Force Sensing Using Dual-Layer Cover Glass with Gel Adhesive and Capacitive Sensing

• US 20160103530A1
• Filed: 12/17/2015
• Published: 04/14/2016
• Est. Priority Date: 09/21/2012
• Status: Abandoned Application

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Leung, Omar Sze, Harley, Jonah A., Babiarz, Kristina A., Wright, James E., Leong, Craig Christopher
• Application Number:
  US14/973,011
• Publication Number:
  US 20160103530A1
• Time in Patent Office: Days
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

A two-layer cover with a compressible layer separating first and second layers. In some cases, capacitive sensing between the first and second layers can determine both touch locations and applied force.

Claims

1-40. -40. (canceled)

41. An electronic device comprising:

a first substrate;

a second substrate;

a compressible layer positioned between the first and second substrates and comprising a set of compressible structures having a polygonal shape; and

a pair of electrodes positioned on opposite sides of the compressible layer;

wherein the compressible layer is configured to compress in response to a force of a touch on a surface of the electronic device.

42. The electronic device of claim 41, further comprising a touch electrode disposed on the first substrate, wherein the touch electrode is configured to detect a location of the touch on the surface.

43. The electronic device of claim 42, wherein the touch electrode is interleaved with one of the pair of electrodes.

44. The electronic device of claim 41, wherein:

a first electrode of the pair of electrodes is positioned within a first transparent conductive electrode layer configured to provide a sense signal to the pair of electrodes, and

a second electrode of the pair of electrodes is positioned within a second transparent conductive electrode layer configured to provide a drive signal from the pair of electrodes.

45. The electronic device of claim 44, wherein the first electrode is positioned over the second electrode.

46. The electronic device of claim 41, wherein the compressible layer includes one or more of:

a foam, a gel, or a liquid.

47. The electronic device of claim 46, wherein the foam, gel or liquid is an optically translucent or transparent substance.

48. The electronic device of claim 41, wherein the compressible layer includes a material having a Poisson'"'"'s ratio of less than approximately 0.48.

49. The electronic device of claim 41, wherein the compressible structures have a compression resistance substantially linear in compression with respect to a compression parameter.

50. The electronic device of claim 41, wherein the compressible structures have a compression resistance that is substantially polynomial in compression with respect to a compression parameter.

51. The electronic device of claim 41, wherein the compressible structures are substantially smaller than an optical wavelength.

52. A touch-sensitive device including:

a flexible cover element;

a substrate disposed below the flexible cover element;

a compressible layer positioned between the flexible cover element and the substrate and including a set of force-sensitive structures having a density that varies with a distance from the flexible cover element; and

a pair of electrodes positioned along opposite sides of the compressible layer.

53. The touch-sensitive device of claim 52, wherein the pair of electrodes are operatively coupled to circuitry configured to determine an amount of force of a touch on the flexible cover element.

54. The touch-sensitive device of claim 52, wherein the pair of electrodes include a sense electrode positioned over the compressible layer and a drive electrode positioned below the compressible layer.

55. The touch-sensitive device of claim 52, wherein the force-sensitive structures have a compression resistance that is substantially nonlinear in compression.

56. An electronic device comprising:

a cover;

a display positioned below the cover;

a substrate positioned below the cover;

a compressible layer positioned between the cover and the substrate and including an array of compressible structures having a polygonal shape; and

an array of sense electrodes positioned over the compressible layer; and

an array of drive electrodes positioned below the compressible layer;

wherein the compressible layer is configured to compress in response to a force of a touch on a surface of the electronic device.

57. The electronic device of claim 56, further comprising an array of touch electrodes positioned below the cover and configured to estimate a location of a touch on the surface of the electronic device.

58. The electronic device of claim 57, wherein the array of touch electrodes are interleaved with the array of sense electrodes.

59. The electronic device of claim 56, wherein:

the compressible layer includes an index-matched liquid or gel disposed within the array of compressible structures; and

the gel or liquid has an index of refraction that is substantially the same as an index of refraction of the compressible structures.

60. The electronic device of claim 56, wherein in response to a deformation of the cover, the array of sense electrodes are configured to provide a signal indicative of an applied force.