Inductive communication system and method

• US 6,459,882 B1
• Filed: 04/01/1998
• Issued: 10/01/2002
• Est. Priority Date: 05/18/1995
• Status: Expired due to Term

• Current Assignee: Freelinc Holdings, LLC
• Original Assignee: Aura Communications, Inc.
• Inventors: Palermo, Vincent, Cobler, Patrick J., Butler, Neal R.
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US09/053,107
• Time in Patent Office: 1,644 Days
• Field of Search: 455/41, 455/11.1, 455/66, 455/101, 455/133, 455/575, 455/74, 455/274, 455/131, 455/134, 455/73, 455/82, 343/742, 343/862
• US Class Current: 455/41.1
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H04B 1/385 Transceivers carried on the body, e.g. in helmets
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays
• CPC Class Codes: H04M 1/6066 including a wireless connection
• CPC Class Codes: H04M 1/737 Characterised by transmission of electromagnetic waves other than radio waves, e.g. infrared waves

Abstract

A system and method communicate signals between a portable unit and a communications system. The portable device communicates with a base unit using inductive coupling. The base unit is further connected to a wider communication system such as a telephone network. Multiple, orthogonally arranged transducers are used in the base unit to provide a more complete magnetic field and to prevent mutual inductance nulls which are otherwise present in a magnetic field. The use of short-range inductive coupling minimizes the power requirements and limits interference with other sources. The inductive coupling may also be used to recharge a battery in the portable device.

Claims

1. An inductive communications system supporting bidirectional communications, comprising:

a base unit transducer system including (i) at least three orthogonal transducers, (ii) a selector, coupled to said orthogonal transducers, for selectively energizing at least one of said orthogonal transducers to generate a first inductive field and (iii) a receiver circuit connected to said orthogonal transducers, for receiving and decoding a second inductive field on at least one of said orthogonal transducers; and

a portable unit, disposed away from said base unit transducer system and within the first inductive field, the portable unit including;

a portable unit transducer system including a single inductive transducer for generating the second inductive field, the base unit transducer system selecting, based on a field received from the single inductive transducer of the portable unit, one or more of the at least three orthogonal transducers of the base unit transducer system for transmission of a field to the portable unit.

2. The communications system of claim 1 wherein said base unit is connected to a communications network.

3. The communications system of claim 1 wherein said portable unit is a headpiece including a microphone and a speaker.

4. The communications system of claim 1 wherein said first inductive field and second inductive field are based on different carrier frequencies.

5. The communications system of claim 1 wherein said selector selects said at least one orthogonal transducer based on a strength of received signals.

6. The communications system of claim 1 wherein said portable unit transducer system includes a transmitter transducer for generating said second inductive field and a receiver transducer for converting said first inductive field.

7. A method for inductive communication, the method comprising:

at a first device, receiving a first set of signals;

selectively applying, based on a field received from a single inductive transducer of a second device, said first set of signals to at least one transducer of a transducer system having at least three orthogonal transducers, thereby generating a first inductive field based upon said first set of signals;

receiving said first inductive field at the single inductive transducer of the second device;

at the second device, generating a second inductive field based upon a second set of signals; and

selectively receiving the second inductive field on at least one of said orthogonal transducers of the transducer system at the first device.

8. The method of claim 7 wherein said second set of signals is based on sound.

9. The method of claim 7 wherein said first set of signals is based on sound.

10. The method of claim 7 wherein said communications network comprises a telephone system.

11. The method of claim 7 wherein said communications network comprises a cellular telephone system.

12. An inductive communications system suitable for communication with a network, comprising:

a base unit supporting two-way communication with the network, the base unit including a base unit transducer system including a set of three orthogonal transducers; and

a portable unit including a single transducer, the portable unit supporting two-way communication with the base unit by means of first and second inductive fields produced respectively by the base unit transducer system and the single transducer, one of the set of three orthogonal transducers generating the first inductive field, the base unit selecting, based on a field received from the single inductive transducer of the portable unit, one or more of the three orthogonal transducers of the base unit for transmission of a field to the portable unit.

13. A system for communicating information over a wireless link, the system comprising:

a first station including three inductive transducers, each oriented orthogonal to the others; and

a second station including a single inductive transducer, the first and second stations being movable relative to each other, signals being transmitted as varying magnetic fields in bidirectional communications between the stations through inductive coupling of the transducers at any angular orientation of the stations relative to each other within a range of distance, the first station selecting, based on a field received from the single inductive transducer of the second station, one or more of the three inductive transducers of the first station for transmission of a field to the second station.

14. A system as in claim 13, wherein the first station transmits information to the second station by generating a field of magnetically encoded signals that are detected by a transducer at the second station.

15. A system as in claim 13, wherein an inductive transducer of the first station is selected to transmit magnetically encoded signals depending on which of the multiple inductive transducers at the first station receives a strongest signal.

16. A system as in claim 14, wherein the wireless link between the first station and second station supports two-way full duplex communication.

17. A system as in claim 13, wherein the first station transmits information over one of the three inductive transducers.

18. A system as in claim 13, wherein the wireless link between the first station and second station supports two-way half duplex communication.

19. A system as in claim 13, wherein at least one of the inductive transducers at the first station is an inductive loop coil.

20. A system as in claim 13, wherein the second station is disposed in a headset and the first station is a cellular device.

21. A system as in claim 13 wherein the first station receives information from another device and relays it to the second station over a varying magnetic field.

22. A system as in claim 13, wherein the first station is a portable device in communication with a network system.

23. A system as in claim 13 further comprising:

multiplexor electronics for selecting which of the three inductive transducers at the first station generates the varying magnetic field.

