Patent attributes
A touch-screen device includes an imaging waveguide, in which the imaging waveguide has a radiation receiving surface and an imaging surface different than the radiation receiving surface. The imaging waveguide is configured to receive, at the radiation receiving surface, radiation emitted by a contact receiving structure, and transmit the received radiation from a position on the radiation receiving surface to a position and/or angle of incidence on the imaging surface as a function of the position on the radiation receiving surface at which the transmitted radiation was received. An imaging sensor coupled to the imaging surface of the imaging optical waveguide is configured to detect radiation incident upon the imaging surface of the imaging optical waveguide. A processing device coupled to the imaging sensor is configured to determine contact points on the exposed contact surface of a contact receiving structure based on radiation detected by the imaging sensor.