Electronic tag authentication device and communication adjustment method with electronic tag

• US 7,388,499 B2
• Filed: 11/23/2004
• Issued: 06/17/2008
• Est. Priority Date: 07/30/2004
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kai, Manabu, Hayashi, Hiroyuki, Maniwa, Toru, Andrenko, Andrey
• Primary Examiner(s): GOINS, DAVETTA WOODS
• Application Number:
  US10/995,661
• Publication Number:
  US 20060022884A1
• Time in Patent Office: 1,302 Days
• Field of Search: 340/572.7, 340/572.8, 340/572.1, 340/572.2, 340/10.1, 340/10.33, 340/539.13, 340/539.1, 340/572.4, 340/10.3, 342/432, 342/463, 342/464, 342/450, 342/383, 342/373, 343/700.MS, 343/853
• US Class Current: 340/572.7
• CPC Class Codes: H01Q 3/2623 composed of two antennas
• CPC Class Codes: H01Q 3/28 varying the amplitude
• CPC Class Codes: H01Q 3/40 with phasing matrix

Abstract

The electronic tag authentication device of the present invention authenticates the contents of an electronic tag attached to goods. The electronic tag authentication device comprises an antenna directivity change unit for changing the directivity of an antenna for transmitting/receiving electrical waves in order to authenticate the contents of the electronic tag.

Claims

1. An electronic tag authentication device, comprising:

an antenna directivity change unit for changing a directivity of an antenna for transmitting/receiving electrical waves in order to authenticate contents of an electronic tag attached to goods, wherein

said antenna comprises a plurality of element antennas; and

said antenna directivity change unit comprises, in accordance with the plurality of element antennas;

a plurality of power feeding units capable of adjusting the amplitude and phase of a power feeding signal supplied to each element antenna; and

a switching unit for changing the connection state between the plurality of power feeding units and the plurality of element antennas,

said power feeding units each comprise a phase shifter electrically controlled externally and a power divider,

said phase shifter is controlled by a computer through a control motor, and

said power divider comprises an impedance conversion unit controlled by a computer through a micro-electro-mechanical system unit.

2. The electronic tag authentication device according to claim 1, wherein said power feeding unit is composed of T-character type power feeding network.

3. The electronic tag authentication device according to claim 1, wherein said power feeding unit is composed of hybrid type power feeding network.

4. An adjustment method of communication between an electronic tag attached to goods and an electronic tag authentication device according to claim 1, the method comprising:

disposing goods whose tag content is known, inside a boundary of a reading range of an electronic tag authentication device; and

changing the directivity of the antenna of the relevant electronic tag authentication device in such a way that the known tag contents can be correctly read during an operation of another electronic tag authentication device whose reading target is a range adjacent to said reading range.