Abstract: In a touch sensitive user interface environment having a series of possible touch points on an activation surface, with the monitoring of the touch points being achieved by sensing activation values at a plurality of positions around the periphery of the activation surface, a method of determining where at least one touch point has been activated on the surface, the method including the steps of: (a) determining at least one intensity variation in the activation values; and (b) utilizing a gradient measure of the sides of the at least one intensity variation to determine the location of at least one touch point on the activation surface.

Abstract: An apparatus and method for transmitting, collimating and redirecting light from a point-like source to produce a collimated optical signal in a substantially planar form are provided. In one embodiment the apparatus is manufactured as a unitary transmissive body comprising a collimation element and a redirection element, and optionally a transmissive element. In another embodiment the apparatus is assembled from one or more components. The apparatus and method are useful for providing sensing light for an optical touch input device.