JP2007295168A - Tag device and ic tag system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tag device which is capable of being conducive to the saving of power, ensuring necessary communications when it enters a previously determined communication area, and hardly interfering with other radio communications. <P>SOLUTION: The tag device 2 contains a first communication module 21 which is capable of receiving first radio waves radiated from a reader/writer, low in directivity, and diffractive; and a second communication module 22 which makes wireless communications with the reader/writer using second radio waves higher than the first radio waves in directivity and travel rectilinear. The first communication module 21 recognizes that it enters a previously set communication area when it receives the first radio waves. The second communication module 22 opens up the prescribed wireless communications with the reader/writer when the first communication module 21 has made the recognition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tag device and an IC tag system that includes the tag device and a reader / writer and can perform wireless communication using electromagnetic waves (radio waves) between them.

2. Description of the Related Art Conventionally, for example, a wireless tag device used for a management system for managing a person or an animal entering or leaving a specific facility is known (see, for example, Patent Document 1).
This tag device has a power-saving mode in which only a specific circuit operates during reception standby, and is configured to react only to a specific radio frequency during communication, thus enabling the extension of the built-in battery life and battery replacement. Less frequent.
Thus, the conventional tag device has an advantage that it can contribute to power saving by extending the life of the built-in battery.
Japanese Patent Laid-Open No. 2003-115033

By the way, the wireless tag device can constitute an IC tag system capable of performing bidirectional wireless communication with a reader / writer.
Therefore, in this type of IC tag system, when wireless communication is performed between the tag device and the reader / writer, necessary communication is ensured when the tag device enters a preset communication area. It is desirable, but it is difficult to set. Moreover, at that time, it is desirable that the tag device does not give interference to other wireless communication.

Therefore, in view of the above points, an object of the present invention is to contribute to power saving, to secure necessary communication when entering a preset communication area, and to other wireless communication. An object of the present invention is to provide a tag device that does not cause interference.
Another object of the present invention is to provide an IC tag system that can ensure communication when a tag device enters a preset communication area and that does not interfere with other wireless communication. There is.

  The tag device according to claim 1 of the present invention is wireless using a first communication means capable of receiving a first radio wave having a low directivity and a second radio wave having a higher directivity than the first radio wave. Second communication means capable of communication, wherein the first communication means is capable of receiving the first radio wave and recognizes that it is in a communication area set in advance when receiving the first radio wave. The second communication means starts predetermined wireless communication using the second radio wave on the condition that the second communication means has been recognized.

  According to a second aspect of the present invention, there is provided a tag device comprising: a first communication unit capable of receiving a first radio wave having a low directivity emitted from a reader / writer; and a second communication unit having a higher directivity than the first radio wave. Second communication means for performing wireless communication with the reader / writer using radio waves, and first receiving the first radio waves from the reader / writer using the first communication means, When the second communication means recognizes that it has entered the communication area set in advance when it is detected, the second communication means uses the second radio wave to communicate with the reader / writer. Communication control means for starting predetermined wireless communication.

A tag device according to a third aspect of the present invention is the tag device according to the first or second aspect, wherein the second communication means uses the second radio wave to perform communication with the reader / writer. The wireless communication is one of one-way and two-way wireless communication.
A tag device according to a fourth aspect of the present invention is the tag device according to the first, second, or third aspect, wherein the first radio wave is a diffractive radio wave with low directivity, The second radio wave is a radio wave having strong directivity and straightness.

The tag device according to claim 5 of the present invention is the tag device according to claim 4, wherein the first radio wave is a long-wave radio wave, and the second radio wave is a VHF-band radio wave or UHF-band radio wave. .
A tag device according to a sixth aspect of the present invention is the tag device according to any one of the second to fifth aspects, wherein the first communication means can receive a first radio wave from the reader / writer. The size of the first communication area is relative to the size of the second communication area in which the second communication means can perform two-way wireless communication with the reader / writer using the second radio wave. It is set small.

