JP2007243705A - External transmission/reception apparatus, transmission/reception system, and transmission/reception method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a location in which a wireless transmission device is present. <P>SOLUTION: An external transmission/reception apparatus 10 transmits a transmission signal. A wireless transmission device 20 is activated when it receives a transmission signal from the external transmission/reception apparatus 10, and transmits a reply signal at an amplitude level corresponding to that of the transmission signal. ID information is written in the reply signal. Furthermore, the external transmission/reception apparatus 10 determines a distance (communication distance) between itself and the wireless transmission device based on a status (such as an amplitude level) of a reply signal when it receives the reply signal from the wireless transmission device 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an external transmission / reception device communicating with a wireless transmission device, a transmission / reception system for communication between the wireless transmission device and the external transmission / reception device, and transmission / reception executed between the wireless transmission device and the external transmission / reception device. Regarding the method.

  In recent years, a transmission / reception system in which an external transmission / reception device and a wireless transmission device exchange data signals in a non-contact manner using radio waves in a radio frequency band has been put into practical use. A typical example of a wireless transmission device is a so-called RFID (Radio Frequency Identification) tag. RFID tags are also called wireless tags, and are used in various frequency bands.

  For example, in a wireless tag (so-called IC card) having a communication frequency of 13.56 MHz, the following communication is performed between an external transmission / reception device (for example, a reader / writer) and a wireless transmission device (for example, a wireless tag). Is executed. Here, a case where the reply method from the wireless tag is a load modulation method will be described.

  First, in the reader / writer, a 13.56 MHz carrier wave is amplitude-modulated (Amplitude Shift Keying; ASK) based on transmission data, and an electromagnetic wave (or microwave) corresponding to the modulated carrier wave is transmitted from the transmission / reception coil.

  Next, in the wireless tag, the electromagnetic wave from the reader / writer is received by the transmission / reception coil, and power supply power for operation of the internal circuit is generated. Some wireless tags include a driving power source such as a battery. In that case, driving power may not be generated from a received signal. Also, transmission data is restored from the modulated carrier wave by the demodulation circuit, and the microcomputer mounted on the wireless tag reads reply data (for example, a data string stored in the storage unit) according to the transmission data. Further, the output circuit of the non-related tag amplitude-modulates a subcarrier (for example, a 212 KHz subcarrier) based on the return data, and changes the impedance to the transmission / reception coil in accordance with the modulation subcarrier.

  On the other hand, the reader / writer transmits an electromagnetic wave corresponding to a carrier wave having a constant amplitude. Here, according to the impedance change in the wireless tag, the impedance of the reader / writer with respect to the transmission / reception coil also changes. As a result, the carrier wave in the reader / writer is load-modulated, so that the sub-carrier corresponding to the return data is sent from the wireless tag.

  In this way, the reader / writer can acquire the information stored in the wireless tag in a non-contact manner.

  The range in which the external transmission / reception device can communicate with the wireless transmission device is determined by the strength of the signal (radio wave) from the external transmission / reception device. That is, in the conventional transmission / reception system, in order to ensure a certain communicable range, the external transmission / reception apparatus is set to transmit a signal at a certain level according to the communicable range.

The transmission / reception system can be applied to various fields. For example, a wireless tag is attached to the storage container, and data (for example, type, concentration, date of manufacture, etc.) relating to the contents (solid, liquid, or gas) stored in the storage container is stored in the wireless tag. . If it does in this way, the information regarding the contents can be easily acquired without contact, and the contents stored in the storage container can be recognized. Such recognition of the contents is necessary, for example, for a DMFC (direct methanol fuel cell) that generates power using a methanol aqueous solution as a direct fuel. In DMFC, it is important to manage the concentration of aqueous methanol solution that serves as fuel in order to generate electricity smoothly and obtain maximum output.
JP-A-9-130999

  However, in the conventional transmission / reception system, it is assumed that information can be surely exchanged between the external transmission / reception device and the wireless transmission device without contact. That is, it is assumed that the wireless transmission device exists in a communicable range (a range in which the external transmission / reception device and the wireless transmission device can communicate). Therefore, the case where the wireless transmission device does not exist within the communicable range is not discussed. In the conventional transmission / reception system, the wireless transmission device only communicates with the external transmission / reception device in response to a signal from the external transmission / reception device, and a device for detecting the location of the wireless transmission device has been proposed in the past. It has not been.

  In addition, when a product such as liquid or gas is stored and handled in a storage container, it is often required to manage the content of the contents stored in the storage container. For example, in DMFC, it is necessary to manage the remaining amount of aqueous methanol solution in order to continue power generation. In general, when the contents are liquid, the contents can be managed by estimating the liquid level based on the conductivity or dielectric constant of the contents, or by using ultrasonic reflection. There is a way to estimate the level. However, since the number of parts of the circuit for estimating the liquid level is large, the circuit scale is large and the cost is high, so that there is a problem that the practicality is low.

  An object of the present invention is to detect the location of a wireless transmission device. More specifically, an object of the present invention is to provide a system capable of managing the internal capacity by detecting the location of a wireless transmission device.

  According to one aspect of the present invention, the external transmission / reception device communicates with the wireless transmission device. When receiving the transmission signal, the wireless transmission device transmits a reply signal having a predetermined amplitude level. The external transmission / reception device includes a transmission signal supply unit, a transmission / reception unit, a signal state detection unit, and a control unit. The transmission signal supply unit supplies a transmission signal. The transmission / reception unit transmits the transmission signal supplied by the transmission signal supply unit. The transmission / reception unit receives a return signal from the wireless transmission device. The signal state detection unit detects the state of the reply signal received by the transmission / reception unit. The control unit obtains a communication distance between the transmission / reception unit and the wireless transmission device based on the signal state detected by the signal state detection unit.

  In the external transmission / reception device, since the distance to the wireless transmission device can be obtained, the location of the wireless transmission device can be detected.

  Preferably, the external transmission / reception device further includes a reception amplification unit. The reception amplification unit amplifies the amplitude level of the reply signal received by the transmission / reception unit to a predetermined level. The signal state detection unit obtains the amplification degree of the reply signal by the reception amplification unit. The control unit obtains the communication distance based on the amplification degree obtained by the signal state detection unit.

  The longer the distance between the transmission / reception unit and the wireless transmission device, the lower the amplitude level of the reply signal received by the transmission / reception unit, and the greater the amplification of the reply signal by the reception amplification unit. In the external transmission / reception device, the control unit derives the communication distance from the amplification degree obtained by the signal state detection unit in consideration of the relationship between the amplification degree and the communication distance. Thereby, the distance to the wireless transmission device can be obtained.

  Preferably, the control unit includes a correspondence table in which a plurality of amplification degrees and a plurality of communication distances are associated one to one. The control unit detects a communication distance corresponding to the amplification degree obtained by the signal state detection unit from the correspondence table.

