Radio frequency identification tag and method

• US RE37,956 E1
• Filed: 08/22/1997
• Issued: 01/07/2003
• Est. Priority Date: 01/11/1994
• Status: Expired due to Fees

• Current Assignee: C W Over Solutions Incorporated
• Original Assignee: C W Over Solutions Incorporated
• Inventors: Blama, Michael J.
• Primary Examiner(s): Frech, Karl D.
• Application Number:
  US08/916,572
• Time in Patent Office: 1,964 Days
• Field of Search: 235/435, 235/492, 235/494, 235/487, 333/175, 333/185, 333/219, 343/895, 361/301.2, 361/763, 361/765, 361/782, 361/766, 361/821
• US Class Current: 235/435
• CPC Class Codes: G06K 19/0672 with resonating marks

Abstract

A method of and apparatus for identifying an item to or with which a radio frequency identification tag is attached or associated is provided. The tag is made of a nonconductive material to have a flat surface on which a plurality of circuits are pressed, stamped, etched or otherwise positioned. Each circuit has a capacitance and an inductance. The capacitance is formed from the capacitive value of a single capacitor. The inductance is formed from the inductive value of a single inductor coil having two conductive ends each connected to the capacitor. Each tag is associated with a binary number established from a pattern of binary ones and zeros which depend on the resonance or nonresonance of each circuit, respectively and the circuits position with respect to the binary table. The binary number may be converted to a decimal number using the binary table for conversion.

Claims

1. A tag which uses radio frequency waves transmitted from a scanning device in order to identify an item to which said tag is attached or with which said tag is associated comprising:

an insulating layer having a top surface, a bottom surface, and side surfaces;

thin conductive metallic means adjacent either said top surface or said bottom surface of said tag for forming a plurality of circuits, wherein each circuit of said plurality of circuits has a unique resonant frequency formed by one-to-one correspondence of a capacitance made up of a single capacitor and an inductance made up of a single inductor coil having two conductive ends with a first conductive end being connected to said single capacitor in order for said inductor coil to wind around said capacitor to end in a second conductive end which crosses said single inductor coil in a layer above said inductor coil so that said second conductive end is above said inductor coil and separated from said inductor coil by an insulated layer in order for said second conductive end to connect to said capacitor to close each said circuit without shorting out the circuit; and

wherein said tag is associated with a binary number established by a pattern of ones and zeros depending on each circuits'"'"' resonance or nonresonance, respectively, and each circuits'"'"' position on said tag with respect to a binary table.

2. The tag as in claim 1 wherein said capacitor is a dielectric dot.

3. The tag as in claim 2 wherein said inductor coil is made from a conductive material.

4. The tag as in claim 3 wherein said conductive ends of said inductor coil are connected to said capacitor in such a way so as to be in adjacent layers separated by an insulating material.

5. The tag as in claim 4 wherein said plurality of circuits are located on a surface of said tag at spaced intervals of a distance far enough apart so that adjacent circuits do not electronically interfere with each other.

6. The tag as in claim 5 wherein said tag associates a bit of information with each said circuit on said tag'"'"'s surface.

7. The tag as in claim 6 wherein said tag is made of a nonconductive material.

8. The tag as in claim 7 wherein said nonconductive material of said tag is paper.

9. The tag as in claim 8 wherein said paper tag is disposable.

10. The tag as in claim 7 wherein said nonconductive material is plastic.

11. The tag as in claim 10 wherein said plastic tag is reusable.

12. The tag as in claim 7 wherein said pattern of binary ones and zeros is established by varying numbers and positions of circuits being left blank.

13. The tag as in claim 12 wherein said blank position on said tag was created by not printing or etching a circuit in a position where a circuit could have been printed or etched respectively.

14. The tag as in claim 13 wherein said pattern of binary ones and zeros is established by disabling a circuit on said tag.

