Method and apparatus to automatically search data carriers, such as RFID tags and machine-readable symbols

• US 6,286,763 B1
• Filed: 09/21/1999
• Issued: 09/11/2001
• Est. Priority Date: 09/21/1999
• Status: Expired due to Term

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Bodnar, Daniel B., Reynolds, Andrew E., Wiklof, Christopher A.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US09/401,365
• Time in Patent Office: 721 Days
• Field of Search: 235/472.01, 235/472.02
• US Class Current: 235/472.01
• 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 7/10386 the interrogation device being of the portable or hand-handheld type, e.g. incorporated in ubiquitous hand-held devices such as PDA or mobile phone, or in the form of a portable dedicated RFID reader

Abstract

A data carrier reader is capable of executing a number of different reading methods. A method for reading single RFID tags can store read data to a buffer for eventual transmission to a host, and can suppress redundant data. Still another method associates data read from an RFID tag with a particular object or item using a data coded in a machine-readable symbol. In a further method, the machine-readable symbol is automatically read when the RFID tag is within a predetermined proximity of the reader. In each method, the data carrier reader provides the user a consistent and intuitive output to identify the successful and unsuccessful operations such as reading an RFID tag or machine-readable symbol.

Claims

1. A method of operating a data carrier reader, comprising:

receiving a plurality of characteristic data strings from each of a number of RFID tags, including at least one RFID tag of interest;

comparing at least a portion of each of the received characteristic data strings to at least one identifier stored in a buffer, the identifier corresponding to the RFID tag of interest;

producing a first human-perceptible indication in response to the number of received characteristic data strings that correspond to the at least one identifier; and

automatically operating a symbol reader when a rate of response corresponding to the at least one identifier exceeds a threshold value.

2. The method of claim 1, further comprising:

producing a second human-perceptible indication in response to the number of received characteristic data strings that do not correspond to the at last one identifier.

3. The method of claim 1, further comprising:

producing a second human-perceptible indication in response to the number of received characteristic data strings that do not correspond to the at last one identifier, wherein the first human-perceptible indication is a first sound and the second human-perceptible indication is a second sound, different from the first sound.

4. The method of claim 1, further comprising:

determining a hit rate of response corresponding to a number of received characteristic data strings that correspond to the at least one identifier;

determining a miss rate of response corresponding to the number of received characteristic data strings that do not correspond to the at least one identifier; and

determining the threshold value from the hit rate of response and the miss rate of response.

5. The method of claim 1, further comprising:

reading a symbol; and

comparing at least a portion of the read symbol to the at least one identifier stored in a buffer.

6. The method of claim 1, further comprising:

reading a symbol;

comparing at least a portion of the read symbol to the at least one identifier stored in a buffer; and

automatically ceasing to power the symbol reader after reading the symbol.

7. The method of claim 1, further comprising:

reading a symbol;

comparing at least a portion of the read symbol to the at least one identifier stored in a buffer; and

automatically transferring the characteristic data string read from the RFID tag of interest to a host if the at least a portion of the read symbol corresponds to the at least one identifier stored in a buffer.

8. A method of operating a data carrier reader, comprising:

receiving a plurality of responses from a number of RFID tags including at least one RFID tag of interest; and

automatically operating a symbol reader when a rate of the responses from the RFID tag of interest exceeds a threshold rate of response.

9. The method of claim 8, further comprising:

producing a first human-perceptible indication corresponding to a number of the responses received from the RFID tag of interest.

10. The method of claim 8, further comprising:

producing a first human-perceptible indication corresponding to a number of the responses received from the RFID tag of interest; and

producing a second human-perceptible indication in response to a number of the responses received from the RFID tags other than the RFID tag of interest.

11. The method of claim 8, further comprising:

determining the threshold rate of response from the ratio of the responses of the RFID tags other than the RFID tag of interest and the responses of the RFID tag of interest.

12. The method of claim 8, further comprising:

reading a symbol; and

comparing at least a portion of the read symbol to at least a portion of at least one of the plurality of responses.

13. The method of claim 8, further comprising:

reading a symbol;

comparing at least a portion of the read symbol to at least a portion of at least one of the plurality of responses; and

automatically ceasing to power the symbol reader after reading the symbol.

14. The method of claim 8, further comprising:

reading a symbol;

comparing at least a portion of the read symbol to at least a portion of at least one of the plurality of responses; and

automatically transferring at least a portion of the response received from the RFID tag of interest to a host if the at least a portion of the read symbol corresponds to the at least a portion of the at least one of the plurality of responses.