RFID interrogator configured for protection against electromagnetic interference of a remote device having an RFID tag

• US 8,581,694 B2
• Filed: 03/07/2013
• Issued: 11/12/2013
• Est. Priority Date: 11/19/2008
• Status: Expired due to Fees

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Stevenson, Robert A., Tyers, Geddes Frank, Frysz, Christine A.
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): GIRMA, FEKADESELASS
• Application Number:
  US13/787,922
• Publication Number:
  US 20130201005A1
• Time in Patent Office: 250 Days
• Field of Search: 340/5.61, 340/10.1
• US Class Current: 340/5.61
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: B60R 2325/105 Radio frequency identification data [RFID]
• CPC Class Codes: B60R 25/00 Fittings or systems for preventing or indicating unauthorised use or theft of vehicles locks for vehicles E05B77/00-E05B85/00
• 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: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
• CPC Class Codes: G06K 7/10217 parameter settings controlling the transmission power of the interrogator
• CPC Class Codes: G08B 13/248 EAS system combined with another detection technology, e.g. dual EAS and video or other presence detection system
• CPC Class Codes: G16H 40/63 for local operation

Abstract

An RFID tag interrogator is described. The interrogator comprises a time-out circuit and an actuatable RF signal generator for transmitting an electromagnetic signal. Upon first actuation, the RF signal generator transmits a first electromagnetic signal having a first limited total continuous transmit time that is no longer than a predetermined transmit-time. That transmission is followed by an interim period of a defined length where the time-out circuit renders the interrogator incapable of transmitting the electromagnetic signal. The interim period is followed by the RF signal generator transmitting a second electromagnetic signal having a second limited total continuous transmit time that is no longer than the predetermined transmit time. The time-out circuit prevents the first, second and subsequent transmissions of the electromagnetic signal that are each no longer than the predetermined transmit time after a prior electromagnetic signal has been transmitted until the interim period has expired.

Claims

1. An interrogator for an RFID tag, the interrogator comprising:

a) a time-out circuit and an actuatable RF signal generator for transmitting an electromagnetic signal,

b) wherein upon first actuation of the RF signal generator, regardless whether an RFID tag is detected, or not, the RF signal generator transmits a first electromagnetic signal having a first limited total continuous transmit time that is no longer than a predetermined transmit time, followed by an interim period of a defined length where the time-out circuit renders the interrogator incapable of transmitting the electromagnetic signal, followed by the RF signal generator transmitting a second electromagnetic signal having a second limited total continuous transmit time that is no longer than the predetermined transmit time,

c) wherein no matter how frequently the RF signal generator is actuated, the time-out circuit prevents the first, second and subsequent transmissions of the electromagnetic signal that are each no longer than the predetermined transmit time after a prior electromagnetic signal has been transmitted from the RF signal generator until the interim period has expired.

2. The interrogator of claim 1 wherein the electromagnetic signal comprises an RFID communication signal.

3. The interrogator of claim 1 wherein the electromagnetic signal comprises an RFID interrogation or tag search signal.

4. The interrogator of claim 1 wherein the electromagnetic signal comprises an RFID test signal.

5. The interrogator of claim 1 wherein the electromagnetic signal comprises an RFID read signal or an RFID write signal.

6. The interrogator of claim 1 wherein the predetermined transmit time is no greater than about five seconds.

7. The interrogator of claim 1 wherein the interim period when the time-out circuit delays a subsequent transmission of the electromagnetic signal is at least about two seconds.

8. The interrogator of claim 7 wherein the predetermined transmit time is about 500 milliseconds or less, but greater than zero.

9. The interrogator of claim 1 wherein the first, second and subsequent electromagnetic signals are selected from the group consisting of an RFID test signal, an RFID tag search signal, an RFID interrogation signal, an RFID read signal, and an RFID write signal.

10. The interrogator of claim 1 wherein the first, second and subsequent electromagnetic signals comprises a modulated signal.

11. The interrogator of claim 1 comprising a read-only or a reader/writer device.

12. The interrogator of claim 1 being configured for communication with a remote computer or computer network.

13. The interrogator of claim 1 being programmable to actively search for or communicate with an RFID tag.

14. The interrogator of claim 1 comprising a read-only or a reader/writer device.

15. The interrogator of claim 1 comprising a portion of an animal or an article tracking system.

16. The interrogator of claim 1 comprising a portion of an electronic article surveillance (EAS) system.

17. The interrogator of claim 1 comprising a check-out station for purchase of goods.

18. The interrogator of claim 1 wherein the electromagnetic signal is transmitted in the LF or HF frequency range.

19. The interrogator of claim 1 comprising a barcode reader.

20. The interrogator of claim 1 wherein the interrogator is configured to write data received from a barcode reader to an RFID tag.