JPH11102419A - Reader/writer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect communicable mobile information by sending an identification signal by radio and to prevent interference between reader/writers with each other, when plural reader/writers are installed in neighborhood in a reader/ writer which performs radio communication to a corresponding mobile information communication body. SOLUTION: In this reader/writer 1, a communication means consists of a modulating part 12 and a demodulating part 13 which send and receive a radio signal via an antenna 11, a sending timing of an identification signal from the other reader/writer is detected based on the identification signal which is received by a CPU 18 from the other reader/writer, and the communication means sends an identification signal to an IC card 2, or the like, in a timing that is shifted from the detected sending timing. Further, a detecting means which performs detection and a communication controlling means which controls transmission are configured by the processing of the CPU 18. Also, the CPU 18 is connected to the communication means and an external information terminal 3 through interfaces 14 and 17, and various information is outputted from a displaying part 15 and a loudspeaker 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reader / writer (RWU) for detecting a mobile information communication body such as an IC card capable of communicating by wirelessly transmitting an identification signal and performing wireless communication with the mobile information communication body. In particular, the present invention relates to a reader / writer that prevents interference with other reader / writers installed nearby.

[0002]

2. Description of the Related Art For example, an IC card formed by embedding a microcomputer chip and a memory chip on a card substrate having a size similar to that of a credit card or the like has been put to practical use in various fields such as finance, distribution, transportation, and medicine. Is planned. In an IC card system using such an IC card, for example, power is transmitted and supplied from a reader / writer to the IC card, and information such as a control code and data is communicated between the reader / writer and the IC card. Have been done.

In power transmission and information communication between a reader / writer and an IC card, a non-contact method using electromagnetic waves is employed in addition to a contact method in which terminals are brought into contact with each other. FIG. 9 shows an example of an IC card system employing such a non-contact method. The IC card system includes the reader / writer 1 and the IC card 2 described above.
And an information terminal device 3 connected to the reader / writer 1.

The reader / writer 1 wirelessly transmits an identification signal to detect a communicable IC card 2 and performs wireless communication with the detected IC card 2. That is, a response signal is transmitted to the reader / writer 1 from the IC card 2 that has received the identification signal transmitted from the reader / writer 1,
As a result, in the reader / writer 1, I
It is confirmed whether or not the C card 2 exists, and when the IC card 2 exists in the area, the IC card 2 can be authenticated or the like to perform wireless communication.

A communicable area in which wireless communication can be performed between the reader / writer 1 and the IC card 2 is determined by, for example, the transmission output strength of a wireless signal communicated between them. The information terminal device 3 is composed of, for example, a personal computer (PC) or the like serving as a host. In the information terminal device 3, information communication with the reader / writer 1, finance, distribution, transportation, medical care, etc. And the like are performed.

FIG. 10 shows an example of a transmission protocol of wireless communication performed by the above-described IC card system. That is, in the reader / writer 1, the identification signal is polled (Pollin) in the card selection phase, for example.
g) Transmission is performed at regular time intervals according to the method, and it is confirmed whether or not the IC card 2 exists in the communicable area. Further, when the reader / writer 1 detects the IC card 2 in the communicable area by the above-mentioned response signal, the reader / writer 1 transmits a signal (Authentication1, 2) for authenticating the IC card 2 in a card authentication phase. For example, a unique identifier is received from the IC card 2 and the IC card 2 is authenticated.

When the reader / writer 1 authenticates that the IC card 2 is properly registered as described above, the reader / writer 1 reads out the contents of the data stored in the IC card 2 in the data exchange phase, for example. Wireless communication with the IC card 2 by transmitting a signal (Read block), a signal (Write block) for rewriting the content of data stored in the IC card 2, and the like.

[0008]

However, in such a reader / writer, one reader / writer and one reader / writer are usually used.
Since information communication is performed between two IC cards, for example, when a non-contact IC card is applied to a train ticket and a plurality of reader / writers are installed at a ticket gate of a station, the plurality of different reader / writers are used. Is installed nearby,
There was a problem that interference occurred between reader / writers. For example, when another reader / writer is installed near a certain reader / writer and the communicable areas of these reader / writers overlap, identification signals from these different reader / writers are transmitted simultaneously. In this case, the transmitted identification signals interfere with each other, and the reader / writer cannot normally detect a communicable IC card.

That is, as shown in FIG.
The identification signal from the reader / writer 1a in the card selection phase and the other reader / writer 1 in the card identification phase
If the identification signal from b is transmitted to the IC card 2 at the same transmission timing, these identification signals will interfere with each other, so that the IC card 2 must receive these identification signals normally. Can not. For this reason,
In the reader / writer 1a and the other reader / writer 1b, there is a problem that the IC card 2 cannot be detected even though there is an IC card with which communication is possible.

