Patent ID: 6222528
Filing Date: 2001-04-24
Classification: G06F

Abstract:
A data input device for sensing a position of a probe relative to a touchpad surface, wherein the data input device comprises:a pad means for sensing the position of the probe, and wherein the pad means further comprises:a plurality of first electrode strips disposed in a first parallel direction and spaced apart in at least a first electrode array, wherein at least a portion of the touchpad surface overlaps at least a portion of the first electrode array;a sense electrode disposed co-planar with the first electrode array, and including fringe electric fields between the first electrode array and the sense electrode to thereby develop capacitive balances, wherein the probe disrupts the fringe electric fields when the probe comes in proximity to the pad means, thereby altering the capacitive balances, and wherein the at least a portion of the touchpad surface overlaps at least a portion of the common sense electrode;measuring means electrically coupled to the pad means for measuring the capacitive balances in the pad means to thereby determine the position of the probe relative to the pad means; andinterpolation means electrically coupled to the measuring means for determining probe position at a resolution which is less than a distance between individual electrodes of the at least a first electrode array.