RFID tag, antenna, and printer system

• US 6,929,412 B1
• Filed: 06/07/2004
• Issued: 08/16/2005
• Est. Priority Date: 09/12/2003
• Status: Active Grant

• Current Assignee: TSC Auto ID Technology Co., Ltd.
• Original Assignee: Printronix
• Inventors: Schumaker, Richard E., Barrus, Gordon B., Gibbs, Duane C., Concepcion, Rudy Jr., Smith, Kevin Mark, Edwards, Andrew W.
• Primary Examiner(s): CHAU, MINH H
• Application Number:
  US10/863,055
• Time in Patent Office: 435 Days
• Field of Search: 400/61, 400/62, 400/70, 400/76, 340/572.1, 340/572.4, 3405726-5728, 340/825.69, 340/825.72, 340/572, 343/702, 343/741, 343/850, 343/866, 343/873, 343/895, 101/35
• US Class Current: 400/76
• CPC Class Codes: B41J 11/0095 Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end
• CPC Class Codes: B41J 3/4075 Tape printers; Label printers
• CPC Class Codes: B41J 3/44 Typewriters or selective printing mechanisms having dual functions or combined with, or coupled to, apparatus performing other functions
• 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 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 5/02 the verifying forming a part of the marking action
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles

Abstract

An RFID label with embedded tag is passed through an RFID antenna in a printer system, where the RFID antenna allows a roll of such labels to pass in close proximity to the antenna and still allow each individual RFID tag to be read and/or programmed. The RFID antenna is formed with two parallel microstrip transmission lines coupled to an RF phase splitter there between.

Claims

1. A printer system, comprising:

a roll of labels, wherein each label comprises a radio frequency identification (RFID) tag;

an RFID reader system comprising;

an RFID reader; and

an RFID antenna coupled to the RFID reader, wherein the RFID antenna comprises;

two non-overlapping parallel transmission lines; and

a phase splitter coupled between the two transmission lines; and

a print head, wherein the RFID antenna is between the roll of labels and the print head.

2. A printer system, comprising:

a roll of labels, wherein each label comprises a radio frequency identification (RFID) tag;

an RFID reader system comprising;

an RFID reader; and

an RFID antenna coupled to the RFID reader, wherein the RFID antenna comprises;

two parallel transmission lines;

a resistor coupled to an end of each of the two transmission lines; and

a phase splitter coupled between the two transmission lines; and

a print head, wherein the RFID antenna is between the roll of labels and the print head.

3. A printer system, comprising:

a roll of labels, wherein each label comprises a radio frequency identification (RFID) tag;

an RFID reader system comprising;

an RFID reader; and

an RFID antenna coupled to the RFID reader, wherein the RFID antenna comprises;

two parallel transmission lines; and

a phase splitter coupled between the two transmission lines, wherein the transmission lines are orientated parallel to a path of the roll of labels across the RFID antenna; and

a print head, wherein the RFID antenna is between the roll of labels and the print head.

4. The printer system of claim 3, wherein the transmission lines are RF transmission lines and the phase splitter is an RF signal phase splitter.

5. The printer system of claim 3, further comprising a coaxial cable coupling the RFID reader to the RFID antenna.

6. The printer system of claim 3, wherein the print head is a thermal print head.

7. The printer system of claim 3, wherein the RFID tag is located in an approximately middle section of the label along the width-wise direction.

8. The printer system of claim 7, wherein the RFID tag can be located in any lengthwise position in the label.

9. The printer system of claim 3, wherein the roll of labels moves under the print head to allow writing to and reading from the RFID tags during the moving.

10. The printer system of claim 3, wherein the length of the transmission lines can be changed to control longitudinal write and read distances of the RFID tag.

11. The printer system of claim 3, wherein the RFID reader system writes to and reads from the RFID tag.

12. The printer system of claim 3, wherein the RFID reader system operates in a frequency range of approximately 902 MHz to 928 MHz.

13. The printer system of claim 3, wherein the two transmission lines are formed from a conductive material.

14. The printer system of claim 13, wherein the conductive material is copper.

15. The printer system of claim 13, wherein the RFID antenna further comprises a printed circuit board ground plane, wherein the two transmission lines are secured above the printed circuit board ground plane.

16. The printer system of claim 15, further comprising a dielectric layer separating the printed circuit board ground plane from the two transmission lines.

17. The printer system of claim 3, wherein the RFID antenna further comprises a printed circuit board ground plane and a dielectric layer, wherein the dielectric layer is between the two transmission lines and the printed circuit board ground plane.

18. The printer system of claim 17, wherein the two transmission lines are encapsulated in a second dielectric layer.

19. A printer system, comprising:

a roll of labels, wherein each label comprises a radio frequency identification (RFID) tag;

an RFID reader system comprising;

an RFID reader; and

an RFID antenna coupled to the RFID reader, wherein the RFID antenna comprises;

two parallel transmission lines; and

a phase splitter coupled between the two transmission lines, wherein the two transmission lines are approximately 180 electrical degrees out of phase with respect to each other; and

a print head, wherein the RFID antenna is between the roll of labels and the print head.

20. A printer system, comprising:

a roll of labels, wherein each label comprises a radio frequency identification (RFID) tag;

an RFID reader system comprising;

an RFID reader; and

an RFID antenna coupled to the RFID reader, wherein the RFID antenna comprises;

two parallel transmission lines formed from a conductive material;

a printed circuit board ground plane, wherein the two transmission lines are secured above the printed circuit board ground plane; and

a phase splitter coupled between the two transmission lines, wherein the phase splitter is further secured to the printed circuit board ground plane; and

a print head, wherein the RFID antenna is between the roll of labels and the print head.

21. An RFID antenna for use in a printer system for printing RFID labels, the system including an RFID reader coupled to the RFID antenna and RFID labels passing in close proximity to the RFID antenna, the RFID antenna comprising:

a dielectric layer;

two parallel transmission strips located above a top surface of the dielectric layer, wherein the two transmission lines are approximately 180 electrical degrees out of phase with respect to each other; and

a phase splitter coupled between the two transmission strips.

22. The RFID antenna of claim 21, further comprising a coaxial cable coupled to the phase splitter and the RFID reader.

23. The RFID antenna of claim 21, wherein the two transmission strips comprise a conductive material.

24. The RFID antenna of claim 21, further comprising a second dielectric layer encapsulating the two transmission strips.

25. The RFID antenna of claim 21, further comprising a ground plane, wherein the dielectric layer is between the ground plane and the two transmission strips.

26. The RFID antenna of claim 25, further comprising a second dielectric layer encapsulating the two transmission strips.

27. An RFID antenna for use in a printer system for printing RFID labels, the system including an RFID reader coupled to the RFID antenna and RFID labels passing in close proximity to the RFID antenna, the RFID antenna comprising:

a dielectric layer;

two parallel transmission strips located above a top surface of the dielectric layer; and

a phase splitter coupled between the two transmission strips; and

two resistors each coupled between the ends of the two transmission strips and a printed circuit board ground plane.

28. The RFID antenna of claim 27, wherein the phase splitter is coupled to the other ends of the two transmission strips.

29. An RFID antenna for use in a printer system for printing RFID labels, the system including an RFID reader coupled to the RFID antenna and RFID labels passing in close proximity to the RFID antenna, the RFID antenna comprising:

a dielectric layer;

two non-overlapping parallel transmission strips located above a top surface of the dielectric layer; and

a phase splitter coupled between the two transmission strips.