Three-dimensional information detecting system, three-dimensional information detecting device and input device for three-dimensional information detecting system

• US 20040181360A1
• Filed: 12/17/2003
• Published: 09/16/2004
• Est. Priority Date: 12/18/2002
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Fukushima, Masamitsu, Oda, Yasuo, Ito, Masamitsu
• Granted Patent: US 6,928,383 B2
• Time in Patent Office: Days
• US Class Current: 702/152
• CPC Class Codes: G08B 13/26 by proximity of an intruder causing variation in capacitance or inductance of a circuit

Abstract

A motion capture system includes a motion capture detecting device with sensor coils that are sequentially selected by a control section. Signals are communicated between respective input coils of input elements of an input device and the sensor coils by electromagnetic coupling. The signals received by each of the selected coils are detected by a detecting section. Three-dimensional coordinates and directions of each of the input elements are calculated by a control section so that the input elements become continuous, based on the detected signals by the detecting section.

Claims

1. A three-dimensional information detecting system, comprising:

a plurality of input elements each having at least one input coil, at least one of said input elements being connected with another input element to be relatively movable;

a plurality of sensor coils disposed along a detection surface, at least two of said sensor coils being arranged to intersect one other, said sensor coils being electromagnetically coupled to at least one of the input coils;

a sensor coil selector circuit for selectively switching the sensor coils;

a signal generating circuit for generating a signal to be communicated between each of the input coils and selected sensor coils, by electromagnetic coupling;

a signal detector for detecting signals received by each of the selected sensor coils or each of the input coils; and

a calculating means for calculating the coordinates and the direction of each of the plurality of input elements in a three-dimensional space, based on the detection signals detected by the signal detector.

2. The three-dimensional information detecting system according to claim 1, wherein the calculating means calculates an X-axis coordinate and a Y-axis coordinate of each input element, based on signals from at least three points in the vicinity of the peak value of the detection signals corresponding to each input element and detected by the detector, and wherein the calculating means determines a height of each input element from the width of a signal distribution at a predetermined level value of the detection signals.

3. The three-dimensional information detecting system according to claim 2, wherein the calculating means determines a tilt angle θ

and an azimuth angle φ

for each input element based on the relationship between detection signals corresponding to each input element, the detection signals having been detected by the signal detector.

4. The three-dimensional information detecting system according to claim 3, wherein the calculating means determines a tilt angle θ

and an azimuth angle φ

for each input element based on the sub-signal ratio of detection signals corresponding to each each input element.

5. The three-dimensional information detecting system according to claim 3, wherein the calculating means determines a tilt angle θ

and an azimuth angle φ

of each input element based on the ratio of left/right half side widths of detection signals corresponding to each input element.

6. The three-dimensional information detecting system according to claim 3, wherein the calculating means corrects the detected X-axis coordinate, Y-axis coordinate, and height of each input element by using the tilt angle θ

and the azimuthal angle φ

that have been determined.

7. The three-dimensional information detecting system according to claim 1, wherein, based on coordinates for a first input element, the calculating means calculates coordinates for other input elements.

8. The three-dimensional information detecting system according to claim 7, wherein the calculating means causes the coordinates of the end of said first input element to conform to the coordinates of an end of a second input element connected to said first input element.

9. The three-dimensional information detecting system according to claim 1, further comprising a plurality of oblique sensor coils disposed to intersect one another and also intersect said detection surface sensor coils.

10. The three-dimensional information detecting system according to claim 1, wherein the input element includes an input coil.

11. The three-dimensional information detecting system according to claim 10 wherein the input coil is wound around a magnetic material.

12. The three-dimensional information detecting system according to claim 1, wherein the input element includes a plurality of input coils.

13. The three-dimensional information detecting system according to claim 12, wherein said plurality of input coils are disposed so that the central axes thereof orthogonally intersect one another.

14. The three-dimensional information detecting system according to claim 13, wherein said plurality of input coils are disposed so that the central positions thereof conform to each other.

15. The three-dimensional information detecting system according to claim 13, wherein at least one of the plurality of input coils is disposed so that the central position thereof deviates from those of the other input coils.

16. The three-dimensional information detecting system according to claim 1, wherein at least one of the input elements has a sphere and an input coil disposed within the sphere.

17. The three-dimensional information detecting system according to claim 1, wherein the signal generating circuit generates signals having a plurality of frequencies corresponding to the respective input elements, and wherein signals of mutually different frequencies are communicated between each input element and a plurality of the selected sensor coils.

18. The three-dimensional information detecting system according to claim 1, wherein signals are transmitted from each of the input elements by supplying currents to each of the input elements from the signal generating circuit, and wherein the signal detector detects the signals generated in each of the sensor coils.

