Article management system

• US 10,049,239 B2
• Filed: 06/19/2017
• Issued: 08/14/2018
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hattori, Wataru, Ohashi, Keishi
• Primary Examiner(s): Nguyen, Nam V
• Application Number:
  US15/626,338
• Publication Number:
  US 20170293779A1
• Time in Patent Office: 421 Days
• Field of Search: 3405721, 3405727, 340 101- 105, 340 1326, 705 22, 705 28, 235492, 235493, 235435
• CPC Class Codes: B65G 2203/046 RFID
• CPC Class Codes: G06K 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device
• 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 7/10415 the interrogation device being fixed in its position, such as an access control device for reading wireless access cards, or a wireless ATM banking machines in general G07F19/00
• CPC Class Codes: G06Q 10/0833 Tracking
• CPC Class Codes: G06Q 10/0875 Itemisation or classification of parts, supplies or services, e.g. bill of materials

Abstract

An article management system according to the present invention includes: a reader antenna (102) including an open-type transmission line terminated in an impedance matched state; an RF tag (104) that is placed at a location that is electromagnetically coupled to the reader antenna (102) and is visible from the reader antenna (102) in a state where a management target article (105) is placed in the vicinity of the RF tag; a management target article arrangement region in which the management target article (105) is placed, the management target article arrangement region being set in a location where the management target article (105) is electromagnetically coupled to a tag antenna of the RF tag (104); and an RFID reader (103) that sends a transmitted signal to the reader antenna (102) and receives a response signal output from the tag antenna via the reader antenna (102). The presence or absence of the management target article (105) is detected by detecting a change in operating characteristics of the tag antenna due to the management target article based on a change in intensity or phase of a reflected signal from the RF tag (104).

Claims

1. A radio frequency identification (RFID) system comprising:

a reader antenna comprising an open-type transmission line terminated in an impedance-matched state, the reader antenna being configured to transmit and receive a radio signal;

a radio frequency (RF) tag disposed in a predetermined place within an area where the RF tag is electromagnetically coupled to the reader antenna, the RF tag being configured so that a signal intensity of a reflected signal to be output is decreased when a distance between the RF tag and an article becomes equal to or smaller than a predetermined distance; and

an RFID reader connected to the reader antenna and configured to read tag information specific to the RF tag based on the reflected signal whose intensity is equal to or larger than a predetermined signal intensity, and

the article is arranged in a region other than a region sandwiched between the reader antenna and the RF tag.

2. The RFID system according to claim 1, wherein the RFID reader communicates with the RF tag by using a radio signal in a UHF band or a microwave band.

3. The RFID system according to claim 1, wherein a plurality of RF tags are provided for one open-type transmission line, each of the RF tags being disposed in a place where the RF tag is electromagnetically coupled to the open-type transmission line included in the reader antenna.

4. The RFID system according to claim 1, wherein tag information held by the RF tag is associated with the place where that tag is disposed.

5. The RFID system according to claim 1, wherein

assuming that a wavelength of a signal used for communication between the RFID reader and the RF tag is represented by λ

and a first distance between the article and a tag antenna is represented by L1, the article is placed at a location where a relationship of L1≤

λ

is satisfied,

assuming that a second distance that is a line-of-sight distance between the reader antenna and the tag antenna is represented by L2, the RF tag is placed at a location where a relationship of L2≤

λ

is satisfied, and

the first distance and the second distance satisfy a relationship of L2>

L1.

6. An article management system comprising:

a reader antenna comprising an open-type transmission line terminated in an impedance-matched state, the reader antenna being configured to transmit and receive a radio signal;

a radio frequency (RF) tag disposed in a predetermined place within an area where the RF tag is electromagnetically coupled to the reader antenna, the RF tag being configured so that a signal intensity of a reflected signal to be output is decreased when a distance between the RF tag and an article becomes equal to or smaller than a predetermined distance; and

a radio frequency identification (RFID) reader connected to the reader antenna, wherein

the article is arranged in a region other than a region sandwiched between the reader antenna and the RF tag, and

the RFID reader detects the article to be managed by detecting a change in intensity or a phase of the reflected signal from the RF tag, the article to be managed being adjacent to a near-field of the RF tag.

7. The article management system according to claim 6, wherein the near-field is a reactive near-field.

8. The article management system according to claim 6, wherein

assuming that a wavelength of a signal used for communication between the RFID reader and the RF tag is represented by λ

and a first distance between the article and a tag antenna is represented by L1, the article is placed at a location where a relationship of L1≤

λ

is satisfied,

assuming that a second distance that is a line-of-sight distance between the reader antenna and the tag antenna is represented by L2, the RF tag is placed at a location where a relationship of L2≤

λ

is satisfied, and

the first distance and the second distance satisfy a relationship of L2>

L1.

9. A human body detection system comprising:

a reader antenna comprising an open-type transmission line terminated in an impedance-matched state, the reader antenna being configured to transmit and receive a radio signal;

a radio frequency (RF) tag disposed in a predetermined place within an area where the RF tag is electromagnetically coupled to the reader antenna, the RF tag being configured so that a signal intensity of a reflected signal to be output is decreased when a distance between the RF tag and an article becomes equal to or smaller than a predetermined distance; and

a radio frequency identification (RFID) reader connected to the reader antenna, wherein

the article is arranged in a region other than a region sandwiched between the reader antenna and the RF tag, and

the RFID reader detects a human body by detecting a change in intensity or a phase of the reflected signal from the RF tag, the article to be managed being adjacent to a near-field of the RF tag.

10. The human body detection system according to claim 9, wherein the near-field is a reactive near-field.

11. The human body detection system according to claim 9, wherein

assuming that a wavelength of a signal used for communication between the RFID reader and the RF tag is represented by λ

and a first distance between the article and a tag antenna is represented by L1, the article is placed at a location where a relationship of L1≤

λ

is satisfied,

assuming that a second distance that is a line-of-sight distance between the reader antenna and the tag antenna is represented by L2, the RF tag is placed at a location where a relationship of L2≤

λ

is satisfied, and

the first distance and the second distance satisfy a relationship of L2>

L1.