Multi-layer coversheet for saw touch panel

• US 8,638,318 B2
• Filed: 05/28/2010
• Issued: 01/28/2014
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: Gao, Ting, Loayza, Jorge G., Kent, Joel C.
• Primary Examiner(s): Eisen, Alexander
• Assistant Examiner(s): LAM, NELSON C
• Application Number:
  US12/789,733
• Publication Number:
  US 20110291996A1
• Time in Patent Office: 1,341 Days
• Field of Search: 345173-179, 178 1804- 1807
• US Class Current: 345/177
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A touch panel includes a surface acoustic wave propagating substrate having top and bottom surfaces and a multi-layer coversheet that is positioned over the substrate. The coversheet includes a load-spreading layer, a compliant layer and an anti-sticking layer. The load-spreading layer has top and bottom surfaces, and the top surface receives touch input from an object. The compliant layer has top and bottom surfaces and the top surface of the compliant layer is coupled to the bottom surface of the load-spreading layer. The anti-sticking layer has top and bottom surfaces and the top surface of the anti-sticking layer is coupled to the bottom surface of the compliant layer. The bottom surface of the anti-sticking layer is positioned proximate to the top surface of the substrate.

Claims

1. A touch panel, comprising:

a surface acoustic wave propagating substrate having top and bottom surfaces; and

a multi-layer coversheet configured to be positioned over the substrate, the coversheet comprising;

a load-spreading layer having top and bottom surfaces, the top surface configured to receive touch input from an object;

a compliant layer having top and bottom surfaces, the top surface of the compliant layer configured to be coupled to the bottom surface of the load-spreading layer; and

an anti-sticking layer having top and bottom surfaces, the top surface of the anti-sticking layer configured to be coupled to the bottom surface of the compliant layer, the bottom surface of the anti-sticking layer configured to be positioned proximate to the top surface of the substrate.

2. The touch panel of claim 1, wherein the anti-sticking layer comprises non-stick properties.

3. The touch panel of claim 1, wherein the anti-sticking layer comprises a thin layer of stiff material.

4. The touch panel of claim 1, wherein the anti-sticking layer is a coating comprising non-stick properties.

5. The touch panel of claim 1, wherein the coversheet further comprises at least one additional layer or coating.

6. The touch panel of claim 1, wherein the coversheet is substantially transparent.

7. The touch panel of claim 1, wherein the compliant layer comprises an elastomeric material and the load-spreading layer comprises a material that is relatively stiff with respect to the elastomeric material.

8. The touch panel of claim 1, wherein the substrate comprises at least one of metal, glass, ceramic or a composite material.

9. The touch panel of claim 1, wherein the load-spreading layer comprises glass, glass microsheet or Polyethylene Terephthalate (PET).

10. The touch panel of claim 1, wherein the anti-sticking layer is coupled to the compliant layer using at least one of coating, evaporation, spraying, dipping, plasma treatment, laminating, printing, heat and co-extrusion.

11. The touch panel of claim 1, wherein the coversheet further comprises an additional compliant layer and an additional load-spreading layer between the load-spreading layer and the compliant layer, wherein the additional compliant layer has top and bottom surfaces, wherein the top surface of the additional compliant layer is configured to be coupled to the bottom surface of the load-spreading layer, wherein the additional load-spreading layer has top and bottom surfaces, wherein the additional load-spreading layer is configured to be stiffer than the additional compliant layer, wherein the top surface of the additional load-spreading layer is configured to be coupled to the bottom surface of the additional compliant layer, and wherein the bottom surface of the additional load-spreading layer is configured to be coupled to the top surface of the compliant layer.

12. The touch panel of claim 1, wherein the load-spreading layer is between 50 microns and 600 microns thick, and wherein the compliant layer is at least 75 microns thick.

13. A touch panel, comprising:

a surface acoustic wave propagating substrate having top and bottom surfaces; and

a multi-layer coversheet configured to be positioned over the substrate, the coversheet comprising;

a flexible display layer having top and bottom surfaces and configured to display an image, the top surface of the flexible display layer configured to receive touch input from an object;

a compliant layer having top and bottom surfaces, the top surface of the compliant layer configured to be coupled to the bottom surface of the flexible display layer; and

an anti-sticking layer having top and bottom surfaces, the top surface of the anti-sticking layer configured to be coupled to the bottom surface of the compliant layer, the bottom surface of the anti-sticking layer configured to be positioned proximate to the top surface of the substrate.

14. The touch panel of claim 13, wherein the flexible display layer comprises an organic light-emitting diode (OLED) display layer.

15. The touch panel of claim 13, wherein the flexible display layer comprises an electrophoretic display (EPD) layer.

16. The touch panel of claim 13, wherein the anti-sticking layer comprises non-stick properties.

17. The touch panel of claim 13, wherein at least one of the substrate, the compliant layer or the anti-sticking layer comprise substantially opaque materials.

18. The touch panel of claim 13, wherein the anti-sticking layer comprises a thin layer of stiff material.

19. The touch panel of claim 13, wherein the anti-sticking layer is a coating having non-stick properties.

20. The touch panel of claim 13, wherein the anti-sticking layer is coupled to the compliant layer using at least one of coating, evaporation, spraying, dipping, plasma treatment, laminating, printing, heat and co-extrusion.