Force determination employing sheet sensor and capacitive array

• US 10,048,789 B2
• Filed: 06/01/2015
• Issued: 08/14/2018
• Est. Priority Date: 02/12/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Filiz, Sinan, Grunthaner, Martin P., Smith, John Stephen, Ogata, Charley T., Sauer, Christian M., Choi, Shin John, Butler, Christopher J., Martisauskas, Steven J.
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): NEUPANE, KRISHNA P.
• Application Number:
  US14/727,601
• Publication Number:
  US 20160139716A1
• Time in Patent Office: 1,170 Days
• Field of Search: None
• 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 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A device configured to sense a touch on a surface of the device. The device includes a cover and a force-sensing structure disposed below the cover. The force-sensing structure may be positioned below a display and used in combination with other force-sensing elements to estimate the force of a touch on the cover of a device.

Claims

1. An electronic device comprising:

a cover;

a strain-sensitive gasket disposed along a perimeter of the cover, the strain-sensitive gasket having a first force sensing range for sensing forces applied to the cover;

a display positioned below the cover;

a force-sensing structure disposed below the display, wherein the force-sensing structure comprises;

a first capacitive plate;

a second capacitive plate disposed below the first capacitive plate; and

a compressible element disposed between the first and second capacitive plates; and

a plate affixed to and supporting the force-sensing structures;

wherein the force-sensing structure has a second force sensing range for sensing forces applied to the cover, the second force sensing range begins at a first threshold that corresponds to a minimum force that can be detected by the force-sensing structure, the first force sensing range ends at a second threshold that corresponds to a maximum force that can be detected by the strain-sensitive gasket, and the first threshold is less than the second threshold.

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

sensing circuitry that is operatively coupled to the force-sensing structure, wherein the sensing circuitry is configured to estimate the force of a touch on the cover based on a change in capacitance between the first capacitive plate and the second capacitive plate.

3. The electronic device of claim 1, wherein the force-sensing structure is separated from the display by a compliant layer including an air gap.

4. The electronic device of claim 1, wherein the force-sensing structure is separated from the display by a compliant layer comprised of compressible foam.

5. The electronic device of claim 1, wherein the force-sensing structure is separated from the display by a compliant layer comprised of an array of compliant pillars and an optically transparent fluid.

6. The electronic device of claim 1, further comprising:

a housing having a bezel surrounding the cover; and

an oleophobic coating disposed over at least a portion of a gap between the cover and the bezel;

wherein the strain-sensitive gasket is disposed in the gap.

7. An electronic device comprising:

a housing;

a cover disposed within an opening of the housing;

a strain-sensitive gasket disposed between the cover and the housing along a perimeter of the cover, the strain-sensitive gasket having a first force sensing range; and

a force-sensing structure disposed below the cover, the force-sensing structure having a second force sensing range;

wherein the second force sensing range begins at a first threshold, the first force sensing range ends at a second threshold, and the first threshold is less than the second threshold.

8. The electronic device of claim 7, further comprising a plate fixed relative to the housing and supporting the force-sensing structure.

9. The electronic device of claim 7, wherein the strain-sensitive gasket comprises:

a gasket first capacitive plate;

a gasket second capacitive plate; and

a gasket compressible element disposed between the gasket first capacitive plate and the gasket second capacitive plate.

10. The electronic device of claim 7, further comprising:

a display disposed between the cover and the force-sensing structure; and

a compressible layer comprising an air gap between the display and the force-sensing structure.

11. The electronic device of claim 10, wherein:

the air gap of the compressible layer is configured to at least partially collapse in response to a force of a touch that exceeds the first threshold.

12. The electronic device of claim 7, further comprising:

a display disposed between the cover and the force-sensing structure; and

a compressible layer between the display and the force-sensing structure, wherein

the compressible layer is configured to at least partially collapse in response to a force of a touch that exceeds the first threshold.

13. The electronic device of claim 7, wherein the force-sensing structure comprises:

a first capacitive plate;

a second capacitive plate; and

a compressible element disposed between the first capacitive plate and the second capacitive plate.

14. The electronic device of claim 7, wherein the force-sensing structure comprises a strain gauge.

15. An electronic device comprising:

a cover;

a capacitive sense layer comprising a strain-sensitive gasket positioned along a perimeter and below the cover, the strain-sensitive gasket having a first force sensing range;

a compressible layer below the capacitive sense layer; and

a force-sensing structure disposed below the compressible layer, wherein the force-sensing structure comprises;

a first capacitive plate;

a compressible element disposed on one side of the first capacitive plate; and

a second capacitive plate disposed on a side of the compressible element that is opposite the first capacitive plate;

wherein, the force-sensing structure has a second force sensing range, the second force sensing range begins at a first threshold, the first force sensing range ends at a second threshold, and the first threshold is less than the second threshold.

16. The electronic device of claim 15, further comprising:

a plate positioned below the force-sensing structure and supporting the force-sensing structure.

17. The electronic device of claim 15, wherein the compressible layer comprises an air gap.

18. The electronic device of claim 15, further comprising:

a display positioned below the cover; and

a backlight positioned below the display, wherein the capacitive sense layer is disposed between the display and the backlight.

19. The electronic device of claim 15, further comprising:

sensing circuitry is operatively coupled to the capacitive sense layer and the force-sensing structure, wherein the sensing circuitry is configured to estimate the force of a touch on the cover based on a change in mutual capacitance between the capacitive sense layer and the second capacitive plate of the force-sensing structure.

20. The electronic device of claim 19, wherein the sensing circuitry is configured to:

obtain a first capacitance between the first capacitive plate and the second capacitive plate of the force-sensing structure;

obtain a second capacitance between the first capacitive plate and the capacitive sense layer; and

generate an estimate of a force of a touch on the cover using the first and second capacitances.