Dual mode touch system

• US 20050243070A1
• Filed: 04/29/2004
• Published: 11/03/2005
• Est. Priority Date: 04/29/2004
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sirotich, Roberto A. L., Ung, Chi Man Charles, Booth, David Kenneth
• Granted Patent: US 7,460,110 B2
• Time in Patent Office: Days
• US Class Current: 345/176
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An apparatus for detecting a pointer includes a waveguide and a touch surface over the waveguide on which pointer contacts are to be made. At least one reflecting device extends along a first side of the waveguide and touch surface. The reflecting device defines an optical path between the interior of the waveguide and the region of interest above the touch surface. At least one imaging device looks across the touch surface and into the waveguide. The imaging device captures images of the region of interest and within the waveguide including reflections from the reflecting device.

Claims

1. An apparatus for detecting a pointer comprising:

a waveguide;

a touch surface over said waveguide on which pointer contacts are to be made;

at least one reflecting device extending along a first side of said waveguide and touch surface, said reflecting device defining an optical path between the interior of said waveguide and a region of interest above said touch surface; and

at least one imaging device looking across said touch surface and into said waveguide, said at least one imaging device capturing images of said region of interest and within said waveguide including reflections from said reflecting device.

2. An apparatus according to claim 1 further comprising first reflective surfaces extending along a second side of said waveguide and touch surface, said second side joining said first side at a first corner, said first reflective surfaces facing the interior of said waveguide and said region of interest, said imaging device capturing images of said region of interest and within said waveguide including reflections from said reflecting device and said first reflective surfaces.

3. An apparatus according to claim 2 further comprising a processing device to process images captured by said imaging device to determine the location of said pointer relative to said touch surface.

4. An apparatus according to claim 3 wherein said imaging device looks into said waveguide and into said region of interest from a second corner diagonally opposite said first corner.

5. An apparatus according to claim 4 further including a lens through which said imaging device looks into said waveguide.

6. An apparatus according to claim 5 wherein said lens is constituted by a shaped portion of said waveguide.

7. An apparatus according to claim 6 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said imaging device being accommodated by said cutout, said cutout including a highly polished surface through which said imaging device looks.

8. An apparatus according to claim 3 wherein said pointer is illuminated when in contact with said touch surface, said imaging device capturing images including the illuminated pointer and reflections thereof in said reflecting device and first reflective surfaces.

9. An apparatus according to claim 8 wherein said pointer illuminates when contacting said touch surface.

10. An apparatus according to claim 9 wherein said pointer emits infrared radiation when contacting said touch surface, said pointer and reflections thereof appearing in captured images as bright regions against a dark background.

11. An apparatus according to claim 3 further comprising at least one light source operable to provide backlight illumination for said imaging device, said pointer and reflections thereof appearing in captured images as dark regions against a bright background when a pointer is brought into contact with said touch surface and occludes said illumination.

12. An apparatus according to claim 11 wherein said illumination is infrared illumination.

13. An apparatus according to claim 12 wherein said imaging device looks into said waveguide and into said region of interest from a second corner diagonally opposite said first corner, said apparatus comprising a pair of light sources each providing backlight illumination for said imaging device, one of said light sources extending along a side of said waveguide from said second corner to said reflecting device and another of said light sources extending from said second corner to said first reflective surfaces.

14. An apparatus according to claim 13 wherein said illumination sources provide backlight illumination for said imaging device when a passive pointer is used to contact said touch surface and are conditioned to an off state when an active pointer is used to contact said touch surface.

15. An apparatus according to claim 14 wherein said active pointer generates output that is used to condition said illumination sources to said off state.

16. An apparatus according to claim 15 wherein said active pointer illuminates when in contact with said touch surface, said active pointer generating said output when illuminated.

17. An apparatus according to claim 16 wherein said active pointer illuminates in the infrared range.

18. An apparatus according to claim 3 wherein said reflecting device is a turning prism assembly.

19. An apparatus according to claim 3 further comprising second reflective surfaces extending along a third side of said waveguide and touch surface, said third side joining said first side at a second corner, said second reflective surfaces facing the interior of said waveguide and said region of interest, said at least one imaging device capturing images of said region of interest and within said waveguide including reflections from said reflecting device and said first and second reflective surfaces.

