Method and system for multi-touch decoding

摘要

A touch sensor capable of detecting multiple touches thereto is coupled with a digital device having multi-touch decoding capabilities. These multi-touch decoding capabilities comprise touch data acquisition, touch identification, touch tracking and processed touch data output to a device associated with the touch sensor. Touch identification comprises touch location(s) peak detection, touch location(s) nudging and touch location(s) interpolation. Touch data acquisition locates potential touches on the touch sensor. Peak detection identifies where potential touch locations are on the touch sensor. Once a potential touch location(s) has been identified, touch location nudging examines each adjacent location thereto and interpolation examines the adjacent touch location values to generate a higher resolution location of the touch. Touch tracking compares time sequential “frames” of touch identification data and then determines which touches are associated between frames for further processing, e.g., determining gesturing actions.

主权项

1. A method for decoding multiple touches on a touch sensing surface, said method comprising the steps of:
scanning a plurality of channels aligned on an axis for determining self values of the channels;
determining left and right slope values for at least one self value, wherein local maximum self values are determined by detecting a slope sign transition and potential maximum self values are each determined by a predetermined change of slope ratios between respective left and right slope; scanning a plurality of nodes of those channels that have the local maximum self value for determining mutual values of the nodes; and comparing the mutual values to determine which one of the nodes has the largest mutual value, wherein the node having the largest mutual value on the local maximum self value channel is a potential touch location.