APPARATUS FOR COMMUNICATING WITH RFID TAG

• US 20100141395A1
• Filed: 01/22/2010
• Published: 06/10/2010
• Est. Priority Date: 09/25/2007
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: NAGAI, Takuya
• Application Number:
  US12/692,034
• Publication Number:
  US 20100141395A1
• Time in Patent Office: Days
• US Class Current: 340/10.400
• 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 7/10386 the interrogation device being of the portable or hand-handheld type, e.g. incorporated in ubiquitous hand-held devices such as PDA or mobile phone, or in the form of a portable dedicated RFID reader
• CPC Class Codes: H04B 5/0031 for data transfer
• CPC Class Codes: H04B 5/0062 in RFID [Radio Frequency Identification] Systems
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

The disclosure discloses an apparatus for communicating with an RFID tag, comprising; a radio communication device; a tag number estimation portion configured to estimate the number of RFID tag circuit elements in a peripheral area of said apparatus; a storage device configured to store a list of identification information of each of a plurality of said RFID tag circuit elements; and a mode switching portion configured to switch a mode into a plural tag detection mode in which identification information is sequentially specified in said list stored in said storage device before the RFID tag circuit element corresponding to the specified identification information is detected through said radio communication device, or a response determination mode in which identification information is obtained from each of all the RFID tag circuit elements in said peripheral area through said radio communication device before presence of each of the RFID tag circuit elements respectively corresponding to the identification information in said list is determined on the basis of the obtained identification information, according to an estimation result by said tag number estimation portion.

Claims

1. An apparatus for communicating with a radio frequency identification (RFID) tag, comprising;

a radio communication device configured to conduct radio communication with a plurality of RFID tag circuit elements, each of the RFID tag circuit elements having an IC circuit part storing information and a tag antenna capable of transmission and reception of the information;

a tag number estimation portion configured to estimate the number of said RFID tag circuit elements in a peripheral area of said apparatus;

a storage device configured to store a list of identification information of each of a plurality of said RFID tag circuit elements as search targets; and

a mode switching portion configured to switch a mode into a plural tag detection mode or a response determination mode on the basis of a estimation result by said tag number estimation portion, the plural tag detection mode being a mode in which identification information is sequentially specified in said list stored in said storage device before the RFID tag circuit element corresponding to the specified identification information is detected through said radio communication device, the response determination mode being a mode in which identification information is obtained from each of all the RFID tag circuit elements in said peripheral area through said radio communication device before presence of each of the RFID tag circuit elements respectively corresponding to the identification information in said list is determined on the basis of the obtained identification information.

2. The apparatus according to claim 1, wherein:

said mode switching portion switches a mode into said plural tag detection mode in the case that the number of said identification information included in said list stored in said storage device is less than a predetermined first threshold value.

3. The apparatus according to claim 1, wherein:

said mode switching portion switches a mode into said response determination mode in the case that the number of said RFID tag circuit elements in said peripheral area estimated by said tag number estimation portion is less than a predetermined second threshold value and into said plural tag detection mode in the case that the number of said RFID tag circuit elements in said peripheral area estimated by said tag number estimation portion is not less than said second threshold value.

4. The apparatus according to claim 3, wherein:

said tag number estimation portion conducts communication for estimation with said RFID tag circuit elements in said peripheral area through said radio communication device and estimates the number of said RFID tag circuit elements in the peripheral area according to a communication result.

5. The apparatus according to claim 4, wherein:

said tag number estimation portion includes;

a transmission control portion for estimation configured to create a all-tag reading command to obtain identification information stored in said IC circuit parts of all the RFID tag circuit elements in said peripheral area and to transmit the command to said RFID tag circuit element through said radio communication device; and

a reception control portion for estimation capable of receiving a response signal by using one of a plurality of identification slots divided, said response signal transmitted from said RFID tag circuit element in response to said all-tag reading command created and transmitted by said transmission control portion for estimation, and

said tag number estimation portion estimates the number of said RFID tag circuit element in said peripheral area on the basis of a reception state of the response signal by said reception control portion for estimation when the number of said identification slots is limited to a predetermined value or less.