20. An apparatus according to claim 19 wherein said imaging device looks into said waveguide and region of interest from a fourth side of said waveguide, said fourth side being opposite said first side.

21. An apparatus according to claim 20 wherein said imaging device is generally centrally disposed along said fourth side.

22. An apparatus according to claim 21 further including a lens through which said imaging device looks into said waveguide.

23. An apparatus according to claim 22 wherein said lens is constituted by a shaped portion of said waveguide.

24. An apparatus according to claim 22 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said imaging device being accommodated by said cutout, said cutout including a highly polished surface through which said imaging device looks.

25. An apparatus according to claim 21 further comprising at least one light source operable to provide backlight illumination for said imaging device, said pointer and reflections thereof appearing in captured images as dark regions against a bright background when a pointer is brought into contact with said touch surface and occludes said illumination.

26. An apparatus according to claim 25 wherein said illumination is infrared illumination.

27. An apparatus according to claim 25 wherein said apparatus comprises a pair of light sources, each providing backlight illumination for said imaging device, said light sources extending along said fourth side on opposite sides of said imaging device.

28. An apparatus according to claim 27 wherein said illumination sources provide backlight illumination for said imaging device when a passive pointer is used to contact said touch surface and are conditioned to an off state when an active pointer is used to contact said touch surface.

29. An apparatus according to claim 28 wherein said active pointer generates output that is used to condition said illumination sources to said off state.

30. An apparatus according to claim 29 wherein said active pointer illuminates when in contact with said touch surface, said active pointer generating said output when illuminated.

31. An apparatus according to claim 30 wherein said active pointer illuminates in the infrared range.

32. An apparatus according to claim 1 further comprising at least one illumination source extending along a second side of said waveguide and touch surface, said second side joining said first side at a first corner diagonally opposite said imaging device.

33. An apparatus according to claim 32 comprising a pair of illumination sources, one of said illumination sources extending along said second side and another of said illumination sources extending along a third side of said waveguide and touch surface, said third side extending from imaging device to said one illumination source, said illumination sources providing backlight illumination for said imaging device.

34. An apparatus according to claim 33 further including a lens through which said imaging device looks into said waveguide.

35. An apparatus according to claim 34 wherein said lens is constituted by a shaped portion of said waveguide.

36. An apparatus according to claim 35 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said imaging device being accommodated by said cutout, said cutout including a highly polished surface through which said imaging device looks.

37. An apparatus according to claim 33 wherein said illumination sources provide backlight illumination for said imaging device when a passive pointer is used to contact said touch surface and are conditioned to an off state when an active pointer is used to contact said touch surface.

38. An apparatus according to claim 37 wherein said active pointer generates output that is used to condition said illumination sources to said off state.

39. An apparatus according to claim 38 wherein said active pointer illuminates when in contact with said touch surface, said active pointer generating said output when illuminated.

40. An apparatus according to claim 39 wherein said active pointer illuminates in the infrared range.

41. An apparatus according to claim 3 wherein said first reflective surfaces are constituted by a continuous mirror abutting the second side of said waveguide and extending above said touch surface.

42. An apparatus according to claim 41 further comprising second reflective surfaces extending along a third side of said waveguide and touch surface, said third side joining said first side at a second corner, said second reflective surfaces facing the interior of said waveguide and said region of interest, said at least one imaging device capturing images of said region of interest and within said waveguide including reflections from said reflecting device and said first and second reflective surfaces.

43. An apparatus according to claim 42 wherein said second reflective surfaces are constituted by a continuous mirror abutting the third side of said waveguide and extending above said touch surface.

44. An apparatus according to claim 3 wherein said first reflective surfaces are constituted by a polished second side surface of said waveguide and a mirror extending along said second side above said touch surface.

45. An apparatus according to claim 44 further comprising second reflective surfaces extending along a third side of said waveguide and touch surface, said third side joining said first side at a second corner, said second reflective surfaces facing the interior of said waveguide and said region of interest, said at least one imaging device capturing images of said region of interest and within said waveguide including reflections from said reflecting device and said first and second reflective surfaces.

46. An apparatus according to claim 45 wherein said second reflective surfaces are constituted by a polished third side of said waveguide and a mirror extending along said third side above said touch surface.

