Patent ID: 7333094

Claim:
An optical touch panel comprising: a support; an optical fiber illumination assembly arranged along and above at least part of a periphery of said support to define a detection region, said assembly including: at least one optical fiber having a core and cladding, said at least one optical fiber having a cross section defining a circumference, said at least one optical fiber having at least one light scattering discontinuity at least one location therealong, said at least one optical fiber having optical power at least one light transmissive region having a focus located in proximity to said discontinuity, said at least one optical fiber extending along three sides of said detection region; and a light source arranged for directing light along said at least one optical fiber; at least one light detector, arranged to detect changes in the light received from said optical fiber illumination assembly produced by the presence of a finger or stylus in said detection region, said at least one detector comprising a pair of detectors located at adjacent corners of said detection region alongside ends of said at least one optical fiber; and detection circuitry receiving at least one output from said at least one light detector and providing an output indication of the two dimensional location of finger or stylus impingement in said detection region, said detection circuitry operating at least partially by triangulation.