System and method of detecting contact on a display

• US 8,094,137 B2
• Filed: 07/23/2007
• Issued: 01/10/2012
• Est. Priority Date: 07/23/2007
• Status: Active Grant

• Current Assignee: Smart Technologies Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Morrison, Gerald
• Primary Examiner(s): ABDULSELAM, ABBAS I
• Application Number:
  US11/781,811
• Publication Number:
  US 20090027357A1
• Time in Patent Office: 1,632 Days
• Field of Search: 345/166, 345/173, 345/175, 178/18.01, 349/64, 250/221, 250/222.1, 385/17
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A system for detecting contact on a display is provided. The system comprises a planar medium associated with the display and includes at least one edge facet and opposing surfaces. The system also includes one or more optical sources operatively coupled to the at least one edge facet for transmitting an optical signal into the planar medium such that the transmitted optical signal is totally internally reflected between the at least one edge facet and opposing surfaces. An optical sensing device is positioned to substantially face at least a portion of the edge facet and adapted to detect at least one object contacting a first surface of the opposing surfaces. The optical sensing device is operative to detect a portion of the optical signal emitted from the first surface at a location corresponding to the object contacting the first surface.

Claims

1. A system for detecting contact on a display, the system comprising:

a planar medium associated with the display and including at least one edge facet and opposing surfaces;

at least one optical source operatively coupled to the at least one edge facet for transmitting an optical signal into the planar medium such that the transmitted optical signal is totally internally reflected between the at least one edge facet and opposing surfaces; and

an optical sensing device positioned to substantially face at least a portion of the at least one edge facet and adapted to detect at least one object contacting a first surface of the opposing surfaces, wherein the optical sensing device is operative to detect a portion of the optical signal emitted from the first surface at a location corresponding to the at least one object contacting the first surface.

2. The system according to claim 1, wherein the at least one edge facet comprises a single circular shaped edge facet having an optically reflective surface.

3. The system according to claim 1, wherein the at least one edge facet comprises at least one curved edge facet and at least one straight edge facet each having an optically reflective surface.

4. The system according to claim 1, wherein the at least one edge facet comprises a first edge facet, a second edge facet, a third edge facet, and a fourth edge facet each comprising an optically reflective surface.

5. The system according to claim 1, wherein the optical sensing device comprises at least one of the group consisting of at least one photodetector and at least two camera devices.

6. A system for detecting contact on a display, the system comprising:

a planar medium associated with the display and including at least one edge facet and opposing surfaces;

at least one optical source operatively coupled to the at least one edge facet for transmitting an optical signal into the planar medium such that the transmitted optical signal is totally internally reflected between the at least one edge facet and opposing surfaces; and

at least two camera devices positioned to substantially face at least a portion of the at least one edge facet and adapted to detect at least one object contacting a first surface of the opposing surfaces, wherein the at least two camera devices are operative to capture images of a portion of the optical signal emitted from the first surface at a location corresponding to the at least one object contacting the first surface.

7. The system according to claim 6, further comprising at least one processor coupled to the at least two camera devices, wherein the at least one processor is adapted to process pixel information corresponding to the at least one object contacting the first surface.

8. The system according to claim 7, further comprising a master controller coupled to the at least one processor, wherein the master controller is adapted to generate location coordinate information corresponding to the at least one object contacting the first surface.

9. The system according to claim 8, further comprising at least one application program operative to receive the location coordinate information for displaying an annotation associated with the at least one object contacting the surface.

10. The system according to claim 8, further comprising at least one application program operative to receive the location coordinate information for executing a response based the at least one object contacting the surface.

11. The system according to claim 6, wherein the at least one edge facet comprises a single circular shaped edge facet having an optically reflective surface.

12. The system according to claim 6, wherein the at least one edge facet comprises at least one curved edge facet and at least one straight edge facet each having an optically reflective surface.

13. The system according to claim 6, wherein the at least one edge facet comprises a first edge facet, a second edge facet, a third edge facet, and a fourth edge facet each comprising an optically reflective surface.

14. The system according to claim 13, wherein the optically reflective surface comprises at least one of copper reflective tape and silver reflective tape.

15. The system according to claim 6, wherein the planar medium comprises an acrylic sheet coupled to the display, the acrylic sheet having substantially the same shape as the display.

16. The system according to claim 15, wherein the acrylic sheet comprises fire polished acrylic edges.

17. The system according to claim 6, wherein the at least one optical source comprises a light emitting diode (LED).

18. The system according to claim 17, wherein the light emitting diode (LED) comprises a viewing half angle of about 0-90 degrees.

