view, and a large field of view in the projected image.


X'talVisor is a natural extension of retro-reflective projection technology (RPT). RPT consists of a projector, a half-mirror for reflecting projection images, and a retro-reflective screen for image projection. RPT makes it possible to project stereoscopic color images to a free-form surface screen with high contrast and brightness, but the large half-mirror covers most of the wearer's face.

In X'talVisor, the large half-mirror is replaced by an all-reflective spherical micro mirror. The pre-distorted image from the projector is concentrated by a condenser lens. The mirror is placed near the focal point of the lens so that the required mirror size becomes negligible. With a micro-spherical mirror, the image is expanded and distorted. Since the projected image is already pre-distorted, the image projected to the retro-reflective screen is not distorted, while the field of view is large. Because the mirror size is quite small, X'talVisor can display images without covering the wearer's face, so it enables natural, open-face-to-face exchanges.


X'talVisor allows "image experiences" to permeate deeply into our daily lives. Unlike conventional wearable displays, 3D scenography with heightened presence can be experienced with the same ease and comfort as wearing headphones to listen to music. For example, when users add a headset to X'talVisor, they can carry on conversations from remote locations as if they are in the same space. X'talVisor also enables training in mixed-reality environments with the same unimpeded feeling as in the real world, with no need for large systems such as flight simulators, CAVEs, etc.


Tetsuri Sonoda
The University of Tokyo
tetsuri (at)


Tomohiro Endo
Nagoya University

Naoki Kawakami
Yusuke Suzuki
Susumu Tachi
The University of Tokyo