Transcapacitive and absolute capacitive sensing profiles

Patent metadata

Field	Value
Publication number	US-11093093-B2
Application number	US-202016834976-A
Country	US
Kind code	B2
Filing date	Mar 30, 2020
Priority date	Mar 14, 2014
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

A processing system includes a sensor module configured to receive first and second signals from first and second sensor electrodes, respectively, and generate a combination signal. The processing system further includes a determination module configured to determine, using the first sensor electrode, an absolute capacitive coupling to an input object; determine, using the first and second sensor electrodes, a transcapacitive coupling; determine a ratio of the absolute to transcapacitive coupling; determine, using the combination signal, in absence of a predetermined low ground mass state, and when the ratio fails to exceed a predetermined threshold, first positional information regarding a location of the input object; and determine, when the ratio fails to exceed the predetermined threshold and in presence of the predetermined low ground mass state, second positional information regarding the location of the input object in the sensing region using an absolute capacitive scan.

First claim

What is claimed is:

1. A processing system comprising:
a sensor module comprising sensing circuitry coupled to a plurality of sensor electrodes in an input device, the sensor module configured to:
drive a first modulated signal onto a first sensor electrode among the plurality of sensor electrodes and a second modulated signal onto a second sensor electrode among the plurality of sensor electrodes,
receive, simultaneously, a first resulting signal from the first sensor electrode and a second resulting signal from the second sensor electrode, and
generate, based at least in part on the first resulting signal and the second resulting signal, a first combination signal; and

a determination module coupled to the plurality of sensor electrodes, the determination module configured to:
determine, using the first sensor electrode, a change in an absolute capacitive coupling between the first sensor electrode and an input object in a sensing region of the input device;
determine, using the first sensor electrode and the second sensor electrode, a change in a transcapacitive coupling between the first sensor electrode and the second sensor electrode;
determine whether a ratio of the change in the absolute capacitive coupling to the change in the transcapacitive coupling exceeds a first predetermined threshold;
determine whether the input device is disposed in a predetermined low ground mass state;
determine, using the first combination signal, when the input device is not disposed in the predetermined low ground mass state, and when the ratio fails to exceed the first predetermined threshold, first positional information regarding a location of the input object in the sensing region; and
determine, when the ratio fails to exceed the first predetermined threshold and when the input device is disposed in the predetermined low ground mass state, second positional information regarding the location of the input object in the sensing region using an absolute capacitive scan of the sensing region.

2. The processing system of claim 1 , wherein the determination module is further configured to:
determine whether the ratio of the change in the absolute capacitive coupling to the change in the transcapacitive coupling fails to exceed a second predetermined threshold, wherein the second predetermined threshold is lower than the first predetermined threshold; and
determine, using the first combination signal, when the ratio fails to exceed the second predetermined threshold, regardless of whether the input device is disposed in the predetermined low ground mass state, third positional information regarding a location of the input object in the sensing region.

3. The processing system of claim 1 , wherein the determination module is further configured to:
determine, when the ratio exceeds the first predetermined threshold, and regardless of whether the input device is disposed in the predetermined low ground mass state, third positional information regarding the location of the input object in the sensing region using an absolute capacitive scan of the sensing region.

4. The processing system of claim 1 ,
wherein the plurality of sensor electrodes comprises a grid electrode array, the grid electrode array comprising a first subset of sensor electrodes perpendicular to a second subset of sensor electrodes,
wherein the first subset of sensor electrodes comprises at least one absolute capacitive receiver electrode,
wherein the second subset of sensor electrodes comprises a plurality of overguarded transmitter electrodes,
wherein the sensor module is further configured to generate a second combination signal that comprises effects of an absolute capacitive coupling between the at least one absolute capacitive receiver electrode and one or more input objects, and
wherein the second combination signal further comprises effects of transcapacitance between the plurality of overguarded transmitter electrodes.

5. The processing system of claim 1 ,
wherein the sensor module is further configured to generate a baseline combination signal when no input object is located in the sensing region, and
wherein the determination module is further configured to compare first combination signal to the baseline combination signal to determine the first positional information.

6. The processing system of claim 1 , wherein the sensor module is further configured to perform a transcapacitive scan of the sensing region using the plurality of sensor electrodes, and wherein the determination module is further configured to switch, in response to determining an input device state, to performing the transcapacitive scan.

7. The processing system of claim 1 , wherein generating the first combination signal comprises summing the first resulting signal and the second resulting signal to produce the first combination signal.

8. The processing system of claim 1 , wherein the first modulated signal comprises a first modulated amplitude, and wherein the second modulated signal comprises a second modulated amplitude that is less than the first modulated amplitude.

9. The processing system of claim 1 , wherein the first combination signal comprises effects of the transcapacitive coupling between the first sensor electrode and the second sensor electrode and effects of the absolute capacitive coupling between the second sensor electrode and the input object.

10. The processing system of claim 1 , wherein the input device is disposed in an organic light emitting diode (OLED) display device.

11. The processing system of claim 1 , wherein the first modulated signal and the second modulated signal are driven concurrently.

12. An electronic system comprising:
a display device; and
an input device comprising:
a plurality of sensor electrodes comprising a first sensor electrode and a second sensor electrode,
wherein the first sensor electrode is configured to drive a first modulated signal, and
wherein the second sensor electrode configured to drive a second modulated signal; and

receiver circuitry coupled to the first sensor electrode and the second sensor electrode, the receiver circuitry being configured to receive a first resulting signal from the first sensor electrode and a second resulting signal from the second sensor electrode,
wherein the receiver circuitry is further configured to generate a combination signal based at least in part on the first resulting signal and the second resulting signal,
wherein the input device is configured to determine, using the first sensor electrode, a change in an absolute capacitive coupling between the first sensor electrode and an input object in a sensing region of the input device,
wherein the input device is further configured to determine, using the first sensor electrode and the second sensor electrode, a change in a transcapacitive coupling between the first sensor electrode and the second sensor electrode,
wherein the input device is further configured to determine whether a ratio of the change in the absolute capacitive coupling to the change in the transcapacitive coupling exceeds a first predetermined threshold,
wherein the input device is further configured to determine whether the input device is disposed in a predetermined low ground mass state,
wherein the input device is further configured to determine, using the combination signal, when the input device is not disposed in the predetermined low ground mass state, and when the ratio fails to exceed the first predetermined threshold, first positional information regarding a location of the input object in the sensing region, and
wherein the input device is further configured to determine, when the ra

Assignees

• Synaptics Inc

Inventors

• Weinerth John
• Sobel David
• Solven Derek
• Schwartz Adam
• Reynolds Joseph Kurth
• Dattalo Tracy Scott
• Hoch David

Classifications

• G06F3/041662

  using alternate mutual and self-capacitive scanning · CPC title

• G06F3/0445 Primary

  using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer · CPC title

• G01R27/2605

  Measuring capacitance (capacitive sensors G01D5/24) · CPC title

• G06F3/0442

  using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser · 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