  In the external transmission / reception device, the correspondence table is created based on the relationship between the amplification degree and the communication distance. Thereby, the control part can derive | lead a communication distance from the amplification degree calculated | required by the signal state detection part.

  Preferably, the control unit performs the predetermined calculation based on the relationship between the amplification degree of the return signal and the communication distance with respect to the amplification degree obtained by the signal state detection unit, thereby reducing the communication distance. calculate.

  The relationship between the amplification degree and the communication distance can be expressed as a mathematical expression. If this mathematical formula is used, the control unit can derive the communication distance from the amplification degree obtained by the signal state detection unit.

  Preferably, the signal state detection unit counts the number of error locations occurring in the reply signal received by the transmission / reception unit. The control unit obtains the communication distance based on the number of error locations counted by the signal state detection unit.

  The longer the distance between the transmission / reception unit and the wireless transmission device, the greater the number of error locations that occur in the reply signal received by the transmission / reception unit. In the external transmission / reception device, the control unit derives the communication distance from the number of error points counted by the signal state detection unit in consideration of the relationship between the number of error points and the communication distance. Thereby, the distance to the wireless transmission device can be obtained.

  Preferably, the control unit includes a correspondence table in which a plurality of error locations and a plurality of communication distances are associated one to one. The control unit detects a communication distance according to the number of error locations counted by the signal state detection unit from the correspondence table.

  In the external transmission / reception device, the correspondence table is created based on the relationship between the number of error locations and the communication distance. As a result, the control unit can derive the communication distance from the number of error locations counted by the signal state detection unit.

  Preferably, the control unit performs a predetermined calculation based on a relationship between the number of error locations of the return signal and the communication distance on the number of error locations counted by the signal state detection unit, thereby performing the communication. Calculate the distance.

  The relationship between the number of error locations and the communication distance can be mathematically expressed. If this mathematical formula is used, the control unit can derive the communication distance from the number of error points counted by the signal state detection unit.

  Preferably, the signal state detection unit measures an amplitude level of a reply signal received by the transmission / reception unit. The control unit obtains the communication distance based on the amplitude level measured by the signal state detection unit.

  The longer the distance between the transmission / reception unit and the wireless transmission device, the lower the amplitude level of the reply signal received by the transmission / reception unit. In the external transmission / reception device, the control unit derives the communication distance from the amplitude level measured by the signal state detection unit in consideration of the relationship between the amplitude level and the communication distance. Thereby, the distance to the wireless transmission device can be obtained.

  Preferably, the control unit includes a correspondence table in which a plurality of amplitude levels and a plurality of communication distances are associated one to one. The control unit detects a communication distance corresponding to the amplitude level measured by the signal state detection unit from the correspondence table.

  In the external transmission / reception apparatus, the correspondence table is created based on the relationship between the amplitude level and the communication distance. As a result, the control unit can derive the communication distance from the amplitude level measured by the signal state detection unit.

  Preferably, the control unit performs the predetermined calculation based on the relationship between the amplitude level of the return signal and the communication distance on the amplitude level measured by the signal state detection unit, thereby reducing the communication distance. calculate.

  The relationship between the amplitude level and the communication distance can be expressed as a mathematical expression. If this mathematical formula is used, the control unit can derive the communication distance from the amplitude level measured by the signal state detection unit.

  According to another aspect of the present invention, in the transmission / reception system, an external transmission / reception device that transmits a transmission signal communicates with a wireless transmission device. The wireless transmission device includes a first transmission / reception unit and a reply signal supply unit. The first transmission / reception unit receives a transmission signal from the external transmission / reception device. When the transmission signal is received by the first transmission / reception unit, the response signal supply unit supplies a response signal having an amplitude level corresponding to the amplitude level of the transmission signal. The first transmission / reception unit further transmits the reply signal supplied by the reply signal supply unit. The external transmission / reception device includes a transmission signal supply unit, a second transmission / reception unit, a signal state detection unit, and a control unit. The transmission signal supply unit supplies a transmission signal. The second transmission / reception unit transmits the transmission signal supplied by the transmission signal supply unit. Further, the second transmission / reception unit receives a return signal from the wireless transmission device. The signal state detection unit detects the state of the reply signal received by the second transmission / reception unit. A control part calculates | requires the communication distance between a 1st transmission / reception part and a 2nd transmission / reception part based on the signal state detected by the signal state detection part.

  In the transmission / reception system, the transmission signal is, for example, a carrier wave whose amplitude level is modulated based on a data string indicating a command for prompting transmission of a reply signal. The return signal is, for example, a subcarrier whose amplitude level is modulated based on a predetermined data string. As the communication distance increases, the amplitude level of the carrier wave decreases and the amplitude level of the subcarrier wave also decreases. Therefore, the amplitude level of the reply signal received by the second transceiver is reduced. In addition, the number of error locations generated in the reply signal increases. Thus, the state of the reply signal changes according to the change in the communication distance. In the external transmission / reception device, the control unit derives the communication distance from the signal state detected by the signal state detection unit in consideration of the relationship between the signal state and the communication distance. As a result, the distance to the wireless transmission device can be obtained, so that the location of the wireless transmission device can be detected.

  Preferably, the external transmission / reception device further includes a reception amplification unit. The reception amplification unit amplifies the amplitude level of the reply signal received by the second transmission / reception unit to a predetermined level. The signal state detection unit obtains the amplification degree of the reply signal by the reception amplification unit. The control unit obtains the communication distance based on the amplification degree obtained by the signal state detection unit.

  Preferably, the signal state detection unit counts the number of error locations occurring in the reply signal received by the second transmission / reception unit. The control unit obtains the communication distance based on the number of error locations counted by the signal state detection unit.

  Preferably, the signal state detection unit measures an amplitude level of a reply signal received by the second transmission / reception unit. The control unit obtains the communication distance based on the amplitude level measured by the signal state detection unit.

  Preferably, the reply signal supply unit generates a reply signal having an amplitude level corresponding to the amplitude level of the transmission signal received by the first transmission / reception unit and having a section in which the amplitude level is constant, Supply the generated reply signal.

  In the transmission / reception system, the signal state detection unit can acquire an accurate signal state when the signal state of the return signal is detected in a section in which the amplitude level is constant. As a result, the distance to the wireless transmission device can be accurately obtained.

  In order to generate a reply signal having a section with a constant amplitude level, for example, the reply signal supply unit connects a data string with a constant data value to a predetermined data string, and Based on this, the amplitude level of the subcarrier may be modulated. Further, for example, the return signal supply unit may multiply a data string indicating a random data value by a predetermined data string and modulate the amplitude level of the subcarrier based on the multiplied data string.

  Preferably, the transmission / reception system further includes a storage container in which predetermined contents are stored. The communication distance changes according to the increase or decrease of the contents. The said control part calculates | requires the content of the said predetermined content based on the calculated | required communication distance.

