A touch screen which uses light sources at one or more edges of the screen which directs light across the surface of the screen and at least two cameras having electronic outputs located at the periphery of the screen to receive light from said light sources. A processor receives the outputs of said...http://www.google.de/patents/US20100090985?utm_source=gb-gplus-sharePatent US20100090985 - TOUCH SCREEN SIGNAL PROCESSING
