JP2010213035A - Noncontact ic medium communication equipment, pointing direction switching antenna device, and method for discriminating presence direction of noncontact ic medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide noncontact IC medium communication equipment which detects the presence direction of an RFID tag 50 at high speed. <P>SOLUTION: In the noncontact communication equipment 1 including an antenna unit 30b, a pointing direction control unit 30a, and a digital control circuit 11, the pointing direction control unit 30a is configured to execute pointing direction switching processing (steps S2-S8, S31-S39, S42-S49) for switching the pointing direction of the antenna unit from starting reception of signals from the RFID tag 50 to completion of the reception, and the digital control circuit 11 is configured to execute presence direction discrimination processing (steps S16-S20) for discriminating the presence direction of the RFID tag 50 based on a reception level in each pointing direction, and to execute response data acquisition processing (step S21) for acquiring the response data of the RFID tag 50 from a series of signals which are received from the RFID tag 50 while switching the pointing direction of the antenna unit 30b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides, for example, a non-contact IC medium communication device, a directivity direction switching antenna device, and a non-contact IC medium presence direction determination that detect the presence direction of a non-contact IC medium or communicate with a non-contact IC medium in a specific range. Regarding the method.

  Conventionally, a non-contact IC medium communication device that communicates with a non-contact IC medium in a non-contact manner has been provided. A direction detecting device that detects the direction of a non-contact IC medium (wireless tag) using this non-contact IC medium communication device has also been proposed (see Patent Document 1).

  This direction detection device has a plurality of sets of array antennas and can switch between transmission directivity and reception directivity, executes transmission / reception processing with a non-contact IC medium, switches the directivity direction, and again performs non-contact IC. The process of executing the transmission / reception process with the medium and switching the directivity direction is repeated. Then, the direction detection device compares the received signal strengths in all directivity directions and detects that the directivity direction having the maximum value is the presence direction of the non-contact IC medium.

  However, this method using the direction detection device has a problem in that it takes a long time to detect the direction because the transmission / reception process with the non-contact IC medium must be successful a plurality of times. For this reason, for example, when a non-contact IC medium is moving, there is a problem that it cannot be detected correctly.

  More specifically, since a certain amount of time is required for the transmission / reception process, if a non-contact IC medium comes out of the communicable region even during one of the multiple transmission / reception processes, the transmission / reception process is finally performed. There was a problem that an error occurred without completing. In addition, when the non-contact IC medium is moving, the presence direction of the non-contact IC medium at the time of transmission / reception processing in a certain directional direction and the presence of the non-contact IC medium at the time of transmission / reception processing in another directional direction There was also a problem that the direction might be different.

JP 2008-45554

  In view of the above problems, the present invention provides a non-contact IC medium communication device, a directivity direction switching antenna device, and a non-contact IC medium presence direction determination method capable of detecting the presence direction of a non-contact IC medium at high speed. The purpose is to improve convenience.

  The present invention includes an antenna unit that communicates with a non-contact IC medium, and a directivity direction control unit that controls the directivity direction of the antenna unit, and the directivity direction control unit starts receiving a signal from the non-contact IC medium And a non-contact IC medium communication device that is configured to execute a directivity direction switching process for switching the directivity direction of the antenna unit between the end of reception and the end of reception.

The non-contact IC medium refers to a medium such as an RFID tag that can store information and communicate without contact. This non-contact IC medium is equipped with a passive type that does not have a power source and obtains an induced electromotive force from the outside and transmits a signal, a semi-passive type that has a power source and receives a signal from the outside, and transmits a signal, And an active type that transmits a signal by itself.
According to the present invention, the existence direction of the non-contact IC medium can be detected at high speed.

  As an aspect of the present invention, a signal processing unit for processing a signal communicating with the non-contact IC medium is provided, and the signal processing unit determines the presence direction of the non-contact IC medium based on a reception level in each directivity direction. It is possible to adopt a configuration for executing the existing direction determination process.

The signal communicating with the non-contact IC medium may be a transmission signal transmitted toward the non-contact IC medium, a reception signal received from the non-contact IC medium, or both.
According to this aspect, the existence direction of the non-contact IC medium can be detected.

As another aspect of the present invention, the signal processing unit performs response data acquisition processing for acquiring response data of the non-contact IC medium from a series of signals received from the non-contact IC medium while switching the directivity direction of the antenna unit. It can be configured to execute.
Thereby, the response data of the non-contact IC medium can be acquired.

