Rear-Projected Image

The screen built into the coffee table uses a rear projector which projects the image from behind onto a diffuser, which is a screen made of film. This technology is sometimes found in museum exhibits, such as this:

Infrared Multi-Touch Sensing

The table uses a method called Frustrated Total Internal Reflection (FTIR) to sense touches. Lots of LEDs emit infrared light which, due to the shallow angle they hit the surface of the film screen, reflect themselves completely within the screen. When someone touches against the screen, the infrared waves are frustrated in many directions, some of which escape the film.

These waves are picked up by two infrared cameras underneath the tabletop. Software processes these images to interpret touch gestures to be sent to the computer.

Completely Functional OS

This table runs a completely functional Linux operating system capable of everything on a typical personal computer - web browsing, word processing, games, and more. The multi-touch capabilities allow for more advanced user input; touch gestures can be interpretted as simple clicks or scrolls, but different sizes, amounts, and shapes of touches can also be utilized by software programmers writing for this platform.

Some of Our Parts

Table we're working with:

Infrared LEDs and aluminium frame with holes for the afformentioned LEDs:

Screen materials: