Patent ID: 8368663

Claim:
A method of operating a touch panel system for detecting one or more objects in proximity with a touchable surface of a touch panel, the method comprising: scanning at least a portion of the touch panel to measure a level of ambient infrared radiation using at least one infrared sensor; switching to a shadow mode of operation if the level of ambient infrared radiation exceeds a first threshold; detecting a first shape of an object adjacent the touch panel while in the shadow mode of operation; switching to a reflective mode of operation if the level of ambient infrared radiation does not exceed both the first threshold and a second threshold, wherein the switching between the shadow mode and the reflective mode changes an angle of illumination of the object adjacent to the touch panel; detecting a second shape of the object while in the reflective mode of operation; analyzing the detected first and second shapes; and determining a three-dimensional shape and thickness of the object based at least in part on the changes in the angle of illumination analysis of the first and second shapes.