As demonstrated by New York University consulting research scientist and Perceptive Pixel founder Jeff Han at the 2006 Technology Entertainment Design (TED) conference, multi-touch technology allows a user (or users) to affect the screen with as many fingers as possible at the same time. This makes typing, magnification of pictures, windows and text, as well as shaping images on the screen, possible with intuitive hand movements. For example, one application Han demonstrated allowed him to quickly finger-draw crude puppets onto a large touch screen and then animate them with finger movements.
Previous touch screens have used technology such as resistive metal coatings that register changes in electrical current at the point of contact or spring mounted strain gauges, but those only allowed the software to process a single touch at a time. On the Perceptive Pixel touch screen, light-emitting diodes (LEDs) line the edges of a 6-millimeter-thick piece of clear acrylic, reflecting infrared light along predictable paths on the screen's surface, a phenomenon known as total internal reflection. When something touches the screen, the light disperses outside of the surface from the contact point. A camera behind the acrylic captures the light diffused from any and all contact points, and image-processing software interprets the touches in real time.
In the future, Han said, he hopes that the technology will pave the way for large interactive whiteboards and touch-screen tables and walls that multiple users can interface with. Han said that this is the most interesting application of the technology, since a group of users could all collaborate on one project, on one screen, at the same time.
The first wall-sized version of Perceptive Pixel's multi-touch screen is set to go to an undisclosed U.S. military customer within the month.
###