  In the above transmission / reception system, the control unit can derive the internal capacity from the communication distance in consideration of the relationship between the communication distance and the internal capacity. Thereby, the internal volume of the content accommodated in the container main body can be managed.

  Preferably, the transmission / reception system further includes a container main body and a floating member. The storage container main body stores a predetermined content that is liquid. The floating member floats on the liquid surface of the predetermined content stored in the storage container body. The wireless transmission device is installed on the surface of the floating member. The control unit of the external transmission / reception device determines the content of the predetermined content stored in the storage container body based on the determined communication distance.

  In the transmission / reception system, the floating member moves up and down in accordance with the increase / decrease in the content of the contents stored in the storage container body. Further, the communication distance also changes according to the fluctuation of the internal capacity. Considering the relationship between the communication distance and the internal capacity, the control unit can derive the internal capacity from the communication distance. Thereby, the internal volume of the content accommodated in the container main body can be managed. In order to make the relationship between the communication distance and the internal capacity unambiguous, for example, the second transmitting / receiving unit of the external transmission / reception device is moved to a position corresponding to the moving direction of the floating member (for example, the moving direction of the floating member). It may be arranged on the extension line).

  Preferably, the transmission / reception system further includes a container main body and a partition member. A predetermined content is accommodated in the container main body. The partition member is arranged inside the container main body and moves in accordance with the increase or decrease in the internal content of the predetermined content stored in the container main body. The wireless transmission device is installed on the partition member. The control unit of the external transmission / reception device determines the content of the predetermined content stored in the storage container body based on the determined communication distance.

  In the transmission / reception system, the communication distance also changes according to the increase / decrease in the content of the contents stored in the storage container body. Considering the relationship between the communication distance and the internal capacity, the control unit can derive the internal capacity from the communication distance. Thereby, the internal volume of the content accommodated in the container main body can be managed. In order to make the relationship between the communication distance and the internal capacity unambiguous, for example, the second transmitting / receiving unit of the external transmission / reception device is positioned at a position corresponding to the moving direction of the partition member (for example, the moving direction of the partition member). On the extension line).

  Preferably, the transmission / reception system further includes a container main body. The storage container main body stores a predetermined content, and the outer shape expands and contracts according to the increase or decrease of the content. The wireless transmission device is installed on the surface of the container main body. The control unit of the external transmission / reception device determines the content of the predetermined content stored in the storage container body based on the determined communication distance.

  In the transmission / reception system, the communication distance also changes according to the increase / decrease in the content of the contents stored in the storage container body. Considering the relationship between the communication distance and the internal capacity, the control unit can derive the internal capacity from the communication distance. Thereby, the internal volume of the content accommodated in the container main body can be managed. In order to make the relationship between the communication distance and the internal capacity unambiguous, for example, the second transmission / reception unit of the external transmission / reception device is positioned at a position corresponding to the expansion / contraction direction of the container body (for example, on the extension line in the expansion / contraction direction) ).

  Preferably, the transmission / reception system further includes a fuel cell unit that generates electric power for driving the electronic device. The said container main body accommodates the liquid fuel for fuel cells. The fuel cell unit includes a power generation unit that generates power using the liquid fuel stored in the storage container body. The control unit of the external transmission / reception device determines the internal volume of the liquid fuel stored in the storage container body based on the determined communication distance.

  In the transmission / reception system, the internal volume of the liquid fuel stored in the storage container body can be managed.

  Preferably, the transmission / reception system further includes an infusion storage container, a floating member, and a container mounting stand. The infusion solution storage container stores a predetermined infusion solution. The floating member floats on the liquid surface of the predetermined infusion stored in the infusion container. The container attachment stand attaches the infusion container. The wireless transmission device is installed on the surface of the floating member. The control unit of the external transmission / reception device obtains the internal volume of the predetermined infusion contained in the infusion container based on the obtained communication distance.

  In the transmission / reception system, the floating member moves up and down in accordance with the increase / decrease in the volume of the infusion stored in the infusion container main body. Further, the communication distance also changes according to the fluctuation of the internal capacity. Considering the relationship between the communication distance and the internal capacity, the control unit can derive the internal capacity from the communication distance. Thereby, the internal volume of the infusion accommodated in the infusion solution container main body can be managed. In order to make the relationship between the communication distance and the internal capacity unambiguous, for example, the second transmitting / receiving unit of the external transmission / reception device is positioned at a position corresponding to the moving direction of the floating member (for example, the container mounting portion of the container mounting stand). ).

  Preferably, the transmission / reception system further includes a paper feed tray (for example, a rectangular box shape) and a printer main body. The paper feed tray accommodates printer paper. The printer main body has a tray storage portion (concave portion). The tray storage unit receives the paper feed tray and stores the paper feed tray. The paper feed tray includes a paper feed tray main body (for example, rectangular box shape), a paper feed plate (for example, rectangular shape), and an urging member (for example, an elastic body). The paper feed plate is disposed inside the paper feed tray main body, and the printer paper is placed thereon. The urging member connects one end portion of the bottom surface of the sheet feed tray body and one end portion of the sheet feed plate in the insertion direction of the sheet feed tray. The urging member urges the sheet feeding plate in a direction away from the bottom surface of the tray body. The wireless transmission device is installed at one end of the sheet feeding plate. The control unit of the external transmission / reception device obtains the number of printer papers stored in the paper feed tray based on the obtained communication distance.

  In the above transmission / reception system, when the number of sheets of printer paper decreases, one end of the sheet feeding plate moves away from the bottom surface of the tray body by the restoring force of the urging member. Thereby, the communication distance also changes. Considering the relationship between the communication distance and the number of sheets, the control unit can derive the number of sheets from the communication distance. As a result, the number of printer sheets stored in the sheet feed tray can be managed. In order to make the relationship between the communication distance and the number of sheets unambiguous, for example, the second transmission / reception unit of the external transmission / reception device is moved to a position corresponding to the moving direction of the sheet feeding plate (for example, the upper surface of the tray storage unit). ).

  Preferably, the transmission / reception system further includes an ink cartridge, a floating member, and a cartridge holder. The ink cartridge contains predetermined ink. The floating member floats on the surface of the ink stored in the ink cartridge. The cartridge holder portion is formed in the printer main body, and the ink cartridge is accommodated therein. The wireless transmission device is installed on the surface of the floating member. The control unit of the external transmission / reception device obtains the internal volume of the ink stored in the ink cartridge based on the obtained communication distance.

  In the transmission / reception system, the floating member moves up and down in accordance with the increase or decrease in the content of the ink stored in the ink cartridge. Further, the communication distance also changes according to the fluctuation of the internal capacity. Considering the relationship between the communication distance and the internal capacity, the control unit can derive the internal capacity from the communication distance. Thereby, the internal volume of the ink accommodated in the ink cartridge can be managed. In order to unify the relationship between the communication distance and the internal capacity, for example, the second transmission / reception unit of the external transmission / reception device may be installed at a position corresponding to the moving direction of the floating member.

