JP2006268359A - Non-contact IC tag and non-contact IC tag communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high security function and prevent read / write for illegal purposes.
A function for detecting the intensity of a radio wave from a reader / writer is provided inside a tag so that switching between a long-distance mode and a short-distance mode can be performed by an instruction from the reader / writer. In the short distance mode, a response is made only when the strength of the radio wave is greater than or equal to the specified level, and no response is made if the strength of the radio wave is lower than the specified level. In the long distance mode, the above restriction is not performed. The long distance / short distance mode set by the instruction from the reader / writer is stored in the non-volatile memory inside the tag, so that the next time the power is supplied even if it is out of the power supply area from the reader / writer. The mode state is maintained by reading the memory.
[Selection] Figure 1

Description

  The present invention relates to a non-contact IC tag using electromagnetic waves as a communication medium, and a non-contact IC tag communication system using the non-contact IC tag.

  In recent years, research and development of RFID (Radio Frequency Identification) has been actively conducted as a non-contact automatic recognition technique using electromagnetic waves. RFID performs non-contact communication using electromagnetic waves between a small transponder (IC tag, IC card) equipped with a semiconductor memory (IC chip) and a communication antenna and an interrogator (reader / writer) to exchange data. It is attracting attention as a next-generation barcode.

  The advantages over bar codes include the large amount of information and the ability to write data because an IC chip is used for data exchange. There are also RFID systems that allow a communication distance of 10 m or more, depending on the performance and type of a chip equipped with a small responder.

  Applications of such an RFID system capable of long-distance communication include a logistics management system, a process management system, a traceability system, an entrance / exit management system, a position detection system, and the like.

  However, such an RFID system capable of long-distance communication also has a demerit because long-distance communication is possible. By installing a reader / writer in the vicinity of the system, there is a risk of unauthorized reading of highly confidential customer information.

  The communication distance between the non-contact IC tag and the reader / writer is almost determined by the antenna structure of the non-contact IC tag and the reader / writer and the output of the reader / writer if the communication frequency and the chip performance are determined. . Therefore, when the communication distance is increased, a reader / writer with an increased output is used, and when the communication distance is decreased, a reader / writer with a smaller output is used, or a reader / writer that can change the output is used.

  For example, in the following Patent Document 1, referring to FIG. 4, the signal strength detection means 435 for detecting the signal strength of the signal received from the IC card 1 and the IC card according to the signal strength detected by the signal strength detection means. Transmission power switching means 414 and 417 for switching the wireless transmission power of the first and second radio transmission power. The wireless transmission power can be increased to increase the communication distance with the IC card, and when the IC card approaches, the transmission power is weakened to stabilize the operation of the IC card.

  There has also been proposed a method of switching the communication distance by the control on the IC card side instead of the control on the reader / writer side.

  For example, in Patent Document 2 below, referring to FIG. 5, a non-contact IC card having a long reception distance by providing a switch 504 for changing the connection with the loop antenna 503 in the loop antenna 503 portion of the non-contact IC card 501. In the system, the changeover switch 504 is connected to the loop antenna 503 having the maximum area to maximize the antenna gain, and in the non-contact IC card system having high confidentiality, the changeover switch 504 is set to the loop antenna having the minimum area so that remote reading can be rejected. By connecting to the terminal 503, the antenna gain is minimized, so that the non-contact IC card 501 used in a long-distance system or a system requiring high security can be used.

Japanese Patent Laid-Open No. 2002-170082 JP 2003-168088 A

  However, in the above-mentioned Patent Document 1, since the communication distance depends on the reader / writer and is not related to the communication performance of the tag, the tag is read for illegal purposes by preparing a reader / writer for long distance. The problem arises that it is easy to do.

  Moreover, although the said problem does not arise in above-mentioned patent document 2, when the user who owns an IC card has to perform switching operation of communication distance manually, bothering remains, and forgetting switching operation However, there is still a risk that a tag may be read for illegal purposes by preparing a reader / writer for a long distance.

  The present invention provides a non-contact IC tag capable of automatically switching a communication distance and a non-contact IC tag communication system using the same.

  That is, according to the present invention, the information storage unit for storing information, the control circuit unit for controlling communication with the reader / writer, the demodulation circuit unit for restoring the modulated wave from the reader / writer, and the reader / writer A modulation circuit unit that generates a signal to be returned, a power supply circuit unit that activates an IC, and an antenna unit that transmits and receives radio waves to and from the IC tag, and has a function of switching a communication distance inside the IC tag A non-contact IC tag is obtained.

