Touch sensor and method of making

• US 20040090429A1
• Filed: 11/12/2002
• Published: 05/13/2004
• Est. Priority Date: 11/12/2002
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Geaghan, Bernard O., Cross, Elisa M., Moshrefzadeh, Robert S.
• Application Number:
  US10/292,165
• Publication Number:
  US 20040090429A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface

Abstract

The present invention provides a touch sensor that includes a first layer movable toward a second layer in response to a touch input, the location of the touch input being determinable from signals detected due to the movement of the first layer. The first and second layers are bonded together through a plurality of spacers distributed over the touch sensitive area of the sensor. The present invention also provides methods for bonding spacers to the first and second layers to make a touch sensor.

Claims

1. A touch sensor having a touch-sensitive area comprising:

a first layer and a second layer separated by a gap, the first layer movable toward the second layer in response to a touch in the touch-sensitive area to generate a signal for determining the touch location; and

a plurality of double-bonded spacers disposed within the touch-sensitive area and bonded to both the first and second layers.

2. The touch sensor of claim 1, further comprising a plurality of single-bonded spacers, each bonded only to the first layer or the second layer.

3. The touch sensor of claim 1, wherein further comprising a deformable material substantially filling the gap between the first and second layers.

4. The touch sensor of claim 3, wherein the deformable material comprises a liquid.

5. The touch sensor of claim 1, wherein the first layer is a topsheet comprising a first resistive layer and the second layer is a substrate comprising a second resistive layer.

6. The touch sensor of claim 5, wherein the signal is generated when the first resistive layer contacts the second resistive layer.

7. The touch sensor of claim 5, wherein the signal is generated when the first resistive layer is brought into local proximity with the second resistive layer sufficient for detectable capacitive coupling.

8. The touch sensor of claim 5, wherein the substrate, the topsheet and the first and second resistive coatings are transparent.

9. The touch sensor of claim 5, wherein the substrate comprises glass.

10. The touch sensor of claim 5, wherein the topsheet comprises PET.

11. The touch sensor of claim 5, wherein at least one of the first and second resistive coatings comprises a metal oxide.

12. The touch sensor of claim 5, wherein at least one of the first and second resistive coatings comprises a conductive polymer.

13. The touch sensor of claim 5, wherein the topsheet includes a hard coat on its outer surface.

14. The touch sensor of claim 5, wherein the topsheet includes an antireflective coating.

15. The touch sensor of claim 5, wherein the topsheet includes a diffusive coating.

16. The touch sensor of claim 1, wherein the double-bonded spacers comprise an acrylic material.

17. The touch sensor of claim 1, wherein the double-bonded bonded spacers comprise an adhesive material.

18. The touch sensor of claim 1, wherein the double-bonded bonded spacers comprise a pressure sensitive adhesive.

19. The touch sensor of claim 1, wherein the double-bonded spacers comprise a light diffusing material.

20. The touch sensor of claim 1, wherein the double-bonded spacers comprise a light absorbing material.

21. The touch sensor of claim 1, wherein the double-bonded spacers comprise a deformable material.

22. The touch sensor of claim 1, wherein the double-bonded spacers are arranged in rows and columns.

23. The touch sensor of claim 1, wherein the double-bonded spacers are spaced apart approximately 1 cm or less.

24. The touch sensor of claim 1, wherein the double-bonded spacers are approximately 1 to 100 microns in diameter or width.

25. The touch sensor of claim 1, wherein the double-bonded spacers are approximately 0.5 to 50 microns in height.

26. The touch sensor of claim 1, wherein the double-bonded spacers comprise hemispherical dots.

27. The touch sensor of claim 1, wherein the double-bonded spacers comprise elongated shapes.

28. The touch sensor of claim 1, wherein the double-bonded spacers comprise lines.

29. The touch sensor of claim 1, wherein the touch sensor is flexible.

30. The touch sensor of claim 1, wherein the first and second layers are sealed together around their peripheries.

31. The touch sensor of claim 1, further comprising electrodes configured to apply and sense signals for determining the touch location.

32. The touch sensor of claim 1, wherein the first and second layers are generally rectangular.

33. A method of making a touch sensor comprising:

configuring a first layer and a second layer separated by a gap;

disposing a plurality of spacers in a touch-sensitive area between the first and second layers; and

bonding the plurality of spacers to both the first layer and the second layer, wherein the first layer is capable of being moved toward the second layer in response to a touch in the touch-sensitive area to generate a signal for determining the touch location.

34. The method of claim 33, wherein the disposing and bonding steps comprise:

forming the plurality of spacers adhered to one of the first and second layers;

applying a bonding medium to at least a portion of the formed spacers; and

contacting the applied bonding medium on the spacers with the other of the first and second layers.

35. The method of claim 34, wherein the step of forming the spacers comprises screen printing.

36. The method of claim 34, wherein the step of forming the spacers comprises offset printing.

37. The method of claim 34, wherein the step of forming the spacers comprises ink jet printing.

38. The method of claim 34, wherein the step of forming the spacers comprises stenciling.

39. The method of claim 34, wherein the step of forming the spacers comprises embossing.

40. The method of claim 34, wherein the step of forming the spacers comprises micromolding.

41. The method of claim 34, wherein the bonding medium comprises a radiation curable adhesive.

42. The method of claim 34, wherein the step of applying the bonding medium comprises coating the bonding medium onto a pad and touching the bonding medium on the pad to spacers.

43. The method of claim 34, wherein the step of applying the bonding medium comprises screen printing.

44. The method of claim 34, wherein the step of applying the bonding medium comprises stenciling.

45. The method of claim 34, wherein the step of applying the bonding medium comprises ink jet printing.

46. The method of claim 34, wherein the step of applying the bonding medium comprises offset printing.

47. The method of claim 33, wherein the disposing and bonding steps comprise:

printing an adhesive material to form the plurality of spacers on one of the first and second layers; and

contacting the printed adhesive spacers with the other of the first and second layers.

48. The method of claim 47, wherein the step of printing an adhesive material comprises ink jet printing.

49. The method of claim 47, wherein the step of printing an adhesive material comprises screen printing.

50. The method of claim 47, wherein the step of printing an adhesive material comprises transferring the adhesive material from a micromold.

51. The method of claim 47, wherein the adhesive material comprises a pressure sensitive adhesive.

52. The method of claim 47, further comprising partially curing the adhesive material after the printing step and before the contacting step.

53. The method of claim 47, further comprising curing the adhesive material after the contacting step.

54. A display system comprising:

an electronic display coupled to a central processor; and

a touch sensor couple to the central processor through a controller unit, the touch sensor configured to communicate information from touch inputs to the central processor, the touch sensor comprising

a first layer and a second layer separated by a gap, the first layer movable toward the second layer in response to a touch in the touch-sensitive area to generate a signal for determining the touch location; and

a plurality of double-bonded spacers disposed within the touch-sensitive area and bonded to both the first and second layers.