Flexible Touch Sensor Input Device

• US 20130215035A1
• Filed: 02/21/2012
• Published: 08/22/2013
• Est. Priority Date: 02/21/2012
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: David Brent Guard
• Inventors: Guard, David Brent
• Granted Patent: US 9,471,185 B2
• Time in Patent Office: Days
• US Class Current: 345/168
• 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 3/0221 Arrangements for reducing keyboard size for transport or storage, e.g. foldable keyboards, keyboards with collapsible keys G06F3/0216 takes precedence; for keyboards integrated in a laptop computer G06F1/1666
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: H03K 2217/960785 with illumination

Abstract

In one embodiment, an input device includes a flexible outer layer and a flexible touch sensor layer. The flexible outer layer is formed from a solidified material. The flexible touch sensor includes a substrate and a plurality of electrodes coupled to at least one side of the substrate. The electrodes are operable to detect touches of the flexible outer layer. Each of the electrodes have a shape formed by a plurality of lines of metal, which may be fine lines of metal (FLM), that occupy less than 100% of the area of the shape of the electrode.

Claims

1. An input device comprising:

a flexible outer layer formed from a solidified material; and

a flexible touch sensor layer comprising a substrate and a plurality of electrodes coupled to at least one side of the substrate, the plurality of electrodes operable to detect touches of the flexible outer layer, each of the electrodes having a shape formed by a plurality of flexible lines of metal that occupy less than 100% of the area of the shape of the electrode.

2. The input device of claim 1, wherein the flexible lines of metal have widths of about 2 μ

m to about 10 μ

m.

3. The input device of claim 1, wherein the flexible lines of metal have widths of more than about 10 μ

m.

4. The input device of claim 1, wherein the flexible lines of metal comprise a hatched or mesh pattern that occupies between 1% and 10% of the area of the shape of the electrode.

5. The input device of claim 1, wherein the solidified material is a polymer with a dielectric constant greater than about 3

6. The input device of claim 1, wherein the solidified material is selected from the group consisting of polymer, rubber, and silicone.

7. The input device of claim 1, wherein:

the solidified material has a dielectric constant less than about 3; and

the input device further comprises a touch input element having a dielectric constant greater than about 3.

8. The input device of claim 1, wherein the plurality of electrodes comprises a plurality of sense electrodes and a plurality of drive electrodes, the plurality of sense electrodes disposed on a first side of the substrate and the plurality of drive electrodes disposed on a second side of the substrate that is opposite the first side.

9. The input device of claim 1, wherein the plurality of electrodes comprises a plurality of sense electrodes and a plurality of drive electrodes, the plurality of sense electrodes and the plurality of drive electrodes disposed on one side of the substrate.

10. The input device of claim 1, wherein the flexible outer layer is opaque.

11. The input device of claim 1, wherein the flexible outer layer is transparent.

12. The input device of claim 1, wherein:

the input device is a keyboard that is substantially flat; and

the flexible outer layer comprises a graphics layer indicating outlines of keys of the keyboard.

13. The input device of claim 1, wherein the input device is a keyboard comprising a plurality of three-dimensional protrusions that protrude above a surface of the flexible outer layer, at least a first of the protrusions corresponding to a key of the keyboard.

14. The input device of claim 13, wherein:

at least one of the three-dimensional protrusions comprises a dial having a shape of a cylinder;

a portion of the flexible touch sensor layer is disposed in the dial;

the dial is operable to remain stationary while a user twists one or more fingers around an outer surface of the dial; and

the portion of the flexible touch sensor layer that is disposed in the dial is operable to detect the one or more fingers twisting around the outer surface of the dial.

15. The input device of claim 1, the outer layer further comprising a touch pad area, wherein:

a portion of the flexible touch sensor layer is disposed under the touch pad area; and

the portion of the flexible touch sensor layer under the touch pad area is operable to detect movements of a touch object as the touch object moves across the touch pad area.

16. An input device comprising:

a flexible outer layer formed from a solidified material; and

a flexible touch sensor layer comprising a substrate and a plurality of electrodes coupled to at least one side of the substrate, the plurality of electrodes operable to detect touches of the flexible outer layer, each of the electrodes having a shape formed by a plurality of lines of metal.

17. The input device of claim 16, wherein the lines of metal are fine lines of metal (FLM), and comprise a hatched or mesh pattern that occupies between 1% and 10% of the area of the shape of the electrode.

18. The input device of claim 16, wherein the plurality of electrodes comprises a plurality of sense electrodes and a plurality of drive electrodes, the plurality of sense electrodes disposed on a first side of the substrate and the plurality of drive electrodes disposed on a second side of the substrate that is opposite the first side.

19. The input device of claim 16, wherein the plurality of electrodes comprises a plurality of sense electrodes and a plurality of drive electrodes, the plurality of sense electrodes and the plurality of drive electrodes disposed on one side of the substrate.

20. The input device of claim 16, wherein:

the input device is a keyboard that is substantially flat; and

the flexible outer layer comprises a graphics layer indicating outlines of keys of the keyboard.

21. The input device of claim 16, wherein the input device is a keyboard comprising a plurality of three-dimensional protrusions that protrude above a surface of the flexible outer layer, at least one of the protrusions corresponding to a key of the keyboard.

22. The input device of claim 16, wherein the flexible touch sensor layer is approximately 50 μ

m thick.

23. The input device of claim 16, wherein the flexible outer surface is continuous and is impenetrable by water.

24. A method for forming an input device, the method comprising:

forming a flexible touch sensor layer by forming a plurality of electrodes on a flexible substrate, the plurality of electrodes configured to form a plurality of capacitive nodes, each capacitive node configured to sense touch of an object proximate a touch sensing area of the substrate, each of the electrodes having a shape formed by a plurality of fine lines of metal (FLM) that occupy less than 100% of the area of the shape of the electrode;

placing the flexible touch sensor layer in a mould having a shape of a keyboard; and

forming the input device using an in-mould lamination (IML) process, the IML process comprising injecting a material in liquid form into the mould;

wherein;

the material, once solidified, forms an outer layer of the input device in the shape of the keyboard; and

the flexible touch sensor layer is disposed under the outer layer and is operable to detect which keys of the keyboard have been touched.

25. The method of claim 24, wherein:

the keyboard is substantially flat; and

the material has a dielectric constant greater than about 3.

26. The method of claim 24, wherein:

the keys of the keyboard are three-dimensional protrusions that protrude above a surface of the outer layer of the keyboard; and

the method further comprises forming the input device using a plurality of non-flexible touch input elements as the keys of the keyboard.

27. The method of claim 24, wherein:

the keys of the keyboard are three-dimensional protrusions that protrude above a surface of the outer layer of the keyboard; and

the method further comprises pre-shaping the flexible sensor layer using a vacuum forming process.