  As an aspect of the present invention, a detection unit for detecting the signal is provided, and the directivity direction switching process receives a detection signal obtained by detecting the signal from the detection unit, and determines a switching direction of the directivity direction based on the detection signal. It can be set as the structure to do.

The switching timing is determined by storing the switching time in an appropriate storage means and reading the switching time, or by determining in advance in a program for performing switching control and determining by the program control. Can be configured.
According to this aspect, the control in the directivity direction can be started after receiving the signal, and the time suitable for starting the control of the switching timing can be easily obtained.

  As an aspect of the present invention, the directivity direction switching process may be configured to switch the directivity direction to a predetermined direction after a predetermined time from receiving the detection signal.

The predetermined time may be a time later than a known time from when the response request signal is transmitted until the signal of the non-contact IC medium returns.
According to this aspect, the response request signal can be detected to determine the switching direction of the directivity direction, and the directivity direction can be switched at a stable timing.

Further, as an aspect of the present invention, the directivity direction switching process is performed in such a manner that the directivity direction control unit receives a direction switch instruction signal from a transmission signal processing unit that processes a signal transmitted to the non-contact IC medium, and It can be configured to execute.
According to this aspect, the directivity direction can be switched at an appropriate timing without providing a detection unit in the directivity variable antenna.

  Further, as an aspect of the present invention, a transmission antenna that transmits a response request signal for requesting a response to the non-contact IC medium is provided separately from the antenna unit, and the transmission antenna is connected to each directivity direction by the antenna unit The response request signal can be transmitted to an area wider than the reception area in FIG.

  Thereby, even if the non-contact IC medium is a passive type that operates by obtaining an induced electromotive force without mounting a battery, the presence direction can be detected after the power is stably supplied. Therefore, the stability of communication with the non-contact IC medium is improved, and it is possible to prevent the non-contact IC medium from going out of the communicable region by switching the directivity direction.

  The present invention also includes a plurality of antenna elements, a phase shifter that arbitrarily changes the phase of the signal for each antenna element, a detection circuit that detects a signal used for communication with a non-contact IC medium, and the detection circuit. It can be set as a directivity direction switching antenna apparatus provided with the control circuit which controls the phase change by the said phase shifter based on a detection signal.

  Thus, the directivity direction switching antenna device can be connected to the existing reader / writer device to form a non-contact IC medium communication device.

Further, the present invention switches the directivity direction of the antenna unit between the start of reception of a signal from the non-contact IC medium and the end of reception, and the presence of the non-contact IC medium based on the reception level in each directivity direction A non-contact IC medium existence direction determining method for determining the direction can be used.
Thereby, the presence direction of the non-contact IC medium can be determined.

  According to the present invention, the existence direction of the non-contact IC medium can be detected at high speed.

The block diagram which mainly shows the structure of a reader / writer. The block diagram which mainly shows the structure of a directivity variable antenna. The flowchart of direction change. Explanatory drawing explaining directivity direction switching. The flowchart of the operation | movement which detects the presence direction of a RFID tag. Explanatory drawing explaining the method to detect an existing direction from a response signal. FIG. 6 is a block diagram illustrating a configuration of a directivity variable antenna according to a second embodiment. 10 is a flowchart of switching of directivity directions according to the second embodiment. Explanatory drawing explaining the directivity direction switching of Example 2. FIG. It is a block diagram which shows the structure of the directivity variable antenna of Example 3. 10 is a flowchart of directing direction switching according to the third embodiment. Explanatory drawing explaining the direction-of-direction switch of Example 3. FIG. FIG. 9 is a block diagram illustrating a configuration of a reader / writer according to a fourth embodiment. FIG. 6 is a block diagram illustrating a configuration of a directivity variable antenna according to a fourth embodiment. Explanatory drawing explaining each communication area | region for transmission of Example 4 and reception.

  The present invention uses a variable directivity antenna capable of switching the directivity direction, and acquires the signal level in each directivity direction by switching the directivity direction while the non-contact IC medium transmits one response signal. It is.

  As a result, it is possible to accurately detect the presence direction of the non-contact IC medium in a short time.

  Also, since the response signal can be received only once, it is possible to reduce the possibility that the moving non-contact IC medium will go out of the communicable area in the middle of processing and receive the response signal, resulting in an error. It is.

