Electronic identification system extended-range reader

• US 6,414,597 B1
• Filed: 06/21/1996
• Issued: 07/02/2002
• Est. Priority Date: 06/21/1996
• Status: Expired due to Fees

• Current Assignee: Avid Marketing Incorporated
• Original Assignee: Avid Marketing Incorporated
• Inventors: Lu, Gui-Yang, Wooldridge, Sammy E.
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US08/667,418
• Time in Patent Office: 2,202 Days
• Field of Search: 340/825.69, 340/825.72, 340/825.54, 340/572, 340/573, 340/10.1, 340/572.7, 235/380
• US Class Current: 340/572.7
• 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 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22

Abstract

An extended-range reader for use in identifying the tag of an object. The reader includes a winding of conducting wire for generating an interrogating magnetic field. The winding may be either a coil assembly consisting of a plurality of coils spaced at intervals along a common axis or a solenoid. The winding is limited to those having values of D/L less than four where D is the smallest transverse dimension of the winding and L is the length. The winding is adapted to receive a structure within the winding for providing objects a passageway through the winding. The axis of the winding may be either straight or curved. To improve the magnetic field generating capability of the winding, a magnetic shunt encircling the winding can be added. Also included is a structure within the winding for providing objects a passageway through the winding, the structure having openings for object ingress and egress. Where the structure is intended to provide a natural environment for the objects, the structure, except for the openings, can be made pervious or impervious to liquids or gases.

Claims

1. A reader for use in identifying an object, the reader comprising:

a winding of conducting wire selected from the group consisting of (1) a coil assembly consisting of a plurality of electrically-connected coils spaced at intervals along a common axis, the coil assembly having a length L, the smallest transverse dimension of the coil assembly being D, and (2) a solenoid having a length L, the smallest transverse dimension of the solenoid being D, the value of D/L for the winding being less than four, the winding being adapted to receive a structure within the winding for providing objects a passageway through the winding.

2. The reader of claim 1 wherein the axis of the winding is straight, the axis of the winding being a line that passes through the centroids of the cross-sectional areas of the winding along the length of the winding.

3. The reader of claim 1 wherein the axis of the winding is curved, the axis of the winding being a line that passes through the centroids of the cross-sectional areas of the winding along the length of the winding.

4. The reader of claim 1 wherein the winding comprises a coil assembly.

5. The reader of claim 1 wherein the winding comprises a solenoid.

6. The reader of claim 1 further comprising:

a magnetic shunt encircling the winding.

7. The reader of claim 1 further comprising:

a structure within the winding for providing objects a passageway through the winding, the structure having openings for object ingress and egress.

8. The reader of claim 7 wherein the structure, except for the openings, is impervious to liquids.

9. The reader of claim 7 wherein the structure, except for the openings, is impervious to gases.

10. The reader of claim 7 wherein the structure is pervious to gases.