  An IC tag system according to a seventh aspect of the present invention is an IC tag system including a reader / writer and a tag device that performs wireless communication with the reader / writer, wherein the reader / writer has a preset communication area. The first radio wave having a low directivity is emitted inside, and the second radio wave having a higher directivity than the first radio wave is used to perform wireless communication with the tag device. The tag device can first receive the first radio wave emitted from the reader / writer, recognizes that the self has entered the communication area when the first radio wave is received, and this recognition is a condition. In addition, predetermined wireless communication is started with the reader / writer using the second radio wave.

The IC tag system according to claim 8 of the present invention is the IC tag system according to claim 7, wherein the tag device uses the second radio wave to perform predetermined wireless communication with the reader / writer. , One of one-way and two-way wireless communication.
An IC tag system according to a ninth aspect of the present invention is the IC tag system according to the seventh or eighth aspect, wherein the first radio wave is a diffracted radio wave with weak directivity, and the second radio wave. Is a radio wave with high directivity and straightness.
The IC tag system according to claim 10 of the present invention is the IC tag system according to claim 9, wherein the first radio wave is a long wave radio wave and the second radio wave is a VHF band radio wave or a UHF band radio wave. is there.

An IC tag system according to an eleventh aspect of the present invention is the IC tag system according to any one of the seventh to tenth aspects, wherein the tag device can receive a first radio wave from the reader / writer. The size of the first communication area is set smaller than the size of the second communication area in which the tag device can perform bidirectional wireless communication with the reader / writer using the second radio wave. It is.
An IC tag system according to a twelfth aspect of the present invention is the IC tag system according to any one of the seventh to eleventh aspects, wherein the reader / writer is acquired by wireless communication with the tag device. The predetermined information is authenticated.

In the IC tag system according to the present invention, a communication area that can communicate with the first radio wave is set in advance. In this case, the first radio wave has low directivity or is non-directional and diffractive. Therefore, the size of the communication area can be clarified and the boundary can be clarified.
Therefore, when the tag device according to the present invention enters the communication area, the tag device can surely receive the first radio wave, thereby reliably recognizing that the tag device exists in the communication area. it can. Then, the tag device starts the original wireless communication with the reader / writer by using the second radio wave having high directivity or directivity and straightness on the condition that the tag device is recognized. Can do.

Therefore, the tag device according to the present invention can perform original communication in the wake-up mode only when entering the preset communication area, and can operate in the sleep mode in other cases. Thus, power consumption can be reduced and the battery usage period can be extended.
Further, in the IC tag system according to the present invention, the size and boundary of the preset communication area can be clarified, and the tag device uses the second radio wave only when it is within the communication area. Can communicate with each other. For this reason, the tag device can perform desired original communication with the reader / writer only when it exists in the set communication area and does not perform dark cloud communication, so that security can be ensured.

  Furthermore, in the IC tag system according to the present invention, the tag device emits the second radio wave for the first time in order to perform original communication with the reader / writer when it enters the preset communication area. In other cases, the second radio wave is not emitted. For this reason, it becomes possible to avoid interference (radio wave interference) between a plurality of tag devices as much as possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(System configuration)
As shown in FIG. 1, an IC tag system according to the present invention includes a reader / writer 1 that functions as a parent device and a plurality of tag devices that can perform wireless communication between the reader / writer 1 and function as slave devices. 2a to 2c, the reader / writer 1 can be connected to a LAN or the Internet via the network 3.

The reader / writer 1 emits (radiates) a predetermined first radio wave in a preset communication area, and uses the predetermined second radio wave with the tag devices 2a to 2c in one direction or It is characterized by being able to perform bidirectional wireless communication.
This reader / writer 1 is added to, for example, individual devices having physical functions and information functions distributed in a predetermined living space, such as copiers, personal computers, and home appliances. , Mounted, or attached for use. Further, the reader / writer 1 may be configured to be detachable from these objects to be used.