15. The tag as in claim 7 wherein said nonconductive material of said tag is glass.

16. The tag as in claim 15 wherein said glass is located in a window of an automobile or other vehicle.

17. A method of identifying an item to or with which a radio frequency identification tag is attached or associated, respectively, comprising the method steps of:

providing said radio frequency identification tag having a top surface, a bottom surface and side surfaces with a plurality of circuits each having a capacitance and an inductance both located on either said top surface or said bottom surface of said tag to form a one-to-one correspondence and to have a resonating frequency wherein said capacitance comprises a single capacitor and said inductance comprises a single inductor coil such that said inductor coil has two conductive ends with a first conductive end connected to said capacitor in order for said inductor coil to wind around said capacitor and end in a second conductive end which crosses said single inductor coil in a layer above said inductor coil so that said second conductive end is above said inductor coil and separated from said inductor coil by an insulated layer in order for said second conductive end to connect to said capacitor to close each said circuit without shorting out the circuit;

using a scanning device to interrogate said circuits by means of said scanner transmitting varying radio frequency waves at which said circuits may resonate; and

interrogating said circuits to establish a pattern of binary ones and zeros wherein a binary one is given to a resonant circuit and a binary zero a nonresonant circuit.

18. The method as in claim 17 wherein said step of providing a radio frequency identification tag with a plurality of circuits is accomplished by etching said surface of said tag which has been coated with a layer of conductive material.

19. The method as in claim 17 wherein said step of providing a radio frequency identification tag with a plurality of circuits is accomplished by printing onto or pressing into said surface of said tag a conductive material.

20. A resonant circuit including a single capacitor, a single inductor coil electrically connected to said single capacitor, and an insulating layer separating from each other portions of at least one of said single capacitor and said single inductor coil that cross over each other, and said single capacitor and said single inductor disposed on a same surface of a substrate.

21. A resonant circuit as in claim 20, wherein said resonant circuit is tuned by at least one of changing a mass of the single capacitor and changing a length of the single inductor coil.

22. A resonant circuit as in claim 20, wherein said resonant circuit is associated with a three-state system established by resonating at a high quality level, resonating at a low quality level, or not resonating.

23. A resonant circuit as in claim 20, wherein said single inductor coil includes first and second ends, and each of said first and second ends are connected to said capacitor.

24. A resonant circuit as in claim 20, wherein said single inductor coil is of a first width substantially narrower than a second width of said capacitor.

25. A resonant circuit as in claim 24, wherein said single inductor coil is of a first length substantially longer than a second length of said capacitor.

26. A resonant circuit as in claim 20, wherein said single inductor coil is of a first length substantially longer than a second length of said single capacitor.

27. A resonant circuit having two opposing sides including a single capacitor, and a single inductor coil electrically connected to said single capacitor, and said capacitor and said single inductor coil are located on the same side of a resonance tag and disposed on a common surface of a substrate, wherein the substrate is adjacent to one of said two opposing sides of said resonant circuit.

28. A resonant circuit as in claim 27, wherein said resonant circuit is tuned by at least one of changing a mass of the single capacitor and changing a length of the single inductor coil.

29. A resonant circuit as in claim 27, wherein said resonant circuit is associated with a three-state system established by resonating at a high quality level, resonating at a low quality level, or not resonating.

30. A resonant circuit as in claim 27, wherein said single inductor coil includes first and second ends, and each of said first and second ends are connected to said single capacitor.

31. A resonant circuit as in claim 27, wherein said single inductor coil is of a first width substantially narrower than a second width of said single capacitor.

32. A resonant circuit as in claim 31, wherein said single inductor coil is of a first length substantially longer than a second length of said single capacitor.

33. A resonant circuit as in claim 27, wherein said single inductor coil is of a first length substantially longer than a second length of said single capacitor.

34. A resonant circuit which resonates radio frequency waves transmitted from a scanning device and having a resonant frequency associated therewith, comprising:

35. A method of producing or manufacturing one or more resonant circuits disposed on a substrate of a radio frequency identification tag, comprising sequential, non-sequential or independent steps of:

36. The method as in claim 35, wherein at least one of said disposing steps is accomplished by etching the substrate of the radio frequency identification tag which has been coated with a layer of conductive material.

37. The method as in claim 35, wherein at least one of said disposing steps is accomplished by printing onto or pressing into the substrate of the radio frequency identification tag a conductive material.

38. A method of producing or manufacturing one or more resonant circuits including a single capacitor and a single inductor coil having first and second ends and each disposed on a same side of a substrate of a radio frequency identification tag, comprising sequential, non-sequential or independent steps of:

39. The method as in claim 38, wherein at least one of said disposing steps is accomplished by etching the substrate of the radio frequency identification tag which has been coated with a layer of conductive material.

40. The method as in claim 38, wherein at least one of said disposing steps is accomplished by printing onto or pressing into the substrate of the radio frequency identification tag a conductive material.