sensing used FTIR.
[size=0.8em]Jeff Han
Han had discovered that the "robust" multitouch sensing was possible using "frustrated total internal reflection" (FTIR), a technique from the biometrics community used for fingerprint imaging. FTIRworks by shining light through a piece of acrylic or plexiglass. The light (infrared is commonly used) bounces back and forth between the top and bottom of the acrylic as it travels. When a finger touches down on the surface, the beams scatter around the edge where the finger is placed, hence the term "frustrated." The images that are generated look like white blobs and are picked up by an infrared camera. The computer analyzes where the finger is touching to mark its placement and assign a coordinate. The software can then analyze the coordinates to perform a certain task, like resize or rotate objects.
Jeff Han demonstrates his new "interface-free" touch-driven screen.
After the TED talk became a YouTube hit, Han went on to launch a startup called Perceptive Pixel. A year following the talk, he told Wired that his multitouch product did not have a name yet. And although he had some interested clients, Han said they were all "really high-end clients. Mostly defense."
Last year, Hann sold his company to Microsoft in an effort to make the technology more mainstream and affordable for consumers. "Our company has always been about productivity use cases," Han told AllThingsD. "That's why we have always focused on these larger displays. Office is what people think of when they think of productivity.