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

• US 20150301646A1
• Filed: 04/26/2013
• Published: 10/22/2015
• 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.
• Granted Patent: US 10,248,264 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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:

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.

5. The capacitive sensor of claim 1 wherein the capacitive sensing circuit includes a sampling capacitor electrically coupled to the processing unit.

6. The capacitive sensor of claim 1 wherein the plurality of electrodes include a sense electrode and a bias electrode spaced apart from the sense electrode.

7. The capacitive sensor of claim 1 wherein the plurality of electrodes include a sense electrode and a strobe electrode spaced apart from the sense electrode.

8. The capacitive sensor of claim 1 wherein the processing unit is a time domain differential processing circuit configured to determine the rate of change of the capacitive sensing circuit output.

9. The capacitive sensor of claim 8 wherein the time domain differential processing circuit is adapted to determine a touch signature based on the rate of change of the capacitive sensor circuit output and at least one of a capacitive value and a time domain.

2-4. -4. (canceled)

10. A capacitive sensor comprising:

a substrate for receiving a touch input thereon;

an electrode subjacent the substrate and including a capacitance adapted to vary in response to the touch input; and

a processing unit coupled to the electrode and adapted to determine a signature of the touch input based on the electrode capacitance, wherein the signature includes variations in the electrode capacitance corresponding to movement of a touch input generally perpendicular to the substrate and against the substrate.

11. The capacitive sensor of claim 10 wherein the processing unit is adapted to measure the rate of change of the electrode capacitance over a first time domain to determine the signature of the touch input.

12. The capacitive sensor of claim 11 wherein the processing unit is adapted to measure the rate of change of the electrode capacitance over a second time domain to determine the signature of the touch input, the second time domain being greater than the first time domain.

13. The capacitive sensor of claim 10 wherein the processing unit is adapted to measure a change in the electrode capacitance relative to ground.

14. The capacitive sensor of claim 10 wherein the touch signature includes fluid movement of an object toward the capacitive sensor.

15. The capacitive sensor of claim 10 wherein the touch signature includes staggered movement of an object toward the capacitive sensor.

16. The capacitive sensor of claim 10 wherein the touch signature includes fluid movement of an object toward and away from the capacitive sensor.

17. The capacitive sensor of claim 10 wherein the touch signature includes staggered movement of an object toward and away from the capacitive sensor.

18. The capacitive sensor of claim 10 wherein the touch signature includes a flattening of the touch input against the substrate.

19-70. -70. (canceled)

71. A method comprising:

providing a plurality of electrodes including electrode rows and electrode columns;

measuring the rate of change of the capacitance of at least one of the plurality of electrodes; and

determining the presence of a stimulus based on the measured rate of change.

72. The method according to claim 71 wherein the measuring step includes:

strobing one of the electrode rows; and

sampling the voltage on an adjacent electrode row.

73. The method according to claim 75 wherein the measuring step includes:

strobing one of the electrode columns; and

sampling the voltage on an adjacent electrode column.

74. The method according to claim 71 wherein the measuring step includes:

strobing one of the electrode rows; and

sampling the voltage on at least one of the electrode columns.

75. The method according to claim 74 wherein the measuring step includes:

strobing one of the electrode columns; and

sampling the voltage on at least one of the electrode rows.

76. The method according to claim 71 wherein at least two of the electrode rows define a first mutual capacitance, the method further including measuring the rate of change of the first mutual capacitance.

77. The method according to claim 76 wherein at least two of the electrode columns define a second mutual capacitance, the method further including measuring the rate of change of the second mutual capacitance.

78-132. -132. (canceled)