Further, for example, even if the communicable areas of the reader / writers installed in the vicinity do not overlap, the reader / writers interfere with each other due to weak electromagnetic coupling between the antenna coils of the reader / writers. As described above, there is a problem that the IC card cannot be normally detected.

Similarly, in the above-described reader / writer, for example, an IC card communicable with another reader / writer installed near the reader / writer is detected, and the other reader / writer and the IC card are detected. Even during wireless communication with the card, the identification signal is transmitted. For this reason, in such a case, the signals transmitted from the plurality of different reader / writers to the IC card cause interference with each other, and the other reader / writer described above and the IC are transmitted to the IC card.
There was a problem that wireless communication with the card was interrupted.

That is, as shown in FIG.
For example, when the reader / writer 1a and another reader / writer 1b are installed in the vicinity, wireless communication is performed between the other reader / writer 1b and the IC card 2 in the card authentication phase or the data exchange phase. Even in the middle,
An identification signal may be transmitted from the reader / writer 1a in the card selection phase. In such a case, if signals transmitted from the plurality of different reader / writers 1a and 1b overlap at the same timing,
These signals interfere with each other, and a problem has occurred in that the above-described wireless communication between the reader / writer 1b and the IC card 2 is interrupted.

As described above, in the interference area due to the electromagnetic coupling of a plurality of different reader / writers, the signals transmitted from the plurality of different reader / writers interfere with each other, and for example, the other reader / writer is transmitted by the transmitted identification signal. Disturbing the communication between the writer and the IC card,
This has made such communication impossible at all. Note that such interference between reader / writers has occurred due to, for example, an asynchronous transmission timing of an identification signal transmitted from the reader / writer at regular time intervals.

The present invention has been made to solve such a conventional problem, and detects an communicable mobile information communication body by wirelessly transmitting an identification signal, and wirelessly communicates with the mobile information communication body. When performing communication, for example, even when another reader / writer is installed in the vicinity, the identification signal transmitted from the other reader / writer and the identification signal transmitted from itself interfere with each other. It is an object of the present invention to provide a reader / writer capable of preventing the occurrence of the problem.

Further, the present invention detects a mobile information communication body capable of communicating by wirelessly transmitting an identification signal, and performs wireless communication with the mobile information communication body. When wireless communication is being performed between the writer and the mobile information communication body, it is possible to prevent the signal transmitted from the other reader / writer from being interfered by the identification signal transmitted from itself. Accordingly, an object of the present invention is to provide a reader / writer which can prevent the wireless communication performed between the other reader / writer and the mobile information communication body from being interrupted.

[0016]

In order to achieve the above object, in a reader / writer according to the present invention, an identification signal is wirelessly transmitted to detect a communicable mobile information communication body, and the mobile information communication body is detected. When performing wireless communication, transmission processing of an identification signal is performed as follows. That is, the communication unit receives the wireless signal, and the detection unit detects the transmission timing of the identification signal from the other reader / writer based on the identification signal received from the other reader / writer. Then, the communication control means causes the communication means to transmit the identification signal at a timing shifted from the detected transmission timing.

Therefore, for example, even when another reader / writer is installed near a certain reader / writer, transmission of the identification signals from the plurality of different reader / writers is performed at transmission timings shifted from each other. In addition, it is possible to prevent the identification signals from the plurality of different reader / writers from interfering with each other. As described above, in the reader / writer, the identification signal transmitted from another reader / writer is constantly monitored, for example, and the transmission timing of the identification signal from itself and the transmission timing of the identification signal from the other reader / writer are shifted. , It is possible to prevent the identification signals transmitted from the plurality of different reader / writers from interfering with each other, whereby the mobile information Can be reliably detected.

In the reader / writer according to the present invention, the identification signal is wirelessly transmitted to detect a communicable mobile information communication body, and the wireless communication with the mobile information communication body is performed as follows. The identification signal is transmitted. That is, the communication unit receives the wireless signal, and the detection unit detects the notification signal transmitted from another reader / writer that has identified the mobile information communication unit and that starts wireless communication with the mobile information communication unit. Then, the communication control means stops transmission of the identification signal from the communication means based on the detection signal being detected by the detection means.

Therefore, in the reader / writer, for example, even when another reader / writer is installed in the vicinity, when wireless communication is started between the other reader / writer and the mobile information communication body, Since the transmission of the identification signal is stopped by detecting the notification signal transmitted from the other reader / writer, the identification signal transmitted from itself and the signal transmitted for communication from the other reader / writer are not included. Interference can be avoided,
It is possible to prevent the wireless communication performed between the other reader / writer and the mobile information communication body from being interrupted.

Here, the mobile information communication body referred to in the present invention includes not only the above-mentioned IC card but also a name plate attached to a person, a tag attached to a product or article, and an identification attached to livestock. And a delivery plate attached to a parcel delivery package, a delivery plate attached to a container, a number identification plate attached to an automobile, and the like.

