Apparatus and method for determining a stimulus, including a touch input and a stylus input

Abstract

A capacitive sensor associated with a substrate is presented. The electrode includes a self-capacitance; and a processing unit electrically coupled to the electrode and configured to register a first touch signature during a first touch event in response to an object approaching the electrode. The first touch signature occurring over a total time domain (T) between a first time and a second time, between a first substantially constant self-capacitance and a second substantially constant self-capacitance.

1 . A capacitive sensor comprising:
 an electrode including a self-capacitance;   a touch substrate adjacent the electrode; and   a processing unit electrically coupled to the electrode and configured to register a first touch signature during a first touch event in response to an object approaching the electrode, the first touch signature occurring over a total time domain (T) between a first time and a second time, between a first substantially constant self-capacitance and a second substantially constant self-capacitance;   a filter disposed between the electrode and the processing unit to affect a signal indicative of a touch signature during the first touch event in response to an object approaching the electrode, wherein the first touch signature includes a rate of change (ds/dt) of the electrode self-capacitance during a total time domain (T) in combination with at least one of the following parameters of the first touch event;   an interval change in self-capacitance (ds) during the total time domain (T), wherein the interval change in self-capacitance (ds) is less than a total change in self-capacitance (S) for the first touch event.   an interval time domain (di) corresponding to the interval change in self-capacitance (ds), wherein the interval time domain (dt) is less than the total time domain (T) for the touch event.