Force Sensing Architectures

• US 20170242506A1
• Filed: 02/17/2017
• Published: 08/24/2017
• Est. Priority Date: 02/19/2016
• Status: Abandoned Application

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Patel, Dhaval C., Cheung, Eugene C., Ko, Pey-Jiun, Chen, Po-Jui, Rumford, Robert W., Terry, Steve L., Lin, Wei, Niu, Xiaofan, Zhou, Xiaoqi, Gu, Yi, Chuo, Yindar, Das, Rasmi R., Scardato, Steven M., Ahn, Se Hyun, Yin, Victor H., Bae, Wookyung, Boitnott, Christopher L., Tung, Chun-Hao, Son, Mookyung, Kang, Sunggu, Gupta, Nathan K., Zhong, John Z.
• Application Number:
  US15/435,649
• Publication Number:
  US 20170242506A1
• Time in Patent Office: Days
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01L 9/0052 of piezoresistive elements circuits therefor G01L9/06
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/13398 Spacer materials; Spacer properties
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• 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 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04146 using pressure sensitive conductive elements delivering a boolean signal and located between crossing sensing lines, e.g. located between X and Y sensing line layers
• 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
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

An electronic device with a force sensing device is disclosed. The electronic device comprises a user input surface defining an exterior surface of the electronic device, a first capacitive sensing element, and a second capacitive sensing element capacitively coupled to the first capacitive sensing element. The electronic device also comprises a first spacing layer between the first and second capacitive sensing elements, and a second spacing layer between the first and second capacitive sensing elements. The first and second spacing layers have different compositions. The electronic device also comprises sensing circuitry coupled to the first and second capacitive sensing elements configured to determine an amount of applied force on the user input surface. The first spacing layer is configured to collapse if the applied force is below a force threshold, and the second spacing layer is configured to collapse if the applied force is above the force threshold.

Claims

1. An electronic device, comprising:

a user input surface defining an exterior surface of the electronic device;

a first capacitive sensor comprising a first pair of sensing elements having an air gap therebetween and configured to determine a first amount of applied force on the user input surface that results in a collapse of the air gap; and

a second capacitive sensor below the first capacitive sensor comprising a second pair of sensing elements having a deformable element therebetween and configured to determine a second amount of applied force on the user input surface that results in a deformation of the deformable element.

2. The electronic device of claim 1, wherein:

the first pair of sensing elements comprises;

a shared sense element; and

a first drive element set apart from and capacitively coupled to the shared sense element; and

the second pair of sensing elements comprises;

the shared sense element; and

a second drive element set apart from and capacitively coupled to the shared sense element.

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

a display layer comprising;

a display element positioned below the user input surface; and

a back polarizer positioned below the display element;

a sheet of conductive material formed over a back surface of the back polarizer to produce a conducting surface on the back surface of the back polarizer; and

a conductive border formed along at least one edge of the sheet of conductive material.

4. The electronic device of claim 3, wherein the conductive border is positioned outside of a user-viewable region of the display layer.

5. The electronic device of claim 3, wherein the sheet of conductive material comprises silver nanowire.

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

a display element coupled to the first drive element; and

a base structure, wherein;

the display element is configured to flex relative to the base structure;

the deformable element is coupled to the base structure; and

the air gap is positioned between the deformable element and the display element.

7. The electronic device of claim 6, wherein the shared sense element is coupled to the deformable element.

12. The capacitive force sensor of claim 6, wherein the first drive layer comprises:

an insulating substrate;

a sheet of conductive material formed over a back surface of the insulating substrate to produce a conducting surface on the back surface of the insulating substrate; and

a conductive border formed along at least one edge of the sheet of conductive material.

13. The capacitive force sensor of claim 12, wherein the conductive border comprises a continuous conductive border that extends along the edges of the sheet of conductive material.

14. The capacitive force sensor of claim 12, wherein the conductive border comprises one or more conductive strips formed along a respective edge of the sheet of conductive material.

8. A capacitive force sensor for an electronic device, comprising:

a first drive layer;

a second drive layer positioned relative to the first drive layer;

a shared sense layer between the first and second drive layers;

a first spacing layer between the first drive layer and the shared sense layer; and

a second spacing layer between the shared sense layer and the second drive layer.

9. The capacitive force sensor of claim 8, wherein:

the first spacing layer comprises an air gap; and

the capacitive force sensor further comprises;

a pair of opposed surfaces defining the air gap; and

an anti-adhesion layer configured to prevent adhesion between the opposed surfaces.

10. The capacitive force sensor of claim 9, wherein the second spacing layer comprises an array of deformable protrusions extending from a base layer.

11. The capacitive force sensor of claim 8, further comprising sensing circuitry operatively coupled to the first drive layer, the second drive layer, and the shared sense layer, and configured to determine:

a first amount of applied force resulting in a change in thickness of the first spacing layer; and

a second amount of applied force resulting in a change in thickness of the second spacing layer.

15. An electronic device, comprising:

a cover defining a user input surface of the electronic device;

a first sensing element coupled to the cover within an interior volume of the electronic device;

a frame member coupled to the cover and extending into the interior volume of the electronic device;

a second sensing element coupled to the frame member; and

a third sensing element coupled to a base structure and set apart from the sense layer.

16. The electronic device of claim 15, wherein:

the frame member defines an opening; and

the third sensing element capacitively couples with the second sensing element through the opening.

17. The electronic device of claim 15, wherein the first sensing element comprises a continuous layer of transparent conductive material covering substantially an entire surface of a substrate.

18. The electronic device of claim 17, wherein:

the second sensing element comprises a plurality of sensing regions; and

the continuous layer of transparent conductive material overlaps multiple sensing regions of the plurality of sensing regions.

19. The electronic device of claim 18, wherein:

the third sensing element comprises a plurality of drive regions; and

each drive region overlaps multiple sensing regions of the plurality of sensing regions.

20. The electronic device of claim 17, wherein:

the first sensing element further comprises a connection element electrically coupled to the continuous layer of transparent conductive material; and

the electronic device further comprises;

sensing circuitry configured to provide an electrical signal to the first sensing element; and

a connector segment electrically coupling the sensing circuitry to the connection element.