  In addition, when it is desired to communicate only a non-contact IC medium in a desired area among all areas communicable with a directivity variable antenna, the reception level in each directional direction is acquired at high speed, and this is processed. Thus, it is also possible to obtain communication data of only a non-contact IC medium existing in a region narrowed down like a pencil beam antenna.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, the variable directivity antenna 30 detects information (ID read command) transmitted from the reader / writer 10 to the RFID tag 50 (non-contact IC medium), and using this as a trigger, the variable directivity antenna 30 performs directivity of the radio wave by self-control. A first embodiment for switching the direction will be described.

FIG. 1 is a block diagram mainly showing the configuration of the reader / writer 10 of the non-contact communication device 1 (non-contact IC medium communication device) composed of the reader / writer 10 and the directivity variable antenna 30.
The reader / writer 10 has a digital control circuit 11 as a signal processing unit, a modulator 12 (MOD: Modulator), a transmission side amplifier 13 (AMP: Amplifier), and a circulator 14 connected in this order on the transmission side. An RF cable 42 is connected to the subsequent stage. On the receiving side of the reader / writer 10, a demodulator 17 (DEM) and a receiving side amplifier 16 are connected in this order after the circulator 14, and a digital control circuit 11 is connected after the receiving side amplifier 16. Yes.

  With this configuration, the digital control circuit 11 transmits various command data such as an ID read command to be transmitted to the RFID tag 50, the modulator 12 modulates this, and the transmission side amplifier 13 amplifies and amplifies this. The transmitted signal is transmitted from the circulator 14 through the RF cable 42 to the directivity variable antenna 30 (directivity direction switching antenna device).

The response signal from the directivity variable antenna 30 is transmitted to the reception side amplifier 16 through the circulator 14, and the signal amplified by the reception side amplifier 16 is modulated by the demodulator 17 to become a digital signal and transmitted to the digital control circuit 11. Is done.
The digital control circuit 11 receives this digital signal and executes various processes such as calculation and storage in a memory.

FIG. 2 is a block diagram illustrating a configuration of mainly the directivity variable antenna 30 of the non-contact communication apparatus 1.
The directivity variable antenna 30 is an antenna device having directivity. The directivity variable antenna 30 includes, as a control system, a CPU 32 (central processing unit) as a control circuit, a plurality of D / A converters 36 (DAC: Digital Analog Converter), and a plurality of phases. Devices 37 are connected in this order. A memory 31 is connected to the CPU 32.

  Further, in the variable directivity antenna 30, a plurality of phase shifters 37 and a plurality of antenna elements 38 are connected in this order as a communication signal system at the subsequent stage of the RF cable 42. A detection circuit 33 (DEM: Demodulator) is connected in parallel with the phase shifter 37 as a detection unit for detecting a communication signal transmitted through the RF line 44. The detection circuit 33 is connected to the CPU 32 at the subsequent stage.

  Here, the antenna unit 30 b is configured by the plurality of antenna elements 38. The antenna element 38 can be an appropriate antenna capable of non-contact communication, such as a loop antenna or a UHF antenna. In addition, the memory 31, CPU 32, detection circuit 33, a plurality of D / A converters 36, and a plurality of phase shifters 37 constitute a directivity direction control unit 30a.

  A transmission signal transmitted from the reader / writer 10 via the RF cable 42 is transmitted to the antenna element 38 via the RF line 44 and each phase shifter 37 provided for each antenna element 38. A reception signal received from the RFID tag 50 is transmitted in the reverse order.

  Here, the phase shifter 37 functions as a phase shifter that arbitrarily changes the phase of the signal. More specifically, a transmission signal and a reception signal from each antenna element 38 are phase-shifted to a desired value by the phase shifter 37. At this time, only radio waves in the direction in which all the signals after the phase shift are in phase are transmitted and received with high sensitivity, and radio waves in different directions have a phase difference when the antenna elements 38 are radiated and reached. The strength decreases according to the angle. With such setting of each phase shifter 37, the directivity variable antenna 30 can switch the directivity direction of transmission / reception of radio waves.

  The transmission signal transmitted from the reader / writer 10 via the RF cable 42 is also transmitted to the detection circuit 33. The detection circuit 33 detects this transmission signal and transmits the detection signal to the CPU 32.

