INTERACTIVE SYSTEM WITH SUCCESSIVELY ACTIVATED ILLUMINATION SOURCES

• US 20140022448A1
• Filed: 01/14/2011
• Published: 01/23/2014
• Est. Priority Date: 01/14/2010
• 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: McGibney, Grant, Holmgren, David, Hewitt, Lawrence Bruce
• Granted Patent: US 9,329,700 B2
• Time in Patent Office: Days
• US Class Current: 348/370
• CPC Class Codes: G06F 3/0308 comprising a plurality of distinctive and separately oriented light emitters or reflectors associated to the pointing device, e.g. remote cursor controller with distinct and separately oriented LEDs at the tip whose radiations are captured by a photo-detector associated to the screen
• 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

Abstract

An illumination assembly for an interactive input system (20), comprises at least one imaging device (60) capturing image frames of a region of interest; a plurality of illumination sources (84a, 84b, 84c) associated sociated with the imaging device and being located at different positions relative to the imaging device, the illumination sources providing illumination to the region of interest; and a controller (72) communicating with the illumination sources, the controller conditioning the illumination sources so that the illumination sources provide illumination to the region of interest in succession, the timing of image frame capture by the imaging device being coordinated with the illumination pattern of the illumination sources.

Claims

1. An illumination assembly for an interactive input system, comprising:

at least one imaging device capturing image frames of a region of interest;

a plurality of illumination sources associated with said imaging device and being located at different positions relative to said imaging device, said illumination sources providing illumination to said region of interest; and

a controller communicating with said illumination sources, said controller conditioning said illumination sources so that the illumination sources provide illumination to said region of interest in succession, the timing of image frame capture by said imaging device being coordinated with the illumination pattern of said illumination sources.

2. The illumination assembly of claim 1, wherein one illumination source is generally vertically aligned with the at least one imaging device.

3. The illumination assembly of claim 2 wherein said one illumination source is positioned above said at least one imaging device.

4. The illumination assembly of claim 2, wherein at least one other illumination source is positioned to one side said imaging device.

6. The illumination assembly of claim 2 wherein at least one other illumination source is positioned on each side of said imaging device.

7. The illumination assembly of claim 6 wherein the at least one other illumination sources are generally in the same plane as said imaging device.

8. The illumination assembly of claim 1 wherein said controller conditions said illumination sources so that for an exposure cycle of said at least one imaging assembly, the imaging assembly captures an image frame with each illumination source on and the other illumination sources off and an image frame with all illumination sources off.

9. The illumination assembly of claim 1 wherein said illumination sources are infrared (IR) illumination sources.

20. The illumination assembly of claim 3, wherein at least one other illumination source is positioned to one side said imaging device.

21. The illumination assembly of claim 20 wherein said at least one other illumination source is in generally the same plane as said at least one imaging device.

22. The illumination assembly of claim 3 wherein at least one other illumination source is positioned on each side of said imaging device.

23. The illumination assembly of claim 22 wherein the at least one other illumination sources are generally in the same plane as said imaging device.

5. The illumination assembly of claim 5 wherein said at least one other illumination source is in generally the same plane as said at least one imaging device.

10. A method comprising:

acquiring image frames of a region of interest over an image sensor exposure cycle, each image frame being acquired in a different lighting scenario; and

processing the image frames to detect the existence of a pointer therein.

11. The method of claim 10 wherein during said acquiring, at least one image frame is captured while an illumination source associated with said image sensor illuminates said region of interest and at least one image frame is captured when no illumination sources associated with said image sensor illuminate said region of interest.

12. The method of claim 11 wherein during said acquiring, image frames are captured while different illumination sources associated with said image sensor illuminate said region of interest.

13. The method of claim 12 wherein during said processing, a difference image frame is formed by subtracting an image frame captured when no illumination sources associated with said image sensor illuminate said region of interest from an image frame captured when an illumination source associated with said image sensor illuminates said region of interest to remove ambient light artifacts and wherein said difference image frame is examined to locate a region in said difference image frame representing said pointer.

14. The method of claim 13 wherein during said processing, the center of said region is determined and designated as the center of said pointer.

15. The method of claim 14 wherein said processing further comprises examining the difference image frame to detect pointer tilt.

16. The method of claim 15 further comprising recalculating the center of said pointer when pointer tilt is detected.

17. The method of claim 13 wherein said processing further comprises examining the acquired image frames captured while different illumination sources associated with said image sensor illuminate said region of interest to detect the shape of the pointer.

18. The method of claim 13 wherein said processing further comprises examining the acquired image frames while different illumination sources associated with said image sensor illuminate said region of interest to detect contact of the pointer with a surface.

19. An interactive input system for carrying out the method of claim 13 comprising a plurality of imaging assemblies for imaging the region of interest from different vantages, illumination sources associated with each imaging assembly and processing structure communicating with the imaging assemblies.

24. The method of claim 14 wherein said processing further comprises examining the acquired image frames captured while different illumination sources associated with said image sensor illuminate said region of interest to detect the shape of the pointer.

25. The method of claim 14 wherein said processing further comprises examining the acquired image frames while different illumination sources associated with said image sensor illuminate said region of interest to detect contact of the pointer with a surface.

26. The method of claim 15 wherein said processing further comprises examining the acquired image frames captured while different illumination sources associated with said image sensor illuminate said region of interest to detect the shape of the pointer.

27. The method of claim 15 wherein said processing further comprises examining the acquired image frames while different illumination sources associated with said image sensor illuminate said region of interest to detect contact of the pointer with a surface.

28. An interactive input system comprising:

a plurality of imaging devices configured to image a region of interest from different vantages;

illumination sources associated with each imaging assembly; and

processing structure communicating with the imaging assemblies, wherein each of said imaging devices is configured to acquire image frames of the region of interest over an image sensor exposure cycle, each image frame being acquired in a different lighting scenario and wherein said processing structure processes the image frames to detect the existence of a pointer therein.

29. The interactive input system of claim 28 wherein said imaging devices are configured to capture image frames while different illumination sources associated with said image sensor illuminate said region of interest.

30. The interactive input system of claim 29 wherein said processing structure is configured to form difference image frames by subtracting image frames captured when no illumination sources associated with each image sensor illuminate said region of interest from image frames captured when an illumination source associated with each image sensor illuminates said region of interest to remove ambient light artifacts and to examine said difference image frames to locate regions in said difference image frames representing said pointer.