Acquiring multiple capacitive partial profiles with orthogonal sensor electrodes

Patent metadata

Field	Value
Publication number	US-9501169-B2
Application number	US-201414318219-A
Country	US
Kind code	B2
Filing date	Jun 27, 2014
Priority date	Jun 27, 2014
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

Embodiments include a method, input device, and processing system for driving a plurality of sensor electrodes for capacitive sensing. The method includes acquiring a first capacitive partial profile by driving a 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 the 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 and second capacitive partial profiles.

First claim

I claim:

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

a determination module configured to determine a first capacitive profile based on at least the first and second capacitive partial profiles.

2. The processing system of claim 1 , wherein acquiring the second capacitive partial profile comprises driving the 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 simultaneously driven with the capacitive sensing signal while the first sensor electrode is driven with the substantially constant voltage, the first sensor electrode located substantially between the second and third sensor electrodes.

3. The processing system of claim 1 , wherein the sensor module is further configured to:
simultaneously drive, during the first time period, the 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;
acquire, during the first time period, the first capacitive partial profile based on the capacitive sensing signal driven onto the first subset;
simultaneously drive, during the second time period, the capacitive sensing signal onto the second subset and the substantially constant voltage onto the first subset; and
acquire, during the second time period, the second capacitive partial profile based on the capacitive sensing signal driven onto the second subset,
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.

4. The processing system of claim 3 , wherein the sensor electrodes are selected for inclusion in the first and second subsets based on a capacitive baseline image.

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

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 first capacitive profile.

7. The processing system of claim 6 , wherein the first capacitive baseline image is obtained using transcapacitive sensing.

8. A method for driving a plurality of sensor electrodes for capacitive sensing, the method comprising:
acquiring, during a first time period, a first capacitive partial profile by driving a 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;
acquiring, during a second time period, a second capacitive partial profile by driving the capacitive sensing signal onto the second sensor electrode while driving the first sensor electrode with the substantially constant voltage, wherein the first and second time periods do not overlap;
driving, during at least one of the first and second time periods, one or more sensor electrodes of a second plurality of sensor electrodes with the substantially constant voltage, the second plurality of sensor electrodes disposed substantially orthogonal to the first plurality of sensor electrodes; and
determining a first capacitive profile based on at least the first and second capacitive partial profiles.

9. The method of claim 8 , wherein acquiring the second capacitive partial profile comprises driving the 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 simultaneously driven with the capacitive sensing signal while the first sensor electrode is driven with a substantially constant voltage, the first sensor electrode located substantially between the second and third sensor electrodes.

10. The method of claim 8 , further comprising:
acquiring the first capacitive partial profile by driving the capacitive sensing signal onto a first subset of the first plurality of sensor electrodes that includes the first sensor electrode, while driving a second subset of the first plurality of sensor electrodes that includes the second sensor electrode with the substantially constant voltage;
acquiring the second capacitive partial profile by driving the second subset of sensor electrodes with the capacitive sensing signal while driving the first subset with the substantially constant voltage,
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 10 , further comprising selecting the sensor electrodes for inclusion in the first and second subsets based on a capacitive baseline image.

12. The method of claim 8 , further comprising:
acquiring a third capacitive partial profile by driving the 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 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 and fourth capacitive partial profiles.

13. The method of claim 8 , further comprising determining a

Assignees

• Synaptics Inc

Inventors

• Losh Jonathan

Classifications

• G06F3/044

  by capacitive means · 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

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0418

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

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title