Force enhanced input device vibration compensation

• US 9,746,952 B2
• Filed: 03/31/2015
• Issued: 08/29/2017
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Huie, Mark Andrew
• Primary Examiner(s): Edouard, Patrick
• Assistant Examiner(s): Shen, Peijie
• Application Number:
  US14/675,638
• Publication Number:
  US 20160291761A1
• Time in Patent Office: 882 Days
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04108 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 Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

An input device includes a first substrate including a force sensor electrode and several proximity sensor electrodes, which are configured to detect one or more input objects in a sensing region. The input device also includes a second substrate mechanically coupled to the first substrate, the second substrate including a first conductive portion. The force sensor electrode and the first conductive portion are configured to form a first variable capacitance for a determination of a first force applied by the one or more input objects to an input surface of the input device. The input device also includes a compensation sensor including a compensation sensor electrode disposed on the first substrate, a second conductive portion of the second substrate, and a compensation spring feature formed on the second substrate. The compensation spring feature is configured to facilitate a deflection of the second conductive portion relative to the compensation sensor electrode.

Claims

1. An input device, comprising:

a first substrate comprising a plurality of proximity sensor electrodes, wherein the plurality of proximity sensor electrodes is configured to detect one or more input objects in a sensing region;

a second substrate coupled to the first substrate, the second substrate comprising a first conductive portion;

a force sensor comprising a force sensor electrode disposed on the first substrate, a force spring feature comprising a first spring constant, and a first conductive portion disposed in the second substrate, wherein the force sensor electrode and the first conductive portion are configured to form a first variable capacitance for a determination of a first force applied by the one or more input objects to an input surface of the input device; and

a compensation sensor comprising a compensation sensor electrode disposed on the first substrate, a second conductive portion of the second substrate, and a compensation spring feature comprising a second spring constant and formed in the second substrate,

wherein the first spring constant of the force sensor is greater than the second spring constant of the compensation sensor,

wherein the second spring constant is configured to produce a first sensor sensitivity in the compensation sensor that is different than a second sensor sensitivity in the force sensor,

wherein the compensation spring feature is configured to facilitate a deflection of the second conductive portion relative to the compensation sensor electrode in response to a second force applied to the input device,

wherein the deflection of the second conductive portion is configured to change a second variable capacitance formed between the second conductive portion and the compensation sensor electrode, and

wherein the determination of the first force is based on the change in the first and second variable capacitance.

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

a spacing layer disposed between the first substrate and the second substrate,

wherein the spacing layer provides a first separation between the force sensor electrode and the first conductive portion, and

wherein the spacing layer provides a second separation between the compensation sensor electrode and the second conductive portion.

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

a third substrate coupled to the second substrate,

wherein the third substrate comprises a transmission element, and

wherein the transmission element is configured to deflect the first conductive portion toward the force sensor electrode in response to the first force applied by the one or more input objects to the input surface.

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

wherein the force spring feature is configured to facilitate a deflection of the force sensor electrode relative to the first conductive portion to change the first variable capacitance.

5. The input device of claim 1,

wherein the compensation spring feature is disposed proximate a center region of the second substrate, and

wherein the force spring feature is disposed proximate an exterior edge of the second substrate.

6. The input device of claim 1,

wherein the first force is applied to the first substrate in a first direction,

wherein the second force is applied to the second substrate in a second direction, and

wherein the second direction is substantially opposite the first direction.

7. The input device of claim 1,

wherein the second force is a vibration internal to the input device.

8. The input device of claim 1,

wherein the input device is communicatively coupled with a processing system comprising:

a determination module configured for processing a first resulting signal and a second resulting signal,

wherein the first resulting signal is based on the change in the first variable capacitance, and

wherein the second resulting signal is based on the change in the second variable capacitance.

19. The input device of claim 1, wherein the compensation sensor is configured to determine a magnitude of a background force that adjusts force information regarding the first force.