For example, in a system in which a tag-attached product is sorted by performing wireless communication between a reader / writer and a tag, even if a plurality of different reader / writers are installed in the vicinity, By applying the present invention to this system, it is possible to prevent signals transmitted from these plural different reader / writers from interfering with each other, thereby enabling accurate sorting of goods and the like. Can be realized.

As described above, the present invention can be applied to any mobile information communication body as long as it performs wireless communication with a reader / writer such as the above-mentioned IC card. The present invention is not limited to a name plate, a tag, or the like, and can be applied to various mobile information communication bodies.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to the drawings. In this example, the mobile information communication body is an IC
A case where a card is used will be described, and a case where the reader / writer of the present invention is applied to an IC card system having the same configuration as that shown in FIG. 9 will be described. As described above, the reader / writer 1 and the I / O
A C card 2 and an information terminal device 3 are provided. The reader / writer 1 transmits an identification signal to detect a communicable IC card 2 and identifies the IC card 2 identified by an authentication process or the like.
Wireless communication with the card 2 is performed. In this example, the reader / writer 1, the IC card 2, and the information terminal device 3 are indicated using the same reference numerals as those shown in FIG.

Further, it is assumed that another reader / writer 1 is installed near the above-mentioned reader / writer 1, and the communicable areas of the plurality of different reader / writers 1 overlap. In this example, a case will be described in which the reader / writer 1 and another reader / writer 1 transmit an identification signal at regular time intervals.

FIG. 1 shows an example of a circuit configuration of a reader / writer 1 according to the present invention. The reader / writer 1 includes an antenna (ANT) 11 for transmitting and receiving radio signals,
A modulation unit 12 for performing a modulation process and a demodulation unit 1 for performing a demodulation process
3, a modulation unit 12, a demodulation unit 13, and a CPU 18 to be described later.
, An information display unit 15, a speaker 16 for outputting sound, an interface 17 for connecting the information terminal device 3 installed outside and a CPU 18 described below, Each of these processing units 1
A CPU 18 for controlling the processing performed by the CPUs 1 to 17 is provided.

The modulation section 12 is composed of, for example, a modulation circuit for modulating data into a radio signal, and has a function of transmitting data to be transmitted from the antenna 11 as a radio signal, thereby transmitting the signal by radio. doing.
The demodulation unit 13 includes, for example, a demodulation circuit that demodulates a radio signal into data, and has a function of detecting a signal received by the antenna 11 with, for example, a coil and demodulating the signal.

The interface 14 is constituted by, for example, a serial input / output interface (SIO: Serial I / O Interface).
It has a function of transferring information to and from the PU 18. In this example, the modulation unit 12 and the demodulation unit 13 are C
A communication unit that transmits and receives wireless signals by controlling transmission and reception of wireless signals via the antenna 11 is controlled by the PU 18 via the interface 14.

The display section 15 is composed of, for example, a liquid crystal display, and has a function of being controlled by the CPU 18 to display and output information such as a message to the user of the IC card 2 on a display screen. The speaker 16 is controlled by the CPU 18 so that the IC card 2
It has a function of outputting information such as a message to a user by voice. The interface 17 is composed of, for example, a serial input / output interface (SIO) and has a function of transferring information between the CPU 18 and the information terminal device 3.

The CPU 18 includes the above-described processing units 11 to 1
7 has a function of executing various control processes and various arithmetic processes. For example, various control and processes are performed by expanding and executing a predetermined control program in a RAM.
The CPU 18 controls the modulating unit 12 and the like in the card selection phase to transmit the identification signal at regular time intervals to check whether the IC card 2 exists in the communicable area. I do. Further, a response signal is transmitted from the IC card 2 that has received the identification signal, and the CPU 18 uses the demodulation unit 13 and the like to perform IC response.
When a response signal from the card 2 is received, authentication processing of the IC card 2 is performed in a card authentication phase.

Further, as a result of the above-described authentication processing, when it is confirmed that the IC card 2 is properly registered, the CPU 18 controls the modulation unit 12 and the like in the data exchange phase, and 2 is wirelessly communicated. In this example, power is also transmitted from the reader / writer 1 to the IC card 2, and the IC card 2 performs various processing operations using the power received from the reader / writer 1. Further, the CPU 18 communicates information with the information communication terminal 3 via the interface 17, and the information communication terminal 3 performs the arithmetic processing of the information received from the reader / writer 1 in this manner.

Further, the CPU 18 is provided with, for example, a timer for measuring the time. In the CPU 18, based on the identification signal received from the other reader / writer 1 by the demodulation unit 13 or the like, the other reader / writer is used. A process is performed to detect the transmission timing of the identification signal from No. 1. In this example, the CPU 18 detects the transmission timing of the identification signal from another reader / writer 1 in this manner,
Detection means is configured to detect the transmission timing of the identification signal from the other reader / writer based on the identification signal received from the other reader / writer.