19. The system according to claim 6, wherein the at least one optical source comprises a laser device.

20. The system according to claim 6, wherein the transmitted optical signal comprises an infrared signal.

21. The system according to claim 6, wherein the transmitted optical signal comprises visible light.

22. The system according to claim 6, wherein the at least two camera devices comprise complementary metal oxide semiconductor (CMOS) cameras.

23. The system according to claim 6, wherein the portion of the optical signal emitted from the location on the first surface comprises a frustrated total internal reflection (FTIR) optical signal generated at the location based on the at least one object contacting the location.

24. The system according to claim 6, further comprising a screen associated with the display, wherein the screen is coupled to a second surface of the opposing surfaces.

25. The system according to claim 6, wherein the planar medium comprises an integral component of the display.

26. The system according to claim 6, wherein the at least one object comprises a finger associated with a user interacting with the first surface of the planar medium.

27. The system according to claim 6, wherein the at least one object comprises a cylindrical pen shaped object adapted to be used by a user interacting with the first surface of the planar medium.

28. The system according to claim 6, wherein the transmitted optical signal comprises a modulated signal.

29. The system according to claim 6, wherein the transmitted optical signal comprises an encoded signal.

30. The system according to claim 29, wherein the encoded signal comprises a binary sequence.

31. The system according to claim 28, wherein the modulated signal comprises a pseudo random binary sequence (PRBS) modulated signal.

32. The system according to claim 28, wherein the modulated signal comprises an intensity modulated signal.

33. A method of detecting contact to a display, comprising:

transmitting an optical signal into a planar medium associated with the display, wherein within the planar medium the transmitted optical signal is totally internally reflected;

positioning an optical sensing device to substantially face a side location associated with the planar medium;

contacting a surface location on the first surface using at least one object; and

detecting using the optical sensing device a portion of the optical signal emitted from the surface location based on the object contacting the surface location.

34. A method of detecting contact to a display, comprising:

transmitting an optical signal into a planar medium associated with the display, wherein within the planar medium the transmitted optical signal is totally internally reflected;

positioning a first camera device to substantially face a first side location associated with the planar medium, wherein the first camera device receives images from a first surface of the planar medium;

positioning a second camera device to substantially face a second side location associated with the planar medium, wherein the second camera device receives images from the first surface of the planar medium;

contacting a surface location on the first surface using at least one object; and

capturing using the first and second camera images of a portion of the optical signal emitted from the surface location based on the object contacting the surface location.

35. The method according to claim 34, further comprising determining a coordinate position associated with the at least one object at the surface location based on the captured images.

36. The method according to claim 34, wherein the captured images of the portion of the optical signal emitted from the surface location comprises an illuminated region.

37. The method according to claim 34, wherein a second surface of the planar medium is coupled to the display.

38. The method according to claim 34, wherein the portion of the optical signal emitted from the surface location is based on a Frustrated Total Internal Reflection (FTIR) of the optical signal at the contacted surface location.

39. The method according to claim 34, wherein the portion of the optical signal emitted from the surface location is responsive to a change in refractive index associated with the surface location.

40. The method according to claim 34, wherein the first camera includes a first field of view and the second camera includes a second field of view, the first and second field of view having an area of overlap.

41. The method according to claim 40, wherein contacting the surface location on the first surface using the at least one object comprises changing a refractive index value associated with the first surface at the contacted surface location.

42. A passive touch system, comprising:

a touch screen having opposing surfaces and adapted to receive an optical signal that is totally internally reflected within the opposing surfaces, wherein upon an object contacting a surface location associated with the opposing surfaces a portion of the optical signal is emitted from the surface location; and

at least two cameras associated with the touch surface and positioned substantially at a side location to the touch surface, wherein at the surface location images of the portion of the optical signal emitted from the surface location are captured by the at least two cameras for determining a coordinate position associated with the object contacting the surface location.

43. The system according to claim 42, further comprising at least one first processor operatively coupled to the at least two cameras, the at least one first processor adapted to receive the captured images and generate pixel data associated with the captured images.

44. The system according to claim 43, further comprising a second processor operatively coupled to the at least one first processor, wherein the second processor receives the generated pixel data and generates location coordinate information for the object at the surface location.

45. The system according to claim 42, wherein the at least two cameras comprise complementary metal oxide semiconductor (CMOS) cameras.