  Preferably, the wireless transmission device further includes a storage unit that stores content information that is information regarding the content. When the transmission signal is received by the first transmission / reception unit, the response signal supply unit supplies the response signal based on the content information stored in the storage unit. The external transmission / reception device further includes an information detection unit that acquires the content information from the reply signal received by the second transmission / reception unit. The transmission / reception system further includes a display unit that displays at least one of the content obtained by the control unit of the external transmission / reception device and the content information detected by the information detection unit.

  In the transmission / reception system, it is possible to visually manage the content of the contents and information about the contents.

  According to yet another aspect of the present invention, a transmission / reception method is executed between an external transmission / reception device and a wireless transmission device. The transmission / reception method includes steps (A) to (E). In step (A), the external transmission / reception device transmits a transmission signal. In step (B), the wireless transmission device receives a transmission signal and transmits a reply signal having a predetermined amplitude level in response to the received transmission signal. In step (C), the external transmission / reception device receives the reply signal. In step (D), the state of the reply signal received in step (C) is detected. In step (E), based on the signal state detected in step (D), a communication distance between the external transmission / reception device and the wireless transmission device is obtained.

  Preferably, the step (D) includes a step (a) and a step (b). In step (a), the amplitude level of the reply signal received in step (C) is amplified to a specified level. In step (b), the amplitude level amplification in step (a) is obtained. In the step (E), the communication distance is obtained based on the amplification degree obtained in the step (b).

  Preferably, in the step (D), the number of error locations occurring in the reply signal received in the step (C) is counted. In the step (E), the communication distance is obtained based on the number of error locations counted in the step (D).

  Preferably, in the step (D), the amplitude level of the reply signal received in the step (C) is measured. In the step (E), the communication distance is obtained based on the amplitude level measured in the step (D).

  Preferably, in the step (B), the wireless transmission device generates a reply signal having a predetermined amplitude level and a section in which the amplitude level is constant, and transmits the generated reply signal.

  As described above, since the communication distance between the external transmission / reception device and the wireless transmission device can be obtained, the location of the wireless transmission device can be detected. Moreover, the internal volume of the content accommodated in the predetermined storage container can be managed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

<Overall configuration>
FIG. 1 shows a configuration of a transmission / reception system according to an embodiment of the present invention. In this system, a carrier wave having a frequency of 13.56 MHz is exchanged between the external transmission / reception device 10 and the wireless transmission device 20.

  The wireless transmission device 20 is, for example, an RFID (Radio Frequency Identification) tag, and stores ID information that is a data string unique to itself. The external transmission / reception device 10 is, for example, a reader / writer, and transmits a modulated carrier wave as a transmission signal. The transmission signal includes an instruction for prompting a reply signal including ID information.

  The wireless transmission device 20 is activated when it receives a transmission signal from the external transmission / reception device 10. The wireless transmission device 20 superimposes a modulated subcarrier on the carrier wave of the external transmission / reception device 10 by performing predetermined processing according to the transmission signal and load-modulating the carrier wave of the external transmission / reception device 10. That is, the wireless transmission device 20 transmits the modulated subcarrier as a return signal. The reply signal includes ID information stored in the wireless transmission device 20 (in some cases, the reply signal may simply be 1-bit information indicating the presence of the wireless transmission device 20). .)

  When the external transmission / reception device 10 receives the return signal from the wireless transmission device 20, the distance (communication distance) between itself and the wireless transmission device 20 based on the state (amplitude level, etc.) of the return signal. Ask for.

<Internal configuration of external transmission / reception device>
FIG. 2 shows an internal configuration of the external transmission / reception apparatus 10 shown in FIG. The external transmission / reception device 10 includes a control unit 11, a transmission signal supply unit 12, a transmission / reception unit 13, a decoding unit 14, and a signal state detection unit 15.

  The control unit 11 is a microcomputer, for example, and outputs ID reply command information when receiving an information acquisition command from the host computer. The ID reply command information is a data string indicating a command for causing the wireless transmission device 20 to send a reply signal.

  The transmission signal supply unit 12 modulates a carrier wave (here, 13.56 MHz) according to the ID reply command information from the control unit 11. Thereby, a transmission signal is supplied as a modulated carrier wave. When the transmission signal supply unit 12 completes the transmission of the transmission signal, the transmission signal supply unit 12 supplies a constant amplitude carrier wave having a constant amplitude level (here, a carrier wave having an amplitude level of 100 V and a frequency of 13.56 MHz).

  The transmission / reception unit 13 includes a tuning capacitor C1, a series resistor R1, and a transmission / reception coil L1. The transmission / reception unit 13 transmits the modulated carrier wave (transmission signal) supplied by the transmission signal supply unit 12. The transmission / reception unit 13 receives a modulated subcarrier (return signal) from the wireless transmission device.

  The decoding unit 14 demodulates and decodes the modulated subcarrier (return signal) received by the transmission / reception unit 13 to detect ID information.

  The signal state detection unit 15 detects the state of the modulated subcarrier (return signal) received by the transmission / reception unit 13.

  Further, the control unit 11 has an amplification degree correspondence table and an error location number correspondence table. The control unit 11 obtains the communication distance based on the signal state detected by the signal state detection unit 15. The communication distance is the distance between the external transmission / reception device 10 and the wireless transmission device 20. Further, the control unit 11 outputs measurement result information including the obtained communication distance and the ID information detected by the decoding unit 14 to the host computer.

[Internal configuration of transmission signal supply unit]
FIG. 3 shows an internal configuration of the transmission signal supply unit 12 shown in FIG. The transmission signal supply unit 12 includes an encoding processing unit 101, an error correction code addition unit 102, a transmission data generation unit 103, and a modulation circuit 104.

[Internal configuration of decoding unit and signal state detection unit]
FIG. 4 shows an internal configuration of the decoding unit 14 and the signal state detection unit 15 shown in FIG. The decoding unit 14 includes a reception amplification circuit 105, a demodulation circuit 106, an error correction circuit 107, a decoding processing unit 108, and an information detection unit 109. The signal state detection unit 15 includes an amplification degree calculation unit 110 and an error location counting circuit 111. The amplification degree calculation unit 110 obtains the ratio (amplification degree) of the amplitude level of the reply signal before amplification to the amplitude level of the reply signal after amplification. The error location counting circuit 111 counts the number of error locations that have occurred in the return data for which error correction processing is executed in the error correction circuit 107.

<Internal configuration of wireless transmission device>
FIG. 5 shows an internal configuration of the wireless transmission device 20 shown in FIG. The wireless transmission device 20 includes a storage unit 21, a transmission / reception unit 22, a voltage generation unit 23, a decoding unit 24, a control unit 25, and a reply signal supply unit 26.

  The storage unit 21 is, for example, an EEPROM, and stores ID information unique to the wireless transmission device 20.

