Multi-Mode Tags and Methods of Making and Using the Same

• US 20080088417A1
• Filed: 10/11/2007
• Published: 04/17/2008
• Est. Priority Date: 10/11/2006
• Status: Active Grant

• Current Assignee: Ensurge Micropower ASA
• Original Assignee: Kovio Incorporated (Ensurge Micropower ASA)
• Inventors: SMITH, Patrick, Subramanian, Vivek, Cleeves, James Montague, Pavate, Vikram
• Granted Patent: US 7,750,792 B2
• Time in Patent Office: Days
• US Class Current: 340/10.41
• 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: G08B 13/2448 Tag with at least dual detection means, e.g. combined inductive and ferromagnetic tags, dual frequencies within a single technology, tampering detection or signalling means on the tag
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Multi-mode (e.g., EAS and RFID) tags and methods for making and using the same are disclosed. The tag generally includes an antenna, an electronic article surveillance (EAS) function block coupled to the antenna, and one or more identification function blocks coupled to the antenna in parallel with the EAS function block. The method of reading the tag generally includes the steps of applying an electric field to the tag, detecting the tag when the electric field has a relatively low power, and detecting an identification signal from the tag when the electric field has a relatively high power. The present invention advantageously enables a single tag to be used for both inventory and anti-theft purposes, thereby improving inventory management and control at reduced system and/or “per-article” costs.

Claims

1. A multi-mode identification tag, comprising:

a) an antenna;

b) an electronic article surveillance (EAS) function block coupled to the antenna;

and

c) one or more RFID function blocks coupled to the antenna in parallel with the EAS function block.

2. The multi-mode identification tag of claim 1, further comprising a rectifier coupled to the antenna in parallel with the EAS function block.

3. The multi-mode identification tag of claim 1, wherein the tag has (i) a high Q state in an electric field having a relatively low power and (ii) a low Q state in an electric field having a relatively high power.

4. The multi-mode identification tag of claim 3, further comprising a rectifier coupled to the antenna in parallel with the EAS function block, wherein the rectifier is substantially non-operational or disabled when the tag has the high Q state, and the rectifier is operational or enabled when the tag has the low Q state.

5. The multi-mode identification tag of claim 3, wherein the RFID function block(s) are substantially non-operational, disabled or electrically disconnected from a power supply when the tag has the high Q state, and the RFID function block(s) are substantially operational, enabled or electrically connected to the power supply when the tag has the low Q state.

6. The multi-mode identification tag of claim 3, wherein when the tag is in an electric field having a power above a first predetermined threshold, a sufficient number of the RFID function block(s) are enabled or electrically connected to the power supply to lower the Q of the tag to the low Q state.

7. The multi-mode identification tag of claim 6, wherein when the power of the electric field is below a second predetermined threshold, a sufficient number of the RFID function block(s) are disabled or electrically disconnected from the power supply to maintain the Q of the tag in the high Q state, the second predetermined threshold being less than or equal to the first predetermined threshold.

8. The multi-mode identification tag of claim 3, wherein the rectifier has a resonating circuit with a load effective to reduce the Q of the tag.

9. The multi-mode identification tag of claim 8, wherein the resonating circuit includes a programmable threshold device.

10. The multi-mode identification tag of claim 3, wherein the rectifier receives a signal having a characteristic frequency from the antenna and provides upper and lower power supplies to the RFID function block(s).

11. The multi-mode identification tag of claim 1, wherein the RFID function block(s) comprise a demodulator or clock extractor configured to receive a signal from the antenna and provide a clock signal to remaining RFID function block(s) in response thereto.

12. The multi-mode identification tag of claim 11, wherein the RFID function block(s) further comprise logic configured to receive the clock signal from the demodulator or clock extractor and provide an identification signal in response thereto.

13. The multi-mode identification tag of claim 12, wherein the logic comprises a memory storing a bit string, and the identification signal comprises the bit string.

14. The multi-mode identification tag of claim 13, wherein the logic is configured to silence the tag for a period of time and re-transmit the bit string thereafter.

15. The multi-mode identification tag of claim 12, wherein the RFID function block(s) further comprise a modulator or output stage configured to transmit the identification signal or a modulated identification signal to the antenna.

16. The multi-mode identification tag of claim 1, wherein the EAS function block comprises a capacitor.

17. The multi-mode identification tag of claim 16, wherein the capacitor has a predetermined breakdown voltage.

18. The multi-mode identification tag of claim 1, wherein the antenna comprises a coil and a tuning element.

19. The multi-mode identification tag of claim 18, wherein the tuning element comprises a second coil, a capacitor or capacitor plate, or a tuning ring.

20. A method of reading an identification tag, comprising:

a) applying an electric field to the tag;

b) detecting the tag when the electric field has a relatively low power; and

c) detecting an identification signal from the tag when the electric field has a relatively high power.

21. The method of claim 20, wherein the tag includes an antenna having a high Q state when the power of the electric field is below a first threshold and a low Q state when the power of the electric field is above a second threshold, the second threshold being greater than or equal to the first threshold.

22. The method of claim 21, wherein the tag comprises a rectifier that is substantially non-operational or disabled when the tag has the high Q state, and the rectifier is operational or enabled when the tag has the low Q state.

23. The method of claim 21, wherein the tag comprises one or more RFID function block(s) that are substantially non-operational, disabled or electrically disconnected from a power supply when the tag has the high Q state, and the RFID function block(s) are substantially operational, enabled or electrically connected to the power supply when the tag has the low Q state.

24. The method of claim 23, wherein when the power of the electric field is above a first predetermined threshold, a sufficient number of the RFID function block(s) are enabled or electrically connected to the power supply to lower the Q of the tag to the low Q state.

25. The method of claim 24, wherein when the power of the electric field is below a second predetermined threshold, a sufficient number of the RFID function block(s) are disabled or electrically disconnected from the power supply to maintain the Q of the tag in the high Q state, the second predetermined threshold being less than or equal to the first predetermined threshold.