Tensioned touch panel and method of making same

• US 8,067,710 B2
• Filed: 05/04/2007
• Issued: 11/29/2011
• 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: Auger, Paul A., Butmir, Amir
• Primary Examiner(s): Luebke; Renee
• Assistant Examiner(s): CAROC, LHEIREN MAE ANGLO
• Application Number:
  US11/744,505
• Publication Number:
  US 20080083602A1
• Time in Patent Office: 1,670 Days
• Field of Search: 200/600
• 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 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 tensioned prior to being secured to said support structure so that after said conductive membrane is secured to said support structure while under tension, said conductive membrane is under sufficient tension to inhibit slack from developing in said conductive membrane as a result of changes in environmental conditions.

2. A tensioned touch panel according to claim 1 wherein said conductive membrane is subjected to stress at a level 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 prior to being secured to said support structure.

3. A tensioned touch panel according to claim 2 wherein said stress level is below the yield point of said conductive membrane and below a level at which said conductive membrane exhibits significant creep.

4. A tensioned touch panel according to claim 3 wherein said stress level is in the range of from about 1000 to 1500 psi.

5. A tensioned touch panel according to claim 3 wherein said conductive membrane is adhered to said spacer.

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

7. A tensioned touch panel according to claim 6 wherein said rail is generally T-shaped in side section.

8. A tensioned touch panel according to claim 5 wherein said conductive membrane is adhered to said spacer via an ultraviolet curing adhesive.

9. A tensioned touch panel according to claim 5 wherein said conductive membrane is adhered to said spacer via a cyanoacrylate adhesive.

10. A tensioned touch panel according to claim 3 wherein said conductive membrane includes a film and a conductive layer on said film, said conductive layer facing said conductive surface.

11. A tensioned touch panel according to claim 10 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.

12. A tensioned touch panel according to claim 10 wherein said conductive layer covers the entirety of a major surface of said film.

13. A tensioned touch panel comprising:

a substrate having a conductive surface disposed thereon and a spacing element generally about the periphery of said substrate; and

a conductive membrane overlying said conductive surface in spaced apart relation and being permanently secured to said spacing element, said conductive membrane being tensioned prior to being permanently secured to said spacing element and being under tension while being secured to said spacing element.

14. A tensioned touch panel according to claim 13 wherein said conductive membrane is adhered to said spacing element.

15. A tensioned touch panel according to claim 14 wherein said conductive membrane is subjected to stress at a level 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.

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

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

18. A tensioned touch panel according to claim 14 wherein said conductive membrane is adhered to said spacer via an ultraviolet curing adhesive.

19. A tensioned touch panel according to claim 14 wherein said conductive membrane is adhered to said spacer via a cyanoacrylate adhesive.

20. A tensioned touch panel according to claim 13 wherein said spacing element is generally T-shaped in side section.

21. A tensioned touch panel according to claim 13 wherein said conductive membrane includes a film and a conductive layer on said film, said conductive layer facing said conductive surface.

22. A tensioned touch panel according to claim 21 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 spacing element.

23. A tensioned touch panel according to claim 21 wherein said conductive layer covers the entirety of a major surface of said film.