  Furthermore, according to the present invention, there is obtained a non-contact IC tag characterized in that automatic switching control of communication distance is performed by a control signal from the reader / writer.

  Furthermore, according to the present invention, there can be obtained a non-contact IC tag having a radio wave intensity detection circuit unit for detecting the radio wave intensity from the reader / writer.

  Furthermore, according to the present invention, a non-contact IC tag is obtained, wherein the information storage unit is a nonvolatile memory capable of storing a communication distance setting state.

  Furthermore, according to the present invention, there is provided a non-contact IC tag comprising means for determining whether to respond to a signal from a reader / writer according to the intensity of electromagnetic waves from the reader / writer. It is done.

  Further, according to the present invention, the information storage unit for storing information, the control circuit unit for controlling communication with the reader / writer, the demodulation circuit unit for demodulating the modulated wave from the reader / writer, and the reader / writer A non-contact IC comprising a modulation circuit section for generating a signal to be returned, a power supply circuit section for activating the IC, and an antenna section for transmitting and receiving radio waves to and from the outside of the tag, and having a function of switching a communication distance inside the tag A tag communication system is obtained.

  Furthermore, according to the present invention, there is obtained a non-contact IC tag communication system in which automatic switching control of communication distance is performed by a control signal from the reader / writer.

  Furthermore, according to the present invention, there can be obtained a non-contact IC tag communication system characterized by having a radio wave intensity detection circuit unit for detecting the radio wave intensity from the reader / writer.

  Further, according to the present invention, there is obtained a non-contact IC tag communication system, wherein the information storage unit described above is a nonvolatile memory capable of storing a communication distance setting state.

  Further, according to the present invention, there is provided a non-contact IC tag communication system, characterized by comprising means for determining whether to respond to a signal from the reader / writer according to the intensity of the electromagnetic wave from the reader / writer. Is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the non-contact IC tag which can perform automatic switching operation of a communication distance by the control signal from a reader / writer, and the non-contact IC tag communication system using the same. As a result, even if an attempt is made to read a tag using a long-distance reader / writer from a place away from an unauthorized purpose, the tag does not respond. In order to set the long distance mode, the mode must be switched by bringing the reader / writer close to each other, so that it is possible to prevent fraud, and the switching operation of the communication distance is manually performed by the user who owns the IC card. The effect that is eliminated is obtained.

  Hereinafter, an internal circuit and an operation principle of a non-contact IC tag according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic diagram of communication between a reader / writer and an IC tag. Non-contact communication is performed by electromagnetic waves between the antenna 2 connected to the reader / writer 1 and the antenna 4 connected to the IC tag 3 to exchange data. A radio wave intensity detection circuit 5 that detects the intensity of radio waves from the reader / writer 1 is provided inside the IC chip 3. In this example, an analog / digital converter was used and the intensity of electromagnetic waves was measured.

  In addition, an information storage unit 10 that stores information, a demodulation circuit unit 7 that restores a modulated wave from the reader / writer, a modulation circuit unit 6 that generates a signal to be returned to the reader / writer, and power are supplied to each circuit. A power supply circuit unit 8 is also provided.

  In response to a signal instruction from the reader / writer, the control circuit 9 switches between the long distance mode and the short distance mode of the communication system. In the short distance mode, a response is made only when the strength of the radio wave is greater than or equal to the specified level, and no response is made if the strength of the radio wave is lower than the specified level. In the long distance mode, the above restriction is not performed. Further, the long distance / short distance mode set by the instruction from the reader / writer is stored in the nonvolatile memory 10 inside the tag, so that the next power supply is performed even if the reader / writer is out of the power supply area from the reader / writer. The mode state can be maintained by reading the memory when it is done.

  Next, the physical distribution management system using the non-contact IC tag capable of automatically switching the communication distance shown in the above embodiment will be described.

  In FIG. 2, by attaching an IC tag 103 to a product 104 manufactured in a factory A101, a predetermined operation such as product information and distribution management of the product 104 is performed by an installed reader / writer 102.