When the CPU 18 detects the transmission timing of the identification signal from the other reader / writer 1 as described above, the modulation unit 12 and the like transmit the identification signal at a timing shifted from the detected transmission timing. Is done. In the present example, the CPU 18 controls the transmission processing of the identification signal in this manner, so that the modulation unit 1 described above is shifted at a timing shifted from the detected transmission timing.
Communication control means for causing the identification signal to be transmitted by the communication means composed of 3 and the like.

In this embodiment, when the CPU 18 identifies the IC card 2 by the authentication process and starts wireless communication with the IC card 2, the CPU 18 controls the above-described modulator 12 and the like. It is assumed that a notification signal for notifying the start of wireless communication with the IC card 2 is transmitted to another reader / writer 1.
Further, the CPU 18 constantly monitors, for example, whether or not a notification signal from another reader / writer has been received by the demodulation unit 13 or the like, and when it detects that a notification signal from another reader / writer 1 has been received, The transmission process of the identification signal by the modulation unit 12 and the like is stopped.

In this example, the CPU 18 detects the notification signal from the other reader / writer 1 as described above, and the mobile information communication body transmitted from the other reader / writer that has identified the mobile information communication body is identified. Detecting means for detecting a notification signal for starting the wireless communication of the present invention. Further, in this example, the CPU 18 stops the transmission of the identification signal as described above, and is configured by the modulation unit 12 and the like based on the detection of the notification signal by the notification signal detection unit. Communication control means for stopping transmission of the identification signal from the communication means.

In this embodiment, the transmission of the identification signal stopped by receiving the notification signal from another reader / writer 1 is performed when the identification signal from the other reader / writer 1 is received. That is, when the wireless communication between the other reader / writer 1 and the IC card 2 ends and the transmission of the identification signal starts again, the control is restarted under the control of the CPU 18. Note that, for example, I
Reader / writer 1 that has completed wireless communication with C card 2
In this case, the CPU 18 may start transmitting the identification signal again based on the reception of the signal from another reader / writer 1.

With the above configuration, in the reader / writer 1,
An identification signal is wirelessly transmitted to detect a communicable IC card 2 and wireless communication is performed with the IC card 2. For example, a radio signal is transmitted from the reader / writer 1 with a transmission power of 320 mW, and the transmitted radio signal is, for example, 2 mW.
It propagates while attenuating in space by an attenuation constant such as 5 dBm. Also, as described above, the reader / writer 1
Then, various processes such as control of the transmission timing of the identification signal and a process of stopping the transmission of the identification signal are performed. In this example, the configuration of the other reader / writer 1 is also
It is assumed that the configuration is the same as that of the reader / writer 1 described above.

FIG. 2 shows an example of a circuit configuration of the IC card 2. The IC card 2 includes an antenna (ANT) 21 for transmitting and receiving radio signals, a bridge circuit (bridge Di) 22, and a transistor. A demodulation unit 24 including a demodulation circuit for performing demodulation processing, an extraction circuit 25 for extracting a specific frequency signal, a frequency divider 26 for dividing the frequency of the signal, An interface 27 for connecting the demodulator 24, the frequency divider 26, and switches 28 and 29 to be described later and a CPU 30 to be described later, switches 28 and 29 for transmitting a radio signal, And a CPU 30 for controlling the components 21 to 29. In this example,
An example of the IC card 2 in which the other processing units 22 to 30 except the above-described antenna 21 are configured by one chip is shown.

As shown in FIG. 2, between the antenna 21 and the bridge 22 and between the bridge 22 and the regulator 2
3, capacitors C1, C2, C3, and C4 are provided between the switches 28 and 29 and the antenna 21, respectively. Further, one end of the bridge 22, the one end of the regulator 23 and the like, and the switches 28 and 29
Are respectively grounded.

For example, the reader / writer 1 is
Is supplied to the CPU 30 and the like via the bridge circuit 22 for performing rectification processing and the regulator 23 for performing smoothing processing. In this example, the IC card 2 is configured to operate using the power supplied from the reader / writer 1. However, for example, the IC card 2 is provided with a battery, and the IC card 2 is operated by the power supplied from the battery or the like. 2 may perform the operation.

When, for example, an identification signal or information communication signal from the reader / writer 1 is received by the antenna 21, these signals are input to the demodulation unit 24 via the bridge circuit 22, and After being demodulated by 24, it is input to the CPU 30 via the interface 27. Note that the signal received by the antenna 21 has a signal-to-noise (S / N) ratio of, for example, 30 dB.
4 is input.