24. A system as in claim 13, wherein the information is transmitted based on amplitude modulation.

25. A system as in claim 13, wherein the information is transmitted based on frequency modulation.

26. A system as in claim 13, wherein the information is digital, voice or audio data.

27. A system as in claim 13, wherein information is transmitted from the first station to the second station based on a first frequency and information is transmitted from the second station to the first station based on a second frequency.

28. A system as in claim 13, wherein the second station is disposed in a headset.

29. A system as in claim 28, wherein the headset includes a microphone and a speaker.

30. A system as in claim 13, wherein the first station is a cellular device.

31. A system as in claim 13, wherein a frequency for transmitting information over the wireless link is selected to avoid interference.

32. A system as in claim 13, wherein separate transmitting and receiving transducers are used to support full duplex operation between the first and second stations.

33. A method for communicating information over a wireless link, the method comprising:

orienting three inductive transducers to be orthogonal to each other at a first station;

providing a single inductive transducer at a second station, the first and second stations being movable relative to each other;

transmitting signals as varying magnetic fields in bidirectional communications between the stations through inductive coupling of the transducers at any angular orientation relative to each other within a range of distance; and

selecting, based on a field received from the single inductive transducer of the second station, one or more of the three inductive transducers of the first station for transmission of a field to the second station.

34. A method as in claim 33 further comprising:

selecting an inductive transducer to generate a varying magnetic field at the first station depending on which of the three inductive transducers at the first station receives a strongest signal.

35. A method as in claim 33, wherein the wireless link between the first station and second station supports two-way full duplex communication.

36. A method as in claim 33, wherein the first station transmits information over one of the three inductive transducers.

37. A method as in claim 33, wherein the wireless link between the first station and second station supports two-way duplex communication.

38. A method as in claim 33, wherein at least one of the inductive transducers at the base station is an inductive loop coil.

39. A method as in claim 33, wherein the second station is disposed in a headset and the first station is a cellular device.

40. A method as in claim 33 further comprising:

receiving information from a device at the first station; and

at the first station, relaying the information from the device to the second station via the varying magnetic fields between the stations.

41. A method as in claim 33, wherein the first station is a portable device in communication with a network.

42. A method as in claim 33 further comprising:

selecting which of the multiple inductive transducers at the first station will be used to generate the varying magnetic field, and multiplexing a corresponding signal from the first station to a selected inductive transducer.

43. A method as in claim 33 further comprising:

transmitting the information based on amplitude modulation.

44. A method as in claim 33 further comprising:

transmitting the information based on frequency modulation.

45. A method as in claim 33, wherein the information is digital, voice or audio data.

46. A method as in claim 33, wherein information is transmitted from the first station to the second station based on a first frequency and information is transmitted from the second station to the first station based on a second frequency.

47. A method as in claim 33 further comprising:

disposing the second station in a headset.

48. A method as in claim 47, wherein the headset includes a microphone and a speaker.

49. A method as in claim 33, wherein the first station is a cellular device.

50. A method as in claim 33 further comprising:

selecting a carrier frequency for transmitting information over the wireless link to avoid interference.

51. A method as in claim 33, wherein separate transmitting and receiving transducers are used to support full duplex operation between the first and second stations.

52. A system for communicating information over a wireless link, the system comprising:

a first station including an inductive transducer system for generating an inductive field in each of the three orthogonal orientations; and

a second station including a single inductive transducer, the first and second stations being movable relative to each other, signals being transmitted as varying magnetic fields in bidirectional communications between the stations through inductive coupling of the transducers at any angular orientation of the stations relative to each other within a range of distance, the first station selecting, based on a field received from the single inductive transducer of the second station, one or more of the three orthogonal orientations of the first station for transmission of a field to the second station.

53. A system as in claim 52, wherein an orientation of the inductive field transmitted from the first station is selected to transmit magnetically encoded signals depending on an orientation of the inductive transducer at the second station.

54. A system as in claim 52, wherein the second station is disposed in a headset and the first station is a cellular device.

55. A system as in claim 52 wherein the first station receives information from another device and relays it to the second station over a varying magnetic field.

56. A system as in claim 52, wherein information is transmitted from the first station to the second station based on a first frequency and information is transmitted from the second station to the first station based on a second frequency.

57. A system as in claim 52, wherein the second station is disposed in a headset.

58. A system as in claim 52, wherein a frequency for transmitting information over the wireless link is selected to avoid interference.

59. A method for communicating information over a wireless link, the method comprising:

providing an inductive transducer system at a first station for generating an inductive field in one of three orthogonal orientations;

providing a single inductive transducer at a second station, the first and second stations being movable relative to each other;

transmitting signals as varying magnetic fields in bidirectional communications between the stations through inductive coupling of the transducers at any angular orientation relative to each other within a range of distance; and

selecting, based on a field received from the single inductive transducer of the second station, one of the three orthogonal orientations of the inductive field of the first station for transmission of a field to the second station.

60. A method as in claim 59 further comprising:

selecting an orientation of the inductive field transmitted by the inductive transducer system of the first station to communicate information to the second station.

61. A method as in claim 59, wherein the second station is disposed in a headset and the first station is a cellular device.

62. A method as in claim 59 further comprising:

receiving information from a device at the first station; and

at the first station, relaying the information from the device to the second station via the varying magnetic fields between the stations.

63. A method as in claim 59, wherein information is transmitted from the first station to the second station based on a first frequency and information is transmitted from the second station to the first station based on a second frequency.

64. A method as in claim 59 further comprising the step of:

disposing the second station in a headset.

65. A method as in claim 59 further comprising:

selecting a carrier frequency for transmitting information over the wireless link to avoid interference.