DEVICE AND METHOD FOR INTERFERENCE AVOIDANCE IN AN INPUT DEVICE

• US 20120182229A1
• Filed: 01/19/2011
• Published: 07/19/2012
• Est. Priority Date: 01/19/2011
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Schwartz, Adam, Dattalo, Tracy Scott, Shepelev, Petr
• Granted Patent: US 9,965,104 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 a plurality of transmitter signals based on a first class of 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 a first transmitter signal of the plurality of transmitter signals with a sensor electrode of the plurality of sensor electrodes, wherein the first transmitter signal is selected based on the relative ranking for the plurality of transmitter signals; and

shift from transmitting the first transmitter signal to transmitting a second transmitter signal of the plurality of transmitter signals based on an amount of a second class of interference in the first transmitter signal, wherein the second transmitter signal is selected based on the relative ranking for the plurality of transmitter signals.

2. The input device of claim 1, wherein the first class of interference comprises background interference and wherein the second class of interference comprises input object coupled interference.

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

4. The input device of claim 1, wherein the processing system is configured to determine the relative ranking for the plurality of transmitter signals based on the first class of interference for each transmitter signal of the plurality of transmitter signals by:

ordering each of the plurality of transmitter signals based on an amount of the first class of interference for each transmitter signal of the plurality of transmitter signals.

5. The input device of claim 1, wherein the processing system is configured to determine the relative ranking for the plurality of transmitter signals based on the first class of interference for each transmitter signal of the plurality of transmitter signals by:

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

6. The input device of claim 1, wherein the processing system is configured to shift from transmitting the first transmitter signal to transmitting the second transmitter signal based on the amount of the second class of interference for the first transmitter signal by:

shifting from transmitting the first transmitter signal to transmitting the second transmitter signal when the amount of the second class of interference for the first transmitter signal exceeds a threshold.

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

a display device;

wherein the first class of 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.

8. 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 a plurality of transmitter signals based on a first class of 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 a first transmitter signal of the plurality of transmitter signals with a sensor electrode of a plurality of sensor electrodes, wherein the first transmitter signal is selected based on the relative ranking for the plurality of transmitter signals; and

wherein the transmitter module is further configured to shift from transmitting the first transmitter signal to transmitting a second transmitter signal of the plurality of transmitter signals based on an amount of a second class of interference for the first transmitter signal, wherein the second transmitter signal is selected based at least in part on the relative ranking for the plurality of transmitter signals.

9. The processing system of claim 8, wherein the first class of interference comprises background interference and wherein the second class of interference comprises input object coupled interference.

10. The processing system of claim 8, wherein the ranking module is further configured to determine the relative ranking for the plurality of transmitter signals based on the first class of interference for each transmitter signal of the plurality of transmitter signals by:

ordering each of the plurality of transmitter signals based on an amount of the first class of interference for each transmitter signal of the plurality of transmitter signals.

11. The processing system of claim 8, wherein the transmitter circuitry is further configured to shift from transmitting the first transmitter signal to transmitting the second transmitter signal when the amount of the second class of interference for the first transmitter signal exceeds a threshold.

12. The processing system of claim 8, 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 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.

13. The processing system of claim 8, wherein said processing system further comprises:

receiver circuitry configured to receive a first resulting signal with the 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 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.

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

determining 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, 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 a first transmitter signal of the plurality of transmitter signals with a sensor electrode, wherein the first transmitter signal is selected based on the relative ranking for the plurality of transmitter signals; and

shifting from transmitting the first transmitter signal to transmitting a second transmitter signal of the plurality of transmitter signals based on an amount of a second class of interference for the first transmitter signal, wherein the second transmitter signal is selected based at least in part on the relative ranking for the plurality of transmitter signals.

15. The method of claim 14, further comprising determining a background interference as the first class of interference and determining an input object coupled interference as the second class of interference.

16. The method of claim 14, wherein determining the relative ranking for the plurality of transmitter signals based on the first class of interference for each transmitter signal of the plurality of transmitter signals comprises:

ordering each of the plurality of transmitter signals based on an amount of the first class of interference for each transmitter signal of the plurality of transmitter signals.

17. The method of claim 14, wherein determining the relative ranking for the plurality of transmitter signals based on the first class of interference for each transmitter signal of the plurality of transmitter signals comprises:

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

18. The method of claim 14, further comprising shifting from transmitting the second transmitter signal to transmitting a third transmitter signal of the plurality of transmitter signals based on an amount of the second class of 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.

19. The method of claim 14, further comprising shifting from transmitting the first transmitter signal to transmitting the second transmitter signal when the amount of the second class of interference for the first transmitter signal exceeds a threshold.

20. The method of claim 14, 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 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.