WAVEGUIDE CONFIGURATIONS FOR OPTICAL TOUCH SYSTEMS

• US 20080074402A1
• Filed: 09/21/2007
• Published: 03/27/2008
• Est. Priority Date: 09/22/2006
• Status: Active Grant

• Current Assignee: Zetta Research and Development LLC - RPO Series (Zetta Research, LLC)
• Original Assignee: RPO Pty Limited (RPO, Inc.)
• Inventors: Maxwell, Ian, Gordon, Graeme, Charters, Robert, Atkins, Graham, Cornish, Benjamin, Kukulj, Dax
• Granted Patent: US 8,674,963 B2
• Time in Patent Office: Days
• US Class Current: 345/176
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

The present invention relates to waveguide structures and optical elements for use in an optical touch screen sensor. The waveguide structures and optical elements allow for reduced bezel width and simplified assembly of optical touch screens sensors, and relaxed component tolerances.

Claims

1. A waveguide structure for a touch screen, wherein said touch screen defines a plane, said waveguide structure having at least one optical waveguide adapted to carry a signal for said touch screen, said waveguide structure being configured such that, in use, said at least one optical waveguide extends entirely below said plane.

2. A waveguide structure according to claim 1 wherein said touch screen includes an upper portion for receiving user input.

3. A waveguide structure according to claim 2 wherein said plane is defined by said upper portion.

4. A waveguide structure according to any one of the preceding claims wherein said touch screen includes a periphery defined by a plurality of sides.

5. A waveguide structure according to claim 4 wherein said touch screen is substantially rectangular in shape.

6. A waveguide structure according to any one of the preceding claims wherein said signal comprises an input signal or an output signal.

7. A waveguide structure according to any one of the preceding claims wherein said signal is light having a predetermined wavelength.

8. A waveguide structure according to claim 7 wherein said predetermined wavelength is in the infrared region of the spectrum.

9. A waveguide structure according to claim 7 wherein said predetermined wavelength is in the visible region of the spectrum.

10. A waveguide structure according to any one of the preceding claims wherein each said at least one optical waveguide extends entirely below said plane.

11. A waveguide structure according to any one of the preceding claims wherein said waveguide structure is configured such that, in use, said at least one optical waveguide passes through a maximum of two mutually perpendicular planes.

12. A waveguide structure according to any one of the preceding claims wherein said waveguide structure is formed from polymeric materials.

13. A waveguide structure according to any one of the preceding claims wherein said waveguide structure is formed as a substantially rectangular two-dimensional sheet.

14. A waveguide structure according to any one of the preceding claims wherein said waveguide structure is substantially flexible.

15. A waveguide structure according to claim 14 wherein said waveguide structure is bendable through at least 90°

.

16. A waveguide structure according to any one of claims 4-15 wherein said waveguide structure extends around at least a portion of said periphery.

17. A waveguide structure according to any one of claims 4-16 wherein said waveguide structure extends around adjacent sides of said periphery.

18. A waveguide structure according to any one of claims 4-17 wherein said waveguide structure extends around the entire said periphery.

19. A waveguide structure according to any one of the preceding claims wherein said waveguide structure is disposed substantially perpendicularly to said plane of said touch screen.

20. A waveguide structure according to any one of the preceding claims wherein said waveguide structure comprises a plurality of transmit waveguides adapted to carry an input signal to said touch screen and/or a plurality of receive waveguides adapted to carry an output signal from said touch screen.

21. A waveguide structure according to claim 20 wherein said transmit waveguides are grouped on said waveguide structure to define a transmit section, and/or said receive waveguides are grouped on said waveguide structure to define a receive section.

22. A waveguide structure according to claim 20 or claim 21 wherein each said waveguide includes an input portion for receiving an input signal and an output portion for transmitting an output signal.

23. A waveguide structure according to claim 22 wherein said waveguides are positioned such that said input portions of said transmit waveguides and said output portions of said receive waveguides are disposed on a first side of said waveguide structure, and said output portions of said transmit waveguides and said input portions of said receive waveguides are disposed on a second side of said waveguide structure.

24. A waveguide structure according to claim 23 wherein said first and second sides are substantially mutually opposed.

25. A waveguide structure according to claim 23 or claim 24 wherein said input portions of said transmit waveguides are grouped into an input array, and said output portions of said receive waveguides are grouped into an output array, each said array extending along a portion of said first side.

26. A waveguide structure according to any one of claims 23-25 wherein said output portions of said transmit waveguides and said input portions of said receive waveguides are substantially evenly spaced along substantially the entire length of said second side.

27. A waveguide structure according claim 22 wherein said waveguides are positioned such that said input portions of said transmit waveguides and said output portions of said receive waveguides are disposed on opposite sides of said waveguide structure, and said output portions of said transmit waveguides and said input portions of said receive waveguides are disposed on a common side of said waveguide structure.

28. A waveguide structure according claim 27 wherein said output portions of said transmit waveguides and said input portions of said receive waveguides are substantially evenly spaced along substantially the entire length of said common side.

29. A waveguide structure according to any one of the preceding claims wherein said waveguide structure includes at least one fold line defined by a line of weakness or printed indicia.

30. A waveguide structure according to any one of claim 4-12 wherein said waveguide structure is formed from one or more substantially L-shaped two-dimensional sheets.

31. A waveguide structure according to claim 30 wherein said waveguide structure extends underneath and substantially parallel to said plane of said touch screen.

32. A waveguide structure according to claim 30 or claim 31 wherein said waveguide structure lies substantially within said periphery.

