Transparent force sensitive structures in an electronic device

• US 9,886,118 B2
• Filed: 01/25/2016
• Issued: 02/06/2018
• Est. Priority Date: 09/30/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Vosgueritchian, Michael, Pedder, James E., Smith, John Stephen, Wen, Xiaonan
• Primary Examiner(s): Chow, Van
• Application Number:
  US15/005,256
• Publication Number:
  US 20170090638A1
• Time in Patent Office: 743 Days
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: H01L 27/1218 with a particular composition or structure of the substrate
• CPC Class Codes: Y10S 977/762 Nanowire or quantum wire, i.e. axially elongated structure having two dimensions of 100 nm or less

Abstract

One or more transparent transistor force sensitive structures can be included in an electronic device. The transistor force sensitive structures(s) is used to detect a force that is applied to the electronic device, to a component in the electronic device, and/or to an input region of the electronic device. As one example, the one or more transparent transistor force sensitive structures may be included in a display stack of a display in an electronic device.

Claims

1. An electronic device, comprising:

a cover layer configured to receive a touch input;

a display layer positioned below the cover layer;

a force layer positioned below the cover layer and configured to detect strain based on the touch input, the force layer comprising;

a first plurality of transistor force sensitive structures positioned over a first surface of a substrate;

at least one first gate contact electrically connected to each transistor force sensitive structures in the first plurality of transistor force sensitive structures, the at least one first gate contact configured to receive a first gate signal to adjust a gauge factor of at least one transistor force sensitive structure by depleting charge carriers from a semiconducting layer in the at least one transistor force sensitive structure; and

a processing device configured to receive strain signals from the first plurality of transistor force sensitive structures and configured to estimate an amount of force associated with the touch input.

2. The electronic device of claim 1, further comprising a second plurality of transistor force sensitive structures positioned over a second surface of the substrate.

3. The electronic device of claim 2, further comprising at least one second gate contact electrically connected to each transistor force sensitive structure in the second plurality of transistor force sensitive structures, the at least one second gate contact configured to receive a second gate signal to adjust a gauge factor of at least one transistor force sensitive structure in the second plurality of transistor force sensitive structures by depleting charge carriers from a semiconducting layer in the at least one transistor force sensitive structure.

4. The electronic device of claim 3, wherein the second gate signal is the same signal as the first gate signal.

5. The electronic device of claim 1, wherein the display layer is positioned over the force layer.

6. The electronic device of claim 1, wherein the display layer is positioned below the force layer.

7. The device of claim 1, wherein the force layer comprises a transparent force layer, the substrate comprises a transparent substrate, and the first plurality of transistor force sensitive structures comprises a first plurality of transparent transistor force sensitive structures.

8. An electronic device, comprising:

a cover layer configured to receive a touch input;

a display layer positioned below the cover layer;

a force layer positioned below the cover layer and configured to detect an amount of strain based on the touch input, the force layer comprising;

a first transistor force sensitive structures positioned over a first surface of a substrate, the first transistor force sensitive structure comprising;

a first gate electrode positioned over a first semiconducting layer;

a first source electrode at least partially positioned on a surface of the first semiconducting layer below the first gate electrode;

a first drain electrode at least partially positioned on the surface of the first semiconducting layer below the first gate electrode;

a first strain signal line connected to the source electrode; and

a second strain signal line connected to the drain electrode;

a first gate contact electrically connected to the first gate electrode, the first gate contact configured to receive a first gate signal to adjust a gauge factor of the first transistor force sensitive structure by depleting charge carriers from the first semiconducting layer; and

a processing device configured to receive a first strain signal transmitted by the first or the second strain signal line that represents the amount of strain and configured to estimate an amount of force associated with the touch input.

9. The electronic device of claim 8, further comprising a second gate electrode positioned below the first semiconducting layer.

10. The electronic device of claim 9, wherein the first gate contact is electrically connected to the second gate electrode to adjust the gauge factor of the first transistor force sensitive structure by depleting charge carriers from the first semiconducting layer.

11. The electronic device of claim 9, wherein a second gate contact is electrically connected to the second gate electrode, the second gate contact configured to receive a second gate signal to adjust the gauge factor of the first transistor force sensitive structure by depleting charge carriers from the first semiconducting layer.

12. The electronic device of claim 8, wherein the display layer is positioned over the force layer.

13. The electronic device of claim 8, wherein the display layer is positioned below the force layer.

14. The electronic device of claim 8, wherein the first gate contact is positioned in a non-display area of the force layer.

15. The electronic device of claim 8, further comprising a second transistor force sensitive structure positioned over a second surface of the substrate, the second transistor force sensitive structure that includes:

a third gate electrode positioned over a second semiconducting layer;

a second source electrode at least partially positioned on a surface of the second semiconducting layer below the third gate electrode;

a second drain electrode at least partially positioned on the surface of the second semiconducting layer below the third gate electrode;

a third strain signal line connected to the source electrode; and

a fourth strain signal line connected to the drain electrode.

16. The electronic device of claim 15, wherein the first gate contact is electrically connected to the third gate electrode, the first gate contact configured to receive the first gate signal to adjust a gauge factor of the second transistor force sensitive structure by depleting charge carriers from the second semiconducting layer.

17. The electronic device of claim 15, wherein a second gate contact is electrically connected to the third gate electrode, the second gate contact configured to receive a second gate signal to adjust a gauge factor of the second transistor force sensitive structure by depleting charge carriers from the second semiconducting layer.

18. The electronic device of claim 15, wherein the processing device is configured to receive a second strain signal from the third or the fourth strain signal line and configured to estimate an amount of force associated with the touch input.

19. The electronic device of claim 15, further comprising a fourth gate electrode positioned below the second semiconducting layer.

20. The electronic device of claim 19, wherein the first gate contact is electrically connected to the fourth gate electrode, the first gate contact configured to receive the first gate signal to adjust a gauge factor of the second transistor force sensitive structure.

21. The electronic device of claim 19, wherein a second gate contact is electrically connected to the fourth gate electrode, the second gate contact configured to receive a second gate signal to adjust a gauge factor of the second transistor force sensitive structure.

22. The electronic device of claim 8, wherein the substrate comprises a glass substrate.

23. The electronic device of claim 8, wherein the gate electrode and the first semiconducting layer are each formed with indium tin oxide.

24. The electronic device of claim 8, wherein the gate electrode is formed with indium tin oxide and the first semiconducting material is formed with one of a silver nanowire and a zinc oxide.

25. The electronic device of claim 8, further comprising sense circuitry operably connected between at least one of the first or the second strain signal lines and the processing device.