Acquiring multiple capacitive partial profiles for interleaved capacitive sensing

Patent metadata

Field	Value
Publication number	US-9678599-B2
Application number	US-201615340806-A
Country	US
Kind code	B2
Filing date	Nov 1, 2016
Priority date	Jun 27, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Embodiments include a method, input device, and processing system for operating a plurality of sensor electrodes for capacitive sensing. The method includes acquiring a first capacitive partial profile by driving a first capacitive sensing signal onto a first sensor electrode of a first plurality of sensor electrodes while driving a second sensor electrode of the first plurality of sensor electrodes with a substantially constant voltage. The method further includes acquiring a second capacitive partial profile by driving a second capacitive sensing signal onto the second sensor electrode while driving the first sensor electrode with the substantially constant voltage, and determining a first capacitive profile based on at least the acquired first capacitive partial profile and the second capacitive partial profile.

First claim

We claim:

1. A processing system, comprising:
a sensor module comprising sensor circuitry configured to couple with a first plurality of sensor electrodes and with a second plurality of sensor electrodes, the sensor module configured to:
drive, during a first time period, a first capacitive sensing signal onto a first sensor electrode of the first plurality of sensor electrodes and a substantially constant voltage onto a second sensor electrode of the first plurality of sensor electrodes;
acquire, during the first time period, a first capacitive partial profile based on the driven first capacitive sensing signal;
drive, during a second time period that is non-overlapping with the first time period, a second capacitive sensing signal onto the second sensor electrode and the substantially constant voltage onto the first sensor electrode;
acquire, during the second time period, a second capacitive partial profile based on the driven second capacitive sensing signal; and
drive, during at least one of the first time period and the second time period, one or more sensor electrodes of the second plurality of sensor electrodes with the substantially constant voltage.

2. The processing system of claim 1 , further comprising:
a determination module configured to determine a first capacitive profile based on at least the first capacitive partial profile and the second capacitive partial profile.

3. The processing system of claim 1 , wherein acquiring the second capacitive partial profile comprises:
driving the second capacitive sensing signal onto a third sensor electrode of the first plurality of sensor electrodes;
wherein the second sensor electrode and the third sensor electrode are driven with the second capacitive sensing signal while the first sensor electrode is driven with the substantially constant voltage; and
wherein the first sensor electrode is located substantially between the second sensor electrode and the third sensor electrode.

4. The processing system of claim 1 , wherein the sensor module is further configured to:
drive, during the first time period, the first capacitive sensing signal onto a first subset of the first plurality of sensor electrodes that includes the first sensor electrode, and the substantially constant voltage onto a second subset of the first plurality of sensor electrodes that includes the second sensor electrode, wherein acquiring the first capacitive partial profile is based on the driven first capacitive sensing signal driven onto the first subset;
drive, during the second time period, the second capacitive sensing signal onto the second subset and the substantially constant voltage onto the first subset, wherein acquiring the second capacitive partial profile is based on the driven second capacitive sensing signal onto the second subset; and
wherein the first plurality of sensor electrodes are arranged in parallel, and wherein sensor electrodes of the first subset are disposed in an alternating arrangement with sensor electrodes of the second subset.

5. The processing system of claim 1 , wherein the sensor module is further configured to:
acquire a third capacitive partial profile by driving a third capacitive sensing signal onto a fourth sensor electrode of the second plurality of sensor electrodes while driving a fifth sensor electrode of the second plurality of sensor electrodes with the substantially constant voltage; and
acquire a fourth capacitive partial profile by driving a fourth capacitive sensing signal onto the fifth sensor electrode while driving the fourth sensor electrode with the substantially constant voltage;
wherein the determination module is further configured to determine a second capacitive profile based on at least the third capacitive partial profile and the fourth capacitive partial profile.

6. The processing system of claim 1 , wherein the sensing module is further configured to determine a second capacitive baseline image based on a comparison of a first capacitive baseline image with the determined first capacitive profile.

7. A method for driving sensor electrodes for capacitive sensing, the method comprising:
acquiring, during a first time period and while driving a second sensor electrode of a first plurality of sensor electrodes with a substantially constant voltage, a first capacitive partial profile by driving a first capacitive sensing signal onto a first sensor electrode of the first plurality of sensor electrodes;
acquiring, during a second time period that is non-overlapping with the first time period, a second capacitive partial profile by driving a second capacitive sensing signal onto the second sensor electrode while driving the first sensor electrode with the substantially constant voltage;
driving, during at least one of the first time period and the second time period, one or more sensor electrodes of a second plurality of sensor electrodes with the substantially constant voltage; and
determining a first capacitive profile based on at least the first capacitive partial profile and the second capacitive partial profile.

8. The method of claim 7 , wherein acquiring the second capacitive partial profile comprises:
driving the second capacitive sensing signal onto a third sensor electrode of the first plurality of sensor electrodes; and
wherein the second sensor electrode and the third sensor electrode are driven with the second capacitive sensing signal while the first sensor electrode is driven with the substantially constant voltage.

9. The method of claim 8 , wherein the first sensor electrode is located substantially between the second sensor electrode and third sensor electrode.

10. The method of claim 7 , wherein acquiring the first capacitive partial profile comprises:
driving the first capacitive sensing signal onto a first subset of the first plurality of sensor electrodes that includes the first sensor electrode;
wherein acquiring the second capacitive partial profile comprises driving the second capacitive sensing signal onto a second subset of the first plurality of sensor electrodes that includes the second sensor electrode; and
wherein the first plurality of sensor electrodes are arranged in parallel, and wherein sensor electrodes of the first subset are disposed in an alternating arrangement with sensor electrodes of the second subset.

11. The method of claim 7 , further comprising:
acquiring a third capacitive partial profile by driving a third capacitive sensing signal onto a fourth sensor electrode of the second plurality of sensor electrodes while driving a fifth sensor electrode of the second plurality of sensor electrodes with the substantially constant voltage;
acquiring a fourth capacitive partial profile by driving a fourth capacitive sensing signal onto the fifth sensor electrode while driving the fourth sensor electrode with the substantially constant voltage; and
determining a second capacitive profile based on at least the third capacitive partial profile and the fourth capacitive partial profile.

12. The method of claim 7 , further comprising:
determining a second capacitive baseline image based on a comparison of a first capacitive baseline image with the determined first capacitive profile.

13. An input device comprising:
a first plurality of sensor electrodes arranged along a first sensing axis; and
a processing system coupled to the first plurality of sensor electrodes and configured to:
acquire, during a first time period and while driving a second sensor electrode of the first plurality of sensor electrodes with a substantially constant voltage, a first capacitive partial profile by driving a first capacitive

Assignees

• Synaptics Inc

Inventors

• Losh Jonathan

Classifications

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0418 Primary

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G06F2203/04108

  Touchless 2D- 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 without distance measurement in the Z direction · CPC title

• G06F2203/04105

  Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position · CPC title

• G06F3/044

  by capacitive means · CPC title