Input device with deflectable electrode

• US 9,459,734 B2
• Filed: 03/30/2010
• Issued: 10/04/2016
• Est. Priority Date: 04/06/2009
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Day, Shawn P.
• Primary Examiner(s): LEE, NICHOLAS J
• Application Number:
  US12/749,946
• Publication Number:
  US 20100253651A1
• Time in Patent Office: 2,380 Days
• Field of Search: 345/173, 345/174, 345/175
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• 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 input device performance. The devices and methods utilize a set of sensor electrodes comprising at least one transmitter sensor electrode and at least one receiver sensor electrode that are capacitively coupled to form a transcapacitance for capacitively sensing input objects in a sensing region. A measure of the transcapacitance may be used to determine positional information for the input objects in the sensing region. In accordance with the various embodiments, the devices and methods additionally utilize at least one deflectable electrode, where the deflectable electrode is electrically floating. The deflectable electrode is configured to be deflectable toward the set of sensor electrodes, where the deflection causes a change in the transcapacitance.

Claims

1. An input device for capacitively sensing input objects in a sensing region, comprising:

a set of sensor electrodes comprising;

a transmitter sensor electrode, and

a receiver sensor electrode, wherein the transmitter sensor electrode is capacitively coupled to the receiver sensor electrode to form a transcapacitance;

a first deflectable electrode and a second deflectable electrode overlapping at least a portion of the set of sensor electrodes,

wherein the first deflectable electrode is separated by an insulator from the second deflectable electrode,

wherein the first deflectable electrode is configured, when capacitively coupled with an input object, to produce an electrical ground in the input device,

wherein the insulator is configured to prevent a grounding effect at the second deflectable electrode when the second deflectable electrode is not capacitively coupled with the input object, and

wherein deflection of the first deflectable electrode and the second deflectable electrode toward the set of sensor electrodes is configured to cause a change in the transcapacitance; and

a deformable layer overlapping the set of sensor electrodes and configured to facilitate the change in the transcapacitance in response to a pressure applied by the input object to the first deflectable electrode, and

wherein the change in the transcapacitance corresponds to an amount of pressure applied by the input object to the first deflectable electrode.

2. The input device of claim 1 further comprising a processing system coupled to the set of sensor electrodes, the processing system configured to determine a measure of the transcapacitance, the processing system further configured to determine positional information for the input object in the sensing region from the measure of the transcapacitance.

3. The input device of claim 1 further comprising a processing system coupled to the set of sensor electrodes, the processing system configured to determine a measure of the transcapacitance, the processing system further configured to determine pressure information for the input object causing deflection of the first deflectable electrode, wherein the pressure information is based upon a magnitude of a change in the measure of the transcapacitance.

4. The input device of claim 1 further comprising a processing system coupled to the set of sensor electrodes, the processing system configured to determine a measure of the transcapacitance, the processing system further configured to determine a type of the input object based upon a sign of a change in the measure of the transcapacitance.

5. The input device of claim 4 wherein the type of the input object includes conductive objects and nonconductive objects such that the processing system is configured to distinguish between a conductive object and a nonconductive object based upon the sign of the change in the measure of the transcapacitance.

6. The input device of claim 3 further comprising an insulating layer between the first deflectable electrode and the set of sensor electrodes.

7. The input device of claim 3 further comprising at least one gap between the first deflectable electrode and the set of sensor electrodes.

8. An input device for capacitively sensing input objects in a sensing region, comprising:

a set of sensor electrodes comprising;

a transmitter sensor electrode, and

a receiver sensor electrode, wherein the transmitter sensor electrode is capacitively coupled to the receiver sensor electrode to form a transcapacitance;

a substrate; and

a first deflectable electrode and a second deflectable electrode disposed on a surface of the substrate,

wherein the first deflectable electrode is separated by an insulator from the second deflectable electrode,

wherein the first deflectable electrode is configured, when capacitively coupled with an input object, to produce an electrical ground in the input device,

wherein the insulator is configured to prevent a grounding effect at the second deflectable electrode when the second deflectable electrode is not capacitively coupled with the input object,

wherein deflection of the first deflectable electrode and the second deflectable electrode toward the set of sensor electrodes is configured to cause a change in the transcapacitance,

wherein the first substrate comprises a deformable layer overlapping the set of sensor electrodes, the deformable layer being configured to facilitate the change in the transcapacitance in response to a pressure applied by the input object to the first deflectable electrode, and

wherein the change in the transcapacitance corresponds to an amount of pressure applied by the input object to the first deflectable electrode.

