Article sorting system

• US 5,793,305 A
• Filed: 09/29/1995
• Issued: 08/11/1998
• Est. Priority Date: 04/03/1991
• Status: Expired due to Term

• Current Assignee: Tagsys Australia Pty Limited
• Original Assignee: Leigh Holbrook Turner, Peter Harold Cole
• Inventors: Cole, Peter Harold, Turner, Leigh Holbrook
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): MERZ, EDWARD W
• Application Number:
  US08/536,204
• Time in Patent Office: 1,047 Days
• Field of Search: 340/825.54, 340/572, 342/44, 342/51
• US Class Current: 340/10.34
• CPC Class Codes: B07C 3/18 Devices or arrangements for indicating destination, e.g. by code marks applying data to information carriers G06K1/12
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• 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 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• 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
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: G06K 7/10435 the interrogation device being positioned close to a conveyor belt or the like on which moving record carriers are passing conveying in accordance with bodily destination marks, see B65G47/46, sorting of objects carrying identity markings, see B07C5/34
• CPC Class Codes: G07B 15/00 Arrangements or apparatus for collecting fares, tolls or entrance fees at one or more control points handling coins or valuable papers, e.g. banknotes, G07D; apparatus for vending or hiring articles or services activated by coins, credit cards, paper currency or the like G07F7/00, G07F17/00
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 13/2434 Tag housing and attachment details
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: G08B 13/2448 Tag with at least dual detection means, e.g. combined inductive and ferromagnetic tags, dual frequencies within a single technology, tampering detection or signalling means on the tag
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00
• CPC Class Codes: G08B 13/2471 Antenna signal processing by receiver or emitter
• CPC Class Codes: G08B 13/2474 : Antenna or antenna activator geometry, arrangement or layout loop antennae H01Q1/22
• CPC Class Codes: G08B 13/2485 : Simultaneous detection of multiple EAS tags
• CPC Class Codes: H01Q 7/00 : Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/285 : Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An identification system having an electronic label for processing articles such as baggage or carrier cargo. The system uses the principle of electromagnetic communication in which an interrogator containing a transmitter generates an electromagnetic field through which the electronic label containing a label receiving antenna may pass. The electronic label is attached to the article being processed and includes means for sensing the electromagnetic field and means for generating intermittently repeated label reply signals. The system includes a receiver for detecting and decoding the label reply signal. The electronic label replies intermittently as long as it is within the electromagnetic field, and the field is maintained for a period of time which is greater than the time interval between the intermittently repeated label replies. The electronic label also includes means for determining the interval between the intermittently repeated label reply signals without reference to timing signals external to the label. The interval between label reply signals varies from label to label and is greater than the time required for a label reply.

Claims

1. An identification and telemetry system comprising

an interrogator including a transmitter for generating an interrogation signal at an interrogation signal frequency and a receiver for detecting and decoding a reply signal;

an interrogation field creation and confinement means including a transmitter antenna connected to the said transmitter for generating from said interrogation signal an interrogation electromagnetic field through which an object possessing a code responding label may pass;

said code responding label including a label receiving antenna for receiving from the interrogation field a label interrogation signal, means for generating a label reply signal, and means for generating from said label reply signal a reply electromagnetic field;

a receiver antenna connected to said receiver for receiving from said label reply electromagnetic field a reply signal;

wherein object entry and exit regions of said field creation and confinement means form at the interrogation signal frequency waveguides operating below their cut-off frequency.

3. An identification and telemetry system as claimed in claim 1 wherein said interrogation field creation and confinement means includes a magnetically permeable material in a metallically confined return flux path for the magnetic component of said interrogation field.

4. An identification and telemetry system as claimed in claim 1 wherein choke structures which inhibit flow of wall currents are placed in object entry and exit regions of said field creation and confinement means.

2. An identification and telemetry system comprising

an interrogator including a transmitter for generating an interrogation signal at an interrogation signal frequency and a receiver for detecting and decoding a reply signal;

an interrogation field creation and confinement means including a transmitter antenna connected to said transmitter for generating from said interrogation signal an interrogation electromagnetic field through which an object possessing a code responding label may pass;

said code responding label including a label receiving antenna for receiving from said interrogation field a label interrogation signal, a rectifier containing a diode and a reservoir capacitor for converting to do part of the energy supplied as ac via the label interrogation signal, means for generating a label reply signal, and means for generating from said label reply signal a reply electromagnetic field;

a receiver antenna connected to said receiver for receiving from said label reply field a reply signal;

wherein the interrogation signal frequency allows simultaneous use of a monolithically integrated rectifier diode, a monolithically integrated reservoir capacitor and said interrogation field creation and confinement means is such that object entry and exit regions form at the interrogation signal frequency waveguides operating below their cut-off frequency.

5. An identification and telemetry system comprising:

an interrogator containing a transmitter for generation of an interrogation signal at an interrogation signal frequency and a receiver for detection and decoding of a reply signal;

an interrogation region into and out of which objects possessing code responding labels may pass;

an interrogation field creation and confinement means including a transmitter antenna connected to the said transmitter and generating from the said interrogation signal an interrogation electromagnetic field in the said interrogation region;

said code responding labels including a label receiving antenna for receiving from the interrogation electromagnetic field a label interrogation signal, means for generating a label reply signal, and means for generating from that label reply signal a reply electromagnetic field; and

a receiver antenna connected to the said receiver and receiving from the label reply electromagnetic field a reply signal;

said interrogation field creation and confinement means including at least one metallic conduct surrounding said interrogation region and forming an aperture through which the objects gain entry to or exit from the said interrogation region, said aperture being of dimensions less than half of the electromagnetic wave length at the said interrogation frequency.

