RFID Technology

• US 20090231138A1
• Filed: 03/14/2008
• Published: 09/17/2009
• Est. Priority Date: 03/14/2008
• Status: Abandoned Application

• Current Assignee: Chung Nam Electronics Co., Ltd.
• Original Assignee: Chung Nam Electronics Co., Ltd.
• Inventors: LAI, Kin Yue Albert, TIN, Siu Chong, CHEUNG, Chi Chiu, WONG, On Yung Timmy
• Application Number:
  US12/048,842
• Publication Number:
  US 20090231138A1
• Time in Patent Office: Days
• US Class Current: 340/572.400
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• 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: H04Q 2209/47 using RFID associated with sensors
• CPC Class Codes: H04Q 2209/753 where the polling of the sub-stations is synchronous
• CPC Class Codes: H04Q 2209/883 where the sensing device enters an active or inactive mode
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A method of selectively waking up a plurality of RFID tags includes (a) providing a first RFID tag; (b) programming the first RFID tag to respond and wake up only to signals at a first sub-carrier frequency or with a first code; (c) providing a second RFID tag; and (d) programming the second RFID tag to respond and wake up only to signals at a second sub-carrier frequency or with a second code. A method of operating an RFID tag positioning system includes (a) positioning two real time location tracking active RFID readers in two respective locations; (b) positioning a first calibrating RFID tag at a fixed and known position; (c) moving a second calibrating RFID tag along a pre-determined path; (d) obtaining the first RFID reader'"'"'s readings of location-related information of the RFID tags at a point in time; (e) obtaining the second RFID reader'"'"'s readings of location-related information of the RFID tags at that point in time; and (f) comparing the readings with the known positions of the first and second calibrating tags.

Claims

1. A method of selectively waking up at least two RFID tags, including the steps of:

(a) providing a first RFID tag;

(b) programming said first RFID tag to respond to and wake up only to signals with a first characteristic;

(c) providing a second RFID tag; and

(d) programming said second RFID tag to respond to and wake up to only to signals with a second characteristic.

2. A method according to claim 1 further including a step (e) of transmitting signals with said first characteristic to wake up said first RFID tag.

3. A method according to claim 1 further including a step (f) of transmitting signals with said second characteristic to wake up said second RFID tag.

4. A method according to claim 1 wherein said first characteristic and said second characteristic are two different frequency subcarriers.

5. A method according to claim 1 wherein said first characteristic and said second characteristic are two different codes.

6. A method according to claim 1 further including a step (g) of re-programming said first RFID tag to respond to and wake up only to signals with a characteristic different to said first characteristic when said first RFID tag moves from a first zone to a second zone.

7. A method according to claim 1 wherein in said step (a), said first RFID tag is programmed to respond to and wake up only to signals with said first characteristic for a first pre-determined period of time.

8. A method according to claim 7 wherein in said step (a), said first RFID tag is programmed to respond to and wake up only to signals with a characteristic different to said first characteristic after expiration of said first pre-determined period of time.

9. A method according to claim 8 wherein said first RFID tag is adapted to respond to and wake up only to signals with said different characteristic for a second pre-determined period of time.

10. A dual-mode active RFID tag, wherein said tag is adapted to be in a real time location system (RTLS) mode for a first pre-determined period of time and in an inventory mode for a second pre-determined period of time.

11. An RFID tag according to claim 10 wherein when in said RTLS mode, said tag is adapted to provide real time information on its position when queried.

12. An RFID tag according to claim 10 wherein when in said inventory mode, said tag is adapted only to provide identity information when queried.

13. An RFID tag according to claim 10 wherein said tag is adapted to alternate between said RTLS mode and inventory mode.

14. A signal transmission apparatus for transmitting wakeup signals to RFID tags, said apparatus being adapted to transmit signals with information indicative of the cumulative period of time which has lapsed since transmission of the first wakeup signal.

15. An apparatus according to claim 14 wherein said signals include time slots with time index.

16. A method of transmitting wakeup signals to RFID tags, including transmitting signals with information indicative of the cumulative period of time which has lapsed since transmission of the first wakeup signal.

17. A method according to claim 16 wherein said signals include time slots with time index.

18. An RFID tag assembly with at least an active RFID tag and at least a passive RFID tag.

19. An RFID tag assembly according to claim 18 wherein said passive tag module is stored with a unique identity (ID) code.

20. An RFID tag assembly according to claim 18 wherein said active tag module is adapted to respond to and wake up only to signals of a first characteristic.

21. An RFID tag assembly according to claim 18 further including means adapted to read data from and write data to a radio-frequency (RF) terminal of said passive tag module.

22. An RFID tag assembly according to claim 21 wherein said reading/writing means is a baseband coupling circuit.

23. An RFID tag assembly according to claim 18 wherein said active tag module is of passive RFID tag protocol responding capability.

24. A portable RFID reader containing a real time location tracking RFID tag.

25. An RFID reader according to claim 24 wherein said reader is adapted to provide spatial location reference of each reading and/or writing operation.

26. An RFID reader according to claim 24 wherein said reader is adapted to provide time information of each reading and/or writing operation.

27. An RFID reader according to claim 26 wherein said reader is adapted to obtain time information from a network clock server.

28. A portable RFID reader containing a global positioning system (GPS) receiver.

29. An RFID reader according to claim 28 wherein said reader is adapted to provide time information of each reading and/or writing operation.

30. An RFID reader according to claim 28 wherein said reader is adapted to obtain time information from a network clock server.

