Method for identifying changes in signal frequencies emitted by a stylus interacting with a digitizer sensor

• US 20090078476A1
• Filed: 09/24/2008
• Published: 03/26/2009
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: Weizman, Rina, Rimon, Ori, Kerner, Ariel
• Granted Patent: US 8,629,358 B2
• Time in Patent Office: Days
• US Class Current: 178/18.30
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A method for dynamically updating at least one pre-defined value of a parameter used to identify at least one operational mode of an object for user interaction with a digitizer sensor during interaction with the digitizer sensor comprises detecting signal outputs from a plurality of sensing elements of a digitizer sensor during user interaction with the digitizer sensor; characterizing a pattern formed by the signal outputs from the plurality of sensing elements; identifying a pre-defined event associated with an operational mode of the object based on the pattern; determining a value of the parameter from the signal outputs in response to identification of the pre-defined event; and updating the pre-defined value used to identify the operational mode based on the value of the parameter determined from the identified event.

Claims

1. A method for dynamically updating at least one pre-defined value of a parameter used to identify at least one operational mode of an object for user interaction with a digitizer sensor during interaction with the digitizer sensor, the method comprising:

detecting signal outputs from a plurality of sensing elements of a digitizer sensor during user interaction with the digitizer sensor;

characterizing a pattern formed by the signal outputs from the plurality of sensing elements;

identifying a pre-defined event associated with an operational mode of the object based on the pattern;

determining a value of the parameter from the signal outputs in response to identification of the pre-defined event; and

updating the pre-defined value used to identify the operational mode based on the value of the parameter determined from the identified event.

2. The method according to claim 1 comprising identifying the operational mode of the object with the updated pre-defined value.

3. The method according to claim 1, wherein the object is configured for operating in a plurality of operational modes.

4. The method according to claim 3 wherein the plurality of operational modes is selected from a group including:

hovering operation mode, object touching operational mode, right mouse click emulation, and erasing.

5. The method according to claim 1, wherein the pattern formed by the signal outputs is a pattern of signal amplitudes from the plurality of the sensing elements.

6. The method according to claim 1, wherein the pattern of amplitudes is characterized by at least one ratio between amplitudes formed by the signal outputs.

7. The method according to claim 6 wherein the ratio is a ratio between highest amplitude and signal output amplitude of at least one contiguous sensing element.

8. The method according to claim 1, wherein identifying the pre-defined event includes comparing the at least one ratio to a pre-defined threshold.

9. The method according to claim 1, wherein the operational mode associated with the pre-defined event is a hovering operational mode.

10. The method according to claim 1, wherein the pre-defined event is hovering of the object above a pre-defined height from the digitizer sensor.

11. The method according to claim 1, comprising estimating a height of object above the digitizer sensor from the pattern of amplitudes.

12. The method according to claim 11 wherein the height is a function of the at least one ratio and pre-defined coefficients.

13. The method according to claim 11 comprising determining at least two ratios between amplitudes formed by the signal outputs, wherein the at least two ratios are configured to resolve ambiguity between patterns of signal amplitudes that are a function of a height of the object above the digitizer sensor and patterns of signal amplitudes that are a function of a distance between a sensing element closest to the object and the position of the object on a surface of the digitizer sensor.

14. The method according to claim 10, wherein the pre-defined event is hovering of the object between a first pre-defined minimum height and a second pre-defined maximum height above the digitizer sensor.

15. The method according to claim 14, wherein identifying a pre-defined event includes determining the variance in the frequency of the signal outputs over a plurality of cycles of sampling the digitizer sensor outputs.

16. The method according to claim 1, wherein the object is selected from a group including:

stylus, token, and game piece.

17. The method according to claim 1, wherein the parameter is the frequency of the signal outputs.

18. The method according to claim 1, wherein the object includes a passive resonant circuit configured to transmit a signal in response to a triggering pulse.