9. The input device of claim 8 further comprising a processing system coupled to the set of sensor electrodes, the processing system configured to determine a measure of the transcapacitance, the processing system further configured to determine positional information for the input object in the sensing region from the measure of the transcapacitance.

10. The input device of claim 8 further comprising a processing system coupled to the set of sensor electrodes, the processing system configured to determine a measure of the transcapacitance, the processing system further configured to determine pressure information for the input object causing deflection of the first deflectable electrode, the pressure information based upon a magnitude of a change in the measure of the transcapacitance.

11. The input device of claim 8 further comprising a processing system coupled to the set of sensor electrodes, the processing system configured to determine a measure of the transcapacitance, the processing system further configured to determine a type of input object based upon a sign of a change in the measure of the transcapacitance.

12. The input device of claim 11 wherein the type of the input object includes conductive objects and nonconductive objects such that the processing system is configured to distinguish between a conductive object and a nonconductive object based upon the sign of the change in the measure of the transcapacitance.

13. The input device of claim 10 wherein the first deflectable electrode comprises a printed material.

14. The input device of claim 10 wherein the first deflectable electrode comprises a patterned material.

15. The input device of claim 14 wherein the first deflectable electrode is patterned using a lithographic process.

16. The input device of claim 10 further comprising an insulating layer between the first deflectable electrode and the set of sensor electrodes.

17. The input device of claim 10 further comprising at least one gap between the first deflectable electrode and the set of sensor electrodes.

18. The input device of claim 10 wherein the first deflectable electrode overlaps at least a portion of the set of sensor electrodes.

19. An input device for capacitively sensing input objects in a sensing region, comprising:

a set of sensor electrodes comprising;

a set of transmitter sensor electrodes; and

a set of receiver sensor electrodes, wherein each transmitter sensor electrode in the set of transmitter sensor electrodes is capacitively coupled to at least one receiver sensor electrode in the set of receiver sensor electrodes to form a set of transcapacitances; and

a first deflectable electrode and a second deflectable electrode that overlaps at least a portion of the set of sensor electrodes,

wherein the first deflectable electrode is separated by an insulator from the second deflectable electrode,

wherein the first deflectable electrode is configured, when capacitively coupled with an input object, to produce an electrical ground in the input device,

wherein the insulator is configured to prevent a grounding effect at the second deflectable electrode when the second deflectable electrode is not capacitively coupled with the input object, and

wherein deflection of the first deflectable electrode and the second deflectable electrode toward the set of sensor electrodes is configured to cause a change in at least one of the set of transcapacitances;

a deformable layer overlapping the set of sensor electrodes and configured to facilitate the change in the at least one of the set of transcapacitances in response to a pressure applied by the input object to the first deflectable electrode; and

a processing system coupled to the set of sensor electrodes and configured to determine measures of the set of transcapacitances, the processing system further configured to determine positional information for the input object in the sensing region based on the measures of the set of transcapacitances, and

determine pressure information for the input object applying pressure to the first deflectable electrode, the pressure information based upon a magnitude of the change in at least one of the measures of the set of transcapacitances.

20. The input device of claim 19 wherein the processing system is further configured to determine pressure information for the input object by identifying a change in the magnitude of at least one of the measures of the set of transcapacitances beyond a baseline.

21. The input device of claim 19 wherein the processing system is further configured to distinguish between a conductive object and a nonconductive object based upon a sign of the change in at least one of the measures of the set of transcapacitances.

22. The input device of claim 21 wherein the processing system is further configured to distinguish between the conductive object and the nonconductive object by identifying the conductive object in response to a decrease in at least one of the measures of the set of transcapacitances and by identifying the nonconductive object in response to an increase in at least one of the measures of the set of transcapacitances.

