ClearBoard

2001

Hiroshi Ishii (US) (JP)

Minoru Kobayashi
Tangible Media Group

"ClearBoard" combines video drawing on a common white board and a video conferencing function that allows face to face conversation. The seamless integration of interpersonal space and the shared workspace, in which shared information is manipulated collaboratively. By inserting a common drawing surface between two separate spaces, "ClearBoard" is able to achieve isotropy while expanding the space at hand.

The project's goal is the seamless integration of interpersonal space and shared workspace. It supports face-to-face interaction between two interlocutors who are collaboratively sharing and manipulating information. To realize this goal, we came up with a simple concept: people speaking to each other through a glass wall while drawing on both sides of it.

"ClearBoard" combines video-drawing technology that allows simultaneous drawing on a common whiteboard and a video conferencing function that allows face-to-face conversation. Minoru Kobayashi and Hiroshi Ishii collaborated in the design and testing of this system in 1991 when they were colleagues at NTT Human Interface Laboratories. "ClearBoard" consists of two networked terminals connected by a video channel. Each terminal consists of a large screen tilted at a 45-degree angle and covered with a half-silver mirror; a video projector behind the screen from which images are projected; and a camera mounted on the ceiling. When one user draws on the screen with a fluorescent pen, the drawing, the face and the upper body of that user is reflected in the half-silver mirror captured by a camera on the ceiling. When this image is rear-projected onto the other screen, it creates the illusion that the other person is on the other side drawing on the screen.

The installation supports both simple eye contact and "gaze awareness," letting each user know exactly what part of the common drawing surface the other is looking at. Eye movements are linked to thought processes and play an important role in non-verbal communication. Earlier conferencing systems were unable to provide gaze awareness. By inserting a common drawing surface between two separate spaces, "ClearBoard" is able to achieve isotropy while expanding the space at hand.