Force Determination Employing Sheet Sensor and Capacitive Array

• US 20190361560A1
• Filed: 08/12/2019
• Published: 11/28/2019
• 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.
• Granted Patent: US 10,739,899 B2
• Time in Patent Office: Days
• 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 housing defining a bezel around an opening;

a cover disposed over the opening;

a gasket disposed in a gap between the cover and the bezel;

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; and

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

a plate affixed to the housing and supporting the force-sensing structure.

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 a 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 2, wherein the force-sensing structure is separated from the display by a compliant layer including an air gap, and the force of the touch is not sensed until the display begins to compress the force-sensing structure.

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

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

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

an oleophobic coating disposed on at least one surface defining at least a portion of the gap.

7. The electronic device of claim 1, wherein one of the first and second capacitive plates is a drive plate, and the other of the first and second capacitive plates is a sense plate.

8. 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; and

a force-sensing structure disposed below the cover.

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

10. The electronic device of claim 8, wherein the strain-sensitive gasket comprises:

a gasket upper capacitive plate;

a gasket lower capacitive plate; and

a gasket compressible element disposed between the gasket upper capacitive plate and the gasket lower capacitive plate.

11. The electronic device of claim 8, 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.

12. The electronic device of claim 11, 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 a first threshold; and

the first threshold is less than a second threshold that corresponds to a maximum force that can be detected by the strain-sensitive gasket.

13. The electronic device of claim 8, 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 a first threshold, and

the first threshold is less than a second threshold that corresponds to a maximum force that can be detected by the strain-sensitive gasket.

14. The electronic device of claim 8, wherein the force-sensing structure comprises:

an upper capacitive plate;

a lower capacitive plate; and

a compressible element disposed between the upper capacitive plate and the lower capacitive plate.

15. The electronic device of claim 8, wherein the force-sensing structure comprises a strain gauge.

16. An electronic device comprising:

a housing defining a bezel around an opening;

a cover disposed within the opening;

a compliant environmental gasket disposed in a gap between the cover and the bezel;

a display positioned below the cover;

a sheet sensor disposed below the display;

a plate affixed to the housing and supporting the sheet sensor.

17. The electronic device of claim 16, wherein the sheet sensor is a capacitive-plate type force sensor.

18. The electronic device of claim 17, wherein the capacitive-plate type force sensor comprises a shield layer and a sense plate.

19. The electronic device of claim 16, wherein the sheet sensor comprises first and second arrays of capacitive plates.

20. The electronic device of claim 19, wherein the first and second arrays of capacitive plates are separated by at least one of:

a silicone, a compliant gel, or a compressible polymer.