In the CPU 30, the interface 2
The data to be transmitted is converted into a radio signal by opening / closing the switches 28 and 29 via the antenna 2.
1 to the reader / writer 1 or the like. As described above, in the present embodiment, the function as a transmitter (Tx) is configured by the CPU 30 controlling the switches 28 and 29 and performing wireless transmission, and the demodulation unit 24 and the like demodulate the wireless signal. By performing wireless reception in this manner, a function as a receiver (Rx) is configured.

The CPU 30 is provided with, for example, a memory in which a unique identifier is stored. In this embodiment, by notifying the identifier to the reader / writer 1, the reader / writer 1 uses the IC card 2 based on the identifier. Authentication processing is performed. The signal received by the antenna 21 is input to the extraction circuit 25 via the bridge circuit 22, and extracted by the extraction circuit 25.
The 56 MHz frequency component is output to frequency divider 26. The frequency divider 26 divides the input frequency component, and outputs the obtained signal to the CPU 30 or the interface 27 as a clock, for example.

With the above configuration, the IC card 2 receives the identification signal transmitted from the reader / writer 1 and transmits a response signal to the reader / writer 1.
The IC card 2 transmits a unique identifier to the reader / writer 1 to authenticate the reader / writer 1 and performs wireless communication with the reader / writer 1.

FIG. 3 shows the reader / writer 1 and the IC
2 shows an example of a configuration of a signal frame communicated with the card 2. FIG. 3 (a) shows that the reader / writer 1
An example of a signal frame (command block) transmitted to the card 2 is shown. This command block includes a preamble signal PU (2 bytes) which is a carrier reproduction signal, and a synchronization signal (synchronization character) for securing synchronization. S
YN (2 bytes), a node address NAD (1 byte) indicating a transmission source and a destination, and signal length information LEN (1
Byte) and, for example, a command signal I / O for controlling read / write, etc., and selecting service contents when there are a plurality of services with the IC card 2.
It comprises an NS signal (1 byte), a data field (arbitrary number of bytes) containing information to be transmitted, and an error detection code EDC (2 bytes) for detecting an error occurring in the signal.

FIG. 3B shows an example of a signal frame (response block) transmitted from the IC card 2 to the reader / writer 1. The response block is a preamble which is a carrier signal for reproduction. Signal PU
(2 bytes), a synchronization signal (synchronization character) SYN (2 bytes) for ensuring synchronization, a node address NAD (1 byte) indicating a transmission source and a destination, and signal length information L
EN (1 byte), status code STS (1 byte), a data field (arbitrary number of bytes) containing information to be transmitted, and an error detection code EDC (2 bytes) for detecting an error occurring in a signal It is composed of

As described above, the transmission block such as the command block and the response block communicated between the reader / writer 1 and the IC card 2 includes the node address N including the source information and the destination information of the transmission block.
AD is included. In this example, the node address N
Based on the AD, the source and destination of the transmission block received by the reader / writer 1 are detected. That is, the reader / writer 1 determines whether the received transmission block is an identification signal, a notification signal, or the like from another reader / writer 1 by detecting the node address NAD in the transmission block by the CPU 18 described above. Perform the following processing.

The node address NAD described above is
In general, for example, when a plurality of logical connections are present between a plurality of different reader / writers 1 or IC cards 2 at the same time, it is used to distinguish these connections, that is, according to the source and destination information in the node address NAD. , These connections can be distinguished. Various codes such as a cyclic check character CRC can be used as the error detection code EDC.

Next, an IC is provided by the reader / writer 1 described above.
A procedure of a communication process performed on the card 2 will be described.
As described above, it is assumed that another reader / writer 1 is installed in the vicinity of the reader / writer 1 and the communicable areas of the plurality of different reader / writers 1 overlap. In the following, for convenience of explanation, these reader / writers 1 are referred to as reader / writers 1a and other reader / writers 1a.
Description will be made as b.

FIG. 4 shows an example of a temporal flow of processing performed by the reader / writer 1a and another reader / writer 1b. In this flow, the power of the reader / writer 1a is turned on (power is turned on). At this time, for a certain period of time, the reader / writer 1a waits for reception of an identification signal from another reader / writer 1b to check whether or not the identification signal has been transmitted. That is, when the power is turned on, the reader / writer 1a waits in a reception state for a predetermined time, and the identification signal is transmitted at regular time intervals by another reader / writer 1b in the card selection phase, for example. In this case, the identification signal transmitted from the other reader / writer 1b is received by the reader / writer 1a.

The reader / writer 1a, which has received the identification signal from the other reader / writer 1b, transmits the identification signal in a card selection phase, for example, after a lapse of a predetermined time from the reception of the identification signal. Thereafter, the reader / writer 1a constantly monitors, for example, the identification signal from the other reader / writer 1b, and detects the transmission timing of the identification signal from the other reader / writer 1b based on the received identification signal. The validity of the time interval between the transmission timing of the identification signal from the reader / writer 1b and the transmission timing of the identification signal from itself is confirmed.