23. The input device of claim 19 wherein the first deflectable electrode comprises a resistive material.

24. A method for determining user input on a device, comprising:

driving signals onto a set of transmitter sensor electrodes in the device;

receiving, while an input object capacitively couples with a first deflectable electrode, signals on a set of receiver sensor electrodes in the device,

wherein the first deflectable electrode is separated by an insulator from a second deflectable electrode,

wherein the first deflectable electrode produces an electrical ground in the device,

wherein the insulator prevents a ground effect at the second deflectable electrode when the second deflectable electrode is not capacitively coupled with the input object,

wherein deflection of the first deflectable electrode toward the set of transmitter sensor electrodes causes a change in at least one of a set of transcapacitances, and

further wherein a deformable layer overlaps the sets of transmitter and receiver sensor electrodes, the deformable layer being configured to facilitate the change in the at least one of the set of transcapacitances in response to a pressure applied by the input object to the first deflectable electrode;

determining a measure of the set of transcapacitances from the received signals, wherein the measure of the set of transcapacitances corresponds to the pressure applied to the first deflectable electrode;

determining, from the measure of the set of transcapacitances, a magnitude of change in the set of transcapacitances, wherein the magnitude of change satisfies a predetermined threshold level; and

determining an amount of pressure applied by the input object to the first deflectable electrode based on the magnitude of change.

25. The method of claim 24 wherein the at least one deflectable electrode overlaps at least one of the transmitter sensor electrodes and at least one of the receiver sensor electrodes.

26. The method of claim 24 wherein the at least one deflectable electrode comprises a plurality of deflectable electrodes, and wherein each deflectable electrode in the plurality of deflectable electrodes overlaps one of the transmitter sensor electrodes and one of the receiver sensor electrodes.

27. The method of claim 24 further comprising the steps of:

determining positional information for an input object causing deflection of the first deflectable electrode, wherein the positional information is based upon the change in the at least one of the set of transcapacitances; and

providing an output representative of the positional information.

28. The method of claim 27 wherein the step of determining positional information comprises determining the magnitude of the change by comparing the change to a baseline.

29. The method of claim 24 further comprising the steps of:

distinguishing between a conductive object and a nonconductive object based upon a sign of a change in the measure of the set of transcapacitances to determine an object type; and

providing an output representative of the object type.

30. The method of claim 29 wherein the step of distinguishing between a conductive object and a nonconductive object comprises identifying a conductive object in response to a decrease in at least one of the measure of the set of transcapacitances and identifying a nonconductive object in response to an increase in the measure of the set of transcapacitances.

31. A processing system configured to:

drive signals onto a set of transmitter sensor electrodes in an input device;

receive, while an input object capacitively couples with a first deflectable electrode, signals on a set of receiver sensor electrodes in the input device,

wherein the first deflectable electrode is separated by an insulator from a second deflectable electrode,

wherein the first deflectable electrode produces an electrical ground in the input device,

wherein the insulator prevents a ground effect at the second deflectable electrode when the second deflectable electrode is not capacitively coupled with the input object,

wherein deflection of the first deflectable electrode toward the set of transmitter sensor electrodes causes a change in at least one of a set of transcapacitances, and

further wherein a deformable layer overlaps the sets of transmitter and receiver sensor electrodes, the deformable layer being configured to facilitate the change in the at least one of the set of transcapacitances in response to a pressure applied by the input object to the first deflectable electrode;

determine a measure of the set of transcapacitances from the received signals, wherein the measure of the set of transcapacitances corresponds to the pressure applied to the at least one deflectable electrode;

determine, from the measure of the set of transcapacitances, a magnitude of change in the set of transcapacitances, wherein the magnitude of change satisfies a predetermined threshold level; and

determine an amount of pressure applied by the input object to the at least one deflectable electrode based on the magnitude of change.

32. The processing system of claim 31 further configured to:

determine positional information for the input object causing deflection of the first deflectable electrode, wherein the positional information is based upon the change in the at least one of the set of transcapacitances; and

provide an output representative of the positional information.

33. The processing system of claim 32 further configured to:

determine the magnitude of the change by comparing the change to a baseline.

34. The processing system of claim 32 further configured to:

distinguish between a conductive object and a nonconductive object based upon a sign of a change in the measure of the set of transcapacitances to determine an object type; and

provide an output representative of the object type.