  The transmission / reception unit 22 includes a transmission / reception coil L2, a tuning capacitor C2, a resistor R2, and a switch SW. When receiving the modulated carrier wave (transmission signal) from the external transmission / reception device 10, the transmission / reception unit 22 generates an alternating voltage by electromagnetic induction. That is, the transmission / reception unit 22 receives a transmission signal from the external transmission / reception device 10.

  The voltage generator 23 includes a rectifier diode D3, a smoothing capacitor C3, and a Zener diode ZD. The voltage generation unit 23 generates a drive voltage for driving each block in the wireless transmission device 20 using the modulated carrier wave (transmission signal) received by the transmission / reception unit 22.

  The decoding unit 24 demodulates and decodes the modulated carrier wave (transmission signal) received by the transmission / reception unit 22 to generate ID reply command information.

  The control unit 25 outputs reply information including the ID information stored in the storage unit 21 according to the ID reply command information generated by the decryption unit 24. The reply information is a data string indicating information stored in the storage unit 21.

  The reply signal supply unit 26 modulates the subcarrier (here, 212 kHz (= 13.56 MHz / 64)) according to the reply information generated by the control unit 25. Thereby, a reply signal is generated as a modulated subcarrier.

  Further, the transmission / reception unit 22 changes its own impedance in accordance with the modulated subcarrier (return signal) generated by the return signal supply unit 26. In accordance with the impedance change of the transmission / reception unit 22, the impedance of the transmission / reception unit 13 of the external transmission / reception device 10 also changes. Thereby, the modulation subcarrier (reply signal) is superimposed on the carrier wave of the transmission / reception unit 13 of the external transmission / reception device 10. That is, the transmission / reception unit 22 has transmitted a reply signal.

  The amplitude level of the reply signal transmitted from the transmission / reception unit 22 increases or decreases according to the amplitude level of the transmission signal received by the transmission / reception unit 22. For example, when the amplitude level of the transmission signal received by the transmission / reception unit 22 decreases, the amplitude level of the reply signal from the transmission / reception unit 22 also decreases. That is, the ratio between the amplitude level of the transmission signal and the amplitude level of the reply signal is constant.

[Internal structure of decryption unit]
FIG. 6 shows an internal configuration of the decoding unit 24 shown in FIG. The decoding unit 24 includes a demodulation circuit 201, an error correction circuit 202, and a decoding processing unit 203.

[Internal configuration of reply signal supply unit]
FIG. 7 shows the internal configuration of the reply signal supply unit 26. The reply signal supply unit 26 includes an encoding processing unit 204, an error correction code addition unit 205, a reply data generation unit 206, and a modulation circuit 207.

<Relationship between communication distance and reception level>
FIG. 8 shows the relationship between the distance (communication distance) between the external transmission / reception device 10 and the wireless transmission device 20 and the reception level of the return signal in the reception amplifier circuit 105. In general, when the communication distance is constant, the amplitude level of the subcarrier from the wireless transmission device 20 is proportional to the increase in the amplitude level (transmission level) of the carrier wave transmitted from the external transmission / reception device 10. And the amplitude level (reception level) of the modulated subcarrier (return signal) received by the external transmission / reception device 10 also increases. That is, as the transmission level increases, the reception level changes in the order of curve A, curve B, and curve C.

  When the transmission level is constant, the intensity of the signal (transmission electromagnetic field) transmitted from each of the external transmission / reception device 10 and the wireless transmission device 20 is inversely proportional to the square of the communication distance. That is, when the transmission level is constant, the reception level is inversely proportional to the fourth power of the communication distance. For example, on the curve A, as the communication distance increases to “D1”, “D2”, “D3”, the reception level decreases in the order of “L1”, “L2”, “L3”.

<Amplification table>
FIG. 9 shows an amplification degree correspondence table when the amplitude level of the carrier wave transmitted from the transmission / reception unit 13 of the external transmission / reception device 10 is “100 V”. In the amplification degree correspondence table, a plurality of amplification degrees and a plurality of communication distances are associated one-to-one. Each of the amplification degrees is related to the amplification degree of the modulation subcarrier (return signal) in the reception amplification circuit 105. Each of the communication distances relates to the distance between the external transmission / reception device 10 and the wireless transmission device 20. In the amplification degree correspondence table, the higher the amplification degree, the longer the communication distance corresponding to the amplification degree.

<Relationship between communication distance and error rate>
FIG. 10A shows the relationship between the communication distance and the communication S / N. As described above, when the transmission level is constant, the reception level is inversely proportional to the fourth power of the communication distance. Here, assuming that the noise in the communication path between the external transmission / reception device 10 and the wireless transmission device 20 is constant, the communication S / N is inversely proportional to the fourth power of the communication distance. Further, as the communication S / N becomes smaller, an error portion is more likely to occur in the modulated subcarrier (return signal) received by the external transmission / reception device 10.

  As shown in FIG. 10B, the ratio of error locations (error rate) generated in the reply signal is inversely proportional to the fourth power of the communication S / N. In addition, as shown in FIG. 10C, the number of error locations occurring in the reply signal increases when the communication distance exceeds a certain communication distance, and increases so that the error location cannot be specified when the communication distance further increases. I will do it.

<Error location correspondence table>
FIG. 11 shows an example of the error location number correspondence table when the amplitude level of the carrier wave transmitted from the transmission / reception unit 13 of the external transmission / reception device 10 is “100 V”. In the error location number correspondence table, a plurality of error locations and a plurality of communication distances are associated with each other. Each of the number of error locations is related to the number of error locations occurring in the reply data that is error-corrected by the error correction circuit 107. In this error location number correspondence table, the communication distance corresponding to the number of error locations increases as the value of the number of error locations increases.

<Operation>
Next, the operation of the transmission / reception system according to the present embodiment will be described.

[External transmission / reception device]
First, when receiving an information acquisition command from the host computer, the control unit 11 (see FIG. 2) outputs ID reply command information.

  Next, in the transmission signal supply unit 12 (see FIG. 3), the encoding processing unit 101 encodes the ID reply command information from the control unit 11 to generate transmission data.

  Next, the error correction code adding unit 102 performs a predetermined operation on the transmission data generated by the encoding processing unit 102 to generate an error correction code. The error correction code is, for example, a Reed-Solomon code. Thereafter, the error correction code adding unit 102 adds the generated error correction code to the transmission data.

  Next, the transmission data generation unit 103 adds a header to the transmission data from the error correction code addition unit 102 (transmission data to which the error correction code is added). The header includes a synchronization signal and a communication start identifier.

  Next, the modulation circuit 104 modulates a carrier wave according to transmission data (transmission data with a header added) from the transmission data generation unit 103 to generate a modulated carrier wave (transmission signal). For example, the modulation circuit 104 outputs a carrier wave having a high amplitude level (for example, a carrier wave having an amplitude level of 100 V) to the transmission / reception unit 13 during a period in which the data value of the transmission data from the transmission data generation unit 103 is “1”. In the period when the data value of the transmission data is “0”, a carrier wave having a relatively low amplitude level (for example, a carrier wave having an amplitude level of 90 V) is output to the transmission / reception unit 13. That is, the modulation circuit 104 supplies a transmission signal by modulating a carrier wave based on transmission data. This carrier wave is generated by an oscillator (not shown) or the like.

