Radio-Tag Reading System, Radio-Tag Reader, And Radio Tag

• US 20080088414A1
• Filed: 07/24/2004
• Published: 04/17/2008
• Est. Priority Date: 07/29/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Nagai, Yukimassa, Suga, Hiroyoshi
• Granted Patent: US 7,889,058 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08
• 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: H04B 1/59 Responders; Transponders

Abstract

To obtain a radio-tag reading system that can steadily make a detection area of a radio tag match with a communication area, and can start read of ID of the radio tag, which enters the communication area, at a high speed, in a condition that a plurality of radio tags enter the communication area of a radio-tag reader at a time.

The radio-tag reading system comprises a radio-tag reader 3 that includes a communication unit 31 that performs radio communication with a radio tag 2, a radio-tag detection processor 33 that allows the communication unit 31 to transmit a search signal for detecting the entrance of the radio tag 2 into a communication area in which the communication unit 31 can perform radio communication, at a predetermined time interval, to detect the entrance of the radio tag 2 into the communication area according to a response signal to the search signal, and a radio-tag information communication processor 34 that reads the radio tag information of the radio tag 2, upon receiving the response signal from the radio tag 2, and the radio tag 2 including a response processor 22 that, upon receiving a signal from the radio-tag reader 3, transmits a response signal to the signal.

Claims

1-15. -15. (canceled)

16. A radio-tag reading system comprising:

a radio tag that is configured to be attached to an object and stores therein radio tag information, the radio tag information being predetermined information on the object; and

a radio-tag reader that reads the radio tag information from the radio tag, and includes

a communicating unit that performs radio communication with the radio tag;

a radio-tag detecting unit that transmits via the communicating unit a search signal at predetermined time intervals, and detects at least one of movement of the radio tag into and out of a communication area where radio communication is available through the communicating unit based on a response signal to the search signal; and

a radio-tag information processing unit that reads the radio tag information from the radio tag upon receiving the response signal from the radio tag, wherein

the radio tag includes a responding unit that transmits, upon receiving a signal from the radio-tag reader, a response signal in response to the signal.

17. The radio-tag reading system according to claim 16, wherein

the radio-tag detecting unit generates the search signal that includes a command to reduce a transmission rate of the response signal by a predetermined percentage, and

the responding unit transmits the response signal while reducing the transmission rate by the predetermined percentage based on the command.

18. The radio-tag reading system according to claim 17, wherein the radio tag includes a plurality of radio tags.

19. The radio-tag reading system according to claim 18, wherein

the radio tag further stores therein priority information indicating priority among the radio tags,

the radio-tag detecting unit generates the search signal that includes a priority value specifying a priority of a radio tag which is required to respond to the search signal, and

the radio-tag information processing unit reads the radio tag information from radio tags in decreasing order of priority upon receiving response signals from the radio tags, and

the responding unit compares, upon receiving a signal from the radio-tag reader, the priority value contained in the signal with the priority information, and transmits a response signal in response to the signal when a predetermined condition is satisfied.

20. The radio-tag reading system according to claim 19, wherein

the radio tags include a first radio tag with a high priority and a plurality of second radio tags with a priority lower than that of the first radio tag, and

the radio-tag detecting unit sets the priority value that specifies the priority of the first radio tag.

21. The radio-tag reading system according to claim 19, wherein the radio-tag detecting unit transmits the search signal while changing the priority value until a response signal is received.

22. The radio-tag reading system according to claim 19, wherein the priority information is information that uniquely identifies the radio tag.

23. A radio-tag reader that performs radio communication with a radio tag attached to an object, and reads radio tag information from the radio tag, the radio tag information being predetermined information on the object stored in the radio tag, the radio-tag reader comprising:

a communicating unit that performs radio communication with the radio tag;

a radio-tag detecting unit that transmits via the communicating unit a search signal at predetermined time intervals, and detects at least one of movement of the radio tag into and out of a communication area where radio communication is available through the communicating unit based on a response signal to the search signal; and

a radio-tag information processing unit that reads the radio tag information from the radio tag upon receiving the response signal from the radio tag.

24. The radio-tag reader according to claim 23, wherein the radio-tag detecting unit generates the search signal that includes a command to reduce a transmission rate of the response signal by a predetermined percentage.

25. The radio-tag reader according to claim 23, wherein

the radio-tag detecting unit generates the search signal that includes a priority value specifying a priority of a radio tag which is required to respond to the search signal, and

the radio-tag information processing unit reads the radio tag information from radio tags in decreasing order of priority upon receiving response signals from the radio tags.

26. The radio-tag reader according to claim 25, wherein

the radio tag includes a first radio tag with a high priority and a plurality of second radio tags with a priority lower than that of the first radio tag, and

the radio-tag detecting unit sets the priority value that specifies the priority of the first radio tag.

27. The radio-tag reader according to claim 26, wherein the radio-tag detecting unit transmits the search signal while changing the priority value until a response signal is received.

28. A radio tag that is configured to be attached to an object, storing therein radio tag information being predetermined information on the object, and operates based on a radio signal from a radio-tag reader, the radio tag comprising:

a responding unit that transmits, upon receiving a search signal from the radio-tag reader, a response signal while reducing a transmission rate thereof by a predetermined percentage based on a command contained in the search signal.

29. A radio tag that is configured to be attached to an object, storing therein radio tag information being predetermined information on the object and priority information indicating priority among radio tags, and operates based on a radio signal from a radio-tag reader, the radio tag comprising:

a responding unit that compares, upon receiving a signal including a priority value specifying a priority of a radio tag which is required to respond to the signal, the priority value with the priority information, and responds to the signal when a predetermined condition is satisfied.

30. The radio tag according to claim 29, wherein the priority information is information that uniquely identifies the radio tag.