System and method for detecting and characterizing touch inputs at a human-computer interface

A system for detecting inputs at a computing device comprising:

• a substrate comprising:
• a top layer;
• a bottom layer;
• an array of capacitance sensors arranged on the bottom layer;
• and
• an array of support locations arranged on the bottom layer adjacent the array of capacitance sensors;
• an array of drive electrodes and sense electrodes arranged on the top layer of the substrate;
• a touch sensor surface arranged over the array of drive electrodes and sense electrodes;
• an array of spring elements configured to couple the substrate to a chassis and to yield to displacement of the substrate downward toward the chassis responsive to forces applied to the touch sensor surface, each spring element in the array of spring elements coupled to the substrate at a support location in the array of support locations;
• a coupling plate configured to:
• couple to the chassis adjacent the array of spring elements;
• and
• effect capacitance values of the array of capacitance sensors responsive to displacement of the substrate toward the coupling plate;
• and
• a controller configured to, during a scan cycle:
• read a first set of capacitance values between drive electrodes and sense electrodes in the array of drive electrodes and sense electrodes;
• read a second set of capacitance values of capacitance sensors in the array of capacitance sensors;
• detect a lateral position and a longitudinal position of a touch input on the touch sensor surface based on the first set of capacitance values;
• interpret a force magnitude of the touch input based on the second set of capacitance values;
• and
• output the lateral position, the longitudinal position, and the force magnitude of the touch input.