ARTICLE MANAGEMENT SYSTEM

• US 20160292977A1
• Filed: 10/23/2014
• Published: 10/06/2016
• Est. Priority Date: 11/11/2013
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: FUKUDA, Hiroshi
• Granted Patent: US 9,947,195 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10445 the record carriers being fixed to further objects, e.g. RFIDs fixed to packages, luggage, mail-pieces or work-pieces transported on a conveyor belt
• 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 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00
• CPC Class Codes: H01P 5/028 between strip lines
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/48 Earthing means; Earth screens; Counterpoises
• CPC Class Codes: H01Q 13/206 Microstrip transmission line antennas
• CPC Class Codes: H01Q 21/0037 linear waveguide fed arrays
• CPC Class Codes: H01Q 21/0075 Stripline fed arrays H01Q21/065 takes precedence
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

In conventional article management systems, a problem has been presented in that the degree of control over how articles are managed has not been adequate. An article management system having: a line constituted by an open-type transfer line; a distribution area in which articles to be managed are placed, the articles to be managed being placed in the distribution area; an RF tag provided with a tag transmission unit for electromagnetic coupling with the line of the distribution area for the articles to be managed; a signal communication unit provided to the line; an antenna for electromagnetic coupling with the signal communication unit; and an RFID reader for sending out the transmission signal to the line via the antenna, and receiving a response signal output by the tag transmission unit via the line. Any variations in the operating characteristics of the tag transmission unit caused by the articles to be managed are detected as a result of variations in the intensity or phase of the signal reflected from the RF tag, whereby the presence of an article to be managed is detected.

Claims

1. An article management system comprising:

a line constituted by an open-type transfer line terminated with matching termination, the line transmitting and receiving a radio signal;

a distribution area in which an article to be managed is placed, the article to be managed being placed in the distribution area;

an RF tag provided with tag transmission unit for electromagnetic coupling with the line of the distribution area for the article to be managed;

signal communication unit provided to one end of the line;

an antenna configured to perform non-contact signal communication with the signal communication unit; and

an RFID reader for sending out a transmission signal to the antenna, and receiving a response signal output by the tag transmission unit via the antenna,

wherein the RFID reader detects one of presence and absence of the article to be managed by detecting a variation in an operating characteristic of the tag transmission unit caused by the article to be managed as a result of a variation in one of an intensity and a phase of a signal reflected from the RF tag.

2. The article management system according to claim 1, wherein

letting λ

be a wavelength of a signal used for radio communication by the RFID reader and the RF tag, and L1 be a first distance between the article to be managed and the tag transmission unit, the distribution area for the article to be managed is set at a position that satisfies a relation L1≦

λ

, and

letting L2 be a second distance representing a line-of-sight distance between the line and the tag transmission unit the RF tag is set at a position that satisfies a relation L2≦

λ

.

3. The article management system according to claim 2, wherein the first distance satisfies a relation L1>

λ

/2π

, where π

is a ratio of a circumference of a circle to a diameter thereof.

4. The article management system according to claim 2, wherein the second distance satisfies a relation L2>

λ

/2π

, where π

is a ratio of a circumference of a circle to a diameter thereof.

5. The article management system according to claim 2, wherein the first distance and the second distance satisfy a relation L2>

L1.

6. The article management system according to claim 1, wherein a coupling coefficient k1 between the line and the tag transmission unit satisfies 10⁻

5≦

k1≦

10<sup>−

2</sup>.

7. The article management system according to claim 1, wherein a coupling coefficient k1 between the line and the tag transmission unit is smaller than a coupling coefficient k2 between the article to be managed and the tag transmission unit.

8. The article management system according to claim 1, further comprising an article management plate, wherein a grounding wire is placed on a back surface of the article management plate and connected to the line via a matching terminating resistor, the line is placed on a front surface of the article management plate in a mesh shape, the RF tag is placed at a position above the line, and the distribution area for the article to be managed is set at a position above the RF tag.

9. The article management system according to claim 1, further comprising an article management plate, wherein a grounding wire is placed on a back surface of the article management plate and connected to the line via a matching terminating resistor, the line and the grounding wire are alternately placed on a front surface of the article management plate with a spacing between the line and the grounding wire, the RF tag is placed at a position above the line, and the distribution area for the article to be managed is set at a position above the RF tag.

10. The article management system according to claim 1, further comprising an article management plate, wherein the line is placed on a lateral side of the RF tag, the RF tag is placed on a front surface of the article management plate, and the distribution area for the article to be managed is set at a position above the RF tag.

11. The article management system according to claim 1, wherein the antenna is opposed to the signal communication unit.

12. The article management system according to claim 1, wherein the antenna is set on a plane identical to a plane on which the signal communication unit is set.

13. The article management system according to claim 11, wherein

the antenna and the signal communication unit are formed by a rectilinear line, and

the antenna and the signal communication unit form a parallel-coupling transfer line coupler.

14. The article management system according to claim 11, wherein

the antenna and the signal communication unit are formed by an open ring-shaped line, and

the antenna and the signal communication unit form an open ring coupler.

15. The article management system according to claim 11, wherein

the antenna and the signal communication unit are formed by a spiral coil-shaped line, and

the antenna and the signal communication unit form a spiral coil coupler.

16. The article management system according to claim 1, further comprising shielding unit for electromagnetically shielding the antenna and the signal communication unit.