APPARATUS AND METHOD FOR DETERMINING A STIMULUS, INCLUDING A TOUCH INPUT AND A STYLUS INPUT

摘要

A capacitive sensor for detecting a stimulus. The capacitive sensor includes first and second electrodes defining a capacitive coupling, and a processing unit electrically coupled to the first and second electrodes to determine the presence of a stimulus based on the rate of change of the capacitive coupling. A substrate is positioned adjacent the first and second electrodes, wherein the stimulus corresponds to the placement of an object against the substrate. The processing unit is operative to determine a time rate of change based on successive measurements of the capacitive coupling and in response to the capacitive coupling being greater than a predetermined reference value.

主权项

1. A capacitive sensor comprising:
a capacitive sensing circuit defining an output and including a plurality of electrodes; a substrate overlying the capacitive sensing circuit for receipt of an object thereon; and a processing unit electrically coupled to the capacitive sensing circuit and configured to detect placement of the object against the substrate based on the rate of change of the capacitive sensing circuit output, wherein the capacitive sensing circuit output is based on the self-capacitance of at least two of the plurality of electrodes.