19. The three-dimensional information detecting system according to claim 1, wherein signals are transmitted from each of the sensor coils by supplying currents to each of the sensor coils from the signal generating circuit, and wherein the signal detector means detects the signals generated in each of said input elements.

20. The three-dimensional information detecting system according to claim 1, wherein signals are transmitted from each of the sensor coils by supplying currents to each of the sensor coils from the signal generating circuit, wherein after having received the signals, each of the input elements sends back the signals to a plurality of the sensor coils, and wherein the signal detector means detects the signals received by each of the sensor coils.

21. A three-dimensional information detecting device, comprising:

a plurality of sensor coils disposed along a detection surface and configured to intersect each other, said sensor coils being electromagnetically coupled to input coils of a plurality of input means;

selecting means for selectively switching the sensor coils;

signal generating means for generating signals to be communicated between each of the input coils and a plurality of the selected sensor coils, by electromagnetic coupling;

signal detecting means for detecting signals transmitted from the signal generating means and received by each of the selected sensor coils or each of the input coils; and

calculating means for calculating coordinates and directions of each of the input means in a three-dimensional space, based on the signals detected by the signal detecting means.

22. The three-dimensional information detecting device according to claim 21, wherein the calculating means determines an X-axis coordinate and a Y-axis coordinate of each of the input means, based on signals from at least three points in the vicinity of the peak value of the detection signals corresponding to each of the input means and detected by the detecting means, and wherein the calculating means determines a height of each of the input means from the width of a signal distribution at a predetermined level value of the detection signals.

23. The three-dimensional information detecting device according to claim 22, wherein the calculating means determines a tilt angle θ

and an azimuth angle φ

of each of the input means, based on the relationship between the detection signals corresponding to each of the input means, the detection signals having been detected by the detecting means.

24. The three-dimensional information detecting device according to claim 23, wherein the calculating means determines a tilt angle θ

and an azimuth angle φ

of each of the input means, based on the sub-signal ratio of detection signals corresponding to each of the input means.

25. The three-dimensional information detecting device according to claim 23, wherein the calculating means determines a tilt angle θ

and an azimuth angle φ

of each of the input means, based on the ratio of the left/right half side widths of detection signals corresponding to each of the input means.

26. The three-dimensional information detecting device according to claim 25, wherein the calculating means corrects the detected X-axis coordinate, Y-axis coordinate, and height of each of the input means, by using the tilt angle θ

and the azimuthal angle φ

that have been determined.

27. The three-dimensional information detecting device according to claim 26, wherein, based on the coordinates of a first input means, the calculating means calculates coordinates of each of the other input means.

28. The three-dimensional information detecting device according to claim 27, wherein the calculating means causes the coordinates of the end of said first input means to conform to the coordinates of the end of a second input means connected to said first input means.

29. The three-dimensional information detecting device according to any one of claim 28, further comprising a plurality of oblique sensor coils disposed to intersect one another and also intersect said sensor coils.

30. An input device for a three-dimensional information detecting system, comprising:

a plurality of input coils adapted to communicate signals with a plurality of sensor coils by electromagnetic coupling, and

a plurality of input elements carrying said input coils and connected with each other so as to be relatively movable.

31. The input device for a three-dimensional information detecting system according to claim 30, wherein a first input element has a single input coil.

32. The input device for a three-dimensional information detecting system according to claim 30, wherein at least one of said input elements has a plurality of input coils.

33. The input device for a three-dimensional information detecting system according to claim 32, wherein said plurality of input coils are disposed so that the central axes thereof orthogonally intersect each other.

34. The input device for a three-dimensional information detecting system according to claim 33, wherein the plurality of input coils are disposed so that the central positions thereof conform to each other.

35. The input device for a three-dimensional information detecting system according to claim 33, wherein at least one of the plurality of input coils is disposed so that the central position thereof deviates from those of the other input coils.

36. The input device for a three-dimensional information detecting system according to claim 30, wherein at least one of the input elements comprises a sphere, and wherein said input coil is disposed within the sphere.

37. The input device for a three-dimensional information detecting system according to claim 30, wherein each of the input coils is wound around a magnetic material.

38. The input device for a three-dimensional information detecting system according to claim 30, further comprising a plurality of resonant capacitors each connected to a respective input coils, wherein each resonant capacitor and input coil comprise an input coil resonant circuit having a unique resonant frequency differing from the resonant frequencies of the other input coil resonant circuits.

39. The input device for a three-dimensional information detecting system according to claim 38, further comprising a plurality of serial resonant circuits serially connected to the respective input coil resonant circuits and having the same resonant frequencies as those of the respective corresponding input coil resonant circuits.

40. The input device for a three-dimensional information detecting system according to claim 39, further comprising a transmitted signal generating circuit for exciting said serial resonant circuits.

41. The input device for a three-dimensional information detecting system according to claim 40, further comprising a battery for supplying a driving power to said transmitted signal generating circuit.