  Next, when the transmission signal from the transmission signal supply unit 12 is input to the transmission / reception unit 13 (see FIG. 2), the oscillation circuit configured by the tuning capacitor C1, the series resistor R1, and the transmission / reception coil L1 responds to the transmission signal. AC voltage is generated, and a modulated carrier wave (transmission signal) is transmitted as an electromagnetic field from the transmission / reception coil L1.

  Further, when the output of the transmission data from the transmission data generation unit 103 is completed, the modulation circuit 104 generates a constant amplitude carrier wave (here, a carrier wave having an amplitude level of 100 V and a frequency of 13.56 MHz). Thereby, the transmission / reception part 13 transmits a fixed amplitude carrier wave as an electromagnetic field.

[Wireless transmission equipment]
Next, in the wireless transmission device 20 (see FIG. 5), when the transmission / reception coil L2 of the transmission / reception unit 22 receives an electromagnetic field from the external transmission / reception device 10, an oscillation circuit constituted by the transmission / reception coil L2 and the tuning capacitor C2. An AC voltage corresponding to the electromagnetic field from the external transmission / reception device 10 is generated. That is, the transmission / reception unit 22 has received a modulated carrier wave (transmission signal) from the external transmission / reception device 10.

  Next, when the alternating current generated in the transmission / reception unit 22 is input to the voltage generation circuit 23, the rectifier diode D3 and the smoothing capacitor C3 rectify the alternating current to generate a direct current. Further, the Zener diode ZD limits the voltage level of the DC voltage so that the DC voltage generated by the rectifier diode D3 and the smoothing capacitor C2 becomes a predetermined level. Zener diode ZD suppresses the voltage level so that the voltage level of the DC voltage is lower than the upper limit level when the voltage level is higher than a predetermined upper limit level. In this way, a drive voltage is generated, and each block in the wireless transmission device 10 is driven. In addition, the voltage level of the drive voltage can be kept within a predetermined range, and each block can be prevented from being destroyed due to the voltage being too high.

  Next, in the decoding unit 24 (see FIG. 6), the demodulation circuit 201 demodulates the modulated carrier wave (transmission signal) received by the transmission / reception unit 22 to generate transmission data. Note that a header and an error correction code are added to the transmission data.

  Next, the error correction circuit 202 performs error correction processing on the transmission data using the error correction code added to the transmission data generated by the demodulation circuit 201.

  Next, the decoding processing unit 203 decodes the transmission data subjected to the correction processing by the error correction circuit 202, and generates ID reply command information.

  Next, the control unit 25 (see FIG. 5) reads the ID information stored in the storage unit 21 in accordance with the ID reply command information generated by the decryption processing unit 203. And the control part 25 writes the read ID information in reply information, and outputs reply information.

  Next, in the reply signal supply unit 26 (see FIG. 7), the encoding processing unit 204 encodes the reply information from the control unit 25 to generate reply data.

  Next, the error correction code adding unit 205 performs a predetermined operation on the reply data generated by the encoding processing unit 204 to generate an error correction code. Then, the error correction code adding unit 205 adds the generated error correction code to the reply data.

  Next, the reply data generation unit 206 adds a header to the reply data from the error correction code addition unit 205 (reply data to which the error correction code is added). The header includes a synchronization signal and a communication start identifier.

  Next, the modulation circuit 207 modulates the subcarrier according to the reply data (reply data with the header added) from the reply data generation unit 206 to generate a modulated subcarrier (reply signal). For example, the modulation circuit 207 sets the switch SW (FIG. 5) of the transmission / reception unit 22 to a specific frequency (here, 212 kHz subcarrier) during a period in which the data value of the return data from the return data generation unit 206 is “1”. The switch SW is turned off during the period when the data value of the reply data is “0”. That is, the modulation circuit 207 changes (modulates) the connection state of the resistor R2 of the transmission / reception unit 22 according to the reply data. The subcarrier is generated by, for example, a subcarrier generation unit (not shown) in the wireless transmission device 20. The subcarrier generation unit generates a clock signal from the carrier wave received by the transmission / reception unit 22, and generates a subcarrier by dividing the clock signal.

  Next, when the modulation subcarrier (return signal) from the modulation circuit 207 is input to the transmission / reception unit 22 (see FIG. 5), the switch SW is turned on / off according to the return signal. On the other hand, at this time, the transmission / reception unit 13 of the external transmission / reception device 10 transmits a constant amplitude carrier wave. By turning on and off the switch SW, the connection between the oscillation circuit formed by the transmission / reception coil L2 and the tuning capacitor C2 and the resistor R2 is switched. As a result, the impedance of the oscillation circuit in the wireless transmission device 20 changes and the impedance of the oscillation circuit in the external transmission / reception device 10 also changes, and the constant amplitude carrier wave of the external transmission / reception device 10 is load-modulated (so-called load). Modulation method). Therefore, since the modulation subcarrier (frequency component for turning on / off the switch SW) is superimposed on the constant amplitude carrier wave, the transmission / reception unit 22 transmits the modulation subcarrier (reply signal).

[External transmission / reception device]
On the other hand, the transmission / reception unit 13 of the external transmission / reception device 10 (see FIG. 2) has received the modulated subcarrier (return signal) from the wireless transmission device 20.

  Next, in the decoding unit 14 (see FIG. 4), the reception amplification circuit 105 is configured to select a predetermined frequency band (a frequency band corresponding to the data value “1” of the reply data. (13.56 MHz ± 212 kHz) is detected to determine the presence or absence of the subcarrier component. If there is a subcarrier component, it is recognized as a data value “1”, and if there is no subcarrier component, it is recognized as a data value “0”. That is, the reception amplifier circuit 105 inputs the modulated subcarrier wave (return signal) received by the transmission / reception unit 13. The amplitude level of the reply signal changes at a constant ratio according to the amplitude level of the constant amplitude carrier wave received by the transmitting / receiving unit 22 of the wireless transmission device 20. For example, when the amplitude level of the carrier wave of the transmission / reception unit 13 is 100V, the change amount of the subcarrier component (the amplitude level of the reply signal) is approximately 10 mV. Here, when the communication distance is constant, if the amplitude level of the carrier wave is 200 V, which is twice, the change amount of the subcarrier component (amplitude level of the reply signal) is approximately 20 mV.

  Next, the reception amplifier circuit 105 amplifies the amplitude level of the input modulated subcarrier (reply signal) to a predetermined level. For example, the reception amplification circuit 105 amplifies the reply signal with reference to the amplitude level of the constant amplitude carrier wave supplied by the transmission signal supply unit 12. Further, for example, the reception amplification circuit 105 may automatically adjust the amplitude level of the return signal so that it always becomes a constant amplitude of 1 Vp-p regardless of the amplitude level of the transmission signal.

