Flexible switching devices

• US 7,301,435 B2
• Filed: 07/20/2006
• Issued: 11/27/2007
• Est. Priority Date: 05/18/2000
• Status: Expired due to Term

• Current Assignee: Romney Consultants Ltd.
• Original Assignee: Peratech Limited
• Inventors: Lussey, David, Jones, Dianne, Leftly, Steven
• Primary Examiner(s): LEE, KYUNG S
• Application Number:
  US11/489,444
• Publication Number:
  US 20060255903A1
• Time in Patent Office: 495 Days
• Field of Search: 338/13, 338/47, 338/99, 338/101, 338/114, 738/626.8, 737/74, 219/529, 219/545, 428/327, 428/330, 235/462.44, 298/46
• US Class Current: 338/13
• CPC Class Codes: H01H 1/021 Composite material
• CPC Class Codes: H01H 2201/036 Variable resistance
• CPC Class Codes: H01H 3/141 Cushion or mat switches
• CPC Class Codes: Y10T 428/254 Polymeric or resinous material

Abstract

An electronic resistor user interface comprises flexible conductive materials and a flexible variably resistive element capable of exhibiting a change in electrical resistance on mechanical deformation and is characterised by textile-form electrodes (10,12), a textile form variably resistive element (14) and textile-form members (16) connective to external circuitry.

Claims

1. A variable resistance user-interface comprising:

at least two textile-form flexible conductive electrode layers, including a first textile-form flexible conductive electrode layer and a second textile-form flexible conductive electrode layer;

at least two textile-form conductive linking members, including a first textile-form conductive linking member and a second textile-form conductive linking member; and

a textile-form variably resistive element capable of exhibiting a change in electrical resistance upon mechanical deformation,

wherein the textile-form variably resistive element is formed as a coating applied to the first textile-form flexible conductive electrode layer;

wherein the first textile-form flexible conductive electrode layer is connected to the first textile-form conductive linking member, which is in turn connective to external circuitry;

wherein the second textile-form flexible conductive electrode layer is positioned adjacent the textile-form variably resistive element;

wherein the second textile-form flexible conductive electrode layer is connected to the second textile-form conductive linking member, which is in turn connective to the external circuitry; and

wherein the textile-form variably resistive element is positioned between the first textile-form flexible conductive electrode layer and the second textile-form flexible conductive electrode layer.

2. The variable resistance user-interface according to claim 1 in which at least one of the textile-form flexible conductive electrode layers comprises a non-conducting textile into which a conductive yarn is woven, knitted or embroidered.

3. The variable resistance user-interface according to claim 1 in which at least one of the textile-form flexible conductive layers comprises a non-conductive textile to which is applied a conductive printing ink.

4. The variable resistance user-interface according to claim 1 in which the textile-form variably resistive element comprises particulate variably resistive material and an elastomer binder.

5. The variable resistance user-interface according to claim 4 in which the particulate variably resistive material is a polymer composition in which a filler selected from one or more powder-form metallic elements or alloys, electrically conductive oxides of said elements and alloys, and mixtures thereof, is in admixture with a non-conductive elastomer, having been mixed in a controlled manner whereby the filler is dispersed within the non-conductive elastomer and remains structurally intact, and voids present in filler powder become infilled with the non-conductive elastomer during curing of the non-conductive elastomer.

6. The variable resistance user-interface according to claim 1 in which at least one of the first and second textile-form flexible conductive electrode layers is supported by a non-conductive textile having a sub-area greater than the textile-form flexible conductive electrode layer, and

wherein the non-conductive textile support also supports at least one of the first and second textile-form conductive linking members, respectively.

7. The variable resistance user-interface according to claim 6 in which the sub-area carries a terminal at which the first textile-form conductive linking member or second textile-form conductive linking member passes electric current to the external circuitry.

8. The variable resistance user-interface according to claim 1 in which the first textile-form flexible conductive electrode layer is connected to a first textile-form extension and the second textile-form flexible conductive electrode layer is connected to a second textile-form extension,

wherein the textile-form extensions each form a path for holding the first textile-form conductive linking member or second textile-form conductive linking member, respectively;

wherein the first textile-form conductive linking member and the second textile-form conductive linking member are connected to the external circuitry and are comprised of conductive material present as conductive tracks in or on the respective textile-form extensions; and

wherein the textile-form extensions comprise at least one of a textile support, a ribbon and a tape.

9. The variable resistance user-interface as claimed in claim 8 in which the conductive tracks are at least one of woven, knitted, sewn and embroidered and printed on the textile-form extension.

10. The variable resistance user-interface according to claim 1 in which at least one of the textile-form conductive linking members comprises variably resistive material pre-stressed to conductance.

11. The variable resistance user-interface according to claim 1 in which at least one of the textile-form flexible conductive electrode layers comprises a conductive fabric sewn or bonded onto non-conducting textile.

12. The variable resistance user-interface according to claim 1 in which at least one of the textile-form flexible conductive electrode layers comprises a conductive coating applied to non-conductive textile.

13. The variable resistance user-interface according to claim 1 in which the textile-form variably resistive element is fixed in intimate contact with both the first textile-form flexible conductive electrode layer and the second textile-form flexible conductive electrode layer.

14. The variable resistance user-interface according to claim 1 in which the textile-form variably resistive element comprises particulate conducting polymer material and an elastomer binder.

15. The variable resistance user-interface according to claim 14 in which the particulate conducting polymer material is one of the group consisting of polyaniline, polypyrrole and polythiophene.

16. The variable resistance user-interface according to claim 1 in which the textile-form variably resistive element comprises particulate carbon material and an elastomer binder.

17. The variable resistant user-interface according to claim 1 in which the first textile-form flexible conductive electrode layer contains parallel linear electrodes extending in a first direction and the second textile-form flexible conductive electrode layer contains parallel linear electrodes extending in a second direction, perpendicular to the first direction.