33. A waveguide structure according to any one of claims 30-32 wherein said waveguide structure comprises a plurality of transmit waveguides adapted to carry an input signal to said touch screen, or a plurality of receive waveguides adapted to carry an output signal from said touch screen.

34. A waveguide structure according to claim 33 wherein each said waveguide includes an input portion for receiving an input signal and an output portion for transmitting an output signal.

35. A waveguide structure according to claim 34 wherein said waveguides are positioned such that said input portions of said transmit waveguides or said output portions of said receive waveguides are disposed on a first side of said waveguide structure.

36. A waveguide structure according to claim 35 wherein said first side is the terminus of a leg of said L-shaped two-dimensional sheet.

37. A waveguide structure according to any one of claims 34-36 wherein said output portions of said transmit waveguides or said input portions of said receive waveguides are substantially evenly spaced along substantially the entire outer edges of said L-shaped two-dimensional sheet.

38. A waveguide structure according to any one of claims 22-28 and 34-37 wherein said input portions of said transmit waveguides are grouped into an input array, and said output portions of said receive waveguides are grouped into an output array.

39. A waveguide structure according to claim 38 wherein said input array is optically coupleable with a light source.

40. A waveguide structure according to claim 38 or claim 39 wherein said output array is optically coupleable with a light detector.

41. A waveguide structure according to any one of claims 22-28 and 34-40 wherein said output portions of said transmit waveguides and said input portions of said receive waveguides include an integral structure.

42. A waveguide structure according to claim 41 wherein said integral structure is a planar lens.

43. A waveguide structure according to claim 41 wherein said integral structure is a planar internally reflective mirror.

44. An optical element for a touch screen, wherein said touch screen defines a plane, said optical element comprising:

a first reflective surface; and

a connect portion adapted for connection to a waveguide structure having at least one optical waveguide adapted to carry an input or an output signal for said touch screen,

said optical element being configured for use with said touch screen such that, in use, said first reflective surface is positioned above said plane to re-direct said signal to or from said optical waveguide, said connect portion being at least partially below said plane whereby said at least one optical waveguide extends entirely below said plane.

45. An optical element according to claim 44 further including a body of light transmissive material for transmission of said signal between said connect portion and said first reflective surface.

46. An optical element according to claim 44 or claim 45 wherein said first reflective surface focuses said signal in a direction substantially perpendicular to said plane.

47. An optical element according to any one of claims 44 to 46 further including a second reflective surface, such that, in use, said second reflective is surface positioned below said plane.

48. An optical element according to claim 47 wherein said first and/or said second surface is an internally reflective surface.

49. An optical element according to any one of claims 44 to 48 wherein said optical element is formed as a strip of plastic material substantially transparent to light of the infrared or visible region of the spectrum.

50. An optical element according to any one of claims 44 to 49 wherein said optical element is substantially transparent to light of the infrared region of the spectrum and opaque to ambient visible light.

51. An optical element according to any one of claims 44 to 50 wherein said optical element is injection moulded or extruded.

52. An optical element according to any one of claims 44 to 51 wherein said optical element is substantially rigid.

53. An optical element according to any one of claims 44 to 52 further including an optical surface.

54. An optical element according to claim 53 wherein said optical surface is a lens portion.

55. An optical element according to claim 54 wherein said lens portion is planar or arcuate in cross-section.

56. An optical element according to any one of claims 44 to 55 further including a recess such that said optical element is attachable to said touch screen.

57. An optical element according to any one of claims 44 to 56 wherein said waveguide structure is fixedly attached to said optical element.

58. An apparatus for use in an input device, comprising:

a touch screen defining a plane, and having a periphery defined by a plurality of sides and an upper portion for receiving user input;

a waveguide structure having at least one optical waveguide adapted to carry an input or an output signal for said touch screen; and

one or more optical elements extending along at least a portion of said periphery and in optical communication with respective waveguides, each optical element extending from a position below said plane to a position above said plane such that, in use, each said optical element transmits said input or said output signal to or from said upper portion to respective waveguides extending entirely below said plane.

59. A method of transmitting input and output signals for a touch screen device, said touch screen defining a plane and having an upper portion for receiving user input and a periphery, said method of comprising:

providing at least one waveguide structure having at least one optical waveguide adapted to carry an input or an output signal for a touch screen, said at least one optical waveguide extending entirely below said plane;

providing one or more optical elements along at least a portion of said periphery; and

optically coupling said waveguide structure with a respective optical element such that, in use, each said optical element transmits said input or said output signal to or from said upper portion to a respective waveguide extending entirely below said plane.

60. A method according to claim 59 wherein each said optical waveguide extends entirely below said plane.

61. A method of reducing bezel width in a touch screen device, said touch screen defining a plane and having an upper portion for receiving user input and a periphery, said method comprising:

providing at least one waveguide structure having at least one optical waveguide adapted to carry an input or an output signal for said touch screen;

providing one or more optical elements along at least a portion of said periphery; and

optically coupling said at least one optical waveguide with a respective optical element such that, in use, each said optical element transmits said input or said output signal to or from said at least one optical waveguide;

wherein said at least one optical waveguide is terminated at a position below said plane, and wherein said optical elements extend from above said touch screen to a position below said touch screen.

62. A waveguide structure for a touch screen, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

63. An optical element for a touch screen, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

64. An apparatus for use in an input device, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

65. A method of transmitting input and output signals for a touch screen device, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

66. A method of reducing bezel width in a touch screen device, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.