Tracking window for a digitizer system

• US 20060012581A1
• Filed: 07/14/2005
• Published: 01/19/2006
• Est. Priority Date: 07/15/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: Rimon, Ori, Haim, Alon
• Granted Patent: US 7,649,524 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A digitizer apparatus for digitizing user interactions, for example detecting locations of physical objects, comprises: sensing elements, spread across a sensing area, configured for sensing the user interactions, say involving a stylus or like object, and a controller, associated with the sensing elements, configured to dynamically select a tracking window for the interaction, the tracking window comprising a subset of the sensing elements which are activated for sensing the object. The window is selected to center on the interaction based on e.g. last known location data, and thereby save processing resources by sampling only the minimum number of sensing elements necessary at any time.

Claims

1. Digitizer apparatus for digitizing user interactions, comprising:

a plurality of sensing elements, spread across a sensing area, configured for sensing of at least one user interaction; and

a controller, associated with the sensing elements, configured to dynamically select a tracking window of said sensing elements, the tracking window comprising a subset of the sensing elements, the subset being activated for tracking said user interaction.

2. The apparatus of claim 1, wherein said user interactions are sensed via an object.

3. The apparatus of claim 1, wherein at least one of said user interactions is an electromagnetic stylus.

4. The apparatus of claim 1, wherein at least one of said user interactions is a touch.

5. The apparatus of claim 1, wherein said user interactions are sensed via a plurality of objects.

6. The apparatus of claim 1, wherein the controller is arranged to dynamically reconfigure the subset comprising the tracking window for said user interaction.

7. The apparatus of claim 6, wherein the controller is arranged to dynamically reconfigure the subset comprising the tracking window for said user interaction according to at least one of a group of parameters comprising:

previous location, speed, acceleration, direction of progress, and an analysis of interaction history.

8. The apparatus of claim 1, wherein the tracking window has a fixed size.

9. The apparatus of claim 1, wherein the tracking window comprises a predetermined number of sensing elements.

10. The apparatus of claim 1, wherein the sensing elements are arranged in at least two orthogonal axes and said tracking window comprises a predetermined number of sensing elements in a first of said axes.

11. The apparatus of claim 10, wherein the tracking window comprises a predetermined number of sensing elements on two of said axes.

12. The apparatus of claim 1, wherein the tracking window has a dynamically adjusted size.

13. The apparatus of claim 2, wherein said controller has a tracking mode, defined to trigger selection of said tracking window and dynamic updating of said tracking window, to keep track of said object.

14. The apparatus of claim 13, wherein said tracking mode triggers using a narrow range of frequencies, for detecting the respective object.

15. The apparatus of claim 13, wherein said tracking mode triggers using a detection frequency of said respective object, for detecting the respective object.

16. The apparatus of claim 2, wherein said controller has a search mode, defined to trigger using a wide range of frequencies and all the sensing elements for searching for an approximate location and an approximate frequency of the respective object.

17. The apparatus of claim 16, wherein said using a wide range of frequencies comprises using one pulse, the pulse being a superposition of said frequencies.

18. The apparatus of claim 16, wherein said using a wide range of frequencies comprises periodically applying a plurality of pulses, each of the pulses being a superposition of a portion of said frequencies.

19. The apparatus of claim 16, wherein said using a wide range of frequencies comprises periodically applying a plurality of pulses, each of the pulses having one of said frequencies.

20. The apparatus of claim 16, wherein said searching mode is defined to use a low update rate.

21. The apparatus of claim 16, wherein said search mode is defined to sample the whole sensing area.

22. The apparatus of claim 16, wherein the controller is configured to switch to said search mode, when said object changes its frequency.

23. The apparatus of claim 5, wherein the sensing elements are configured to sense a plurality of physical objects.

24. The apparatus of claim 23, wherein the sensing elements are configured to use respective detection frequencies of said physical objects, for detecting a respective physical object.

25. The apparatus of claim 1, further comprising a multiplexer (MUX), associated with said sensing elements and with said controller, and configured for inputting signals from said tracking window and excluding signals not from said tracking window.

26. The apparatus of claim 25, wherein said MUX is configured for selecting a set of signals, said set originating from consecutive ones of said sensing elements.

36. The apparatus of claim 25, wherein said MUX is configured for selecting a set of signals, wherein a portion of said set originates from consecutive sensing elements.

27. A method for detecting locations of physical objects, comprising:

searching for at least one physical object utilizing a plurality of sensing elements, spread across a sensing area, by using at least one frequency, for detecting approximate location and frequency for each respective one of said at least one physical object;

finding a frequency for said respective object;

locating a location of said respective object;

selecting a tracking window for said respective object, the tracking window comprising a portion of said plurality of sensing elements, spread around said location; and

tracking each of said respective object, by applying the frequency for said respective object, on said tracking window, and by dynamically updating said tracking window to keep track of the object.

28. The method of claim 27, wherein said tracking window is selected according to at least one of a group of parameters comprising:

previous location of said respective object, speed of said respective object, acceleration of said respective object, direction of progress of said respective object, and an analysis of history of said respective object.

29. The method of claim 27, wherein the tracking window has a fixed size.

30. The method of claim 27, wherein the tracking window comprises a predetermined number of sensing elements.

31. The method of claim 27, wherein the tracking window has a dynamically adjusted size.

32. The method of claim 27, wherein establishing the location of the respective object precedes the finding of frequency for the respective object.

33. The method of claim 27, wherein the establishing the location of the respective object and the finding of the frequency for the respective object are carried out simultaneously.

34. System for sampling a sensing area having a plurality of sensing elements, comprising:

a plurality of amplifiers, in proximity to said sensing area, for amplifying signals detected by said sensing elements; and

a remote multiplexer (MUX) associated with said amplifiers for inputting signals, the signals originating from a selected portion of said sensing elements.

35. The apparatus of claim 34, wherein said portion is selected according to a tracking window, set for a respective detected physical object.