6. The apparatus according to claim 5, wherein:

said tag number estimation portion estimates the number of said RFID tag circuit elements in said peripheral area on the basis of the number of said identification slots in which a collision of said response signal occurs as said reception state.

7. The apparatus according to claim 5, wherein:

said tag number estimation portion estimates the number of said RFID tag circuit elements in said peripheral area on the basis of the number of said identification slots in which the collision of said response signal does not occur and information can be obtained from said response signal as said reception state.

8. The apparatus according to claim 5, wherein:

said tag number estimation portion estimates the number of said RFID tag circuit elements in said peripheral area on the basis of the number of said identification slots, which are empty, in which said response signal is not present as said reception state.

9. The apparatus according to claim 5, further comprising:

a tag transmission control portion configured to create said all-tag reading command to obtain identification information stored in said IC circuit part of all of the RFID tag circuit elements in said peripheral area in said response determination mode and to transmit the command to said RFID tag circuit element through said radio communication device; and

a tag reception control portion capable of receiving a response signal in said response determination mode by using one of a plurality of identification slots divided, said response signal transmitted from said RFID tag circuit element in response to said all-tag reading command created and transmitted by said tag transmission control portion.

10. The apparatus according to claim 9, wherein:

said tag reception control portion receives the response signal by using the identification slot number larger than the identification slot number used by said reception control portion for estimation.

11. The apparatus according to claim 5, wherein:

said mode switching portion is configured to be capable of switching a mode into a single tag detection mode in which communication for position detection for specific said RFID tag circuit element is conducted through said radio communication device and a position of the specific said RFID tag circuit element is detected on the basis of the communication result.

12. The apparatus according to claim 11, wherein:

said mode switching portion switches a mode into said single tag detection mode when information is obtained from said RFID tag circuit element in said plural tag detection mode, and specifies said RFID tag circuit element from which the information was obtained, so as to detect a position of the RFID tag circuit element.

13. The apparatus according to claim 11, wherein:

said mode switching portion switches a mode into said single tag detection mode when identification information in said list is obtained from the information obtained in said response determination mode, and specifies said RFID tag circuit element corresponding to the obtained identification information, so as to detect a position of the RFID tag circuit element.

14. The apparatus according to claim 11, further comprising

an output control portion configured to set intensity of a power of said radio communication device when said position detection is performed in said single tag detection mode at intensity or less of the power of said radio communication device when information is obtained in said plural tag detection mode or said response determination mode.

15. The apparatus according to claim 14, wherein:

said output control portion can control to increase and decrease intensity of said power in a stepped manner; and

in said single tag detection mode, a position detection of said RFID tag circuit element is performed on the basis of a communication result of said communication for position detection when the intensity of said power is increased and decreased by said output control portion in the stepped manner.

16. The apparatus according to claim 11, wherein:

said radio communication device has an intensity detecting device configured to detect received signal intensity from said RFID tag circuit element; and

in said single tag detection mode, a position detection of said RFID tag circuit element is performed on the basis of a detection result of said intensity detecting device in said communication for position detection.

17. The apparatus according to claim 15, further comprising

an alarm device for making at least one alarm among display alarm, sound alarm, and vibration alarm, on the basis of a position information detected.

18. The apparatus according to claim 17, wherein:

said mode switching portion switches a mode into said single tag detection mode so as to start said communication for position detection and then, in the case that a state in which there is no response from the RFID tag circuit element as a target of the position detection continues for a predetermined time, the mode switching portion switches a mode into said plural tag detection mode or response determination mode while said identification information of the RFID tag circuit element as the target of the position detection is left in said list of said storage device.

19. The apparatus according to claim 11, wherein:

said mode switching portion switches a mode into said single tag detection mode in the case that there is one identification information included in said list stored in said storage device.

20. The apparatus according to claim 11, further comprising a selection operating device capable of selection and input of identification information of at least one RFID tag circuit elements to which communication for search is conducted in said plural tag detection mode or said response determination mode, identification information being selected or inputted from among the identification information included in said list, wherein

in said plural tag detection mode, said information is obtained with said RFID tag circuit element for which said identification information is selected by said selection operating device as a search target;

and

in said response determination mode, said identification information selected by said selection operating device from said list is obtained from the obtained information.