That is, in the reader / writer 1a, it is determined whether or not the transmission timings are sufficiently shifted so that the identification signal transmitted from the reader / writer 1a does not interfere with the identification signal transmitted from the other reader / writer 1b. The validity is confirmed, whereby the identification signal is transmitted from itself at a timing different from the transmission timing from the other reader / writer 1b.

Also, for example, in another reader / writer 1b, a process of receiving an identification signal from a reader / writer 1a located nearby and confirming the validity of the transmission timing of the identification signal based on the received identification signal is also performed. Done. Note that the control of the transmission timing of the identification signal by the reader / writer 1a does not necessarily have to be performed in the manner described above. For example, the identification signal from another reader / writer 1b may be received a plurality of times and the other reader / writer may be received. A configuration may be used in which the transmission interval of the identification signal from 1b is detected, and the identification signal is transmitted using the time of the gap of the detected transmission interval.

FIG. 5 shows, for example, a reader / writer 1a.
2 shows an example of a procedure of a process performed by the reader / writer 1a after the transmission of the identification signal from. That is, the reader / writer 1a performs, for example, transmission processing of an identification signal and waits for reception (step S1), and detects whether or not a response signal has been received from the IC card 2 for the transmitted identification signal (step S2). ), It is detected whether or not the identification signal transmitted from another reader / writer 1b has been received (step S3).

According to this detection process, in the reader / writer 1a, for example, when the response signal from the IC card 2 is not detected and the identification signal from the other reader / writer 1b is detected, A process for confirming the validity of the time interval between the transmission timing of the identification signal and the transmission timing of the identification signal from itself is performed (step S4). As a result of this confirmation processing, if it is confirmed that the current transmission timing of the identification signal from the reader / writer 1a is different from the transmission timing of the identification signal from the other reader / writer 1b, the reader / writer 1a Then, the identification signal is transmitted while maintaining the current transmission timing a fixed time after receiving the identification signal from the reader / writer 1b (step S5).

On the other hand, as a result of the above confirmation processing, it is confirmed that at the current transmission timing by the reader / writer 1a, the identification signal from the reader / writer 1a and the identification signal from the other reader / writer 1b interfere with each other. In this case, the reader / writer 1a changes the transmission timing so that the identification signal from the reader / writer 1a does not interfere with the identification signal from the other reader / writer 1b. Is transmitted (step S6).

In the above processing, for example, when neither the response signal from the IC card 2 nor the identification signal from the other reader / writer 1b is received by the reader / writer 1a (step S3), the reader / writer 1a receives For example, the identification signal is transmitted at an arbitrary transmission timing (step S7). In the above processing, for example, when a response signal from the IC card 2 is received in response to the identification signal transmitted from the reader / writer 1a (step S
2) In the reader / writer 1a, communication processing with the IC card 2 is performed (step S8), and after the communication processing, the identification signal is transmitted again and the reception waits.

As described with reference to FIGS. 4 and 5, in the reader / writer, the identification signal is transmitted at a timing shifted from the transmission timing of the identification signal from another reader / writer. Even when the writer is installed in the vicinity, it is possible to prevent the identification signals transmitted from the plurality of different reader / writers from interfering with each other. It can be ensured that the IC card existing in the inside is reliably detected.

FIG. 6 shows another example of the temporal flow of the processing performed by the reader / writer 1a and the other reader / writer 1b. In this flow, the flow between the other reader / writer 1b and the IC card 2 is shown. When wireless communication is performed between devices, transmission of the identification signal from the reader / writer 1a is temporarily stopped. For example, when the reader / writer 1a and another reader / writer 1b are transmitting identification signals at transmission timings shifted from each other in the card selection phase, the response signal from the IC card 2 is received by the other reader / writer 1b. When the IC card 2 is authenticated, the notification signal described above is broadcast from the other reader / writer 1b.

When the reader / writer 1a receives the notification signal transmitted from the other reader / writer 1b, it suspends the process of transmitting the identification signal and waits for reception, and receives the identification signal from the other reader / writer 1b again. Wait for you.
On the other hand, when the other reader / writer 1b completes communication with the IC card 2 whose link has been established by the authentication processing, transmission of the identification signal is started again in the card selection phase. Upon receiving the identification signal transmitted again from the other reader / writer 1b, the reader / writer 1a releases the transmission stop of the identification signal and restarts the transmission of the identification signal in the card selection phase.

As described above, when communication between the other reader / writer 1b and the IC card 2 ends, a signal indicating the end is transmitted from the other reader / writer 1b. In this case, the reader / writer 1a releases the transmission stop of the identification signal based on the reception of the signal from the other reader / writer 1b and restarts the transmission of the identification signal.

