Interrogator and goods management system adopting the same

• US 7,164,380 B2
• Filed: 08/31/2001
• Issued: 01/16/2007
• Est. Priority Date: 05/22/2001
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Saito, Takeshi
• Primary Examiner(s): Gregory; Bernarr E.
• Application Number:
  US09/942,723
• Publication Number:
  US 20020175804A1
• Time in Patent Office: 1,964 Days
• Field of Search: 342 29- 51, 342/175, 342/195, 343790-792, 343/795, 340/501, 340/505, 340 101- 106, 340/870.18, 340/568.1, 3405721-5729
• US Class Current: 342/42
• 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: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

An interrogator with an antenna that allows information exchanges with multiple transponders in a shorter distance of communication, by securing an intensified and uniform electromagnetic energy concentrated on areas near antenna elements. The interrogator is furnished with a sleeve antenna that includes a monopole conductor of ¼ wavelength (free space wavelength) continuously connected to a core wire of a coaxial cable on one end thereof, and a feed point on the other end, in which the sleeve antenna is grounded at the feed point. The interrogator has a plurality of the transponders arrayed near the antenna, and a plurality of the antennas selected by RF signal selectors. The interrogator antenna allows movable body identification such as in a goods management system for identifying multiply arrayed goods.

Claims

1. An interrogator that forms movable body identification equipment together with plural transponders, comprising:

plural sleeve antennas provided as an antenna that executes an information exchange with the plural transponders by a radio communication using a microwave band;

a transmitting circuit that modulates data into an RF signal, the RF signal being transmitted out via said plural sleeve antennas;

a receiving circuit that receives signals via said plural sleeve antennas; and

RF signal selectors that select one of said plural sleeve antennas, each of the RF signal selectors being in correspondence with each of said plural sleeve antennas.

2. An interrogator according to claim 1, wherein a switching signal to drive the RF signal selector is created on the basis of a pulse count signal being superposed on an RF signal outputted from the interrogator.

3. An interrogator according to claim 1, further comprising an indicator that operates synchronously with the RF signal selector, in combination with the selector.

4. An interrogator according to claim 1, further comprising a sound source that operates synchronously with the RF signal selector, in combination with the selector.

5. An interrogator according to claim 1, wherein the transponders of a flat rectangular shape are arrayed close to said plural sleeve antennas.

6. An interrogator according to claim 1, wherein the plural sleeve antennas are divided into plural antenna groups, and an RF signal from the interrogator is supplied in parallel to the plural antenna groups.

7. An interrogator according to claim 1, wherein the plural sleeve antennas are divided into plural antenna groups, and an RF signal from the interrogator is supplied in parallel to the plural antenna groups, through another RE signal selector that selects one group of the plural antenna groups.

8. An interrogator that forms movable body identification equipment together with plural transponders, comprising:

plural sleeve antennas provided as an antenna that executes an information exchange with the plural transponders by a radio communication using a microwave band;

a transmitting circuit that modulates data into an RF signal, the RF signal being transmitted out via plural sleeve antennas;

a receiving circuit that receives signals via said plural sleeve antennas; and

a grounded conductive plate disposed close to said plural sleeve antennas, on a side opposite to a side on which the transponders related to said plural sleeve antennas are disposed; and

RF signal selectors that select one of the plural sleeve antennas, each of the RF signal selectors being in correspondence with each of said plural sleeve antennas.

9. An interrogator according to claim 8, wherein the transponders of a flat rectangular shape are arrayed close to said plural sleeve antennas.

10. A goods management system comprising:

plural transponders of a flat rectangular shape that are each attached on sides of each of plural goods;

an interrogator that executes an information exchange with the plural transponders by a radio communication using a microwave band; and

a management terminal that controls the plural goods, using information from the interrogator acquired by the information exchange;

wherein the interrogator includes;

plural sleeve antennas for exchanging information with the plural transponders;

a grounded conductive plate disposed close to the plural sleeve antennas, on a side opposite to a side on which the plural transponders related to the plural sleeve antennas are disposed; and

RF signal selectors that select one of the plural sleeve antennas, and

wherein the transponders are arrayed close to the plural sleeve antennas.

11. A goods management system according to claim 10, wherein the plural sleeve antennas are divided into plural antenna groups, and an RF signal from the interrogator is supplied in parallel to the plural antenna groups, through another RF signal selector that selects one group of the plural antenna groups.

12. A goods management system according to claim 11, further comprising an indicator that operates synchronously with the RF signal selector and another RF signal selector, in combination with the selector and another selector.

13. A goods management system according to claim 11, further comprising a sound source that operates synchronously with the RF signal selector and another RF signal selector, in combination with the selector and another selector.