RFID reader/writer

• US 20070175995A1
• Filed: 04/13/2006
• Published: 08/02/2007
• Est. Priority Date: 01/27/2006
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Maniwa, Toru, Kimura, Shigekazu
• Application Number:
  US11/402,812
• Publication Number:
  US 20070175995A1
• Time in Patent Office: Days
• US Class Current: 235/451
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• 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: H04B 5/77 for interrogation

Abstract

A reader/writer 25 transmits an instruction for changing over between antennas 31 and 32, carried on a high frequency wave in the same format as a common command. A part of the antenna is equipped with a command interpretation circuit 30 which demodulates a high frequency wave received from the reader/writer body 25 and obtains a command content. If this command is an antenna changeover instruction of the reader/writer itself, the command interpretation circuit 30 instructs a changeover signal generation unit 28 for generating a changeover signal and changes over antennas by controlling a high frequency wave switch unit 29.

Claims

1. A radio frequency identification (RFID) reader/writer for communicating with an RFID tag, comprising:

a plurality of antennas for the purpose of communicating with an RFID tag from different directions;

a command transmission unit for setting, and transmitting, a changeover command for the antennas; and

an antenna changeover unit for changing over the antennas for use by interpreting the aforementioned command transmitted from the command transmission unit.

2. The radio frequency identification (RFID) reader/writer according to claim 1, wherein

said command transmission unit sets an antenna changeover command in data of a data format for the purpose of communicating with an RFID tag.

3. The radio frequency identification (RFID) reader/writer according to claim 1, comprising

an antenna identifier information retention unit for retaining identifier information of each antenna.

4. The radio frequency identification (RFID) reader/writer according to claim 3, wherein

said identifier information of each antenna is a unique information among different RFID reader/writers, and an antenna changeover is instructed for antennas of an RFID reader/writer other than the RFID reader/writer itself by using said antenna changeover command.

5. The radio frequency identification (RFID) reader/writer according to claim 4,

measuring an amount of radio waves, which are emitted from an RFID reader/writer other than the RFID reader/writer itself, leaking into the itself, and

instructing an antenna changeover of the aforementioned RFID reader/writer other than the RFID reader/writer itself if the amount of the leaking is larger than a predefined value.

6. An antenna changeover method for a radio frequency identification (RFID) reader/writer for communicating with an RFID tag by using a plurality of antennas,

changing over a plurality of antennas by carrying out an antenna changeover instruction transmitted by the same method as a communication with an RFID tag.