SYSTEM AND METHOD FOR READING ONE OR MORE RFID TAGS IN A METAL CASSETTE WITH AN ANTICOLLISION PROTOCOL

• US 20120075074A1
• Filed: 03/23/2010
• Published: 03/29/2012
• Est. Priority Date: 03/23/2009
• Status: Active Grant

• Current Assignee: SATYAtek SA (Steris PLC)
• Original Assignee: SATYAtek SA (Steris PLC)
• Inventors: Frosch, Reinhold, Zielasch, Andreas, Gehrig, Nicolas
• Granted Patent: US 9,727,757 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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 7/10435 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: H01Q 1/2216 used in interrogator/reader equipment
• 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

Abstract

Reading apparatus for objects each bearing at least one RFID tag, said objects being placed in a cassette that can also be furnished with an RFID tag, said system comprising at least one element in the form of a tunnel in which said cassette can be placed, said element comprising at least one antenna and one RFID reader, said antenna comprising at least two coils composed of several turns, said coils being distributed along and around said tunnel.

Claims

1. A reading apparatus for objects with at least one RFID tag, said objects being placed in a cassette which may also be RFID tagged, said apparatus comprising at least one tunnel-shaped element into which said cassette may be placed, said element comprising at least one antenna and an RFID reader, said antenna comprising at least two coils consisting of several windings, said coils being distributed along and around said tunnel

2. The reading apparatus according to claim 1, comprising at least the following functional modules:

AC coding of the tag signal;

digital processing of the signal for detecting collisions at the level of each bit;

specific algorithm for a rapid and reliable detection of all the tags within the field;

I/Q demodulator with adaptive sampling.

3. The apparatus according to claim 1 which reads one or several low-frequency tags which are rod-shaped and have an anti-collision protocol and which are attached to or incorporated into objects consisting of metal and/or synthetic materials, said objects being disposed in a direction within a range of +/−

45°

in relation to the main axis of the tunnel, perpendicular to the direction of the coils.

4. The apparatus according to claim 1, wherein the antenna comprises at least three coils.

5. The apparatus according to claim 1, wherein the outer coils each comprise at least 25 windings.

6. The apparatus according to claim 1, wherein the inner coil(s) comprise(s) as many windings as the outer coils or fewer windings than the outer coils.

7. The apparatus according to claim 1, wherein the wire forming the antenna is a copper wire having a diameter of less than 1 mm.

8. The apparatus according to claim 1, wherein the coils are approximately perpendicular to the tunnel'"'"'s axis.

9. An RFID reading system comprising at least one apparatus according to claim 1 and at least one cassette which may contain RFID-tagged objects.

10. The system according to claim 9, wherein the cassette/s is/are closed.