Air Coil a security badge and a transponder

• US 5,867,100 A
• Filed: 07/11/1996
• Issued: 02/02/1999
• Est. Priority Date: 10/27/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: D'Hont, Loek J.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/678,338
• Time in Patent Office: 936 Days
• Field of Search: 340/572, 29/825, 29/33 R, 29/600, 29/601, 342/42, 342/44, 342/51, 343/866, 343/895, 235/492, 336/170, 336/171
• US Class Current: 340/572.1
• CPC Class Codes: G06K 19/07718 the record carrier being manufactured in a continuous process, e.g. using endless rolls
• 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 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07781 the coil being fabricated in a winding process
• CPC Class Codes: G08B 13/244 Tag manufacturing, e.g. continuous manufacturing processes
• CPC Class Codes: H01F 30/08 without magnetic core
• CPC Class Codes: H01F 41/043 by thick film techniques
• CPC Class Codes: H01F 5/00 Coils superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

In one aspect, the present invention provides an air coil 20. The air coil 20 may be made from a strip of electrically conductive material 22 which has an insulating material overlying it. For example, the conductive material may comprise copper. The strip 22 is wound into a coil to perform a plurality of windings. The insulating material electrically insulates each of the windings from adjacent ones of the windings.

Claims

1. An air coil comprising:

a. a strip of electrically conductive material having a generally rectangular cross-section to present a substantially flat inward facing surface and to present a substantially flat outward facing surface, the strip of conductive material being wound in a spiral coil of over lapping windings with the inward facing surface of one winding facing the outward facing surface of the previous winding; and

b. an insulating material arranged between the windings of the strip of conductive material electrically to insulate the inward facing surface of each one winding from the outward facing surface of the previous winding, the insulating material adhering to the inward facing surface of each one winding and the outward facing surface of the previous winding to form the coil into a fixed, self-supporting component.

2. The coil of claim 1 in which the insulating material is a strip of insulating material.

3. The coil of claim 1 in which the insulating material is a coating of insulating material.

4. The coil of claim 1 in which the strip of conductive material has a width of about 350 micrometers.

5. An air coil comprising:

a. a strip of electrically conductive material having a generally rectangular cross-section to present a substantially flat inward facing surface and to present a substantially flat outward facing surface, the strip of conductive material being wound in a spiral coil of over lapping windings with the inward facing surface of one winding facing the outward facing surface of the previous winding; and

b. a strip of insulating material arranged between the windings of the strip of conductive material electrically to insulate the inward facing surface of each one winding from the outward facing surface of the previous winding, the strip of insulating material having a width greater than the width of the strip of conductive material and the margins of the insulating material extending beyond the margins of the strip of conductive material, the margins of the insulating material extending beyond the margins of the strip of conductive material on at least one side of the conductive material being joined together to form the coil into a fixed, self-supporting component.

6. The coil of claim 5 in which the margins of the insulating material are joined together on both sides of the conductive material.

7. The coil of claim 5 in which the insulating material is a heat deformable plastic.

8. The coil of claim 5 in which the strip of conductive material has a width of about 350 micrometers.

9. A security badge comprising:

a. an air coil including;

i. a strip of electrically conductive material having a generally rectangular cross-section to present a substantially flat inward facing surface and to present a substantially flat outward facing surface, the strip of conductive material being wound in a spiral coil of over lapping windings with the inward facing surface of one winding facing the outward facing surface of the previous winding, the strip of conductive material having opposed ends; and

ii. an insulating material arranged between the windings of the strip of conductive material electrically to insulate the inward facing surface of each one winding from the outward facing surface of the previous winding, the insulating material adhering to the inward facing surface of each one winding and the outward facing surface of the previous winding to form the coil into a fixed, self-supporting component;

b. a transponder circuits electrically connected to the opposed ends of the air coil; and

c. a laminated card containing the air coil and transponder unit.

10. The security badge of claim 9 in which the transponder circuits are disposed inside the spiral of the air coil.

11. The security badge of claim 9 in which the transponder circuits are disposed outside the spiral of the air coil.

12. The security badge of claim 9 in which the card has a thickness of about 0.79 millimeters.

13. A transponder unit comprising:

a. transponder circuits having at least a pair of terminals; and

b. an air coil including;

i. a strip of electrically conductive material having a generally rectangular cross-section to present a substantially flat inward facing surface and to present a substantially flat outward facing surface, the strip of conductive material being wound in a spiral coil of over lapping windings with the inward facing surface of one winding facing the outward facing surface of the previous winding, the strip of conductive material having opposed ends connected to the pair of terminals; and

ii. an insulating material arranged between the windings of the strip of conductive material electrically to insulate the inward facing surface of each one winding from the outward facing surface of the previous winding, the insulating material adhering to the inward facing surface of each one winding and the outward facing surface of the previous winding to form the coil into a fixed, self-supporting component.