Method and apparatus for magnetic induction heating using radio frequency identification of object to be heated

• US 6,320,169 B1
• Filed: 09/06/2000
• Issued: 11/20/2001
• Est. Priority Date: 09/07/1999
• Status: Expired due to Term

• Current Assignee: HR Technology Incorporated
• Original Assignee: Thermal Solutions Incorporated (Rtx Corporation)
• Inventors: Clothier, Brian L.
• Primary Examiner(s): Leung, Philip H.
• Application Number:
  US09/655,942
• Time in Patent Office: 440 Days
• Field of Search: 219/621, 219/620, 219/622, 219/624, 219/626, 219/627, 219/647, 219/649, 219/663, 219/665, 219/497, 219/494, 994/51, 99D/IG.14, 993/25, 340/572.1, 340/825.36, 340/825.37, 340/825.54
• US Class Current: 219/626
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: H05B 2213/06 Cook-top or cookware capable of communicating with each other
• CPC Class Codes: H05B 2213/07 Heating plates with temperature control means
• CPC Class Codes: H05B 6/062 for cooking plates or the like

Abstract

A temperature-regulating induction heating system is provided which comprises an induction heater (20) having apparatus (36, 38, 40) for receiving RFID transmissions and an induction heatable object (22) with an RFID tag (50). The heater (20) includes a component (28) for generating a magnetic field, control circuitry including a microprocessor (32) coupled with the component (28) for selectively initiating and terminating generation of a magnetic field; the receiving apparatus (36, 3 8, 40) provides information to the microprocessor (32) causing initiation of a heating algorithm for the object (22). In preferred forms, the tag (50) and apparatus (36, 38, 40) are designed for two-way information transfer, thereby permitting continuous updating of the information carried by tag (50). In this way, if induction heating of the object (20) is interrupted, it maybe resumed to nevertheless achieve a desired regulation temperature. Advantageously, the RFID tag (50) and apparatus (36, 38, 40) operate during intermittent interruption of the primary magnetic field of the heater (20) to eliminate transmission interference. The tag (50) may be equipped with one or more thermal switches (100, 104, 106) to provide better temperature control.

Claims

1. For use with an induction heating device, an induction heatable object including a component which will be heated when subjected to a magnetic field, and an RFID tag operably coupled with said object, said tag having electronic memory, there being digital electronic information stored in said memory pertaining to the induction heating history previously experienced by said object, said tag operable to transmit said information when interrogated by an RFID tag reader, said tag also operable to store updated information received from a tag writer.

2. The object of claim 1, said object being food servingware.

3. The object of claim 1, said RFID tag carrying information about a heating characteristic of said object.

4. The object of claim 3, said heating characteristic comprising information about the class of objects to which said object belongs.

5. The object of claim 1, including at least one switch operably coupled with said RFID tag and switchable between circuit make and circuit break orientations in response to an external condition experienced by the switch, in order to alter the operation of said RFID tag.

6. The object of claim 5, said switch being a thermal switch switchable between said orientations in response to the temperature of said object.

7. The object of claim 5, said switch being coupled to the antenna of said RFID tag, said switch operable to short said antenna in one of said switch orientations.

8. The object of claim 5, including a pair of separately operable, series-connected switches coupled with said RFID tag.

9. The object of claim 5, said at least one switch operable to prevent transmission of information by the RFID tag in one of said switch orientations.

10. The object of claim 1, said tag operable for receiving and storing digital information in said memory.

11. In an induction heating device including a component for generating a magnetic field in order to inductively heat an object, control circuitry operably coupled with said generating component for selective operation thereof to vary the magnitude of said magnetic field, the improvement which comprises apparatus coupled with said circuitry for transmitting information to and receiving digital information from an RFID tag associated with said object, said control circuitry operable to reduce the magnitude of said magnetic field during the times that said apparatus is transmitting or receiving said digital information.

12. The device of claim 11, said control circuitry including a microprocessor, said apparatus comprising an RFID reader/writer and an RFID antenna.

13. The device of claim 11, said control circuitry including a sensor operable to measure a circuit parameter related to the impedance of the load experienced by said device.

14. The device of claim 11, said sensor comprising a current sensor.

15. The device of claim 11, including electronic memory operably coupled with said control circuitry for storing said digital information received from said RFID tag.

16. The device of claim 11, said component comprising an inverter.

17. The device of claim 11, said control circuitry operable to stop the operation of said component during said times.

18. The combination comprising:

an induction heating device comprising a component for generating a magnetic field in order to inductively heat and object, control circuitry operably coupled with said generating component for selectively altering the magnitude of the generated magnetic field, and apparatus coupled with said circuitry for receiving information from an RFID tag associated with said object; and

an induction heatable object including a component which will be heated when subjected to a magnetic field, and an RFID tag operably coupled with said object,

said RFID tag being operable to transmit information, and said apparatus operable to receive said information,

the operation of said device during the induction heating of said object being at least in part responsive to said information received from said RFID tag.

19. The combination of claim 18, said RFID tag carrying information about a heating characteristic of said object.

20. The combination of claim 19, said heating characteristic comprising information about the class of objects to which said object belongs.

21. The combination of claim 18, said RFID tag being operable for both transmitting and receiving information, said apparatus comprising a read/writer operable for receiving information from said RFID tag, and transmitting other information to the RFID tag.