Here, the first radio wave and the second radio wave are defined in this specification as follows.
That is, the first radio wave means a radio wave that has no directivity or has low directivity and is diffractive, for example, a long wave radio wave having a frequency of 135 [kHz] or the like. It is.
The second radio wave is a radio wave that has directivity or is relatively more directional than the first radio wave and has a straight line, and is, for example, a radio wave in the VHF band or the UHF band. Thus, the frequency is a radio wave of 300 [MHz] or the like.

  The tag devices 2a to 2c first receive the first radio wave emitted from the reader / writer 1 in the sleep mode (low power consumption mode), and the communication set in advance when the first radio wave is received. Recognizing that self is present in the area, on the condition of this recognition, use the second radio wave with the reader / writer 1 in the wake-up mode (normal operation mode) to perform predetermined one-way or two-way The wireless communication is started.

The tag devices 2a to 2c are adapted to be carried and used by, for example, a human, an animal, or a moving body according to an object for which the reader / writer 1 is used.
(Configuration of reader / writer)
As shown in FIG. 1, the reader / writer 1 includes at least a first communication module 11, a second communication module 12, a memory 13, a control unit 14, and a LAN adapter 15.

The first communication module 11 has an antenna (not shown), and emits a first radio wave to be received by the tag devices 2a to 2c from the antenna within a preset communication area. ing. The first radio wave is emitted, for example, continuously or intermittently.
As the first radio wave, a long wave radio wave is used. For example, a radio wave having a frequency of 135 [kHz] is used. The antenna of the first communication module 11 uses a loop antenna or the like in order to take advantage of the nature of long-wave radio waves, that is, directivity is weak and omnidirectional, and diffraction.

Here, the first communication module 11 may not only emit the first radio wave but also receive the first radio wave and transmit / receive it to / from the tag devices 2a to 2c.
The second communication module 12 has an antenna (not shown), and transmits or receives a second radio wave with the antenna so as to perform bidirectional wireless communication with the tag devices 2a to 2c. It has become.

As the second radio wave, a radio wave in the VHF band or the UHF band is used. For example, a radio wave having a frequency of 300 [MHz] is used. The antenna of the second communication module 12 uses a dipole antenna or the like in order to make use of the properties of radio waves in the VHF band and UHF band, that is, high directivity and straightness.
The memory 13 stores in advance a program for performing predetermined processing and controlling each unit. The control unit 14 includes a CPU and the like, and performs predetermined processing and control of each unit in accordance with a program stored in the memory 13.

  The LAN adapter 15 is used to connect the reader / writer 1 to the network 3. Accordingly, the reader / writer 1 is connected to the network 3 via the LAN adapter 15. A network address is assigned to each of the tag devices 2a to 2c, and the tag devices 2a to 2c can be accessed from an external network.

(Configuration of tag device)
Next, since the tag devices 2a to 2b shown in FIG. 1 are all configured similarly in this example, the specific configuration will be described with reference to FIG.
As shown in FIG. 2, the tag device 2 includes a first communication module 21, a second communication module 22, a timer module 23, a memory module 24, a battery module 25, a processing module 26, and a functional module 27. It is comprised including.
The first communication module 21 has an antenna 211 for receiving a first radio wave, and receives the first radio wave emitted from the first communication module 11 of the reader / writer 1 using the antenna 211. Thus, predetermined signal processing is performed.

For example, a loop antenna or a bar antenna is used as the antenna 211 in order to efficiently receive the antenna by taking advantage of the omnidirectionality and diffraction properties that are the characteristics of the first radio wave.
Here, in addition to the function of receiving the first radio wave emitted by the first communication module 11, the first communication module 21 can transmit the first radio wave to the first communication module 11. Two-way wireless communication may be performed between the two.

The second communication module 22 has an antenna 221 for transmitting / receiving a second radio wave, and transmits / receives a second radio wave using the antenna 221, thereby communicating with the second communication module 12 of the reader / writer 1. Two-way wireless communication is performed between them.
The antenna 221 uses a dipole antenna or the like in order to perform efficient bidirectional wireless communication with the second communication module 12 of the reader / writer 1 by making use of the nature of the second radio wave, that is, directivity and straightness. ing.