9. An identification and telemetry system as in claim 5 wherein the said field creation means includes rods or bars of magnetically permeable material placed within a metallic chamber or against the interior walls of a metallic tube.

10. An identification and telemetry system as in claim 5 in which the interrogation field and confinement means includes a magnetically permeable material in a metallically confined return flux path for the magnetic component of the interrogation electromagnetic field.

14. An identification and telemetry system as in claim 5, wherein the interrogation field and confinement means contains a plurality of transmitter antennas and the signals in the said transmitter antennas are adjusted in amplitude and phase so as to reduce stray electromagnetic fields generated in the region external to that in which interrogation of labels is intended to occur.

15. An identification and telemetry system as in claim 5 in which the interrogation field is provided by a plurality of transmitter antennas creating overlapping and interfering fields within the field creation and confinement means.

16. An identification and telemetry system as in claim 5 wherein the said conductor contains a gap providing a pair of terminals for connection to the said transmitter.

18. An identification and telemetry system as in claim 5 in which the interrogation field is provided by a pair of loop antennas configured on a common axis and carrying oppositely phased currents at the interrogation signal frequency.

6. An identification and telemetry system comprising:

an interrogator containing a transmitter for generation of an interrogation signal at an interrogation signal frequency and a receiver for detection and decoding of a reply signal;

an interrogation region into and out of which objects possessing code responding labels may pass;

an interrogation field creation and confinement means including a transmitter antenna connected to the said transmitter and generating from the said interrogation signal an interrogation electromagnetic field in the said interrogation region;

said code responding labels including a label receiving antenna for receiving from the interrogation electromagnetic field a label interrogation signal, means for generating a label reply signal, and means for generating from that label reply signal a reply electromagnetic field; and

a receiver antenna connected to the said receiver and receiving from the label reply electromagnetic field a reply signal;

said field creation and confinement means including a metallic walled tube of cross sectional dimensions less than half a wave length at the interrogation frequency.

7. An identification and telemetry system as in claim 6 wherein the object entry and exit portions of the interrogation field and confinement means form, at the interrogation signal frequency, waveguides operating below their cut-off frequency.

8. An identification and telemetry system as in claim 7 further choke means, disposed in the object entry and exit sections of the said field creation and confinement means, for inhibiting the flow of wall currents.

11. An identification and telemetry system comprising:

an interrogator containing a transmitter for generation of an interrogation signal at an interrogation signal frequency and a receiver for detection and decoding of a reply signal;

an interrogation region into and out of which objects possessing code responding labels may pass;

an interrogation field creation and confinement means including a transmitter antenna connected to the said transmitter and generating from the said interrogation signal an interrogation electromagnetic field in the said interrogation region;

said code responding labels including a label receiving antenna for receiving from the interrogation electromagnetic field a label interrogation signal, means for generating a label reply signal, and means for generating from that label reply signal a reply electromagnetic field; and

a receiver antenna connected to the said receiver and receiving from the label reply electromagnetic field a reply signal;

said interrogation signal frequency allowing the simultaneous use of a monolithically integrated rectifier diode, a monolithically integrated reservoir capacitor and a field creation and confinement means containing a metallic walled tube of cross sectional dimensions less than half a wave length at the interrogation frequency.

12. An identification and telemetry system as in claim 11 wherein the object entry and exit portions of the interrogation field and confinement means form at the interrogation signal frequency waveguides operating below their cut-off frequency.

13. An identification and telemetry system as in claim 12, wherein the system contains a stray field cancellation means connected to the interrogator, receiving from the interrogator a signal at the interrogation frequency and creating, in the region external to the interrogation field and confinement means, a cancellation electromagnetic field so as to cancel in that region the stray electromagnetic field which emerges from the said field creation and confinement means, the signals delivered to the stray field cancellation means being adaptively adjusted to minimize the stray electromagnetic field emerging from the said field creation means.

17. An identification and telemetry system comprising:

an interrogator containing a transmitter for generation of an interrogation signal at an interrogation signal frequency and a receiver for detection and decoding of a reply signal;

an interrogation region into and out of which objects possessing code responding labels may pass;

an interrogation field creation and confinement means including a transmitter antenna connected to the said transmitter and generating from the said interrogation signal an interrogation electromagnetic field in the said interrogation region;

said code responding labels including a label receiving antenna for receiving from the interrogation electromagnetic field a label interrogation signal, means for generating a label reply signal, and means for generating from that label reply signal a reply electromagnetic field;

a receiver antenna connected to the said receiver and receiving from the label reply electromagnetic field a reply signal; and

said interrogation field creation and confinement means contains at least one metallic conductor surrounding said interrogation region, and forming an aperture through which the objects gain entry to or exit from the said interrogation region, said aperture being of dimensions less than half of the electromagnetic wave length at the said interrogation frequency, and the said conductor including a plurality of gaps across which are connected a plurality of series resonating capacitors.