47. An apparatus according to claim 27 wherein said light sources provide backlight illumination for said imaging device having an intensity insufficient to saturate said imaging device and wherein in an active mode, an active pointer emitting light having an intensity greater than that provided by said light sources is used to contact said touch surface.

48. An apparatus for detecting a pointer comprising a touch panel assembly including a touch surface, said touch panel assembly being operable in passive and active modes, in said passive mode, said touch panel assembly detecting passive pointer contacts on said touch surface and in said active mode, said touch panel assembly detecting active pointer contacts on said touch surface.

49. An apparatus according to claim 48 wherein said touch panel assembly is conditioned to one of said modes in response to said pointer.

50. An apparatus according to claim 49 wherein said touch panel assembly is conditioned to said active mode in response to generated output signals.

51. An apparatus according to claim 50 wherein said touch panel assembly remains in said passive mode in the absence of said output signals.

52. An apparatus according to claim 51 wherein said active pointer generates said output signals when in contact with said touch surface.

53. An apparatus according to claim 51 wherein said output signals are generated upon removal of said active pointer from a receptacle of said touch panel assembly.

54. An apparatus according to claim 51 wherein said touch panel assembly further includes at least one imaging device capturing images looking across said touch surface and at least one processing device to process captured images and determine the locations of pointer contacts on said touch surface.

55. An apparatus according to claim 54 further comprising at least one light source to provide backlighting for said imaging device when said touch panel assembly is in said passive mode.

56. An apparatus according to claim 55 wherein said at least one light source and active pointer emit light in the infrared range.

57. An apparatus according to claim 55 wherein said active pointer generates said output signals when in contact with said touch surface.

58. An apparatus according to claim 55 wherein said output signals are generated upon removal of said active pointer from a receptacle of said touch panel assembly.

59. An apparatus according to claim 55 wherein said active pointer carries a visual identifier and wherein said output signals are generated when captured images include said active pointer.

60. An apparatus according to claim 48 wherein said touch panel assembly further includes at least one imaging device capturing images looking across said touch surface and at least one processing device to process captured images and determine the locations of pointer contacts on said touch surface.

61. An apparatus for detecting a pointer comprising:

a waveguide defining a touch surface and being formed of material that produces a region of illumination therein in response to a beam of radiation directed into said waveguide via said touch surface using a pointer;

a first reflective surface extending along a first side of said waveguide; and

at least one imaging device looking into said waveguide and capturing images including said region of illumination and reflections thereof as a result of said first reflective surface.

62. An apparatus according to claim 61 further comprising a processing device to process images captured by said imaging device to determine the location of said pointer relative to said touch surface.

63. An apparatus according to claim 62 wherein said waveguide fluoresces in response to said beam of radiation thereby to generate said region of illumination.

64. An apparatus according to claim 63 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

65. An apparatus according to claim 64 further including a lens through which said imaging device looks into said waveguide.

66. An apparatus according to claim 65 wherein said lens is constituted by a shaped portion of said waveguide.

67. An apparatus according to claim 66 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said imaging device being accommodated by said cutout, said cutout including a highly polished surface through which said imaging device looks.

68. An apparatus according to claim 62 wherein said imaging device is positioned at one corner of said waveguide.

69. An apparatus according to claim 68 further including a lens through which said imaging device looks into said waveguide.

70. An apparatus according to claim 69 wherein said lens is constituted by a shaped portion of said waveguide.

71. An apparatus according to claim 70 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said imaging device being accommodated by said cutout, said cutout including a highly polished surface through which said imaging device looks.

72. An apparatus according to claim 68 wherein said waveguide fluoresces in response to said beam of radiation thereby to generate said region of illumination.

73. An apparatus according to claim 72 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

74. An apparatus according to claim 62 further comprising a second reflective surface extending along a second side of said waveguide, said first and second sides joining at a first corner, said imaging device capturing images including said region of illumination and reflections thereof as a result of said first and second reflective surfaces.

75. An apparatus according to claim 74 wherein said waveguide fluoresces in response to said beam of radiation thereby to generate said region of illumination.

76. An apparatus according to claim 75 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

77. An apparatus according to claim 76 further including a lens through which said imaging device looks into said waveguide.

