Electronic devices with flexible displays

• US 10,198,040 B2
• Filed: 09/22/2016
• Issued: 02/05/2019
• Est. Priority Date: 05/20/2016
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhang, Zhen, Yin, Victor H., Liu, Cyrus Y., Drzaic, Paul S., Bae, Sungwon, Tung, Chun-Hao, Vakhshouri, Kiarash, Kang, Sunggu, Zhong, John Z.
• Primary Examiner(s): Kumar, Srilakshmi K
• Assistant Examiner(s): Castiaux, Brent D
• Application Number:
  US15/272,957
• Publication Number:
  US 20170336831A1
• Time in Patent Office: 866 Days
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1643 the display being associated to a digitizer, e.g. laptops that can be used as penpads details related to the relative motion of the display enclosure with respect to the body enclosure, e.g. to move between laptop and tablet PC configuration G06F1/1615
• CPC Class Codes: G06F 1/1652 the display being flexible, e.g. mimicking a sheet of paper, or rollable
• 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 2203/04103 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 3/0416 Control or interface arrangements specially adapted for digitisers
• 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
• 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

Abstract

An electronic device may have a flexible portion that allows the device to be folded. The device may have a flexible display. The flexible display may have a flexible display layer, a cover layer, a touch sensor interposed between the flexible display layer and the cover layer, a support layer, and a polarizer layer. The polarizer layer may be interposed between the touch sensor and the flexible display or between the touch sensor and the cover layer. The touch sensor may include optically clear adhesive that is flexible and facilitates bending of the display. The optically clear adhesive may include additives such as water vapor penetration reducing additive, anticorrosion additive, ultraviolet-light blocking additive, and index-of-refraction adjustment additive. The support layer may be formed from shape memory alloy or amorphous metal and may have openings to facilitate bending.

Claims

1. An electronic device, comprising:

a housing; and

a flexible display in the housing having a bending region that bends about a bend axis, wherein the flexible display includes;

an array of pixels formed on a flexible display substrate; and

a touch sensor having a touch sensor substrate with opposing first and second surfaces, first conductive structures on the first surface, second conductive structures on the second surface, and optically clear adhesive on the first and second surfaces, wherein the optically clear adhesive comprises water vapor penetration reducing additive and wherein the optically clear adhesive comprises an additive selected from the group consisting of;

a corrosion reducing additive, an ultraviolet light damage prevention additive, and an index-of-refraction adjustment additive.

2. The electronic device defined in claim 1 wherein the optically clear adhesive has an elastic modulus of less than 10⁶ Pa.

3. The electronic device defined in claim 2 wherein the optically clear adhesive includes a first layer on the first surface and a second layer on the second surface, the electronic device further comprising a flexible polymer cover layer, wherein the first layer of the optically clear adhesive attaches the flexible polymer cover layer to the touch sensor.

4. The electronic device defined in claim 3 further comprising a polarizer layer, wherein the second layer of the optically clear adhesive attaches the polarizer to the touch sensor.

5. The electronic device defined in claim 4 wherein the optically clear adhesive comprises an adhesive layer of at least 5 microns in thickness that includes sufficient water vapor penetration reducing additive to limit a water vapor transmission rate through the adhesive layer to less than 5000 g/m²-day at 65°

C. and 90% humidity.

6. The electronic device defined in claim 4 wherein at least some of the optically clear adhesive comprises an anticorrosion additive.

7. The electronic device defined in claim 4 wherein at least some of the optically clear adhesive comprises ultraviolet-light-damage-reducing additive.

8. The electronic device defined in claim 7 wherein the optically clear adhesive with the ultraviolet-light-damage-reducing additive blocks at least 50% of ultraviolet light between 320 nm and 420 nm.

9. The electronic device defined in claim 1 wherein the flexible display further comprises a support layer configured to support the array of pixels formed on the flexible display substrate.

10. The electronic device defined in claim 9 further comprising openings in the support layer that overlap the bend axis.

11. The electronic device defined in claim 9 wherein the support layer comprises metal.

12. The electronic device defined in claim 9 wherein the support layer comprises shape memory alloy.

13. The electronic device defined in claim 9 wherein the support layer comprises amorphous metal.

14. The electronic device defined in claim 13 wherein the optically clear adhesive includes ultraviolet-light blocking additive and anticorrosion additive.

15. The electronic device defined in claim 14 wherein the optically clear adhesive includes a layer having first, second, and third sublayers, wherein the second sublayer is interposed between the first and third sublayers, wherein the first and third sublayers include index-of-refraction adjustment additive, and wherein the second sublayer is free of the index-of-refraction adjustment additive.

16. The electronic device defined in claim 15 wherein the flexible display further comprises a plurality of bistable metal strips that run perpendicular to the bend axis.

17. An electronic device, comprising:

a housing; and

a flexible display in the housing having a bending region that bends about a bend axis between a folded and an unfolded state, wherein the flexible display includes;

an array of pixels formed on a flexible display substrate;

a flexible display cover layer;

a touch sensor between the flexible display cover layer and the array of pixels;

an amorphous metal support layer that supports the array of pixels and the flexible display substrate, wherein the array of pixels and the flexible display substrate are interposed between the amorphous metal support layer and the touch sensor; and

a plurality of bistable metal strips that run perpendicular to the bend axis, wherein the bistable metal strips have a curved cross-sectional profile that maintains the flexible display cover layer in the unfolded state.

18. The electronic device defined in claim 17 wherein the touch sensor has opposing first and second surfaces, first conductive structures on the first surface, second conductive structures on the second surface, and optically clear adhesive on the first and second surfaces, wherein the optically clear adhesive has an additive selected from the group consisting of:

a water vapor penetration reducing additive, a corrosion reducing additive, and an ultraviolet light damage prevention additive.

19. A flexible display, comprising:

an organic light-emitting diode display layer having a flexible substrate;

a flexible display cover layer;

a metal support layer that supports the organic light-emitting diode display layer and that has a yield strain of at least 1%;

a polarizer layer;

a touch sensor substrate having first and second surfaces with conductive capacitive touch sensor electrodes;

a first layer of adhesive that attaches the flexible display cover layer to the touch sensor at the first surface and that has an elastic modulus of less than 10⁶ Pa;

a second layer of adhesive that attaches the polarizer to the touch sensor at the second surface and that has an elastic modulus of less than 10⁶ Pa, wherein the second layer of adhesive contains an ultraviolet light damage prevention additive, and wherein at least one of the first and second layers of adhesive includes a sublayer containing an index-of-refraction adjustment additive and at least one additive selected from the group consisting of;

a water vapor penetration reducing additive and a corrosion reducing additive; and

a patterned metal structure directly on at least a portion of the second layer of adhesive.