Tensioned touch panel and method of making same

• US 7,687,736 B2
• Filed: 04/29/2004
• Issued: 03/30/2010
• Est. Priority Date: 04/29/2004
• Status: Active Grant

• Current Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Butmir, Amir, Auger, Paul Anthony
• Primary Examiner(s): Lee; Kyung
• Application Number:
  US10/834,361
• Publication Number:
  US 20050241929A1
• Time in Patent Office: 2,161 Days
• Field of Search: 200/600, 200/511, 200/512, 200/329, 345/102, 345/173, 345/174, 345/175, 341/22, 341/32
• US Class Current: 200/600
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49105 Switch making
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A tensioned touch panel includes a support structure having a substrate with a generally planer conductive surface disposed thereon and an insulating spacer generally about the periphery of the substrate. A pretensioned conductive member overlies the support structure. The spacer separates the conductive membrane and the conductive surface thereby to define an air gap therebetween. A conductive membrane is secured to the support structure under sufficient tension to inhibit slack from developing in the conductive membrane as a result of changes in environmental conditions. A method of assembling a tensioned touch panel is also provided.

Claims

1. A tensioned touch panel comprising:

a support structure comprising a substrate having a generally planar conductive surface disposed thereon and an insulating spacer generally about the periphery of said substrate; and

a flexible, elastic, conductive membrane overlying said support structure and secured thereto, said spacer separating said conductive membrane and said conductive surface thereby to define an air gap therebetween, said conductive membrane being stressed to a level of pretension prior to being secured to said support structure that is selected to maintain the separation between the conductive membrane and the conductive surface and inhibit slack from developing in said conductive membrane over time and as a result of changes in environmental conditions, after said conductive membrane has been secured to said support structure.

2. A tensioned touch panel according to claim 1 wherein said conductive membrane is affixed to said support structure with an adhesive.

3. A tensioned touch panel according to claim 2 wherein said adhesive is an ultraviolet curing adhesive.

4. A tensioned touch panel according to claim 2 wherein said adhesive is a cyanoacrylate adhesive.

5. A tensioned touch panel according to claim 2 wherein said spacer is a generally continuous rail about the periphery of said substrate.

6. A tensioned touch panel according to claim 5 wherein said rail overlies a peripheral region of said substrate surrounding said conductive surface, said conductive membrane being adhered directly to said rail.

7. A tensioned touch panel according to claim 5 wherein said conductive membrane includes a film and a conductive layer on said film, said conductive layer facing said conductive surface.

8. A tensioned touch panel according to claim 7 wherein said conductive layer covers a portion of a major surface of said film defining a peripheral margin, said peripheral margin corresponding generally in shape to said spacer.

9. A tensioned touch panel according to claim 7 wherein said conductive layer covers the entirety of a major surface of said film.

10. A tensioned touch panel comprising:

a support structure having a conductive surface disposed thereon; and

a flexible, elastic, conductive membrane overlying said conductive surface in spaced apart relation, said conductive membrane being permanently secured to said support structure, said conductive membrane being stressed to a level of pretension prior to being secured to said support structure, the level of pretension being selected to maintain separation between the conductive membrane and the conductive surface and inhibit slack from developing in said conductive membrane over time and over a variety of environmental conditions, after said conductive membrane has been secured to said support structure.

11. A tensioned touch panel according to claim 10 wherein said conductive membrane is affixed to said support structure with an adhesive.

12. A tensioned touch panel according to claim 11 wherein said adhesive is an ultraviolet curing adhesive.

13. A tensioned touch panel according to claim 11 wherein said adhesive is a cyanoacrylate adhesive.

14. A tensioned touch panel according to claim 11 wherein said conductive membrane is stressed to a level of pretension selected to compensate for the coefficient of thermal and hydroscopic or hygroscopic expansion of said conductive membrane over a variety of temperature and humidity conditions.

15. A tensioned touch panel according to claim 14 wherein said level of pretension is below the yield point of said conductive membrane and below a level at which said conductive membrane exhibits significant creep.

16. A tensioned touch panel according to claim 15 wherein said level of pretension is in the range of from about 1000 to 1500 psi.

17. A tensioned touch panel comprising:

a support structure comprising a substrate having a generally planar conductive surface disposed thereon and an insulating spacer generally about the periphery of said substrate; and

a flexible, elastic, conductive membrane overlying said support structure and secured thereto, said spacer separating said conductive membrane and said conductive surface thereby to define an air gap therebetween, said conductive membrane being stressed to a level of pretension prior to being secured to said support structure, said level of pretension being selected to maintain the separation between the conductive membrane and the conductive surface and compensate for the coefficient of thermal and hydroscopic or hygroscopic expansion of said conductive membrane over a variety of temperature and humidity conditions, after said conductive membrane has been secured to said support structure.

18. A tensioned touch panel according to claim 17 wherein said level of pretension is below the yield point of said conductive membrane and below a level at which said conductive membrane exhibits significant creep.

19. A tensioned touch panel according to claim 18 wherein said level of pretension is in the range of from about 1000 to 1500 psi.

20. A tensioned touch panel according to claim 18 wherein said conductive membrane is affixed to said support structure with an adhesive.

21. A tensioned touch panel according to claim 20 wherein said adhesive is an ultraviolet curing adhesive.

22. A tensioned touch panel according to claim 20 wherein said adhesive is a cyanoacrylate adhesive.

23. A tensioned touch panel according to claim 20 wherein said spacer is a generally continuous rail about the periphery of said substrate.

24. A tensioned touch panel according to claim 23 wherein said rail overlies a peripheral region of said substrate surrounding said conductive surface, said conductive membrane being adhered directly to said rail.

25. A tensioned touch panel according to claim 23 wherein said rail is generally L-shaped in side section and includes one arm portion overlying said peripheral region and another arm portion abutting the sides of said substrate, said conductive member being adhered directly to said rail.

26. A tensioned touch panel according to claim 23 wherein said rail is generally C-shaped in side section and includes one arm portion overlying said peripheral region, another arm portion overlying an opposed surface of said substrate and a bight joining said arm portions and abutting the sides of said substrate, said conductive member being adhered to at least one of said rail and opposed surface.

27. A tensioned touch panel according to claim 26 wherein said conductive membrane is affixed to said rail with an adhesive.

28. A tensioned touch panel according to claim 26 wherein said conductive membrane is affixed to said opposed surface with an adhesive.

29. A tensioned touch panel according to claim 18 wherein said conductive membrane includes a film and a conductive layer on said film, said conductive layer facing said conductive surface.

30. A tensioned touch panel according to claim 29 wherein said conductive layer covers a portion of a major surface of said film defining a peripheral margin, said peripheral margin corresponding generally in shape to said spacer.

31. A tensioned touch panel according to claim 29 wherein said conductive layer covers the entirety of a major surface of said film.