  The timer module 23 is a part that performs processing for managing time and activating a tag at a predetermined timing from the state of the sleep mode, for example, every predetermined time, or shifting to the sleep mode when a certain time elapses after activation. is there. Thus, by operating the tag device only for a specific time, it is possible to suppress power consumption and save the battery capacity of the battery module 25. With the function of the timer module 23, the life of the power source can be extended.

The memory module 24 includes a program for realizing a control process as shown in FIG. 3, an ID assigned to each tag device, and authentication information (password) that the reader / writer 1 transmits to the reader / writer 1 for authentication. ) And the like are stored in advance. The memory module 24 is configured using, for example, a semiconductor memory.
The battery module 25 is a part that supplies power to each part of the tag device 2. For this battery module 25, for example, a well-known button battery is used.

The processing module 26 uses a simple CPU (Central Processing Unit) such as a well-known PIC (Programmable Integrated Circuit). The processing module 26 performs a predetermined process according to a program stored in the memory module 24.
For example, the first communication module 21 is used to first receive the first radio wave from the first communication module 11 of the reader / writer 1, and when it has been received, it has entered a predetermined communication area. When the second communication module 22 recognizes and recognizes this, the second communication module 22 starts the one-way or two-way wireless communication with the first communication module 12 of the reader / writer 1 using the second radio wave. Communication control processing is performed.

The function module 27 can have various functions. As physical functions, in addition to simple LED lighting, character display, buzzer for outputting sound, etc., a function having a switch or sensor function, a function having a mechanical function such as an actuator, or the like can be considered. A plurality of types of functions may be provided. About this functional module 27, it is good also as a structure which can add part or all retrofitting.
Since power is supplied to the function module 27 only when the function is manifested, such as during sensor measurement or actuator operation, power consumption can be reduced and the battery capacity of the battery module 25 can be saved.
Since the tag device 2 having such a configuration is a low-power wireless device, no license is required for use.

(Example of communication processing)
Next, an example of communication processing of the IC tag system according to the present invention will be described with reference to FIGS.
Hereinafter, an example of communication processing between the reader / writer 1 and the tag device 2a illustrated in FIG. 1 will be described.
The first communication module 11 of the reader / writer 1 emits a first radio wave in a communication area A set in advance as shown in FIG. Since the first radio wave has weak directivity and is non-directional, the first radio wave is radiated in all directions around the first communication module 11 and is diffractive. be able to.

Under such a state, the tag device 2a is in a sleep mode during normal operation (step S1). Thereby, power consumption can be suppressed and a battery with a small capacity can be used as a power source. In the sleep mode, only the first communication module 21 is in an operating state.
Therefore, when the tag device 2a approaches the reader / writer 1 and enters the communication area A where the first radio wave can be received, the first communication module 21 of the tag device 2a receives the first radio wave (step S2). .

Here, the first radio wave emitted from the first communication module 11 of the reader / writer 1 has a relatively short propagation distance (for example, about 1 [m]), but is omnidirectional and diffractive. As shown in FIG. 4, the communication area A by the first radio wave is a circle having a radius r <b> 1 around the reader / writer 1 in the plane.
For this reason, the communication area A in which the communication is possible can be clearly set in advance, and the first communication module 21 is relative to the first communication module 11 when the communication area A is set. The first radio wave can be reliably received regardless of the specific position and orientation, and when it is outside the communication area A, the first radio wave cannot be received.

Therefore, in this sense, the wireless communication performed by the first communication module 21 of the tag device 2a with the first communication module 11 of the reader / writer 1 depends on the position. I can say that.
Here, the size of the predetermined communication area A shown in FIG. 4 is the transmission capability of the first communication module 11 of the reader / writer 1 (for example, transmission power, radio wave radiation efficiency of the antenna, etc.) and the first of the tag device 2a. Since it depends on the reception capability of the communication module 21 (for example, the reception efficiency of the antenna, the amplification factor of the high frequency amplifier, etc.), it is determined by them.