  The CPU 32 executes various arithmetic operations and control operations in accordance with control signals received from the reader / writer 10 via the control cable 41. Further, the CPU 32 uses the memory 31 as a storage area, and transmits a phase control signal for switching the directivity direction to each phase shifter 37 via the plurality of D / A converters 36 via the control line 43. Thereby, it is possible to control the phase of each phase shifter 37 and switch the directivity direction of the directivity variable antenna 30. Note that switching of the directivity direction of the directivity variable antenna 30 by the CPU 32 can be executed by obtaining a start trigger by various methods, but in the first embodiment, the signal transmission from the detection circuit 33 is started. It is a trigger.

  The memory 31 transmits various data such as switching timing data for switching the directing direction, response waiting time data from when an ID read command is transmitted to the RFID tag 50 until a response signal is received, and transmission from the detection circuit 33. Various programs such as a directivity direction switching program for switching the directivity direction according to the received signal are stored.

  FIG. 3 is a flowchart illustrating an operation when the variable directivity antenna 30 transmits an ID read command received from the reader / writer 10 to the RFID tag 50 and receives a response signal from the RFID tag 50. FIG. FIG. 4 is an explanatory diagram for explaining communication areas (S4), (S6), and (S8) in each of the directivity direction patterns A, B, and C. FIG. 4B shows the reader / writer 10 and the directivity during this operation. It is explanatory drawing explaining the relationship between the property variable antenna 30 and the RFID tag 50 with a time chart.

  The digital control circuit 11 of the reader / writer 10 starts transmission of an ID read command as a response request signal toward the RFID tag 50 (step S1). The ID read command transmitted at this time may be a command for causing the RFID tag 50 to transmit its own ID as a response signal (response data) as shown in (S1) of FIG. 4B, for example. Instead, it may be configured by an appropriate command for requesting the RFID tag 50 to perform processing.

  The directivity variable antenna 30 detects the ID read command transmitted from the reader / writer 10 through the RF cable 42 by the detection circuit 33, and the CPU 32 that receives the detected signal recognizes the response timing from the RFID tag 50. (Step S2).

  More specifically, the response waiting time until the ID read command is transmitted from the antenna element 38, the RFID tag 50 responds with a response signal, and the response signal is received by the directivity variable antenna 30 is known. Therefore, the response waiting time data is read from the memory 31.

  Also, since the response signal transmission time from when the RFID tag 50 starts transmitting the response signal to when the transmission ends is known, switching timing data for switching the directivity direction of the directivity variable antenna 30 within this response signal transmission time is also included. Read from the memory 31.

  The CPU 32 starts an internal timer (step S3), and changes the directivity direction of the directivity variable antenna 30 to the directivity direction pattern A, which is the first pattern, as shown in (S4) of FIGS. Set (step S4). Thereafter, a response signal received from the RFID tag 50 can be received at any time. When the response signal starts to be received, the response signal is transmitted to the reader / writer 10 via the RF cable 42.

  The CPU 32 stands by until the first switching time of the switching timing data elapses and the time is up (step S5: No). If the first switching time has elapsed (step S5: Yes), the CPU 32 sets the directivity direction of the directivity variable antenna 30 to the second pattern, as shown in (S6) of FIGS. The directivity pattern B is set (step S6).

  The CPU 32 waits until the second switching time of the switching timing data elapses and the time is up (step S7: No). If the second switching time has elapsed (step S7: Yes), the CPU 32 sets the directivity direction of the directivity variable antenna 30 to the third pattern as shown in (S8) of FIGS. The directivity direction pattern C is set (step S8), and the directivity direction switching process (steps S2 to S8) is completed.

  The directivity variable antenna 30 transmits the response signal received from the RFID tag 50 to the reader / writer 10 until the end time when the reception of the response signal is completed in the directivity pattern C, and then ends the process. .

  FIG. 5 is a flowchart showing an operation until the reader / writer 10 transmits an ID read command, receives a response signal, and detects the existence direction of the RFID tag 50, and FIG. 6 detects the existence direction from the response signal. It is explanatory drawing explaining the method to do.

  After transmitting the ID read command (step S11), the digital control circuit 11 of the reader / writer 10 starts a response wait timer for waiting for a response signal (step S12).

  If there is no response (step S13: No), the digital control circuit 11 waits until time-out (response waiting time elapses) (step S14: No), and if time-out (step S14: Yes), the RFID tag 50 is The process ends as it does not exist (no tag).

  When there is a response (step S13: Yes), the digital control circuit 11 receives and demodulates the response signal (step S15), and divides the demodulated response waveform into three (step S16). The three divisions are divisions according to the directivity direction switching timing of the directivity variable antenna 30 described above. That is, as shown in FIG. 6, the pattern is divided into each of the directivity direction patterns A, B, and C.