78. An apparatus according to claim 77 wherein said lens is constituted by a shaped portion of said waveguide.

79. An apparatus according to claim 78 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said imaging device being accommodated by said cutout, said cutout including a highly polished surface through which said imaging device looks.

80. An apparatus according to claim 74 wherein said imaging device is positioned at second corner of said waveguide, said second corner being diagonally opposite said first corner.

81. An apparatus according to claim 80 wherein said waveguide fluoresces in response to said beam of radiation thereby to generate said region of illumination.

82. An apparatus according to claim 81 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

83. An apparatus according to claim 80 further including a non-reflective region generally in the plane of at least one of said first and second reflective surfaces adjacent said first corner.

84. An apparatus according to claim 83 wherein said non-reflective region extends in the planes of both of said first and second reflective surfaces.

85. An apparatus according to claim 83 wherein said non-reflective region extends only in the plane of one of said first and second reflective surfaces.

86. An apparatus according to claim 83 wherein said waveguide fluoresces in response to said beam of radiation thereby to generate said region of illumination.

87. An apparatus according to claim 86 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

88. An apparatus according to claim 62 wherein said pointer generates said beam of radiation upon contact with said touch surface.

89. An apparatus according to claim 88 wherein said waveguide fluoresces in response to said beam of radiation thereby to produce said region of illumination.

90. An apparatus according to claim 89 wherein said pointer generates a beam of radiation in the ultraviolet range.

91. An apparatus according to claim 90 wherein said generated beam of radiation is pulsed.

92. An apparatus according to claim 91 wherein said pointer includes an ultraviolet light source that is pulsed when said pointer is in contact with said touch surface, a light pipe to direct light generated by said light source to a tip of said pointer, and a dispersion element adjacent said tip to disperse ultraviolet light exiting said pointer.

93. A tablet for a touch system comprising:

a waveguide defining a touch surface and being formed of material that fluoresces to produce a region of illumination therein in response to a beam of radiation directed into said waveguide via said input surface;

a first reflective surface extending along a first side of said waveguide; and

at least one lens through which an imaging device looks into said waveguide.

94. A tablet according to claim 93 wherein said at least one lens is defined by at least one shaped portion of said waveguide.

95. A tablet according to claim 94 wherein said shaped portion is a smoothly curved cutout provided in said waveguide, said cutout including a highly polished surface.

96. A tablet according to claim 95 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

97. A tablet according to claim 93 wherein said waveguide fluoresces in the ultraviolet range.

98. A tablet according to claim 93 further comprising a second reflective surface extending along a second side of said waveguide, said first and second sides joining at a first corner opposite said lens.

99. A tablet according to claim 98 further including a non-reflective region generally in the plane of at least one of said first and second reflective surfaces adjacent said first corner.

100. A tablet according to claim 99 wherein said non-reflective region extends in the planes of both of said first and second reflective surfaces.

101. A tablet according to claim 99 wherein said non-reflective region extends only in the plane of one of said first and second reflective surfaces.

102. A tablet according to claim 98 wherein said waveguide fluoresces in response to a beam of radiation in the ultraviolet range.

103. An apparatus for detecting a pointer comprising:

a waveguide;

a touch surface over said waveguide on which pointer contacts are to be made;

at least one reflecting device extending along a first side of said waveguide and touch surface, said reflecting device defining an optical path between the interior of said waveguide and a region of interest above said touch surface; and

at least one imaging device looking into said waveguide, said at least one imaging device capturing images within said waveguide including reflections from said reflecting device.

104. An apparatus according to claim 103 further comprising a second reflecting device surfaces extending along a second side of said waveguide, said imaging device capturing images within said waveguide including reflections from said reflecting devices.

105. An apparatus according to claim 104 further comprising a processing device to process images captured by said imaging device to determine the location of said pointer relative to said touch surface.

106. An apparatus according to claim 105 wherein said imaging device looks into said waveguide from a corner thereof.

107. An apparatus according to claim 106 further comprising at least one light source operable to provide backlight illumination for said imaging device, reflections of said pointer appearing in captured images as dark regions against a bright background when a pointer is brought into contact with said touch surface and occludes said illumination.

108. An apparatus according to claim 107 wherein said illumination is infrared illumination.