RFID system preventing recognition error and communication method thereof

• US 20090184838A1
• Filed: 12/04/2008
• Published: 07/23/2009
• Est. Priority Date: 01/23/2008
• Status: Active Grant

• Current Assignee: Intellectual Discovery Co., Ltd.
• Original Assignee: Samsung Techwin Corporation (Hanwha Corporation), Industry-Academic Cooperation Foundation Yonsei University
• Inventors: Cho, Sung-Ho, Jeon, Ki-Yong
• Granted Patent: US 8,134,466 B2
• Time in Patent Office: Days
• US Class Current: 340/686.100
• 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 7/10198 setting parameters for the interrogator, e.g. programming parameters and operating modes
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2485 Simultaneous detection of multiple EAS tags
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

A radio frequency identification (RFID) tag is provided that prevents a recognition error of the RFID tag due to the occurrence of a shadow region. The RFID tag includes a first tag performing communication with an RFID reader and a second tag connected to the first tag and suitable for use with a different communication type from the first tag. Thus, when information stored in the first tag can not be read, the second tag is activated and externally transmits information and when information stored in the first tag can be read, the second tag is 1o deactivated and does not externally transmit information. A communication method of an RFID system including an RFID reader communicating with an RFID tag is also provided.

Claims

1. A radio frequency identification (RFID) tag comprising:

a first tag performing communication with an RFID reader; and

a second tag connected to the first tag and suitable for use with a different communication type from the first tag, wherein when information stored in the first tag is not readable, the second tag is activated and externally transmits information and when information stored in the first tag is readable, the second tag is deactivated and does not externally transmit information.

2. The RFID tag of claim 1, wherein the second tag does not communicate with the RFID reader and communicates with another RFID reader having the same communication type as that of the second tag.

3. The RFID tag of claim 1, wherein the first tag comprises:

a first antenna transmitting and receiving a signal in a wireless manner;

a first demodulator demodulating the signal transmitted from the first antenna;

a first voltage multiplier receiving the signal transmitted from the first antenna and outputting a first power supply voltage;

a memory in which information is stored;

a first control logic operating due to the first power supply voltage, receiving a signal output by the first demodulator, reading and outputting information stored in the memory and transmitting a control signal indicating whether information stored in the memory is successfully read, to the second tag; and

a first modulator modulating a signal output by the first control logic and the modulated signal to the first antenna.

4. The RFID tag of claim 1, wherein the second tag comprises:

a second antenna transmitting and receiving a signal in a wireless manner;

a second demodulator demodulating the signal transmitted from the second antenna;

a second voltage multiplier connected to the first tag and activated or deactivated according to a signal transmitted from the first tag, receiving the signal transmitted from the second antenna and outputting a second power supply voltage during activation, and not outputting the second power supply voltage during deactivation;

a second control logic operating due to the second power supply voltage, receiving a signal output by the second demodulator, and outputting predetermined information; and

a second modulator modulating a signal output by the second control logic and the modulated signal to the second antenna.

5. A communication method of a radio frequency identification (RFID) system comprising first and second RFID readers communicating with an RFID tag in a state where the RFID tag having first and second tags is attached to a product, the communication method comprising:

(a) when the product reaches a first position, the first RFID reader attempting to form a communication connection with the first tag, and when communication connection is successful, the first RFID reader reading information stored in the first tag; and

(b) when the product reaches a second position, the second RFID reader attempting to form a communication connection with the second tag, and when communication connection is successful, the second RFID reader communicating with the second tag and allowing an alarm device to generate an alarm.

6. The communication method of claim 5, wherein, when information stored in the first tag is read in (a), the second RFID reader does not communicate with the second tag, and when information stored in the first tag is not read in (a), the second RFID reader communicates with the second tag.

7. The communication method of claim 5, wherein the first and second RFID readers simultaneously communicate with the RFID tags attached to a plurality of products.

8. A communication method of a radio frequency identification (RFID) system comprising an RFID reader communicating with an RFID tag in a state where the RFID tag having first and second tags is attached to a product, the communication method comprising:

(a) when the product reaches a first position, the RFID reader attempting to form a communication connection with the first tag, and when communication connection is successful, the RFID reader reading information stored in the first tag; and

(b) when the product reaches a second position, the RFID reader changing a communication type to attempt to form a communication connection with the second tag, and when communication connection is successful, the RFID reader communicating with the second tag and generating an alarm.

9. The communication method of claim 8, wherein, when information stored in the first tag is read in (a), the RFID reader does not communicate with the second tag, and when information stored in the first tag is not read in (a), the RFID reader communicates with the second tag.

10. The communication method of claim 8, wherein the RFID reader simultaneously communicates with the RFID tags attached to a plurality of products.