In the figure, the directional patterns A, B, and C are accurately divided at the switching timing. However, a slight error between the switching timing and the division position may be allowed. Further, a predetermined range of the central portion of each directivity pattern may be cut out by removing a little before and after the switching timing. In this case, it is possible to accurately cut out the switching of the directivity pattern and the division position and prevent the influence of noise at the time of switching.
In addition, the directivity directions are three patterns of A, B, and C, and the number of divisions is also three.

  The digital control circuit 11 performs FFT processing on the first divided waveform (the waveform of the directivity direction pattern A), and calculates the reception level (A signal level in FIG. 6) (step S17).

  The digital control circuit 11 performs FFT processing on the divided second waveform (the waveform of the directivity direction pattern B), and calculates a reception level (B signal level in FIG. 6) (step S18).

  The digital control circuit 11 performs an FFT process on the divided third waveform (the waveform of the directivity direction pattern C), and calculates a reception level (C signal level in FIG. 6) (step S19).

  In this way, after performing the FFT process on all the directional pattern and acquiring the reception level, the digital control circuit 11 executes the direction discrimination process (existing direction discrimination process) (step S20).

  In this direction determination process, the direction in which the RFID tag 50 that transmitted the response signal is present can be determined by various methods. Specifically, the direction in which the reception level is the highest can be the direction in which the RFID tag 50 exists. Also, within the range of the directivity direction with the highest reception level, it can be determined whether the center, the right side, or the left side from the magnitude relationship of other reception levels.

  In addition, it can be used as a pencil beam antenna in a pseudo manner to determine whether or not the RFID tag 50 is in a set narrow area. In this case, a reception level ratio, which is a ratio of reception levels in the respective directivity directions, is calculated, and the RFID tag 50 in an area where only the RFID tag 50 whose reception level ratio is within a desired threshold range is obtained. As a result, the boundary of the communicable area is usually ambiguous, but the RFID tag 50 existing within the threshold range clearly divided by the arithmetic expression can be detected.

  The digital control circuit 11 executes a response data acquisition process (step S21) for acquiring data of the RFID tag 50 (there is a tag), and ends the process. At this time, as the data to be acquired, the ID of the RFID tag 50 read from the response signal, the presence direction determined in step S20, and the like may be acquired. Further, the acquired data such as ID and direction may be stored in an appropriate storage unit, or may be output by an appropriate output unit such as transmitted to another device such as a separately connected computer.

  With the above configuration and operation, the direction in which the RFID tag 50 exists can be detected at high speed. Further, communication with the RFID tag 50 in a desired direction can be realized at high speed.

  More specifically, while the RFID tag 50 transmits one response signal, it is possible to switch the directivity direction and acquire the reception level in each directivity direction. For this reason, it is not necessary to communicate with the RFID tag 50 a plurality of times. Therefore, it is possible to significantly reduce the time required for the entire processing by reducing the number of communications.

  In addition, since the directivity direction is switched during reception of the response signal using the variable directivity antenna 30, the response signal itself can be received without interruption even during switching of the directivity direction. Therefore, data such as an ID included in the response signal can be read without any problem, and communication can be established and normal processing can be performed.

  In addition, the reception level in a plurality of directivity directions can be obtained while one response signal is being received, and necessary reception processing can be completed, so that the RFID tag 50 moves relative to the directivity variable antenna 30. Even if it is, it is possible to reduce the possibility that the RFID tag 50 exits the communicable area and becomes an error before the communication is completed.

  Further, the directivity variable antenna 30 itself can detect the detection circuit 33 and determine the switching timing of the directivity direction or execute the switching. Therefore, the reader / writer 10 and the RFID tag 50 can be used without adding a component.

  Further, even if the RFID tag 50 is an active type having a power supply and transmitting a signal itself, the directing direction is switched in response to the RF signal sent from the RFID tag 50 until the presence position need not be detected. Can be prevented. That is, since an operation such as switching of the directivity direction is started only when a response request is transmitted to the RFID tag 50, even if a signal is received from the RFID tag 50 at other timings, the operation cannot be performed.

  Next, a description will be given of a second embodiment in which a response signal from the RFID tag 50 is detected, and using this as a trigger, the directivity variable antenna 30 switches the directivity direction of the radio wave by self-control.

