System and method for differentiating between pointers used to contact touch surface

• US 20040179001A1
• Filed: 03/11/2003
• Published: 09/16/2004
• Est. Priority Date: 03/11/2003
• Status: Active Grant

• Current Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Holmgren, David E., Morrison, Gerald D.
• Granted Patent: US 7,532,206 B2
• Time in Patent Office: Days
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A touch system comprises a touch surface and at least one camera acquiring images of the touch surface. A pointer contact data generator generates pointer position data in response to pointer contact with the touch surface, the pointer position data representing where on the touch surface pointer contact is made. A processor communicates with the at least one camera and the pointer contact data generator. The processor analyzes acquired images to determine the type of pointer used to contact the touch surface, and processes the pointer position data in accordance with the determined type of pointer. In the preferred embodiment the processor distinguishes between pointer tip touch surface contacts, pointer backend touch surface contacts and finger touch surface contacts. A writing function is invoked in response to pointer tip touch surface contacts. An erase function is invoked in response to pointer backend touch surface contacts. Mouse events are generated in response to finger touch surface contacts.

Claims

1. A touch system comprising:

a touch surface to be contacted by a pointer;

at least one imaging device having a field of view looking generally along said touch surface; and

at least one processor communicating with said at least one imaging device and analyzing images acquired by said at least one imaging device to;

(i) determine the type of pointer used to contact said touch surface; and

(ii) determine the location on said touch surface where pointer contact is made.

2. A touch system according to claim 1 wherein said processor determines whether pointer contacts on said touch surface are made using a pen tool or a finger.

3. A touch system according to claim 2 wherein when pointer contacts on said touch surface are made using a pen tool, said at least one processor further determines whether a tip of said pen tool or a backend of said pen tool is used to contact said touch surface.

14. A touch system according to claim 2 wherein when said at least one processor determines that a finger is used to contact said touch surface, said at least one processor invokes a mouse event.

15. A touch system according to claim 2 wherein said at least one processor examines the orientation of the sides of said pointer to determine whether pointer contacts are made using a pen tool or a finger.

16. A touch system according to claim 15 wherein said pen tool has a generally conical tip and wherein said at least one processor examines said images to determine the curve of growth of the sides of the pointer and uses the determined curve of growth to determine the type of pointer.

4. A touch system according to claim 4 wherein said at least one processor invokes a different function depending on whether said tip or backend is used to contact said touch surface.

5. A touch system according to claim 4 wherein when said at least one processor determines that said backend is used to contact said touch surface, said at least one processor invokes an erase function.

6. A touch system according to claim 4 wherein when said at least one processor determines that said tip is used to contact said touch surface, said at least one processor invokes a write function.

7. A touch system according to claim 6 further including a plurality of different pen tools, each pen tool including a unique identifier, wherein when said at least one processor determines that said tip is used to contact said touch surface, said at least one processor further analyzes said images to determine the unique identifier of said pen tool.

8. A touch system according to claim 6 wherein the unique identifier is a tip shape unique to each pen tool.

9. A touch system according to claim 8 wherein the tip shape of each pen tool has an invariant property irrespective of the orientation of the pen tool and wherein said at least one processor examines the invariant property to determine the pen tool used to contact the touch surface.

10. A touch surface according to claim 9 wherein each pen tool has a generally conical tip shape defining an opening angle, the opening angle of the tip being different for each pen tool and constituting said unique identifier.

11. A touch surface according to claim 10 wherein said at least one processor examines said images to determine the curve of growth of the sides of the tip and uses the determined curve of growth to determine the pen tool.

12. A touch system according to claim 8 wherein the unique identifier is a glyph on said tip unique to each pen tool.

13. A touch system according to claim 12 wherein each pen tool is assigned a different color, when said processor determines that said tip is used to contact said touch surface, said processor uses said pointer position data and the determined glyph to invoke a write function in the color assigned to said pen tool.

17. A method of updating image data used to present a displayed image on a touch surface in response to pointer contact on said touch surface, said method comprising the steps of:

displaying an image on said touch surface;

generating pointer position data in response to pointer contact with said touch surface and acquiring images of pointers used to contact said touch surface;

analyzing the acquired images to determine the type of pointer used to contact the touch surface; and

updating image data used to present the displayed image on said touch surface based on the generated pointer position data and the determined type of pointer.

18. The method of claim 17 wherein during said analyzing the determined type of pointer is selected from one of a pen tool and a finger.

19. The method of claim 18 wherein when the determined type of pointer is a pen tool, the images are further analyzed to determine an attribute assigned to said pen tool.

