System and method for multiple object detection on a digitizer system

• US 20080238885A1
• Filed: 03/27/2008
• Published: 10/02/2008
• Est. Priority Date: 03/29/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: Kaplan, Amir, Zachut, Rafi, Morag, Meir, Stern, Yuval
• Granted Patent: US 9,746,981 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: A63F 2003/00665 using inductance
• CPC Class Codes: A63F 2009/241 Touch screen
• CPC Class Codes: A63F 2009/2489 by radio transmitters, e.g. using RFID
• CPC Class Codes: A63F 2300/1068 being specially adapted to detect the point of contact of the player on a surface, e.g. floor mat, touch pad
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A digitizer system comprises at least one object incorporating an electronic tag configured for radiating at least one modulated signal and at least one second signal; a digitizer sensor configured for detecting the at least one second signal while the object is positioned on or over the digitizer sensor; and circuitry configured for identifying the object based on modulation of the at least one modulated signal and for determining a position of the object on or over the digitizer based on the detected second signal on a portion of the digitizer sensor.

Claims

1. A digitizer system comprising:

at least one object incorporating an electronic tag configured for radiating at least one modulated signal and at least one second signal;

a digitizer sensor configured for detecting the at least one second signal while the object is positioned on or over the digitizer sensor; and

circuitry configured for identifying the object based on modulation of the at least one modulated signal and for determining a position of the object on or over the digitizer based on the detected second signal on a portion of the digitizer sensor.

2. The digitizer system according to claim 1 comprising an excitation coil surrounding the digitizer sensor, wherein the excitation coil is in electrical communication with the circuitry and is configured for triggering the electronic tag.

3. The digitizer system according to claim 1 wherein the excitation coil is further configured for receiving the at least one modulated signal radiated by the electronic tag and transmitting the at least one modulated signal to the circuitry configured for identifying the object.

4. The digitizer system according to claim 1 comprising an antenna positioned in the vicinity of the digitizer sensor, wherein the antenna is configured for receiving the at least one modulated signal radiated by the electronic tag and transmitting the at least one modulated signal to the circuitry configured for identifying the object.

5. The digitizer system according claim 2 wherein the excitation coil is further configured for providing a triggering signal to a stylus interacting with the digitizer sensor.

6. The digitizer system according to claim 5, wherein the triggering signal provided for the stylus is at a frequency that is lower than the frequency of the triggering signal provided for the electronic tag.

7. The digitizer system according to claim 5 wherein the triggering signal for the stylus includes a pre-defined frequency band that is significantly wider than the frequency band applied to trigger the electronic tag.

8. The digitizer system according to claim 1 comprising a plurality of objects, each incorporating an electronic tag.

9. The digitizer system according to claim 8, wherein the second signal is a signal common to at least a portion of the electronic tags.

10. The digitizer system according to claim 1, wherein the at least one second signal is a modulated signal.

11. The digitizer system according to claim 1, wherein the at least one modulated signal includes a binary code that comprises a stream of multiple bits.

12. The digitizer system according to claim 1, wherein the modulated signal is modulated based on amplitude shift keying.

13. The digitizer system according to claim 1, wherein the electronic tag comprises a resonance circuit and an integrated circuit, wherein the integrated circuit comprises a modulator circuit configured for generating the at least one modulated signal and memory unit for storing a code defining modulation of the at least one modulated signal.

14. The digitizer system according to claim 13 wherein the memory unit is configured for storing information corresponding to the position of the at least one object on or over the digitizer sensor.

15. The digitizer system according to claim 1, wherein the electronic tag comprises an envelope circuit configured for generating a 4 KHz modulated signal.

16. The digitizer system according to claim 13, wherein the electronic tag comprises at least one dipole, wherein the dipole is configured for concentrating the transmitted signal around a tip.

17. The digitizer system according to claim 16, wherein the dipole is configured for generating radiation having a high near electric field and wherein the digitizer sensor is configured for detecting electric fields.

18. The digitizer system according to claim 1, wherein the electronic tag includes two dipoles spaced apart, wherein the two dipoles are configured for radiating signals with a phase shift between them.

19. The digitizer system according to claim 18, wherein the circuitry is configured differentiating between the signals with a phase shift between them.

20. The digitizer system according to claim 1, wherein the at least one object includes two electronic tags spaced apart.

21. The digitizer system according to claim 1, wherein the electronic tag is a radio frequency identification tag.

22. The digitizer system according to claim 1, wherein the at least one modulated signal represents an identification code configured for identifying the object.

23. The digitizer system according to claim 1, comprising a plurality of objects concurrently positioned on or over the digitizer sensor, each object incorporating the electronic tag.

24. The digitizer system according to claim 1, wherein the digitizer sensor is additionally configured for detecting finger touch.

