RFID loss-prevention using synthesized-beam readers

• US 9,183,717 B1
• Filed: 05/22/2014
• Issued: 11/10/2015
• Est. Priority Date: 05/22/2014
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Diorio, Christopher, Pesavento, Alberto
• Primary Examiner(s): Wang, Jack K
• Application Number:
  US14/285,534
• Time in Patent Office: 537 Days
• Field of Search: 340/572.1, 340/572.3, 340/572.4, 713/168, 705/128
• US Class Current: 1/1
• CPC Class Codes: G06Q 10/00 Administration; Management
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: G08B 13/246 Check out systems combined with EAS, e.g. price information stored on EAS tag anti-theft systems in point of sale systems G07G3/003
• CPC Class Codes: G08B 13/2474 Antenna or antenna activator geometry, arrangement or layout loop antennae H01Q1/22
• CPC Class Codes: G08B 13/2482 EAS methods, e.g. description of flow chart of the detection procedure
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials

Abstract

An RFID loss-prevention system (LPS) based on synthesized-beam readers (SBRs) permits authorized items to leave a facility and may perform a security action if an unauthorized item leaves the facility. A checkout reader first authorizes an item tagged with an RFID tag to exit a facility by reading an identifier from the tag, obtaining an exit authorization, and sending the identifier to a database. An SBR configured to direct at least two beams along a facility exit path reads tagged items exiting the facility, determines at least one of a travel direction and a tag location, and uses the determination to indicate that a tag is exiting or has exited the facility. The LPS then uses the database to determine if the exiting/exited tag is authorized to leave the facility.

Claims

1. A method for a Radio-Frequency Identification (RFID) loss-prevention system (LPS) to permit items to exit a facility, the method comprising:

reading a first identifier from a first RFID tag associated with a first item;

authorizing the first item to exit the facility;

providing the first identifier to a database;

directing, from a synthesized-beam reader, at least two beams along a facility exit path;

reading, in the at least two beams, the first identifier;

determining a first travel direction of the first item using the first identifier read in the at least two beams;

determining that the first item is exiting the facility based on the first travel direction;

accessing the database to determine that the first item is authorized to exit the facility; and

permitting the first item to exit the facility.

2. The method of claim 1, further comprising:

reading, in the at least two beams, a second identifier from a second RFID tag associated with a second item;

determining a second travel direction of the second item using the second identifier read in the at least two beams;

determining that the second item is exiting the facility based on the second travel direction;

accessing the database to determine that the second item is not authorized to exit the facility; and

performing a security action.

3. The method of claim 1 further comprising directing, from the synthesized-beam reader, a third beam for inventorying tagged items in the facility.

4. The method of claim 1, wherein determining that the first item is exiting the facility further comprises determining that the first item has passed a facility boundary.

5. The method of claim 1, further comprising:

reading, in at least one of the at least two beams, a third identifier from a third RFID tag associated with a third item; and

determining that the third item is stationary.

6. The method of claim 5, further comprising at least one of:

suppressing subsequent reads of the third tag;

providing the third identifier to a server; and

providing the third identifier to the database.

7. The method of claim 5, further comprising:

performing a phase measurement on one or more received signals; and

using the phase measurement to determine that at least one of;

the first item is moving; and

the third item is stationary.

8. A Radio-Frequency Identification (RFID) loss-prevention system (LPS) configured to permit authorized items to exit a facility, the LPS comprising:

a first reader configured to;

read a first identifier from a first RFID tag associated with a first item;

authorize the first item to exit the facility; and

provide the first identifier to a database;

a synthesized-beam reader configured to;

direct at least two beams along a facility exit path; and

read, in the at least two beams, the first identifier; and

a processor module configured to;

determine a first travel direction of the first item using the first identifier read in the at least two beams;

determine that the first item is exiting the facility based on the first travel direction;

access the database to determine that the first item is authorized to exit the facility; and

permit the first item to exit the facility.

9. The LPS of claim 8, wherein:

the synthesized-beam reader is further configured to read, in the at least two beams, a second identifier from a second RFID tag associated with a second item; and

the processor module is further configured to;

determine a second travel direction using the second identifier read in the at least two beams;

determine that the second item is exiting the facility based on the second travel direction;

access the database to determine that the second item is not authorized to exit the facility; and

perform a security action.

10. The LPS of claim 8, wherein the synthesized-beam reader is further configured to direct a third beam for inventorying tagged items in the facility.

11. The LPS of claim 8, wherein the processor module is further configured to determine that the first item is exiting the facility by determining that the first item has passed a facility boundary.

12. The LPS of claim 8, wherein:

the synthesized-beam reader is further configured to read, in the at least two beams, a third identifier from a third RFID tag associated with a third item; and

the processor module is further configured to;

determine that the third item is stationary.

13. The LPS of claim 12, wherein the processor module is further configured to at least one of:

suppress subsequent reads of the third tag;

provide the third identifier to a server; and

provide the third identifier to the database.

14. The LPS of claim 12, wherein the processor module is further configured to:

perform a phase measurement on one or more received signals; and

use the phase measurement to determine that at least one of;

the first item is moving; and

the third item is stationary.

15. The LPS of claim 11, wherein the processor module is located in at least one of the first reader, the synthesized-beam reader, a computer, and a server.

16. A synthesized-beam Radio-Frequency Identification (RFID) reader (SBR) configured to permit authorized items to exit a facility, the SBR comprising:

a synthesized-beam antenna configured to generate a plurality of beams; and

a processor block coupled to the antenna and configured to;

cause the antenna to direct at least two beams along a facility exit path;

read, in the at least two beams, a first identifier from a first RFID tag associated with a first item;

determine a first travel direction using the first identifier read in the at least two beams;

determine that the first item is exiting the facility based on the first travel direction;

access a database to determine that the first item is authorized to exit the facility; and

permit the tag to exit the facility.

17. The SBR of claim 16, wherein the processor block is further configured to:

read, in the at least two beams, a second identifier from a second RFID tag associated with a second item;

determine a second travel direction using the second identifier read in the at least two beams;

determine that the second tag is exiting the facility based on the second travel direction;

access the database to determine that the second tag is not authorized to exit the facility; and

perform a security action.

18. The SBR of claim 16, wherein the processor block is further configured to cause the antenna to direct a third beam for inventorying items in the facility.

19. The SBR of claim 16, wherein the processor block is further configured to:

read, in the at least two beams, a third identifier from a third RFID tag associated with a third item;

determine that the third item is stationary; and

at least one of;

suppress subsequent reads of the third tag;

provide the third identifier to a server; and

provide the third identifier to the database.

20. The SBR of claim 19, wherein the processor block is further configured to perform a phase measurement on one or more received signals;

and

use the phase measurement to determine that at least one of;

the first item is moving; and

the third item is stationary.