Laminated acoustic wave touch panel

• US 5,856,820 A
• Filed: 03/27/1997
• Issued: 01/05/1999
• Est. Priority Date: 02/24/1995
• Status: Expired due to Fees

• Current Assignee: The Whitaker Corporation (Meggitt PLC)
• Original Assignee: The Whitaker Corporation (Meggitt PLC)
• Inventors: Bremigan, Charles F. III, Weigers, David G.
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US08/826,207
• Time in Patent Office: 649 Days
• Field of Search: 178/18.03, 178/18.04, 178/19.02, 178/19.04, 345/173, 345/177, 367/907
• 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 laminated acoustic wave touch panel is shown and a method of making the panel is described using an adhesive barrier material. The adhesive barrier material is positioned between a substrate in which a shear wave is to propagate and a backplate in order to form a cavity between the substrate and backplate. An adhesive is injected into the cavity to laminate the substrate to the back plate. The use of the barrier material allows the laminated touch panel to be easily manufactured and allows the adhesive to be constrained to a desired area of the panel. The invention envisions the use of similar and dissimilar materials for the substrate and backplate. The velocity of a shear wave at a given frequency is greater in the backplate than in the substrate in the case where the materials are dissimilar and equal for a given frequency when the materials are the same.

Claims

1. An acoustic wave touch panel comprising:

a substrate capable of supporting an acoustic wave for propagation therein;

a back plate;

an adhesive barrier material positioned between said substrate and said back plate, said barrier material defining a cavity with at least three sides between said substrate and said back plate; and

an adhesive disposed in said cavity between said substrate and said back plate, said adhesive laminating said substrate to said back plate.

2. An acoustic wave touch panel as recited in claim 1 wherein said substrate is capable of supporting a shear wave.

3. An acoustic wave touch panel as recited in claim 2 wherein said shear wave is a zeroth order horizontally polarized shear wave.

4. An acoustic wave touch panel as recited in claim 1 wherein at least one side of said barrier material is positioned adjacent an edge of said substrate.

5. An acoustic wave touch panel as recited in claim 1 wherein said substrate includes an array of reflective elements for reflecting portions of said acoustic wave across a touch region of said substrate and at least one side of said barrier material is adjacent said array.

6. An acoustic wave touch panel as recited in claim 5 wherein said one side of said barrier material is adjacent to both said array and said touch region.

7. An acoustic wave touch panel as recited in claim 1 wherein said barrier material is formed of tape.

8. An acoustic wave touch panel as recited in claim 1 wherein said barrier material is formed of silicone rubber.

9. An acoustic wave touch panel as recited in claim 1 wherein said adhesive cannot support shear waves.

10. An acoustic wave touch panel as recited in claim 9 wherein said acoustic wave has a velocity in said substrate which is less than the velocity of said acoustic wave in said backplate.

11. An acoustic wave touch panel as recited in claim 9 in which said acoustic wave has a velocity in said substrate which is substantially identical to the velocity of said acoustic wave in said backplate.

12. An acoustic wave touch panel as recited in claim 1 wherein said adhesive does not form a mechanical bond between said substrate and said backplate.

13. An acoustic wave touch panel as recited in claim 1 wherein said adhesive supports a shear wave.

14. A acoustic wave touch panel as recited in claim 13 wherein said acoustic wave has a velocity in said substrate which is less than the velocity of said acoustic wave in said backplate.

15. An acoustic wave touch panel, comprising:

a substrate capable of supporting an acoustic wave for propagation therein, said acoustic wave having a first velocity for a given frequency in said substrate;

a backplate, said backplate capable of supporting an acoustic wave having a second velocity for said given frequency, said second velocity being greater than said first velocity;

an adhesive barrier material positioned between said substrate and said backplate, said barrier material defining a cavity with at least three sides between said substrate and said back plate; and

an adhesive disposed in said cavity between said substrate and said back plate, said adhesive laminating said substrate to said back plate.

16. An acoustic wave touch panel as recited in claim 15 wherein said adhesive forms a mechanical bond between said substrate and said backplate.

17. An acoustic wave touch as recited in claim 15 wherein said adhesive cannot support shear waves.

18. An acoustic wave touch panel as recited in claim 15 wherein said substrate is capable of supporting a shear wave.

19. An acoustic wave touch panel as recited in claim 18 wherein said shear wave is a zeroth order horizontally polarized shear wave.

20. An acoustic wave touch panel as recited in claim 15 wherein at least one side of said barrier material is positioned adjacent an edge of said substrate.

21. An acoustic wave touch panel as recited in claim 15 wherein said substrate includes an array of reflective elements for reflecting portions of said acoustic wave across a touch region of said substrate and at least one side of said barrier material is adjacent said array.

22. An acoustic wave touch panel as recited in claim 21 wherein said one side of said barrier material is adjacent to both said array and said touch region.