  Next, the demodulation circuit 106 demodulates the reply signal amplified by the reception amplification circuit 105 to generate reply data. Note that a header and an error correction code are added to the reply data.

  Next, the error correction circuit 107 performs error correction processing on the return data using the error correction code added to the return data from the demodulation circuit 106.

  Next, the decoding processing unit 108 decodes the reply data that has been corrected by the error correction circuit 107, and generates reply information. The reply information includes ID information of the wireless transmission device 20.

  Next, the information detection unit 109 detects ID information from the reply information generated by the encoding process 108.

  On the other hand, in the signal state detection unit 15, the amplification degree calculation unit 110 obtains the amplification degree of the return signal in the reception amplification circuit 105. For example, the amplification degree calculation unit 110 outputs the amplitude level of the reply signal before amplification with respect to the amplitude level of the transmission signal (the amplitude level of the transmission signal supplied by the transmission signal supply unit 12) (the reply signal input to the reception amplification circuit 105). The amplitude level) is quantified. For example, the amplification degree calculation unit 110 quantifies the ratio of the amplitude level of the reply signal before amplification to the amplitude level 1Vp-p.

  The error location counting circuit 111 counts the number of error locations that have occurred in the reply data that is error-corrected by the error correction circuit 107.

  Next, when ID information is detected by the information detection unit 109, the control unit 11 (see FIG. 2) determines that “a reply signal has been received”. On the other hand, when the ID information is not detected by the information detection unit, the control unit 11 determines that the distance between the external transmission / reception device 10 and the wireless transmission device 20 exceeds the communicable distance, Not received ” Thus, by determining whether or not a return signal is received based on whether or not ID information is detected, the communication distance to a specific wireless transmission device can be obtained even if a plurality of wireless transmission devices 10 exist. Can do. In addition, after a plurality of wireless transmission devices sequentially transmit reply signals and the external transmission / reception device receives reply signals from all wireless transmission devices, the communication distance with each of the plurality of wireless transmission devices is increased. It is also possible to ask for it.

  Here, if it is determined that “return signal reception is present”, the control unit 11 uses the amplification degree obtained by the amplification degree calculation unit 110 to determine the distance between the external transmission / reception device 10 and the wireless transmission device 20 (more specifically, The distance between the transmission / reception coil L1 of the transmission / reception unit 13 and the transmission / reception coil L2 of the transmission / reception unit 22 is determined. Specifically, the control unit 11 detects a communication distance corresponding to the amplification degree obtained by the amplification degree calculation unit 110 from the amplification degree correspondence table.

  Next, the control unit 11 writes the obtained communication distance and the ID information detected by the information detection unit 109 in the measurement result information, and outputs the measurement result information to the host computer.

  In this way, the host computer can grasp the distance between the external transmission / reception device 10 and the wireless transmission device 20.

  The control unit 11 can also determine the communication distance by using the number of error locations counted by the error location counting circuit 111 when it is determined that “return signal reception is present”. Specifically, the control unit 11 detects the communication distance corresponding to the number of error locations counted by the error location counting circuit 111 from the error location count correspondence table stored in itself.

<Effect>
As described above, the communication distance can be obtained based on the state of the return signal, and the location of the wireless transmission device can be detected. In addition, the communication distance can be obtained and information stored in the wireless transmission device can be acquired.

  The relationship between the amplification degree and the communication distance can be expressed as a mathematical expression. Therefore, the control unit 11 performs a predetermined calculation based on the relationship between the amplification degree and the communication distance on the amplification degree obtained by the amplification degree calculation unit 110 without using the amplification degree correspondence table. The communication distance may be calculated.

  Also, the relationship between the number of error locations and the communication distance can be expressed as a mathematical expression. The control unit 11 performs communication based on the relationship between the number of error locations and the communication distance on the number of error locations counted by the error location counting circuit 111 without using the error location count correspondence table. The distance may be calculated.

  In addition, information other than ID information (for example, information about a product to which the wireless transmission device is attached) may be written in the storage unit 21 of the wireless transmission device 20.

  Note that the control unit 11 can also determine the communication distance based on the amplitude level of the reply signal received by the transmission / reception unit 13. In this case, the amplification degree calculation unit 110 measures the amplitude level of the reply signal input to the reception amplification circuit 105 (that is, the amplitude level of the reply signal received by the transmission / reception unit 13), and the measured amplitude level is controlled by the control unit. 11 is output.

  In this case, the control unit 11 has an amplitude level correspondence table. FIG. 12 is an amplitude level correspondence table when the amplitude level of the carrier wave transmitted from the transmission / reception unit 13 of the external transmission / reception device 10 is “100 V”. In the amplitude level correspondence table, a plurality of amplitude levels and a plurality of communication distances are associated with each other. Each of the amplitude levels is related to the amplitude level measured by the amplification degree calculation unit 110. In this amplitude level correspondence table, the smaller the amplitude level value, the longer the communication distance corresponding to the amplitude level. The control unit 11 detects a communication distance corresponding to the amplitude level measured by the amplification degree calculation unit 110 from the amplitude level correspondence table.

  Further, since it is possible to formulate the relationship between the amplitude level and the communication distance, the control unit 11 does not use the amplitude level correspondence table, but the amplitude level measured by the amplification degree calculation unit 110. The communication distance may be calculated by performing a predetermined calculation based on the relationship between the amplitude level and the communication distance.

(Modification 1 of embodiment)
In the wireless transmission device 20, the reply signal is amplitude-modulated according to the data value of the reply data. In other words, as the return data transfer rate in the return data generation unit 206 increases, the amplitude level of the modulation subcarrier (return signal) supplied from the modulation circuit 207 varies greatly. Accordingly, in the external transmission / reception device 10, the amplification degree of the reply signal by the reception amplification circuit 105 fluctuates drastically, and the period during which the amplification degree is constant is shortened. In this case, it may be difficult for the amplification degree calculation unit 110 to obtain a stable amplification degree.

<Configuration>
In the transmission / reception system according to the first modification of the present embodiment, the operation by the return signal supply unit 26 (see FIG. 5) of the wireless transmission device 20 is different. In the first modification, when the reply signal supply unit 26 supplies a reply signal based on the reply information, the reply signal supply unit 26 further adds a data string (constant section information) having a constant data value to the reply data. Thereafter, the reply signal supply unit 26 modulates the subcarrier according to the reply data to which the fixed section information is added. Specifically, the reply data generation unit 206 (FIG. 7) of the reply signal supply unit 26 adds a header to the reply data from the error correction code adding unit 205 and further adds certain section information.

<Operation>
Next, the operation of the transmission / reception system according to the first modification will be described. Here, processing from the generation of the return signal to the generation of the measurement result information will be described.