The processing module 26 detects whether or not the first communication module 21 has received the first radio wave. When the processing module 26 recognizes that the first radio wave has been detected, the processing module 26 wakes up the operation from the sleep mode. Switch to the up mode (step S3).
By starting the wake-up mode, the second communication module 22 of the tag device 2a uses the second radio wave to start bidirectional wireless communication with the second communication module 12 of the reader / writer 1 ( Step S4).

Here, the two-way wireless communication between the second communication module 22 and the second communication module 12 uses the second radio wave having high directivity and straightness, and therefore a relatively long distance compared to the first radio wave. However, if there are obstacles, radio waves do not reach and communication is not possible.
For this reason, the communication area B in which communication between the two using the second radio wave is possible is set in advance as shown in FIG. 4, for example, a circle having a radius r2. As can be seen from FIG. 4, the size of the communication area B is larger than the size of the communication area A by the first radio wave (r1 <r2).

However, even if there is the second communication module 22 in the communication area B, communication may or may not be possible due to the difference in the relative relationship between the two (the relative position and orientation of both). It will be. The same can be considered in the communication area A.
Therefore, in this sense, the wireless communication performed by the second communication module 22 of the tag device 2a with the second communication module 12 of the reader / writer 1 is less dependent on the position where the tag device 2a exists. This can be said to be independent communication.

When bidirectional wireless communication using the second radio wave is started between the tag device 2a and the reader / writer 1 in this way, the reader / writer 1 receives the reception ID number, the transmission ID number, the function number, The predetermined information is transmitted to the tag device 2a simultaneously or individually.
Here, the reception ID number is for identifying the tag device 2a on the receiving side. The transmission ID number is for specifying the reader / writer 1 on the transmission side. The function number indicates the number of the function module to be operated.

Therefore, the processing module 26 of the tag device 2a reads the received reception ID number, and determines whether or not the read reception ID number matches the reception ID number stored in the memory module 24 (step). S5).
As a result of the determination, if the two do not match, the process returns to step S1, and if they match, the process proceeds to the next step S6.

In step S6, the transmission ID number, function number, and information transmitted from the reader / writer 1 are read. Then, the corresponding function module is activated based on the read function number (step S7).
In the communication between the reader / writer 1 and the tag device 2a using the second radio wave, the intensity of the second radio wave received by the reader / writer 1 is correlated with the distance between the two radio waves. The reader / writer 1 can measure the approximate position of the tag device 2a depending on the strength.

(Application example)
Next, application examples of the present invention will be described.
(1) A reader / writer is added to an advertising medium installed in a downtown area, etc., and the tag apparatus reacts to the reader / writer when a person who owns the tag apparatus and is interested in the advertising medium approaches it. The present invention can be applied to a system that can communicate with each other.
In this case, it is possible to allow the reader / writer to flow information considering the history information of the owner from the tag device, or to flow information from the reader / writer to the tag device. Is possible. As a result, the effect of SCM and the convenience of the user are improved.

(2) A presence system using a conventional tag device can only detect the presence in a circle in a room. Therefore, the system of the present invention can be applied to a system in which a reader / writer is added to a copying machine or personal computer, and each user of the copying machine or personal computer carries a tag device.
In this case, when the user carrying the tag device approaches the copy machine or personal computer, the reader / writer and the tag device communicate with each other to determine the user's location, and the user's location information is obtained. By using it, the cooperation operation of each device can be achieved, and efficient control of an air conditioner or the like can be performed using the position information.

(3) The biometric authentication system installed at the entrance or the like can be used in combination with the authentication by the tag device.
In this case, a reader / writer is further added to the biometric authentication system installed at the entrance, and when the owner of the tag device approaches the reader / writer, the tag device is interactive with the reader / writer. This is achieved through communication.
That is, at this time, the tag device transmits the ID number and password stored in advance in the memory module to the reader / writer, so that the reader / writer authenticates whether or not the owner of the tag device is the person himself / herself. Can do.

