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

• US 10,248,264 B2
• Filed: 04/26/2013
• Issued: 04/02/2019
• Est. Priority Date: 04/27/2012
• Status: Active Grant

• Current Assignee: Alsentis LLC
• Original Assignee: Alsentis LLC
• Inventors: Caldwell, David W., Schaefer, William D., Bos, Robert G., Kurek, Stefan G.
• Primary Examiner(s): Zhou, Hong
• Application Number:
  US14/396,794
• Publication Number:
  US 20150301646A1
• Time in Patent Office: 2,167 Days
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

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.

Claims

1. A capacitive sensor comprising:

first and second electrodes having a mutual capacitance;

a touch substrate overlying the first and second electrodes; and

a processing unit electrically coupled to the first and second electrodes and configured to register a first touch signature in response to an object approaching one of the first or second 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 mutual capacitance and a second substantially constant mutual capacitance, wherein the first touch signature includes a rate of change (ds/dt) of the mutual capacitance in combination with at least one of the following parameters of the first touch signature;

an interval change in mutual capacitance (ds) during the total time domain (T), wherein the interval change in mutual capacitance (ds) is less than a total change in mutual capacitance (S) for the first touch signature,

an interval time domain (dt) corresponding to the interval change in mutual capacitance (ds), wherein the interval time domain (dt) is less than the total time domain (T) for the first touch signature.

2. The capacitive sensor of claim 1 wherein the first touch signature includes a total change in mutual capacitance (S) during the total time domain (T).

3. The capacitive sensor of claim 1 wherein the interval change in mutual capacitance (ds) is an increase in mutual capacitance.

4. The capacitive sensor of claim 1 wherein the interval change in mutual capacitance (ds) is a decrease in mutual capacitance.

5. The capacitive sensor of claim 1 wherein the interval change in mutual capacitance (ds) is substantially zero during the interval time domain (dt).

6. The capacitive sensor of claim 1 wherein the first electrode is a sense electrode and wherein the second electrode is a strobe electrode spaced apart from the sense electrode.

7. The capacitive sensor of claim 1 wherein the processor is configured to register a second touch signature in response to an object receding from the first and second electrodes.

8. The capacitive sensor of claim 1 wherein the first electrode is an electrode row and wherein the second electrode is an electrode column.