20. The method of claim 19 wherein said assigned attribute is determined by recognizing a unique identifier associated with said pen tool.

21. The method of claim 19 wherein when the determined type of pointer is a pen tool, the images are further analyzed to determine whether a tip or a backend of said pointer is used to contact said touch surface.

22. The method of claim 21 wherein when the backend is used to contact said touch surface, an editing function is performed during said updating.

23. The method of claim 21 wherein when a tip is used to contact said touch surface, a write function is performed during said updating.

24. The method of claim 21 wherein when a tip is used to contact said touch surface, the images are further analyzed to determine a color assigned to said pen tool, said determined color being based on the attribute assigned to said pen tool.

25. The method of claim 24 wherein during said further analysis, the shape of said tip is examined to determine the color assigned to the pen tool.

26. The method of claim 24 wherein during said further analysis, a glyph on said tip is recognized to determine the color assigned to the pen tool.

27. In a touch system including a touch surface, at least one pen tool to contact said touch surface, a processor recording data generated in response to contacts made on said touch surface using said at least pen tool and a camera to acquire an image of said at least one pen tool when said at least one pen tool is generally in contact with said touch surface, a method of updating recorded data comprising the steps of:

examining the acquired image to determine which end of the at least one pen tool is used to contact the touch surface; and

modifying the recorded data based on the end of the at least one pen tool that is used to contact the touch surface.

28. The method of claim 27 wherein during said modifying an erase function is performed when one end of the at least one pen tool is used to contact the touch surface and wherein a write function is performed when an opposite end of the at least one pen tool is used to contact the touch surface.

29. The method of claim 28 wherein said opposite end is a tip, the one end of said pen tool being visually distinct from said tip.

30. The method of claim 29 wherein said touch system includes a plurality of pen tools, each pen tool having a unique identifier assigned to said pen tool.

31. The method of claim 30 wherein each pen tool has a similar one end, said erase function being performed irrespective of the pen tool when a backend is used to contact the touch surface.

32. The method of claim 30 wherein said unique identifier determines a color assigned to said pen tool.

33. The method of claim 27 wherein the recorded data is further updated based on where contacts are made on said touch surface.

34. The method of claim 33 further comprising, the step of presenting an image on said touch surface corresponding to the updated recorded data.

35. The method of claim 34 wherein during said modifying said processor records writing when one end of a pen tool is used to contact said touch surface and erases writing when an opposite end of said pen tool is used to contact said touch surface.

36. In a touch system including a touch surface on which an image is presented, a processor responsive to contacts made on the touch surface using a pointer and generating image data used to present said image, a method of updating said image data comprising the step of:

assessing a pointer attribute to determine the type of pointer used to make said contacts; and

updating the image data based on the type of pointer and the pointer activity on the touch surface.

37. The method of claim 36 wherein said pointer attribute is pointer shape, said pointer shape being assessed by examining an image of said pointer.

38. The method of claim 37 wherein during said assessing the pointer shape is examined to determine if said pointer is a pen tool or a finger.

39. The method of claim 38 wherein during updating an editing function is performed when said pointer is pen tool and wherein a mouse event is invoked when said pointer is a finger.

40. The method of claim 39 wherein during the assessing the orientation of the sides of said pointer is examined to determine if said pointer is a pen tool or finger.

41. The method of claim 38 wherein when said pointer is a pen tool, the pointer shape is further assessed to determine whether the pen tool is a writing tool or an erase tool, when said pen tool is a writing tool, the image data being updated so that said image includes writing corresponding to the writing tool activity on said touch surface and when said pen tool is an erase tool, the image data being updated so that writing in said image corresponding to the erase tool activity on said touch surface is removed.

42. The method of claim 41 wherein opposite ends of the pen tool constitute the writing tool and erase tool, said opposite ends having distinct shapes.

43. The method of claim 40 wherein when a writing tool is used, a unique identifier of the writing tool is examined to determine another attribute assigned to the writing tool.

44. The method of claim 41 wherein when said pointer is a finger, the image data is updated in accordance with an invoked mouse event.

45. The method of claim 36 wherein said pointer attribute is pointer position data generated in response to contacts made on the touch surface, the nature of the pointer position data generated determining the type of pointer.

46. The method of claim 45 wherein the generated pointer position data signifies whether the pointer is a pen tool or a finger.

47. A touch system comprising:

a touch surface on which an image is presented; and

a processor responsive to pointer contacts on the touch surface and generating image data that is used to present said image, said processor assessing a pointer attribute to determine the type of pointer used to make contacts and updating the image data based on the type of pointer and the pointer activity on the touch surface.

