RFID tag detection method and system

• US 8,907,765 B2
• Filed: 12/24/2007
• Issued: 12/09/2014
• Est. Priority Date: 12/24/2007
• Status: Active Grant

• Current Assignee: Ent Services Development Corporation LP (DXC Technology Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Oshima, Hiroshi
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): Nguyen, An T
• Application Number:
  US11/963,982
• Publication Number:
  US 20090160647A1
• Time in Patent Office: 2,542 Days
• Field of Search: 340/540, 340/500, 340/568.1, 340/572.1, 340 101- 105, 340/5.92, 340/5.9, 340/5.1, 340/825
• US Class Current: 340/10.1
• 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 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00
• CPC Class Codes: G08B 21/0244 System arrangements wherein the alarm criteria uses signal delay or phase shift
• CPC Class Codes: G08B 21/0275 Electronic Article Surveillance [EAS] tag technology used for parent or child unit, e.g. same transmission technology, magnetic tag, RF tag, RFID

Abstract

An RFID tag detection method and system are described. The method comprises transmitting, in a predetermined area, a predetermined number of RFID tag request signals. The method also comprises determining that an RFID tag is positioned within the predetermined area based on a comparison of a count of zero or more received RFID tag response signals from the RFID tag with the predetermined number of RFID tag request signals.

Claims

1. An RFID tag detection method comprising:

transmitting, in a predetermined area, a predetermined number of RFID tag request signals;

determining that an RFID tag is positioned within the predetermined area based on a comparison of a count of zero or more received RFID tag response signals from the RFID tag with the predetermined number of RFID tag request signals, wherein a RFID tag response signal consists of a single identifier unique with respect to other RFID tags positioned within the predetermined area, and wherein the determining step comprises reading the single, unique identifier;

repeating the determining step at the predetermined location for each unique RFID tag from which an RFID tag response signal is received, wherein repeating the determining step is based solely on the comparison; and

storing a count of the unique RFID tags determined to be positioned within the predetermined area.

2. The method of claim 1, comprising:

receiving zero or more RFID tag response signals in response to the transmitted RFID tag request signals.

3. The method of claim 1, wherein the comparison comprises:

determining that the count of RFID tag response signals differs from the predetermined number of RFID tag request signals by a predetermined request-response difference threshold.

4. The method of claim 3, wherein the predetermined request-response difference threshold is zero.

5. The method of claim 3, wherein the predetermined request-response difference threshold is one or more.

6. The method of claim 3, wherein the predetermined request-response difference threshold is based on a percentage of the predetermined number of RFID tag request signals transmitted.

7. The method of claim 1, further comprising:

storing an RFID tag identifier corresponding to each unique RFID tag determined to be positioned within the predetermined area.

8. An RFID tag detection system comprising:

an antenna arranged to transmit a tag request and receive a tag response;

a memory comprising a set of executable instructions; and

a processor communicatively coupled with the memory and the antenna and arranged to execute one or more instructions of the set of executable instructions, execution of the one or more instructions by the processor causes the processor to cause the antenna to transmit a predetermined number of RFID tag requests and to determine that an RFID tag is either a not of interest tag based on receipt of RFID tag responses from the RFID tag less than the predetermined number of RFID tag requests transmitted or a tag of interest, wherein a RFID tag response consists of a single identifier unique with respect to other RFID tags positioned within the predetermined area, and wherein the determination comprises reading the single, unique identifier, and to repeat the determination at the predetermined location for each unique RFID tag from which an RFID tag response signal is received, wherein the repeated determination is based solely on the comparison, and to store a count of the unique RFID tags determined to be positioned within the predetermined area.

9. The system as claimed in claim 8, wherein the processor, executing the one or more instructions determines than an RFID tag is a tag of interest if the number of tag responses received from the RFID tag corresponds to the predetermined number of RFID tag requests transmitted.

10. The system as claimed in claim 8, wherein the processor, executing the one or more instructions stores an indication in the memory than an RFID tag is a tag of interest.

11. The system as claimed in claim 8, wherein the processor, executing the one or more instructions causes the antenna to transmit the predetermined number of RFID tag requests in a predetermined area.

12. The system as claimed in claim 11, wherein the processor executing the one or more instructions determines than an RFID tag is within the predetermined area if the number of tag responses received from the RFID tag corresponds to the predetermined number of RFID tag requests transmitted.

13. A memory storing instructions which, when executed by a processor, cause the processor to transmit, in a predetermined area, a predetermined number of RFID tag requests and determine that an RFID tag is positioned within the predetermined area based on comparing a count of zero of more received RFID tag responses from the RFID tag with the predetermined number of RFID tag requests transmitted, wherein a RFID tag response consists of a single identifier unique with respect to other RFID tags positioned within the predetermined area, and wherein the determination comprises reading the single, unique identifier, and to repeat the determination at the predetermined location for each unique RFID tag from which an RFID tag response signal is received, wherein the repeated determination is based solely on the count comparison, and to store a count of the unique RFID tags determined to be positioned within the predetermined area.

14. The memory as claimed in claim 13, wherein the comparing comprises instructions which, when executed by the processor, cause the processor to determine whether the count of RFID tag response signals differs from the predetermined number of RFID tag request signals by a predetermined request-response difference threshold.

15. The memory as claimed in claim 14, wherein the predetermined request-response difference threshold is one or more.

16. The memory as claimed in claim 14, wherein the predetermined request-response difference threshold is based on a percentage of the predetermined number of RFID tag request signals transmitted.

17. The memory as claimed in claim 13, comprising instructions which, when executed by the processor, cause the processor to store an RFID tag identifier corresponding to each unique RFID tag determined to be positioned within the predetermined area.

18. The memory as claimed in claim 13, comprising instructions which, when executed by the processor, cause the processor to transmit the RFID tag requests responsive to detection of a triggering event.