Apparatus and method for communicating with an RFID transponder

• US 20050274799A1
• Filed: 05/03/2005
• Published: 12/15/2005
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: ZIH Corp. (Zebra Technologies Corporation)
• Inventors: Donato, Daniel F., Torchalski, Karl
• Granted Patent: US 8,596,532 B2
• Time in Patent Office: Days
• US Class Current: 235/432
• CPC Class Codes: B41J 3/4075 Tape printers; Label printers
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 17/0025 the arrangement consisting of a wireless interrogation device in combination with a device for optically marking the record carrier
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10158 methods and means used by the interrogation device for reliably powering the wireless record carriers using an electromagnetic interrogation field
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10445 the record carriers being fixed to further objects, e.g. RFIDs fixed to packages, luggage, mail-pieces or work-pieces transported on a conveyor belt
• CPC Class Codes: H04B 5/45 Transponders

Abstract

A system having a UHF RFID transceiver is adapted to communicate exclusively with a single electro-magnetically coupled transponder located in a predetermined confined transponder operating region. The system includes a near field coupling device comprising a plurality of lines connected in parallel with an unmatched load. The near field coupling device may be formed, for example on a printed circuit board with a plurality of electrically interconnected traces and a ground plane. The system establishes, at predetermined transceiver power levels, a mutual electromagnetic coupling which is selective exclusively for a single transponder located in a defined transponder operating region. Also included are methods for selective communication with the transponder in an apparatus such as a printer-encoder.

Claims

1. A method of communicating with a transponder on a carrier substrate in a printer, the method comprising:

energizing a transceiver to a first power level and thereby writing first data to the transponder; and

energizing the transceiver to a second power level different from the first power level and thereby reading second data from the transponder.

2. A method according to claim 1, wherein the second power level is lower than the first power level.

3. A method according to claim 1, further comprising comparing the second data to the first data, the second data including at least a portion of the first data, and thereby determining a defective characteristic of the transponder.

4. A method according to claim 1, wherein said first and second energizing steps comprise writing to and reading from a substantially similar spatial region.

5. A method according to claim 1, wherein said first and second energizing steps comprise writing to and reading from a spatial region of substantially equal area.

6. A method according to claim 1, wherein said first energizing step comprises writing to the transponder independent of writing to other transponders on the carrier substrate, and wherein said second energizing step comprises reading from the transponder independent of reading from other transponders on the carrier substrate.

7. A method according to claim 1, further comprising storing values characteristic of a plurality of read power levels and write power levels, each power level being associated with a characteristic of at least one of the transponder and the carrier substrate, wherein each of said energizing steps comprises energizing the transceiver at one of the read and write power levels according to a characteristic of at least one of the transponder and the carrier substrate.

8. A method according to claim 1, wherein said first energizing step comprises writing the first data to the transponder at a first power level of the transceiver, and further comprising repeating said first energizing step using a power level different than the first power level.

9. A method according to claim 8, wherein said repeating step comprises energizing the transceiver to a higher power level than said first energizing step.

10. A method according to claim 8, wherein said first energizing step comprises writing to the transponder at a first frequency and wherein said repeating step comprises writing to the transponder at a second frequency different than the first frequency.

11. A method according to claim 1, wherein said first energizing step comprises energizing the transponder at a first power level and said second energizing step comprises energizing the transponder at a second power level, the first power level being greater than the second power level, and the first power level being less than three times the second power level.

12. A method according to claim 1, further comprising:

determining rates of successful communication between the transceiver and the transponder for a plurality of power levels and for a plurality of distances between the transceiver and the transponder; and

selecting the first power level associated with a relatively high rate of successful communication between the transceiver and the transponder for a limited range of distance between the transceiver and the transponder.

13. A method according to claim 12, wherein said determining step comprises determining a plurality of read success rates and a plurality of write success rates for a plurality of power levels and for a plurality of distances between the transceiver and the transponder, and further comprising selecting a select distance, the first power level, and the second power level, wherein the first power level is associated with a relatively high write success rate at a limited range of distances including the select distance and wherein the second power level is associated with a relatively high read success rate at a limited range of distances including the select distance.

14. A method according to claim 1, wherein said step of energizing the transceiver to the first power level to write the first data to the transponder occurs before said step of energizing the transceiver to a second power level to read the second data from the transponder.

15. A method according to claim 1, wherein said step of energizing the transceiver to the first power level to write the first data to the transponder occurs after said step of energizing the transceiver to a second power level to read the second data from the transponder.

16. A method of communicating with a transponder on a carrier substrate in a printer, the method comprising:

energizing a transceiver to a plurality of power levels with the transceiver disposed at a plurality of distances from at least one transponder to thereby communicate with the transponder;

determining rates of successful communication between the transceiver and the transponder for the plurality of power levels and for the plurality of distances between the transceiver and the transponder; and

selecting a first power level associated with a relatively high rate of successful communication between the transceiver and the transponder for a limited range of distance between the transceiver and the transponder.

17. A method according to claim 16, wherein said determining step comprises determining a plurality of read success rates and a plurality of write success rates for a plurality of power levels and for a plurality of distances between the transceiver and the transponder, and further comprising selecting a select distance, the first power level, and a second power level, the first power level being associated with a relatively high write success rate at a limited range of distances including the select distance and the second power level being associated with a relatively high read success rate at a limited range of distances including the select distance.

18. A system for communicating with a transponder on a carrier substrate in a printer, the system comprising:

a feed path extending through the printer such that the printer is configured to receive the carrier substrate along the feed path;

a transceiver configured to be energized to communicate with the transponder; and

a controller in communication with the transceiver and configured to selectively energize the transceiver to a first power level for writing data to the transponder and to a second power level for reading data from the transponder, the second power level different from the first power level.

19. A system according to claim 18, wherein the second power lever is less than the first power level.

20. A system according to claim 18, wherein the controller is configured to compare the data read from the transponder to the data written to the transponder and thereby determine a defective characteristic of the transponder.

21. A system according to claim 18, wherein the controller is configured to energize the transponder to write to and read from a substantially similar spatial region.

22. A system according to claim 18, wherein the controller is configured to energize the transponder to write to and read from a spatial region of substantially equal area.

23. A system according to claim 18, further comprising a memory configured to store values characteristic of a plurality of read power levels and write power levels, each power level being associated with a characteristic of at least one of the transponder and the carrier substrate, and wherein the controller is configured to selectively energize the transceiver at one of the read and write power levels stored in the memory according to a characteristic of at least one of the transponder and the carrier substrate.

24. A system for communicating with a transponder on a carrier substrate in a printer, the system comprising:

a feed path extending through the printer such that the printer is configured to receive the carrier substrate along the feed path;

a transceiver configured to be energized to communicate with the transponder; and

a controller in communication with the transceiver and configured to selectively energize the transceiver to a plurality of power levels to thereby communicate with the transponder, determine rates of successful communication between the transceiver and the transponder according to each power level and a distance between the transceiver and the transponder, and select a first power level associated with a relatively high rate of successful communication between the transceiver and the transponder for a limited range of distance between the transceiver and the transponder.

25. A system according to claim 24, wherein said controller is configured to determine a plurality of read success rates and a plurality of write success rates for a plurality of power levels and for a plurality of distances between the transceiver and the transponder, and select a select distance, the first power level, and a second power level, the first power level being associated with a relatively high write success rate at a limited range of distances including the select distance and the second power level being associated with a relatively high read success rate at a limited range of distances including the select distance.