Device and method for interference avoidance in an input device

• US 9,965,104 B2
• Filed: 01/19/2011
• Issued: 05/08/2018
• Est. Priority Date: 01/19/2011
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Shepelev, Petr, Schwartz, Adam, Dattalo, Tracy Scott
• Primary Examiner(s): DAVIS, TONY O
• Application Number:
  US13/009,606
• Publication Number:
  US 20120182229A1
• Time in Patent Office: 2,666 Days
• Field of Search: 345 76, 345170-176
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

Devices and methods are provided that facilitate improved interference avoidance performance. The devices and methods determine a relative ranking for a plurality of transmitter signals based on a first class of interference for each transmitter signal of the plurality of transmitter signals. The devices and methods transmit a first transmitter signal of the plurality of transmitter signals with a sensor electrode of the plurality of sensor electrodes. The first transmitter signal is selected based on the relative ranking for the plurality of transmitter signals. The devices and methods shift from transmitting the first transmitter signal to transmitting a second transmitter signal of the plurality of transmitter signals with the sensor electrode is based on an amount of a second class of interference in the first transmitter signal. The second transmitter signal is selected based on the relative ranking for the plurality of transmitter signals.

Claims

1. An input device comprising:

a plurality of sensor electrodes; and

a processing system coupled to the plurality of sensor electrodes, the processing system configured to;

determine a relative ranking for transmitting a plurality of transmitter signals based on an amount of background interference for each transmitter signal of the plurality of transmitter signals, wherein each transmitter signal of the plurality of transmitter signals comprises a waveform having a set of waveform characteristics that differ from the set of waveform characteristics of any other transmitter signal of the plurality of transmitter signals;

transmit, over a sensor electrode from the plurality of sensor electrodes, a first transmitter signal of the plurality of transmitter signals using the relative ranking;

determine an amount of input object coupled interference in the first transmitter signal;

select, using the amount of the input object coupled interference, a second transmitter signal from the relative ranking; and

transmit, over the sensor electrode, the second transmitter signal.

2. The input device of claim 1, wherein the set of waveform characteristics comprises at least one of a type, frequency, amplitude and phase.

3. The input device of claim 1, wherein the processing system is configured to determine the relative ranking for the plurality of transmitter signals by:

grouping a first subset of the plurality of transmitter signals based on Dull the amount of the background interference in each transmitter signal of the plurality of transmitter signals, wherein the first subset comprises the first and second transmitter signals.

4. The input device of claim 1, wherein the processing system is further configured to:

transmit the second transmitter signal when the amount of the input object interference for the first transmitter signal exceeds a threshold.

5. The input device of claim 1, further comprising:

a display device;

wherein the background interference is associated with the display device;

wherein the plurality of sensor electrodes are configured to sense in a sensing region; and

wherein the sensing region overlaps at least a portion of the display device.

6. A processing system configured for interference avoidance within a capacitive sensor device, the processing system comprising:

a ranking module configured to determine a relative ranking for transmitting a plurality of transmitter signals based on an amount of background interference for each transmitter signal of the plurality of transmitter signals, wherein each transmitter signal of the plurality of transmitter signals having a set of waveform characteristics that differ from the set of waveform characteristics of any other transmitter signal of the plurality of transmitter signals; and

transmitter circuitry configured to;

transmit, over a first sensor electrode from a plurality of sensor electrodes, a first transmitter signal of the plurality of transmitter signals using the relative ranking;

determine an amount of input object coupled interference in the first transmitter signal;

select, using the amount of the input object coupled interference, a second transmitter signal from the relative ranking; and

transmit, over the first sensor electrode, the second transmitter signal.

7. The processing system of claim 6, wherein the transmitter circuitry is further configured to transmit the second transmitter signal when the amount of the input object coupled interference for the first transmitter signal exceeds a threshold.

8. The processing system of claim 6, wherein the processing system further comprises:

receiver circuitry configured to receive a first resulting signal with a second sensor electrode of the plurality of sensor electrodes, wherein the first resulting signal is based on the first transmitter signal; and

a determination module configured to acquire a measurement of a change in a transcapacitive coupling between the first sensor electrode and the second sensor electrode, wherein the measurement is based on the first resulting signal, wherein the determination module is further configured to determine positional information an input object based on the measurement.

9. The processing system of claim 6, wherein said processing system further comprises:

receiver circuitry configured to receive a first resulting signal with the first sensor electrode of the plurality of sensor electrodes, wherein the first resulting signal is based on the first transmitter signal; and

a determination module configured to acquire a measurement of a change in a capacitive coupling between the first sensor electrode and an input object, wherein the measurement is based on the first resulting signals, wherein the determination module is further configured to determine positional information for the input object based on the measurement.

10. A method of interference avoidance within a capacitive sensor device, the method comprising:

determining a relative ranking for transmitting a plurality of transmitter signals based on an amount of background interference for each transmitter signal of the plurality of transmitter signals, wherein each transmitter signal of the plurality of transmitter signals having a set of waveform characteristics that differ from the set of waveform characteristics of any other transmitter signal of the plurality of transmitter signals;

transmitting, over a first sensor electrode, a first transmitter signal of the plurality of transmitter signals using the relative ranking;

determining an amount of input object coupled interference in the first transmitter signal;

selecting, using the amount of the input object coupled interference, a second transmitter signal from the relative ranking; and

transmitting, over the first sensor electrode, the second transmitter signal.

11. The method of claim 10, wherein determining the relative ranking for the plurality of transmitter signals comprises:

grouping a first subset of the plurality of transmitter signals based on the amount of the background interference in each transmitter signal of the plurality of transmitter signals, wherein the first subset comprises the first and second transmitter signals.

12. The method of claim 10, further comprising transmitting a third transmitter signal of the plurality of transmitter signals based on an amount of input object coupled interference in the second transmitter signal, wherein the third transmitter signal is selected based at least in part on the relative ranking for the plurality of transmitter signals.

13. The method of claim 10, wherein the second transmitter signal is transmitted when the amount of the input object coupled interference for the first transmitter signal exceeds a threshold.

14. The method of claim 10, further comprising:

receiving a first resulting signal with a second sensor electrode, wherein the first resulting signal is based on the first transmitter signal;

acquiring a measurement of a change in a transcapacitive coupling between the first sensor electrode and the second sensor electrode, wherein the measurement is based on the first resulting signal; and

determining positional information an input object based on the measurement.