FIGS. 7 and 8 show an example of a procedure of processing performed by the reader / writer 1a and the other reader / writer 1b. FIG. 7 shows an example of a processing procedure performed by the reader / writer 1a. That is, the reader / writer 1a transmits, for example, an identification signal and waits for reception (step S11), and detects whether or not the identification signal transmitted from another reader / writer 1b has been received (step S12).

According to this detection processing, when the reader / writer 1a detects the identification signal from the other reader / writer 1b, the reader / writer 1a transmits the identification signal, for example, at a timing different from the transmission timing of the identification signal from the other reader / writer 1b. After a lapse of a predetermined time from the reception, the identification signal is transmitted (step S13). The reader / writer 1a which has started transmitting the identification signal in this manner is used by another reader / writer 1b.
Is received (step S1).
4) In the reader / writer 1a, the transmission of the identification signal is temporarily stopped (Step S15), and the other reader / writer 1b is stopped.
It waits for an identification signal or the like from the device to be received (step S16).

The reader / writer 1a receives an identification signal or the like from another reader / writer 1b (step S1).
7) The transmission of the identification signal is started again, and the identification signal is transmitted at a timing shifted from the transmission timing from the other reader / writer 1b (step S13). In the above process, when the identification signal from the other reader / writer 1b is not received by the reader / writer 1a because the power of the other reader / writer 1b is turned off (step S12), The reader / writer 1a transmits an identification signal at an arbitrary transmission timing, for example (step S1).
8).

As described with reference to FIGS. 6 and 7, in the reader / writer, the transmission of the identification signal is stopped due to the reception of the notification signal from another reader / writer. It is possible to prevent the transmission of an identification signal during communication between a reader / writer and an IC card, thereby causing interference, thereby enabling communication between another reader / writer and the IC card. It is possible to ensure that the wireless communication to be performed is performed normally without being disturbed. In a system using such a reader / writer, for example, even when a plurality of different reader / writers are installed in the vicinity, when one reader / writer starts communication with an IC card, Since the transmission of the identification signal is stopped, the reader / writer and IC
The wireless communication started with the card can be prevented from being disturbed by another reader / writer.

FIG. 8 shows an example of a processing procedure performed by the other reader / writer 1b. That is, the other reader / writer 1b transmits, for example, an identification signal and waits for reception (step S21), and when there is a response from the IC card 2 to the transmitted identification signal (step S22), 2 is authenticated, and a notification signal is transmitted to the reader / writer 1a installed in the vicinity (step S23).

The other reader / writer 1b performs wireless communication with the authenticated IC card 2 (step S2).
4) When the communication with the IC card 2 is completed, the identification signal is transmitted again in the card selection phase (step S25), and the reception is waited as described above.

As described above, in the reader / writer, even if the communicable area overlaps with another reader / writer installed in the vicinity, for example, the mobile information communication body such as an IC card can be used. Before the start of communication between
The identification signal from itself and the identification signal from another reader / writer can be prevented from being transmitted at the same timing, whereby the identification signals from a plurality of different reader / writers interfere with each other and It is possible to ensure that a mobile information communication body that can communicate with the reader / writer is reliably detected.

Further, in the reader / writer, the transmission of the identification signal is stopped when wireless communication is performed between another reader / writer and a mobile information communication body such as an IC card, so that the identification signal transmitted from the reader / writer can be reduced. It is possible to prevent the signal transmitted from the other reader / writer from interfering with each other, thereby disturbing the wireless communication performed between the other reader / writer and the mobile information communication body. Can be prevented, and the communication can be performed normally.

From the above, for example, it is possible to install a plurality of reader / writers relatively close to each other and to install a plurality of reader / writers having different purposes near the same place. Thus, it is possible to reduce the installation space for the reader / writer. In addition, since a plurality of reader / writers can be installed in the vicinity, it is possible to increase the processing efficiency of the entire reader / writer, for example, by performing the processing by the plurality of reader / writers in parallel.

As a specific example, it is envisaged that a non-contact IC card is applied to a train ticket, for example.
The present invention can be applied to a case where there are a plurality of ticket gates at a station and a plurality of reader / writers are installed nearby. That is, when the distance between the reader / writers installed in each ticket gate is relatively short, the communicable areas of the reader / writers may overlap, but the present invention is applied. Accordingly, it is possible to prevent interference between reader / writers before and during communication between the reader / writer and the IC card, thereby improving the reliability of communication between the reader / writer and the IC card. Can be secured.

Also, when a plurality of types of tickets such as tickets and commuter passes are confirmed by separate reader / writers, respective ticket gates are separately provided, such as a ticket gate and a commuter pass ticket. There is no necessity, and the reader / writers for confirming the plurality of types of tickets can be collectively installed near one ticket gate, for example, so that the installation space of the reader / writers can be reduced. Also, in places where there are many users such as stations, for example, by installing a plurality of reader / writers in the vicinity as described above and performing parallel processing by these reader / writers, for example, Confirmation can be performed efficiently.