31. An active RFID tag with at least two electric power sources, wherein at least one of said electric power sources is rechargeable.

32. An active RFID tag according to claim 31 wherein said electric power sources are electric batteries.

33. An active RFID tag according to claim 31 further including means for recharging said rechargeable electric power source.

34. An active RFID tag according to claim 33 wherein said recharging means is a stationary energy harvesting device or a mobile energy harvesting device.

35. An active RFID tag according to claim 33 wherein said recharging means is a solar cell, kinetic energy harvesting means, piezoelectric cell, or thermoelectric cell.

36. An active RFID tag according to claim 31 further including at least two rechargeable electric sources, wherein said recharging means is adapted to recharge at least one of said rechargeable electric source which is not current in use.

37. An active RFID tag reader with at least two electric power sources, wherein at least one of said electric power sources is rechargeable.

38. An active RFID tag reader according to claim 37 wherein said electric power sources are electric batteries

39. An active RFID tag reader according to claim 37 further including means for recharging said rechargeable electric power source.

40. An active RFID tag reader according to claim 39 wherein said recharging means is a stationary energy harvesting device or a mobile energy harvesting device.

41. An active RFID tag reader according to claim 39 wherein said recharging means is a solar cell, mechanical watch movement with generator, piezoelectric charging means, or thermoelectric charging means.

42. An active RFID tag reader according to claim 37 further including at least two rechargeable electric sources, and wherein said recharging means is adapted to recharge at least one of said rechargeable electric source which is not current in use.

43. A method of calibrating an RFID tag positioning system with at least a first and a second real time location tracking active RFID readers, including the steps of:

(a) positioning said at least two real time location tracking active RFID readers in two respective locations in an environment;

(b) positioning a first calibrating RFID tag at a fixed and known position in said environment;

(c) moving a second calibrating RFID tag along a pre-determined path in said environment;

(d) obtaining said first RFID reader'"'"'s readings of location-related information of said first and second calibrating RFID tags at a point in time;

(e) obtaining said second RFID reader'"'"'s readings of location-related information of said first and second calibrating RFID tags at said point in time; and

(f) comparing said readings of said first RFID reader and of said second RFID reader with said known positions of said first and second calibrating tags.

44. A method according to claim 43 further including a step (g) of disregarding readings from at least one of said active RFID readers.

45. A method according to claim 43 further including a step (h) of assigning different weights to said readings from said at least two active RFID readers when determining the location of an RFID tag.

46. A method according to claim 43 wherein said second calibrating RFID tag is fixedly associated with an optical barcode or an optical descriptor.

47. A method according to claim 43 wherein said second calibrating RFID tag is a passive RFID tag.

48. A method according to claim 43 wherein said fixed and known position occupied by said first calibrating RFID tag is fixedly associated with a landing pattern.

49. An RFID tag including:

an RFID tag integrated circuit;

a high dielectric constant plastic layer with two major surfaces;

a first layer of printed-circuit-board material fixedly secured on a first major surface of said plastic layer;

a second layer of printed-circuit-board material fixedly secured on a second major surface of said plastic layer; and

an antenna formed on said first layer of printed-circuit-board material.

50. An RFID tag according to claim 49 further including at least one metal pin electrically connecting said first and second layers of printed-circuit-board material.

51. An RFID reader including:

a high dielectric constant plastic layer with two major surfaces;

a first layer of printed-circuit-board material fixedly secured on a first major surface of said plastic layer;

a second layer of printed-circuit-board material fixedly secured on a second major surface of said plastic layer; and

an antenna formed on said first layer of printed-circuit-board material.

52. An RFID reader according to claim 51 further including at least one metal pin electrically connecting said first and second layers of printed-circuit-board material.

53. An RFID system including:

a remote controller of an electrical appliance, said remote controller having at least one RFID reader adapted to receive at least identity (ID) data from at least one RFID tag;

a data processing apparatus adapted to receive at least said ID data from said remote controller; and

a visual display unit adapted to visually show at least said ID data of said RFID tag.

54. A system according to claim 53 wherein said remote controller is adapted to receive ranging information of said RFID tag.

55. A system according to claim 54 wherein said data processing apparatus is adapted to receive said ranging information of said RFID tag from said remote controller.

56. A system according to claim 54 wherein said visual display unit is adapted to visually display said ranging information.

57. A system according to claim 53 wherein said electrical appliance is a television set, a DVD player, a blu-ray player, a high definition (HD) DVD player, a digital media player, or a set top box.

58. A system according to claim 53 further including a plurality of RFID readers adapted to obtain data from said RFID tag and to transmit said data to said remote controller.

59. A system according to claim 58 wherein said RFID readers are adapted to determine the location of said RFID tag and to transmit data of said determined location to said remote controller.

60. A system according to claim 58 wherein said remote controller is adapted to transmit said data of said determined location of said RFID to said data processing apparatus.

61. A system according to claim 60 wherein said visual display unit is adapted to visually display said determined location of said RFID.

62. A system according to claim 53 wherein said data processing apparatus is adapted to receive said ID data from said remote controller via a USB dongle or bridge.

63. A system according to claim 53 wherein said at least one RFID reader is a passive RFID reader.

64. A system according to claim 53 wherein said at least one RFID reader is a real time location tracking (RTLS) RFID reader.

65. A system according to claim 53 wherein said remote controller includes at least one RTLS RFID reader and at least one passive RFID reader.