22. The combination of claim 21, said RFID tag having memory for storing received information.

23. The combination comprising:

an induction heating device comprising a component for generating a magnetic field in order to inductively heat an object, control circuitry operably coupled with said generating component for selective operation thereof to vary the magnitude of said magnetic field, and an RFID tag reader coupled with said circuitry; and

an induction heatable object including a component which will be heated when subjected to said magnetic field, and an RFID tag operably coupled with said object,

said control circuitry operable to reduce the magnitude of said magnetic field during the times that said tag is transmitting said information to said reader.

24. The combination comprising:

an induction heating device comprising a component for generating a magnetic field in order to inductively heat an object, control circuitry operably coupled with said generating component for selective operation thereof to vary the magnitude of said magnetic field, and an RFID tag reader coupled with said circuitry, said RFID tag reader including a transmitting antenna, there being no ground plane associated with said transmitting antenna; and

an induction heatable object including a component which will be heated when subjected to said magnetic field, and an RFID tag operably coupled with said object.

25. A method of heating an induction heatable object comprising the steps of:

providing an induction heatable object having an RFID tag operably coupled thereto;

placing said object adjacent a magnetic induction heater, said heater comprising a component for generating a magnetic field in order to inductively heat said object, control circuitry operably coupled with said generating component for selectively altering the magnitude of the generated magnetic field, and apparatus coupled with said circuitry for receiving information from an RFID tag associated with said object; and

causing said RFID tag to transmit information to said apparatus for receipt thereby, and allowing said apparatus and control circuitry to control the operation of said component in at least partial response to the information transmitted by said RFID tag and received by said apparatus.

26. The method of claim 25, said transmitted information comprising a heating characteristic of said object.

27. The method of claim 26, said heating characteristic comprising information about the class of objects to which said object belongs.

28. The method of claim 27, said heating characteristic comprising information about the induction heating history previously experienced by said object.

29. The method of claim 25, including the step of causing said apparatus to transmit further information to said RFID tag.

30. The method of claim 29, said RFID tag storing said further information in RFID tag memory.

31. The combination of claim 29, said further information comprising the time that the last preceding induction heating of said object occurred.

32. The combination of claim 31, including the step of causing said RFID tag to transmit said further information back to an RFID reader.

33. The method of claim 25, including the step of intermittently stopping the operation of said component in order to cease generation of said magnetic field, and causing said RFID tag to transmit said information during at least certain of said intermittent stops in generation of said magnetic field.

34. The method of claim 25, including the step of periodically measuring a parameter of said control circuitry related to the load experienced by said device.

35. The method of claim 34, said parameter comprising the current experienced by at least a part of said control circuitry.

36. In an induction heating device including a component for generating a magnetic field in order to inductively heat an object, control circuitry operably coupled with said generating component for selective operation thereof to vary the magnitude of said magnetic field, the improvement which comprises apparatus coupled with said circuitry for transmitting information to and receiving digital information from an RFID tag associated with said object, said apparatus comprising a transmitting antenna, said transmitting antenna having no ground plane associated therewith.

37. The combination comprising:

an induction heating device comprising a component for generating a magnetic field in order to inductively heat an object, control circuitry operably coupled with said generating component for selective operation thereof to vary the magnitude of said magnetic field, and an RFID tag reader coupled with said circuitry; and

an induction heatable object including a component which will be heated when subjected to said magnetic field, and an RFID tag operably coupled with said object,

said tag having electronic memory, there being digital electronic information stored in said memory pertaining to the induction heating history previously experienced by said object, said tag operable to transmit said information when interrogated by said RFID tag reader.

38. The combination of claim 37, said object being food servingware.

39. The combination of claim 38, said object being food servingware.

40. The combination of claim 38, including at least one switch operably coupled with said RFID tag and switchable between circuit make and circuit break orientations in response to an external condition experienced by the switch, in order to alter the operation of said RFID tag.

41. The combination of claim 40, said switch being a thermal switch switchable between said orientations in response to the temperature of said object.

42. The combination of claim 40, said switch being coupled to the antenna of said RFID tag, said switch operable to short said antenna in one of said switch orientations.

43. The combination of claim 40, including a pair of separately operable, series-connected switches coupled with said RFID tag.

44. The combination of claim 40, said at least one switch operable to prevent transmission of information by the RFID tag in one of said switch orientations.

45. The combination of claim 38, said control circuitry including a sensor operable to measure a circuit parameter related to the impedance of the load experienced by said device.

46. The combination of claim 45, said sensor comprising a current sensor.

47. The combination of claim 38, said component comprising an inverter.

48. The combination of claim 37, said RFID tag memory carrying digital information about a heating characteristic of said object.

49. The combination of claim 48, said heating characteristic comprising information about the class of objects to which said object belongs.

50. The combination of claim 37, including at least one switch operably coupled with said RFID tag and switchable between circuit make and circuit break orientations in response to an external condition experienced by the switch, in order to alter the operation of said RFID tag.

51. The combination of claim 50, said switch being a thermal switch switchable between said orientations in response to the temperature of said object.

52. The combination of claim 50, said switch being coupled to the antenna of said RFID tag, said switch operable to short said antenna in one of said switch orientations.

53. The combination of claim 50, including a pair of separately operable, series-connected switches coupled with said RFID tag.

54. The combination of claim 50, said at least one switch operable to prevent transmission of information by the RFID tag in one of said switch orientations.

55. The combination of claim 37, said control circuit operable to reduce the magnitude of said magnetic field during the times when said tag is transmitting said information to said reader.

56. The combination of claim 55, said control circuitry operable to intermittently stop the operation of said component in order to allow said apparatus to receive said information from said RFID tag.