48. A touch system according to claim 47 further comprising a camera to acquire images of said pointer, said processor examining said images to determine the shape of said pointer thereby to determine its type.

49. A touch system according to claim 48 wherein said processor examines said images to determine whether said pointer is a pen tool or a finger.

50. A touch system according to claim 49 wherein said processor edits said image data when said pointer is a pen tool and invokes a mouse event when said pointer is a finger.

51. A touch system according to claim 50 wherein said processor examines the orientation of the sides of said pointer to determine if the pointer is a pen tool or finger.

52. A touch system according to claim 49 wherein when the pointer is a pen tool, said processor further examines said image to determine whether the pen tool is a writing tool or an erase tool, when the pen tool is a writing tool, said processor updating the image data so that the image includes writing corresponding to the writing tool activity on the touch surface and when the pen tool is an erase tool, said processor updating said image data so that writing in said image corresponding to the erase tool activity on said touch surface is removed.

53. A touch system according to claim 52 wherein opposite ends of the pen tool constitute said writing tool and erase tool, said opposite ends having distinct shapes.

54. A touch system according to claim 52 wherein one end of said pen tool has a generally conical tip and constitutes the writing tool.

55. A touch system according to claim 54 wherein said tip includes a unique identifier, when a writing tool is used to contact said touch surface, said processor examining said images to recognize said identifier and thereby determine another attribute assigned to the writing tool.

56. A touch system according to claim 52 wherein when said pointer is a finger, said processor updates the image data in accordance with an invoked mouse event.

57. A touch system according to claim 47 wherein said processor examines pointer position data generated in response to contacts made on the touch surface to determine the type of pointer used to contact the touch surface.

58. A touch system according to claim 57 wherein the generated pointer position data signifies whether the pointer used to contact the touch surface is a pen tool or a finger.

59. A camera-based touch system comprising

a pair of cameras at spaced locations having overlapping fields of view encompassing an area on which pointer contacts are to be made, said cameras acquiring images and generating corresponding image data;

and

a processor receiving and processing the image data generated by said cameras to determine the location of a pointer relative to the area when the pointer is captured in images acquired by the cameras and analyzing the image data to determine the type of pointer used to contact the area.

60. A touch system according to claim 59 wherein an image is presented on said area, said processor updating image data used to generate the image presented on said area in accordance with the locations where contacts are made on the area and the determined type of pointer.

61. A touch system according to claim 60 wherein said processor determines whether pointer contacts on said area are made using a pen tool or a finger.

62. A touch system according to claim 61 wherein when pointer contacts on said area are made using a pen tool, said processor further determines whether a tip of said pen tool or a backend of said pen tool is used to contact said area.

63. A touch system according to claim 62 wherein when said processor determines that said backend is used to contact said area, said processor uses said pointer position data to invoke an erase function.

64. A touch system according to claim 62 wherein when said processor determines that said tip is used to contact said area, said processor uses said pointer position data to invoke a write function.

65. A touch system according to claim 64 further including a plurality of different pen tools, each pen tool including a unique identifier specifying an attribute assigned to said pen tool, wherein when said processor determines that said tip is used to contact said area said processor further analyzes said acquired images to determine the unique identifier of said tip.

66. A touch system according to claim 65 wherein the unique identifier is a unique tip shape and wherein said assigned attribute is a pen tool color, when said processor determines that said tip is used to contact said area, said processor uses said pointer position and the determined tip shape to invoke a write function in the color assigned to said pen tool.

67. A touch system according to claim 65 wherein the unique identifier is a glyph on said tip and wherein said assigned attribute is a pen tool color, when said processor determines that said tip is used to contact said area, said processor uses said pointer position data and the determined glyph to invoke a write function in the color assigned to said pen tool.

68. A touch system according to claim 61 wherein when said processor determines that a finger is used to contact said area, said processor uses said pointer position data to invoke a mouse event.

69. An interactive input system comprising:

at least one imaging device having an input region within its field of view into which a pointer is moved to generate user input; and

at least one processor communicating with said at least one imaging device and analyzing each image acquired by said at least one imaging device to determine the type of pointer moved into said input region.

70. An input system according to claim 69 wherein the determined type of pointer is used to modify a displayed image.

71. An input system according to claim 70 wherein said at least one processor determines the type of pointer based on shape.

72. An input system according to claim 71 wherein said at least one processor examines the orientation of the sides of said pointer to distinguish between a pen tool and a finger.