Patent ID: 7333095

Claim:
An optical touch panel comprising: a support defining a generally planar surface; an optical 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 light guide, said at least one light guide having at least one light scatterer, said at least one light guide having optical power at least one surface having a focus located in proximity to said light scatterer; wherein said at least one light guide extends along at least three sides of said detection region; and at least one light source arranged for directing light along said at least one light guide, said optical power of said at least one light guide and said at least one light scatterer being operative to direct light, received from said at least one light source along said at least one light guide and scattered by said at least one light scatterer, generally in a plane parallel to said generally planar surface; at least one light detector, arranged to detect changes in the light received from said optical illumination assembly produced by the presence of an object in said detection region; 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 object impingement in said detection region.