6. Infrared: Albatron and HP

Albatron at Computex

Another technology worth a look is the one used in the 22" touchscreen that Albatron presented at the most recent Computex and in HP’s TouchSmart PC. The Poor Man’s Tactile With this technology, infrared diodes placed around the screen generate a very thin beam of light at the surface of the screen. Sensors also placed around the screen detect the topology of the infrared “carpet” covering the screen.

And the HP TouchSmart Too

This approach has more or less the same advantages that FTIR offers: the possibility of using a finger or any other opaque object, low cost, no loss of display quality, easy adaptability to large panels and immunity to wear. The accuracy, however, is not as good, because the touch is detected a little before the finger actually contacts the surface of the screen, which has a negative impact.

Microsoft Surface and TouchWall

Another highly promising technology is surface computing. The principle is similar to what we just discussed, but not quite. Let’s take the example of Microsoft’s Surface.

A view of Microsoft Surface’s innards

This table is made up of a thick layer of acrylic that serves as a projection surface on which the image is created by a standard video projector using DLP technology. Up to that point, there’s no big difference from a standard home cinema setup. But to make this ordinary screen intelligent, Microsoft added a source of infrared light and multiple infrared cameras. The IR source projects its light over the entire surface of the screen. When an object or a finger approaches, it casts a shadow, which the cameras pick up. Image processing determines the position and movement.

Fingers Are Objects Too Thanks to this technique, the screen can recognize objects and interact with them. For example, Microsoft Surface can recognize a camera placed on its surface and react by activating additional functions, such as exchanging snapshots. It can also recognize a cell phone. That multiplies the possibilities for what touchscreens can add to the computing experience.

A Wall Costs Less Than A Table

As interesting as it is, this concept of an interactive table is disconcerting for those of us who are used to sitting in front of a vertical screen. So Microsoft has used the same tactile technology in a more familiar format: TouchWall. The principle? A video projector illuminates a frosted-glass screen from behind, with a set of three lasers forming a carpet of infrared light on the front surface of the screen and an infrared camera detecting the presence of objects.

The $10,000 table

Thus, TouchWall is a blend of the technology used by Microsoft Surface and that used in Albatron and HP’s screens. The advantage of TouchWall is that the fabrication cost is said to be much lower than for Microsoft Surface — Microsoft is talking in terms of a few hundred dollars, whereas the tactile table sells for around $10,000.