US 7,605,699 B2 · System and method for location recognition using IC tags

Abstract

Locations of IC tags affixed to items are automatically recognized without requiring interrogators or antennas are allocated at respective inventory locations. To attain this object, interrogator 1 firstly transmits a unique ID readout command specifying read range, and corresponding IC tags 2a, 2b, 2c sequentially reply their unique IDs (Xa), (Xb), (Xc) respectively. At the same time, interrogator 1 transmits a probe signal send out command specifying ID, and corresponding IC tags 2a, 2b, 2c sequentially send out probe signals respectively. IC tag 2 that detects a probe signal with reception strength more than a predetermined level stores in its memory IDs (Xa), (Xb), (Xc) that interrogator 1 specified as adjacent ID. Then, interrogator 1 transmits an adjacent ID readout command specifying ID, and corresponding IC tags 2a, 2b, 2c sequentially reply adjacent IDs (Xb), (Xa.Xc), (Xb) stored in their memory respectively. Lastly, all possible combinations (Xa-Xb), (Xb-Xa), (Xb-Xc), (Xc-Xb) of unique IDs (Xa), (Xb), (Xc) and adjacent IDs (Xb), (Xa.Xc), (Xb) that controller 3 has collected via interrogator 1 are obtained and any identical combinations are excluded so that (Xa-Xb), (Xb-Xc) remain as final combinations, and the final combinations having one side in common are joined to produce a link pattern of ID information. Thus, it is understood that IC tags 2a, 2b, 2c exist in the same communication area B, and are arranged in order of 2a, 2b, 2c.

Claims9

Dependent claims

A system for location recognition using IC tags, wherein an interrogator makes a first communication with multiple IC tags existing in a communication area A by radio, and at the same time, one of said multiple IC tags makes a second communication with other IC tags existing in a communication area B (<A) by probe signals, the one of said multiple IC tags comprising:

a first responder that responds with own information Xa to the interrogator;
a transmitter that sends said probe signals to the other IC tags when own information Xa is specified by the interrogator;
a receiver that receives a probe signal sent out by one IC tag of the other IC tags whose information Xb is specified by the interrogator;
a storage that stores information Xb of the one IC tag of the other IC tags specified as a source IC tag by the interrogator in a memory when a reception strength of said probe signal is more than a predetermined level;
and
a second responder that responds with the information Xb of the source IC tag stored in the memory to the interrogator in response to a readout command,
wherein relative positions of said multiple IC tags are recognized from the information Xa and the information Xb collected via the interrogator and
wherein the storage stores the information Xb of the one IC tag of the other IC tags until the readout command is received, the readout command specifying the one of said multiple IC tags corresponding to information Xa.

5 more elements

Dependencies are inferred from the claim text.

System and method for location recognition using IC tags

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System and method for location recognition using IC tags

Life of this patent

Abstract

Claims9