(4) In a living space such as a home, a reader / writer is added to a home appliance such as an air conditioner or a TV set in each room, and a family member carries the tag device so that the home appliance The present invention can be applied to a system that performs power on / off control and the like.

It is a block diagram which shows the structure of embodiment of the IC tag system of this invention. It is a block diagram which shows the structure of embodiment of the tag apparatus of this invention. It is a flowchart which shows the example of a communication process of a tag apparatus. It is a figure explaining the communication area which concerns on this invention.

Explanation of symbols

A, B Communication area 1 Reader / writer 2, 2a-2c Tag devices 11, 21 First communication module 12, 22 Second communication module 13 Memory 14 Controller 15 LAN adapter 23 Timer module 24 Memory module 25 Battery module 26 Processing module 27 Functional modules 211, 221 Antenna

Claims (12)

First communication means capable of receiving a first radio wave having low directivity;
At least second communication means capable of wireless communication using a second radio wave having higher directivity than the first radio wave,
The first communication means is configured to be able to receive the first radio wave and recognize that it is in a communication area set in advance when receiving the first radio wave,
The tag device, wherein the second communication means starts predetermined wireless communication using the second radio wave on the condition that the second communication means has been recognized. A first communication means capable of receiving a first radio wave with low directivity emitted from a reader / writer;
Second communication means for performing wireless communication with the reader / writer using a second radio wave having higher directivity than the first radio wave;
The first communication means is used to first receive the first radio wave from the reader / writer, and when it is received, it recognizes that it has entered a preset communication area, Communication control means for causing the second communication means to start predetermined wireless communication with the reader / writer using the second radio wave when recognizing
A tag device comprising:   The predetermined wireless communication performed by the second communication unit with the reader / writer using the second radio wave is one of one-way and two-way wireless communication. Item 3. The tag device according to item 1 or item 2.   3. The first radio wave according to claim 1, wherein the first radio wave is a diffractive radio wave having weak directivity, and the second radio wave is a radio wave having high directivity and straightness. Item 4. The tag device according to Item 3.   The tag device according to claim 4, wherein the first radio wave is a long wave radio wave, and the second radio wave is a VHF band or UHF band radio wave.     The size of the first communication area in which the first communication means can receive the first radio wave from the reader / writer is such that the second communication means uses the second radio wave with the reader / writer. The tag device according to any one of claims 2 to 5, wherein the tag device is set smaller than a size of a second communication area in which bidirectional wireless communication is possible. In an IC tag system including a reader / writer and a tag device that performs wireless communication between the reader / writer,
The reader / writer emits a first radio wave having a low directivity within a preset communication area, and uses the second radio wave having a higher directivity than the first radio wave to communicate with the tag device. Wireless communication between
The tag device can first receive the first radio wave emitted from the reader / writer, recognizes that it has entered the communication area when receiving the first radio wave, and this recognition is a condition. An IC tag system configured to start predetermined wireless communication with the reader / writer using the second radio wave.   8. The predetermined wireless communication performed by the tag device with the reader / writer using the second radio wave is one of one-way and two-way wireless communication. The IC tag system described in 1.   9. The first radio wave according to claim 7, wherein the first radio wave is a diffractive radio wave having low directivity, and the second radio wave is a radio wave having high directivity and straightness. IC tag system.   The IC tag system according to claim 9, wherein the first radio wave is a long wave radio wave, and the second radio wave is a VHF band or UHF band radio wave.   The size of the first communication area where the tag device can receive the first radio wave from the reader / writer is such that the tag device uses a second radio wave between the tag device and the reader / writer. 11. The IC tag system according to claim 7, wherein the IC tag system is set smaller than a size of a second communication area in which communication is possible.   12. The reader / writer is configured to authenticate predetermined information acquired by wireless communication with the tag device. IC tag system.

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