ppcy111 20 Aug 2012, 04:40 posted on 1 0
When a finger or object touches the surface, the infrared light hits the object and is reflected downward and seen by an infrared camera below the surface. That allows the client to implement remarkably richer set of interactions. It also allows the client to track multiple users even if they interact close to – or reach across – one another. The cuts out the visual image from being seen by the camera and allows the camera to only see infrared light that illuminates the objects/fingers on the touch surface. The camera is connected to a computer and a tracking application uses the camera image to track and create multi touch(http://www.uiworks.cn/en/multitouch/) coordinates.