Tabletop Computing: Your current is your password

When a small group crowds around a personal computer to work on a project, there?s often considerable shuffling for a good view of the monitor and control of the mouse or keyboard. A new technology from Mitsubishi Electric Corp. aims to make collaboration easier by borrowing some ideas from a common piece of furniture: the table. Mitsubishi?s DiamondTouch displays a PC screen on a high-tech tabletop. People sitting around it use their fingers to create and manipulate projected virtual objects, with the system knowing whose fingers did what thanks to small currents of electricity that flow through the chairs.

Masakazu Furuichi, chief engineer at the Japanese electronics maker, hopes DiamondTouch will become a tool for games, government decision making, education and in other areas in which several people need to interact intuitively and instantly. But first the price will have to drop; the tables can cost as much as $10,000 each. ?It?s a futuristic way to use a computer without a keyboard or a mouse,? Furuichi says. ?It?s simple to use for everybody, including older people and others who aren?t very used to handling computers.?

How It Works
The way it works is straightforward: A 42-inch panel, which covers almost all of the 47-inch tabletop, has an array of antennae, or touch sensors that conduct electricity, embedded in the surface. Each of the users?up to five people?sits on a pad that conducts a harmlessly low and unnoticeable current. It passes through the body much like the electricity used in bathroom scales that measure body fat. The system can identify each user?s unique current, and thereby knows who is touching the surface. The signals connect to a computer, which controls images relayed from a projector above to the table?s surface. The markings from each person show up on the table in different colors.

The DiamondTouch isn?t cheap and it?s available only by order. The price isn?t expected to drop until there?s enough demand to warrant mass production. During a recent demonstration at the company?s research center near Tokyo, engineers showed off a variety of uses. In one example, a tap on the table switched between ?before? and ?after? satellite pictures of the area hard hit by the 2004 Asian tsunami. A finger dragged across the image drew a line, which could have represented a path for delivering aid.

In another example, the table worked as a giant virtual Scrabble board, with images of letters selected and dragged with simple finger actions. Another learning application showed pictures of animals that had to be matched to their habitats. The technology also has been combined with voice-recognition technology for a video game in which digital images of tanks scuttle across a desert landscape on the tabletop display. The player, pretending to be a commander, can control movement by tapping the display and shouting commands.

Others are exploring tabletop computing. HP Labs, the research arm of United States computer maker Hewlett-Packard Co., recently showed its version of the coffee table touch panel, though it?s still in the development phase.

Though touch panels aren?t commonly built into tables today, they are found in many other places, including automated teller machines, car navigation equipment and even karaoke machines. They are also used in handheld computer devices, portable gaming systems and mobile phones.

The technology will become even more commonplace as more software is developed, said Yuji Mitani, who heads consulting and manufacturing company Touch Panel Laboratories near Tokyo.

Touch panels may be set up in kindergartens for virtual finger painting and other activities. But such uses are likely to come before tables like Mitsubishi?s start to catch on, he said, partly because people aren?t accustomed to sharing one panel in group situations.
?Touch panels are much more direct and immediate? than using a keyboard or a mouse, Mitani said. ?They are going to become more widespread as people come up with more applications.?