19. The method according to claim 18, wherein the resonant circuit is configured for resonating at a different frequency for each operational mode.

20. The method according to claim 18, comprising matching the triggering frequency of an excitation coil surrounding the digitizer sensor to an updated frequency value.

21. The method according to claim 17, wherein the value of frequency used to identify that at least one operational mode is updated based on values of frequencies determined over a plurality of cycles of sampling the digitizer sensor outputs.

22. The method according to claim 1 comprising updating predefined values of the parameter used to identify other operational modes based on the determined value of the parameter determined in response to identification of the pre-defined event.

23. The method according to claim 22 comprising adjusting the change in the value required to switch between operational modes identification of the pre-defined event.

24. The method according claim 1, wherein the object includes a resonant circuit and at least one capacitor connected in parallel to the resonant circuit via a user controllable switch, and wherein an operational mode of the object is selected by activating the switch.

25. The method according to claim 1 wherein the object is a pressure sensitive stylus sensitive to pressure applied to a tip of the stylus.

26. The method according to claim 25, wherein the pressure sensitive stylus includes a resonant circuit, wherein the resonant circuit includes a variable element and wherein the element is varied in response to varying pressure applied on the tip of the stylus.

27. The method according to claim 1 wherein each of the sensing elements is associated with a position on the digitizer sensor.

28. The method according to claim 1, wherein the sensing elements include a grid of conductive lines.

29. A method for identifying that an object configured for interacting with a digitizer sensor is hovering over the digitizer sensor, the method comprising:

detecting the presence of object in the vicinity of the digitizer sensor from detected signal outputs obtained from a plurality of sensing elements of the digitizer sensor;

determining at least one ratio between amplitudes of the signal outputs; and

identifying that the object is hovering based on the at least one ratio.

30. The method according to claim 29, wherein the at least one ratio is a ratio between the highest amplitude and amplitude of a signal output of at least one contiguous sensing element.

31. The method according to claim 29 comprising determining a height of the object above the digitizer sensor based on the pattern of amplitudes.

32. The method according to claim 31 wherein the height determined is a qualitative height.

33. The method according to claim 32 wherein the qualitative measure for height includes low hovering, medium hovering and high hovering of the object.

34. The method according to claim 31, wherein the height is a function of the at least one ratio and pre-defined coefficients.

35. The method according to claim 31 comprising determining at least two ratios between amplitudes formed by the signal outputs, wherein the at least two ratios are configured to resolve ambiguity between patterns of signal amplitudes that are a function of a height of the object above the digitizer sensor and patterns of signal amplitudes that are a function of a distance between a sensing element closest to the object and the position of the object on a surface of the digitizer sensor.

36. The method according to claim 29, wherein the object is selected from a group including:

stylus, token, and game piece.

37. The method according to claim 29, wherein the object interacts with the digitizer sensor in a plurality of operational modes.

38. The method according to claim 37, wherein the plurality of operational modes includes at least one of hovering operation mode, object touching operational mode, right mouse click emulation, and erasing.

39. The method according to claim 29, wherein the object includes a passive resonant circuit configured to transmit a signal in response to a triggering pulse.

40. The method according to claim 39, wherein the resonant circuit is configured for resonating at a different frequency for each operational mode.

41. The method according claim 29, wherein the object includes a resonant circuit and at least one capacitor connected in parallel to the resonant circuit via a user controllable switch, and wherein an operational mode of the object is selected by activating the switch.

42. The method according to claim 29 wherein the object is a pressure sensitive stylus sensitive to pressure applied to a tip of the stylus.

43. The method according to claim 42, wherein the pressure sensitive stylus includes a resonant circuit, wherein the resonant circuit includes a variable element and wherein the element is varied in response to varying pressure applied on the tip of the stylus.

44. The method according to claim 29 wherein each of the sensing elements is associated with a position on the digitizer sensor.

45. The method according to claim 29, wherein the sensing elements include a grid of conductive lines.