Here, in the above-described embodiment, the case where the communicable areas of a plurality of different reader / writers overlap has been described. However, this is not the case. For example, a plurality of different reader / writers may be connected between the antenna coils. Even if installed near enough to cause weak electromagnetic coupling,
As described above, it is possible to prevent interference between reader / writers.

In the above embodiment, the reader / writer and the I
A function configuration for preventing interference of identification signals between reader / writers before communication with the C card is started;
The case where both the reader / writer and the functional configuration for preventing the communication from being disturbed during the communication between the other reader / writer and the IC card are shown, but for example, only one functional configuration is provided. It may be provided in a reader / writer. When both the functional configurations are provided in the reader / writer as in the above-described embodiment, the reader / writer is provided both before and during communication between the reader / writer and a mobile information communication body such as an IC card. Interference between them can be prevented, and the reliability of communication between the reader / writer and the mobile information communication body can be ensured.

Further, in the reader / writer shown in the above embodiment, for example, the CPU executes a control program in a hardware resource having a processor and a memory to control the above-described interference prevention processing between the reader / writers. However, in the present invention, each functional means for executing the processing may be configured as an independent hardware circuit.

In the above embodiment, the case where an IC card is used as the mobile information communication body has been described. However, as described above, any mobile information communication body such as a name plate or a tag may be used. The present invention is often applicable to a reader / writer that performs wireless communication with various mobile information communication bodies.

[0076]

As described above, according to the reader / writer of the present invention, an identification signal is transmitted wirelessly to detect a communicable mobile information communication body and perform wireless communication with the mobile information communication body. In this case, for example, even if there is a possibility that interference due to electromagnetic coupling with other reader / writers installed in the vicinity, even when the transmission timing of the identification signal from the other reader / writer is detected, Since the identification signal is transmitted at a timing shifted from the transmission timing, it is possible to prevent the identification signals transmitted from the plurality of different reader / writers from interfering with each other. It is possible to ensure that a communicable mobile information communication body is detected.

According to the reader / writer of the present invention, when an identification signal is wirelessly transmitted to detect a communicable mobile information communication body and wireless communication with the mobile information communication body is performed, for example, when the mobile information communication body is installed nearby, Even if there is a possibility that interference due to electromagnetic coupling with another reader / writer that is being performed, it is transmitted when communication with the mobile information communication body is started by the other reader / writer. Since the transmission of the identification signal is stopped based on the detection of the notification signal, the identification signal from itself and the signal from the other reader / writer to the mobile information communication object to be communicated with each other interfere with each other. Can be prevented, thereby ensuring that wireless communication between another reader / writer and the mobile information communication body is reliably performed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a circuit configuration of a reader / writer according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a circuit configuration of an IC card.

FIG. 3 is an example of a transmission block communicated between a reader / writer and an IC card.

FIG. 4 is an example of a temporal flow of communication processing performed by a reader / writer.

FIG. 5 is an example of a procedure of a process performed by a reader / writer.

FIG. 6 is an example of a temporal flow of communication processing performed by a reader / writer.

FIG. 7 is an example of a procedure of a process performed by a reader / writer.

FIG. 8 is an example of a procedure of a process performed by a reader / writer.

FIG. 9 is an example of an IC card system.

FIG. 10 is an example of a transmission protocol between a reader / writer and an IC card.

FIG. 11 is a diagram for explaining interference between reader / writers.

FIG. 12 is a diagram for explaining interference between reader / writers;

[Explanation of symbols]

1. reader / writer, 2. IC card, 3. information terminal device, 11 antenna, 12. modulation unit,
13. Demodulation unit, 14 interface, 15
Display, 16. Speaker, 17 Interface, 18. CPU,

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuhiro Okada 3--14-20 Higashinakano, Nakano-ku, Tokyo Kokusai Electric Co., Ltd. (72) Keisuke Igarashi 3-14-20 Higashinakano, Nakano-ku, Tokyo Kokusai Electric Inside the corporation

Claims (2)

[Claims] 1. A reader / writer that wirelessly transmits an identification signal to detect a communicable mobile information communication body and wirelessly communicates with the mobile information communication body, comprising: a communication unit that receives a wireless signal; Detecting means for detecting the transmission timing of the identification signal from the other reader / writer based on the identification signal received from the reader / writer; and transmitting the identification signal by the communication means at a timing shifted from the detected transmission timing. A reader / writer comprising: 2. A reader / writer which wirelessly transmits an identification signal to detect a communicable mobile information communication body and performs wireless communication with the mobile information communication body, a communication means for receiving a wireless signal, Detecting means for detecting a notification signal transmitted from another reader / writer that has identified the communication body and starting a wireless communication with the mobile information communication body, based on the detection signal being detected by the detection means, And a communication control means for stopping transmission of the identification signal from the communication means.