FIG. 7 is a block diagram illustrating a configuration of the directivity variable antenna 30 according to the second embodiment.
In the first embodiment, the transmission signal transmitted from the reader / writer 10 is detected, whereas the detection circuit 33 of the second embodiment detects a reception signal received from the RFID tag 50.

The memory 31 also stores a first switching time from when the response signal is received until the directional pattern is switched from A to B, and a second switching time until the directional pattern is switched from B to C. Yes.
Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted.

  FIG. 8 is a flowchart illustrating an operation when the variable directivity antenna 30 according to the second embodiment processes a response signal received from the RFID tag 50. FIG. 9 illustrates the reader / writer 10 and the variable directivity antenna during the operation. 30 is an explanatory diagram for explaining the relationship between the RFID tag 50 and the RFID tag 50 using a time chart.

  As shown in FIG. 9 (S31), the CPU 32 of the directivity variable antenna 30 sets the directivity direction of the directivity variable antenna 30 to the directivity direction pattern A that is the first pattern (step S31). Thereafter, a response signal received from the RFID tag 50 can be received at any time. When the response signal starts to be received, the response signal is transmitted to the reader / writer 10 via the RF cable 42.

  The digital control circuit 11 of the reader / writer 10 starts transmitting an ID read command toward the RFID tag 50 (step S32). The ID reading command transmitted at this time may be a command that causes the RFID tag 50 to transmit its own ID as a response signal, as shown in FIG. 9, for example. It may be configured by an appropriate command.

  The CPU 32 of the variable directivity antenna 30 starts receiving a response signal from the RFID tag 50 (step S33), and detects the response signal by the detection circuit 33 (step S34). At this time, the CPU 32 that has received the signal detected by the detection circuit 33 recognizes the response start timing from the RFID tag 50.

  More specifically, since the response is detected when the response signal is detected, the memory stores the first switching time until the directional pattern is switched from A to B and the second switching time until the switching from B to C. Read from 31.

  The CPU 32 starts an internal timer (step S35) and waits until the first switching time of the switching timing data elapses and the time is up (step S36: No). If the first switching time has elapsed (step S36: Yes), the CPU 32 sets the directivity direction of the directivity variable antenna 30 to the directivity direction pattern B that is the second pattern, as shown in (S37) of FIG. (Step S37).

  The CPU 32 stands by until the second switching time of the switching timing data elapses and the time is up (step S38: No). If the second switching time has elapsed (step S38: Yes), the CPU 32 sets the directivity direction of the directivity variable antenna 30 to the directivity direction pattern C, which is the third pattern, as shown in (S39) of FIG. (Step S39), the directivity direction switching process (Steps S31 to S39) is completed.

  The directivity variable antenna 30 transmits the response signal received from the RFID tag 50 to the reader / writer 10 until the end time when the reception of the response signal is completed in the directivity pattern C, and then ends the process. .

  The operation from when the reader / writer 10 transmits the ID read command, receives the response signal, and detects the direction in which the RFID tag 50 exists is the same as that described with reference to FIG. Description is omitted.

  With the configuration and operation described above, the same effects as in the first embodiment can be obtained. In addition, the time when the response signal of the RFID tag 50 starts to be received and detected is the time when the timing of switching the directivity direction is started, and an accurate switching timing can be easily obtained.

  Further, since the switching timing is determined after receiving the response of the RFID tag 50, the directing direction can be switched at an appropriate switching timing even when the RFID tag 50 is an active type and transmits a signal itself. Therefore, even if a response request is not transmitted from the reader / writer 10, if an RF signal is received from the active type RFID tag 50, the direction can be switched and the direction can be detected in response to the RF signal.

Next, a third embodiment in which the directivity variable antenna 30 switches the directivity direction of the radio wave by a directivity direction control command from the reader / writer 10 will be described.
FIG. 10 is a block diagram illustrating a configuration of the directivity variable antenna 30 according to the third embodiment. The directivity variable antenna 30 has a configuration obtained by removing the detection circuit 33 from the first embodiment. Except for the fact that the detection circuit 33 is not provided, the configuration is the same as that of the directivity variable antenna 30 of the first embodiment, and thus detailed description thereof is omitted.

  FIG. 11 is a flowchart showing the operation when the variable directivity antenna 30 receives a response signal from the RFID tag 50 while switching the directivity direction by the directivity direction control command received from the reader / writer 10, and FIG. It is explanatory drawing explaining the relationship between the inside reader / writer 10, the directivity variable antenna 30, and the RFID tag 50 with a time chart.