25. The digitizer system according to claim 1, comprising a display having an image that can be changed electronically, displayed thereon wherein the display underlies the digitizer sensor and wherein the digitizer sensor is substantially transparent.

26. The digitizer system according to claim 1, wherein the digitizer sensor is a grid based sensor including horizontal and vertical conducting line.

27. The digitizer system according to claim 1, wherein the digitizer includes conductive loops configured for detecting a magnetic field.

28. A method for detecting at least one an object on a digitizer sensor, the method comprising:

placing at least one object on or over the surface of a digitizer sensor, wherein the at least one object includes an electronic tag;

radiating at least two different signals by the electronic tag, at least one of which is a modulated signal;

detecting the modulated radiation;

identifying the at least one object from a modulation of the modulated signal;

detecting the second signal with the digitizer sensor; and

determining a position of the at least one object on or over the surface of the digitizer sensor based on the detection of the second signal.

29. The method according to claim 28 comprising triggering the electronic tag with an excitation coil surrounding the digitizer sensor.

30. The method according claim 29 comprising detecting the modulated signal with the excitation coil.

31. The method according to claim 28 comprising detecting the modulated signal with antenna positioned in the vicinity of the digitizer sensor.

32. The method according to claim 28 comprising concurrently triggering the electronic tag and a stylus interacting with the digitizer sensor.

33. The method according to claim 32, wherein the triggering signal provided for the stylus is at a frequency that is lower than the frequency of the triggering signal provided for the electronic tag.

34. The method according to claim 32 wherein the triggering signal for the stylus includes a pre-defined frequency band that is significantly wider than the frequency band applied to trigger the electronic tag.

35. The method according to claim 28 comprising placing a plurality of objects on or over the surface of the digitizer sensor, each incorporating the electronic tag;

and detecting position based on the detection of the second signal.

36. The method according to claim 35, wherein the second signal is a signal common to at least some of the electronic tags.

37. The method according to claim 28, wherein the at least one second signal is a modulated signal.

38. The method according to claim 28, wherein the at least one modulated signal includes a binary code that comprises a stream of multiple bits.

39. The method according to claim 28, wherein the modulated signal is modulated based on amplitude shift keying.

40. The method according to claim 28, wherein the electronic tag includes memory capability.

41. The method according to claim 40 wherein the memory unit is configured for storing information corresponding to the position of the at least one object on or over the digitizer sensor.

42. The method according to claim 28, wherein the electronic tag is configured for generating a 4 kHz modulated signal.

43. The method according to claim 28, wherein the electronic tag comprises at least one dipole, wherein the dipole is configured for concentrating the transmitted signal around a tip.

44. The method according to claim 43, wherein the dipole is configured for generating radiation having a high near electric field and wherein the digitizer sensor is configured for detecting electric fields.

45. The method according to claim 28, wherein the electronic tag includes two dipoles spaced apart, wherein the two dipoles are configured for radiating signals with a phase shift between them.

46. The method according to claim 45 comprising determining orientation of the object based on the signals radiated from the two dipoles spaced apart.

47. The method according to claim 28, wherein the at least one object includes two electronic tags spaced apart.

48. The method according to claim 28, wherein the electronic tag is a radio frequency identification tag.

49. The method according to claim 28, wherein the modulated signal represents an identification code configured for identifying the object.

50. The method according to claim 28 comprising positioning a display having an image that can be changed electronically, displayed thereon under the digitizer sensor, wherein the digitizer sensor is substantially transparent.

51. The method according to claim 28, wherein the digitizer sensor is a grid based sensor including horizontal and vertical conducting line.

52. A digitizer system comprising:

at least one object incorporating an electronic tag configured for radiating at least one modulated signal at least partially in the form of an electric field;

a digitizer sensor configured for detecting the electric field radiated from the at least one electronic tag when positioned on or over the digitizer sensor; and

circuitry configured for identifying the object based on modulation of the modulated signal and for determining a position of the object on the digitizer based on the detected electric field on a portion of the digitizer sensor.

53. The digitizer system according to claim 52 wherein the at least one modulated signal is detected by the digitizer sensor.

54. The digitizer system according to claim 52 wherein the at least one modulated signal is implemented to identify the at least one object and determine its position on the digitizer sensor.

55. A digitizer system according to claim 52 comprising a coil in electrical communication with the circuitry, wherein the coil is configured for detecting the modulated signal.

56. The digitizer system according to claim 52, wherein the modulated signal includes a binary code that comprises a stream of multiple bits.

57. The digitizer system according to claim 52, wherein the electronic tag is configured for radiating at least one second signal other than the at least one modulated signal.

58. The digitizer system according to claim 57 wherein the at least one second signal is a modulated signal.

59. The digitizer system according to claim 52, comprising a plurality of objects, each incorporating an electronic tag.

60. The digitizer system according to claim 58, wherein the at least one second signal is a signal common to at least some of the electronic tags incorporated in the plurality of objects.