9. A processing system for an input device comprising a sensing region, a first substrate comprising a first plurality of proximity sensor electrodes, and a second substrate, the processing system comprising:

a sensor module configured to;

obtain, using a force sensor comprising a force spring feature with a first spring constant, a first resulting signal based on a change in a first variable capacitance formed between at least one force sensor electrode disposed on the first substrate and a first conductive portion disposed on the second substrate, wherein the at least one force sensor electrode and the first conductive portion are configured to detect a first force applied by one or more input objects to an input surface of the input device; and

obtain, using a compensation sensor comprising a compensation spring feature with a second spring constant, a second resulting signal based on a change in a second variable capacitance formed between a compensation sensor electrode and a second conductive portion disposed on the second substrate,

wherein the first spring constant of the force sensor is greater than the second spring constant of the compensation sensor, and

wherein the second spring constant is configured to produce a first sensor sensitivity in the compensation sensor that is different than a second sensor sensitivity in the force sensor; and

a determination module configured to;

determine force information corresponding to the first force based on the first resulting signal from the force sensor;

determine calibrated force information based on the second resulting signal from the compensation sensor and the force information,

wherein the compensation spring feature is configured to facilitate a deflection of the second conductive portion relative to the compensation sensor electrode in response to a second force applied to the input device, and

wherein the deflection of the second conductive portion is configured to change the second variable capacitance.

10. The processing system of claim 9,

wherein the first force is applied to the first substrate in a first direction,

wherein the second force is applied to the second substrate in a second direction, and

wherein the second direction is substantially opposite the first direction.

11. The processing system of claim 9,

wherein the force spring feature is configured to facilitate a deflection of the force sensor electrode relative to the first conductive portion to change the first variable capacitance.

12. The processing system of claim 9,

wherein the compensation spring feature is disposed proximate a center region of the second substrate, and

wherein the force spring feature is disposed proximate an exterior edge of the second substrate.

13. The processing system of claim 9,

wherein the determination module is further configured to:

determine, from the first resulting signal, a first force component value corresponding to the first force;

determine, from the second resulting signal, a second force component value corresponding to the second force; and

determine a calibrated force component value based on adding the second force component value to the first force component value.

14. The processing system of claim 13,

wherein the calibrated force component value is based on the change in the second variable capacitance, the second spring constant of the compensation spring feature, and a mass having the second conductive portion.

20. The processing system of claim 9, wherein the determination module is further configured to:

determine a magnitude of a background force based on the second resulting signal from the compensation sensor; and

adjust, using the magnitude of the background force, the force information to produce calibrated force information.

15. A method for manufacturing an input device, comprising:

disposing a force sensor electrode, a compensation sensor electrode, and a plurality of proximity sensor electrodes on a first substrate, wherein the plurality of proximity sensor electrodes are configured to detect one or more input objects in a sensing region; and

coupling a second substrate to the first substrate, the second substrate comprising a first conductive portion, a second conductive portion, a force spring feature, and a compensation spring feature, wherein the force sensor electrode, the first conductive portion, and the force spring feature form a force sensor, wherein the compensation sensor electrode, the second conductive portion, and the compensation spring feature form a compensation sensor,

wherein the force sensor electrode and the first conductive portion are configured to form a first variable capacitance for determination of a first force applied by the one or more input objects to an input surface of the input device,

wherein the compensation spring feature is configured to facilitate a deflection of the second conductive portion relative to the compensation sensor electrode in response to a second force applied to the input device,

wherein the deflection of the second conductive portion is configured to change a second variable capacitance formed between the second conductive portion and the compensation sensor electrode,

wherein the first spring constant of the force sensor is greater than the second spring constant of the compensation sensor,

wherein the second spring constant is configured to produce a first sensor sensitivity in the compensation sensor that is different than a second sensor sensitivity in the force sensor, and

wherein the determination of the first force is based on the change in the second variable capacitance.

16. The method of claim 15, further comprising:

communicatively coupling a processing system to the force sensor electrode and the compensation sensor electrode, the processing system comprising a determination module configured for processing a first resulting signal and a second resulting signal,

wherein the first resulting signal is based on a change in the change in the first variable capacitance between the force sensor electrode and the first conductive portion, and

wherein the second resulting signal is based on the change in the second variable capacitance formed between the compensation sensor electrode and the second conductive portion.

17. The method of claim 16,

wherein the determination module is further configured to:

determine force information applied by the input object to the sensing region based on the first resulting signal; and

determine calibrated force information based on the second resulting signal and the force information.

18. The method of claim 15, further comprising:

coupling a third substrate to the second substrate,

wherein the third substrate comprises a transmission element, and

wherein the transmission element is configured to deflect the first conductive portion toward the force sensor electrode in response to the first force applied by the input object to the first substrate.