  When the finished product 104 is placed on the truck 108 and transported to the factory B110 where the next process is performed, the communication distance is set to the short distance mode by the reader / writer 105 installed in the gate 106 when leaving the factory A from the factory A. This makes it impossible to read the tag by the unauthorized reader / writer 109 installed at a position b away from the factory. Further, when entering the factory B110, the tag 103 is set to the long distance mode by the reader / writer 114 installed in the gate 115, and the product information and logistics management of the product 104 are performed by the reader / writer 111 installed in the factory B110. A predetermined operation is performed.

  As a result, even if the tag 103 is mounted on the product 104, it is possible to prevent the tag from being used in a lead for illegal or criminal purposes.

  Next, a human position detection management system using an IC tag capable of automatically switching the communication distance will be described.

  In this system, as shown in FIG. 3, by installing a plurality of readers / writers (202, 203, 204) in a kindergarten (nursery school) 201, the position of a child 205 to which a name tag 206 mounted with an IC tag is attached. It is a system that detects and knows whereabouts of children in kindergartens and nurseries. A reader / writer 206 is installed at the gate 207 of the kindergarten (nursery school) 201. When the reader / writer 206 goes out of the park from the park, the reader / writer 206 sets the communication distance to the short-distance mode so that the reader / writer 206 can move to a remote location b. It is possible to make the tag unreadable by the installed unauthorized reader / writer 208. When entering the park again from outside the park, the tag 206 is set to the long distance mode by the reader / writer 206 installed at the gate 207, and a plurality of reader / writers (202, 203, 204 installed in the park) are set. ) Makes it easy to grasp the location. Thereby, even if the child keeps wearing the tag 206, it is possible to prevent the tag from being used for illegal or criminal purposes.

It is the figure which showed the structure of the non-contact IC tag which concerns on this invention. It is the figure which showed one Embodiment of the non-contact IC tag communication system which concerns on this invention. It is the figure which showed other embodiment of the non-contact IC tag communication system which concerns on this invention. It is the figure which showed the conventional IC card. It is the figure which showed the other conventional IC card.

Explanation of symbols

1,102,105,109,111,114,202,203,204,206,208 Reader / Writer 2,4 Antenna 3 Inside IC chip 5 Radio wave intensity detection circuit 6 Modulation circuit 7 Demodulation circuit 8 Power supply circuit 9 Control circuit 10 Non-volatile memory 101, 110 Factory 106, 115, 207 Gate 104, 107, 113 Product 108 Track 103, 112, 206 IC tag 205 Child 201 Kindergarten (nursery school)

Claims (10)

An information storage unit for storing information;
A control circuit unit for controlling communication with the reader / writer;
A demodulation circuit unit for restoring a modulated wave from the reader / writer;
A modulation circuit for generating a signal to be returned to the reader / writer;
A power supply circuit section for starting the IC;
It has an antenna part that transmits and receives radio waves with the outside of the IC tag,
A non-contact IC tag having a function of switching a communication distance inside the IC tag.   2. The contactless IC tag according to claim 1, wherein automatic switching control of a communication distance is performed by a control signal from the reader / writer.   2. The non-contact IC tag according to claim 1, further comprising a radio wave intensity detection circuit unit for detecting radio wave intensity from the reader / writer.   The contactless IC tag according to claim 1, wherein the information storage unit is a nonvolatile memory capable of storing a communication distance setting state.   4. The non-contact IC according to claim 1, further comprising means for determining whether to respond to a signal from the reader / writer according to the intensity of the electromagnetic wave from the reader / writer. tag. An information storage unit for storing information;
A control circuit unit for controlling communication with the reader / writer;
A demodulation circuit unit that demodulates the modulated wave from the reader / writer;
A modulation circuit for generating a signal to be returned to the reader / writer;
A power supply circuit section for starting the IC;
It has an antenna part that transmits and receives radio waves with the outside of the tag,
A non-contact IC tag communication system having a function of switching a communication distance inside a tag.   7. The contactless IC tag communication system according to claim 6, wherein automatic switching control of a communication distance is performed by a control signal from the reader / writer.   7. The non-contact IC tag communication system according to claim 6, further comprising a radio wave intensity detection circuit unit that detects radio wave intensity from the reader / writer.   The contactless IC tag communication system according to claim 6, wherein the information storage unit is a nonvolatile memory capable of storing a communication distance setting state. 9. The non-contact IC according to claim 6, further comprising means for determining whether to respond to a signal from the reader / writer according to the intensity of the electromagnetic wave from the reader / writer. Tag communication system.

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