  The digital control circuit 11 (transmission signal processing unit) of the reader / writer 10 transmits the switching timing and switching pattern of the directional direction as a direction switching instruction signal to the CPU 32 of the variable directivity antenna 30 by the control cable 41 (step S41). .

  The CPU 32 of the directivity variable antenna 30 stores the received switching timing and switching pattern in the memory 31 (step S42), and starts an internal timer with the timer value included in this switching timing (step S43).

  The digital control circuit 11 of the reader / writer 10 starts transmitting an ID read command toward the RFID tag 50 (step S44). The ID reading command to be transmitted at this time may be a command that causes the RFID tag 50 to transmit its own ID as a response signal, as shown in FIG. 12 (S44), for example. It may be configured by an appropriate command that requests processing.

  As shown in FIG. 12 (S45), the CPU 32 of the directivity variable antenna 30 sets the directivity direction of the directivity variable antenna 30 to the directivity direction pattern A that is the first pattern (step S45). Thereafter, a response signal received from the RFID tag 50 can be received at any time. When the response signal starts to be received, the response signal is transmitted to the reader / writer 10 via the RF cable 42.

  The CPU 32 stands by until the first switching time of the switching timing data elapses and the time is up (step S46: No). If the first switching time has elapsed (step S46: Yes), the CPU 32 sets the directivity direction of the directivity variable antenna 30 to the directivity direction pattern B that is the second pattern, as shown in (S47) of FIG. (Step S47).

  The CPU 32 stands by until the second switching time of the switching timing data elapses and the time is up (step S48: No). When the second switching time has elapsed (step S48: Yes), the CPU 32 sets the directivity direction of the directivity variable antenna 30 to the directivity direction pattern C that is the third pattern, as shown in (S49) of FIG. (Step S49), the directivity direction switching process (Steps S42 to S49) is completed.

  The directivity variable antenna 30 transmits the response signal received from the RFID tag 50 to the reader / writer 10 until the end time when the reception of the response signal is completed in the directivity pattern C, and then ends the process. .

With the above configuration and operation, the same effects as in the first embodiment can be obtained.
In addition, since the reader / writer 10 instructs the switching timing and switching pattern of the directivity direction of the directivity variable antenna 30, it is not necessary to provide the detection circuit 33 in the directivity variable antenna 30, and the conventional directivity variable antenna 30 is used. Can do.

  Further, in order to execute the switching direction and switching pattern of the directing direction instructed from the reader / writer 10 before transmitting the ID read command, the variable directivity antenna 30 prepares for switching the directing direction before starting the reception of the response signal. be able to. Therefore, the directivity direction can be switched reliably during a short time during which the response signal is received.

  Next, a description will be given of a fourth embodiment in which the variable directivity antenna 30 is used for receiving a signal from the RFID tag 50 and the reader / writer 10 is provided with a wide-area transmission antenna 40 as a transmission antenna.

FIG. 13 is a block diagram mainly showing the configuration of the reader / writer 10.
Unlike the first embodiment, the reader / writer 10 is not provided with the circulator 14, and two types of antennas, that is, a wide-area transmitting antenna 40 and a receiving directivity variable antenna 30 are connected.

The digital control circuit 11 is provided with a modulator 12 and a transmission-side amplifier 13 as a transmission path, and a wide-area transmission antenna 40 is connected downstream thereof.
The digital control circuit 11 is provided with a reception side amplifier 16 and a demodulator 17 as a reception path, and a directional variable antenna 30 is provided upstream thereof.

FIG. 14 is a block diagram mainly showing the configuration of the directivity variable antenna 30.
The directivity variable antenna 30 has the same configuration as that of the third embodiment. The directivity direction control command is received from the reader / writer 10 without the detection circuit 33, and the CPU 32 switches the directivity direction. The variable directivity antenna 30 may have the same configuration as in the first and second embodiments.

FIG. 15 is an explanatory diagram for explaining communication areas of the variable directivity antenna 30 and the wide-area transmitting antenna 40.
The directivity variable antenna 30 can switch the directivity direction to the patterns A to C as in the first to third embodiments, and can communicate with the RFID tag 50 in each directivity direction.

  The wide-area transmitting antenna 40 transmits radio waves to an area that is sufficiently wider than an area in which the variable directivity antenna 30 can communicate. Specifically, for example, if the RFID tag 50 exists in an area where the directivity variable antenna 30 can communicate in any direction, the radio wave can be supplied to the RFID tag 50.

  Since other configurations and operations are the same as those in the first to third embodiments, detailed description thereof is omitted.

With the above configuration, the same effect as that of the third embodiment can be obtained.
Further, the wide area transmission antenna 40 can transmit a transmission signal to the RFID tag 50 in a wide area. For this reason, even if the RFID tag 50 is of a type that is activated by induced electromotive force without having a power source, sufficient power can be supplied.

  More specifically, for example, when the RFID tag 50 exists in the area of the directivity direction pattern A, the RFID tag is transmitted even if the transmission signal is transmitted from the directivity variable antenna 30 of the first to third embodiments in the direction of the directivity direction pattern C. 50, the radio wave reaching 50 may be weak and the RFID tag 50 may not be able to obtain a sufficient induced electromotive force. Even in such a case, if sufficient power can be supplied by the wide-area transmitting antenna 40, the RFID tag 50 can operate by obtaining induced electromotive force, and sufficient radio waves can be transmitted to the directional variable antenna 30 of the directional pattern C. A strong response signal can be transmitted.

  The fourth embodiment is not limited to providing the wide-area transmission antenna 40 with respect to the configuration of the third embodiment, and may be realized by providing the wide-area transmission antenna 40 with respect to the first and second embodiments. Good.

  In each of the above embodiments, the directivity direction switching pattern is set to three directions. However, the present invention is not limited to this, and switching to a plurality of directions can be performed.

  The present invention is not limited only to the configuration of the above-described embodiment, and many embodiments can be obtained.

  The present invention can be used in a technology for contactless communication. Specifically, it can be used for an appropriate communication technique using a UHF antenna or an HF antenna.

DESCRIPTION OF SYMBOLS 1 ... Non-contact communication apparatus, 11 ... Digital control circuit, 30 ... Directional variable antenna, 30a ... Directional direction control part, 30b ... Antenna part, 32 ... CPU, 33 ... Detection circuit, 37 ... Phaser, 38 ... Antenna element , 40 ... Wide-area transmission antenna, 50 ... RFID tag

Claims (9)

An antenna for communicating with a non-contact IC medium;
A directivity direction control unit for controlling the directivity direction of the antenna unit,
The directivity direction control unit is configured to execute directivity direction switching processing for switching the directivity direction of the antenna unit from the start of reception of a signal from the noncontact IC medium to the end of reception. . A signal processing unit for processing a signal communicating with the non-contact IC medium;
The signal processing unit
The non-contact IC medium communication device according to claim 1, wherein the non-contact IC medium communication device is configured to execute an existence direction determination process for determining an existence direction of the non-contact IC medium based on a reception level in each directivity direction. The said signal processing part is a structure which performs the response data acquisition process which acquires the response data of the said non-contact IC medium from the series of signals received from the said non-contact IC medium, changing the directivity direction of the said antenna part. 3. The non-contact IC medium communication device according to 2. A detector for detecting the signal;
4. The non-contact IC according to claim 1, wherein the directivity direction switching process is configured to receive a detection signal obtained by detecting the signal from the detection unit, and to determine a switching direction of the directivity direction based on the detection signal. Media communication device. The directivity direction switching process is:
The non-contact IC medium communication device according to claim 4, wherein the directivity direction is switched to a predetermined direction after a predetermined time from receiving the detection signal. The directivity direction switching process is:
4. The configuration according to claim 1, wherein the directivity direction control unit receives a direction switching instruction signal from a transmission signal processing unit that processes a signal to be transmitted to the non-contact IC medium, and executes the direction switching instruction signal according to the direction switching instruction signal. Non-contact IC medium communication device. In addition to the antenna unit, a transmission antenna for transmitting a response request signal for requesting a response to the non-contact IC medium,
The contactless IC medium communication according to any one of claims 1 to 6, wherein the transmission antenna is configured to transmit the response request signal to an area wider than a reception area in each directivity direction by the antenna unit. apparatus. A plurality of antenna elements;
A phase shifter that arbitrarily changes the phase of the signal for each antenna element;
A detection circuit for detecting a signal used for communication with a non-contact IC medium;
A directivity direction switching antenna apparatus comprising: a control circuit that controls a phase change by the phase shifter based on a detection signal from the detection circuit. Switching the directivity direction of the antenna unit between the start of receiving the signal from the non-contact IC medium and the end of reception,
A non-contact IC medium presence direction determination method for determining the presence direction of the non-contact IC medium based on a reception level in each directivity direction.

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