  The reply data generation unit 206 of the wireless transmission device 20 outputs reply data to which the header, error correction code, and fixed section information are added in order from the top. Specifically, it is output in the order of header, fixed interval information, reply data, and error correction code.

  The modulation circuit 207 continues to output the subcarrier while receiving the predetermined section information from the reply data generation unit 206. In other words, while the modulation circuit 207 receives certain section information, the modulation circuit 107 outputs a subcarrier whose amplitude level is not modulated.

  In the external transmission / reception device 10, while the subcarrier whose amplitude level is not modulated is input to the reception amplification circuit 105, the amplification factor of the return signal in the reception amplification circuit 105 is constant. Therefore, the amplification degree calculation unit 110 can obtain an accurate amplification degree by referring to the amplification degree during a period in which the fluctuation of the amplification degree in the reception amplification circuit 105 is stable. Next, the control part 11 can obtain | require a communication distance based on an exact amplification degree.

<Effect>
As described above, by providing a section in which the amplitude level is not modulated in the reply signal, it is possible to stabilize fluctuations in the amplification degree of the reply signal in the reception amplifier circuit. Thereby, a communication distance can be calculated | required correctly.

(Modification 2 of this embodiment)
In the carrier wave to which the modulation subcarrier (return signal) is added, the frequency band corresponding to the data value “1” (here 13.56 MHz ± 212 kHz) and the frequency band corresponding to the data value “0” (here 13). .56 MHz) is not evenly distributed and is biased to one side, the amplitude level of the modulated subcarrier component fluctuates according to the distribution of the data values, and thus becomes unstable. In this case, in the external transmission / reception device 10, the amplification of the reply signal by the reception amplification circuit 105 becomes unstable, and it becomes difficult for the amplification factor calculation unit 110 to obtain an accurate amplification factor.

<Configuration>
In the transmission / reception system according to the first modification of the present embodiment, the operation by the return signal supply unit 26 (see FIG. 5) of the wireless transmission device 20 is different. In the second modification, the reply signal supply unit 26 multiplies the reply data by the M-sequence code when supplying the reply signal based on the reply information. The M-sequence code is a data string in which a data value “1” and a data value “0” are randomly generated. Specifically, the reply data generation unit 206 multiplies the reply data to which the header and the error correction code are added by the M-sequence code. The M-sequence code is used to make the occurrence probability of each of the data values “1” and “0” uniform in the entire reply data.

<Operation>
Next, the operation of the transmission / reception system according to the first modification will be described. Here, processing from the generation of the return signal to the generation of the measurement result information will be described.

  The reply data generation unit 206 of the wireless transmission device 20 multiplies the reply data to which the header and the error correction code are added by the M-sequence code. As a result, the reply data generation unit 206 outputs reply data having a uniform occurrence probability of each of the data value “1” and the data value “0” to the modulation circuit 207. Therefore, in the modulated subcarrier (reply signal) output from the modulation circuit 207, the frequency band corresponding to the data value “1” and the frequency band corresponding to the data value “0” are uniformly distributed.

  In the external transmission / reception device 10, since the amplitude level of the subcarrier (reply signal) is stable, the amplification of the reply signal by the reception amplifier circuit 105 is stable, and the amplification factor calculation unit 110 obtains a stable amplification factor. Can do. Therefore, the control part 11 can obtain | require a communication distance based on the stable amplification degree.

  Further, the demodulation circuit 106 performs an operation for removing the M-sequence code when demodulating the reply signal from the reception amplification circuit 105. That is, the demodulation circuit 106 demodulates the reply signal from the reception amplifier circuit 105 to generate reply data, and then multiplies the reply data by the reciprocal of the M-sequence code.

<Effect>
As described above, by making the frequency band included in the reply signal uniform, the amplification degree of the reply signal in the reception amplifier circuit can be stabilized. Thereby, a communication distance can be calculated | required correctly.

  Compared with the first modification, the data amount of the reply signal returned from the wireless transmission device 20 does not need to be increased, and thus the communication time can be shortened.

(Application example 1 of this embodiment)
<Configuration>
FIG. 13 shows a configuration of a container management system to which the transmission / reception system according to the present embodiment is applied. The container management system includes an external transmission / reception device 10, a wireless transmission device 20, a storage container 30, and a display device 40. This system manages the contents (liquid) stored in the storage container 30.

[Container 30]
The storage container 30 includes a container body 301 and a floating member 302.

  The container main body 301 has, for example, a shape with a constant cross-sectional area (for example, a cubic shape, a rectangular parallelepiped shape, a cylindrical shape, etc.) and accommodates a liquid.

  The floating member 302 is a plate-like member having a size of several millimeters square, and is floating on the liquid surface of the liquid stored in the container main body 301. The floating member 302 is made of a material having a lower density or specific gravity than the liquid stored in the storage container 301. However, since the floating member 302 only needs to float on the surface of the liquid, the density of the floating member 302 does not need to be lighter than the liquid density. If the surface tension can float on the liquid surface, the density of the floating member 302 is low. It may be heavier than the liquid density. The floating member 302 moves up and down in accordance with an increase or decrease in the internal volume of the liquid stored in the container body 301.

  The wireless transmission device 20 is installed on the surface of the floating member 302.

[External transmission / reception device 10]
The transmission / reception coil L1 of the external transmission / reception device 10 is arranged at a position corresponding to the moving direction of the floating member 302 as a loop-shaped transmission / reception antenna. Here, the transmission / reception coil L1 is disposed on the upper portion of the container 30 located on the extension line in the moving direction of the floating member 302.

  Further, the control unit 11 of the external transmission / reception device 10 calculates the internal volume of the liquid stored in the storage container 30 based on the obtained communication distance. The “distance D1 from the external transmission / reception device 10 to the bottom surface of the container body 301” and the “bottom area S1 of the container body 301” are constant, and the control unit 11 stores these values in advance. In addition, the control unit 11 outputs management information in which the detected ID information and the obtained liquid volume are written instead of the measurement result information to the display device 40.

[Display device 40]
The display device 40 displays management information (ID information, liquid content) from the external transmission / reception device 10.

[Wireless transmission apparatus 20]
FIG. 14 shows an installation example of the wireless transmission device 20 in the floating member 302. The wireless transmission device 20 is formed as an IC chip, for example, and is installed on the surface of the floating member 302 of the container 30. The transmission / reception coil L2 of the wireless transmission device 20 is arranged as a looped transmission / reception antenna. Here, if the entire surface of the floating member 302 is subjected to a waterproof treatment or a water repellent treatment, not only the IC chip can be protected but also the floating property can be improved.

<Operation>
Next, the operation of the container management system shown in FIG. 13 will be described.

  First, various signals (transmission signal, reply signal) are exchanged between the external transmission / reception device 10 and the wireless transmission device 20, and the control unit 11 of the external transmission / reception device 10 obtains the communication distance D2.

  Next, the control unit 11 subtracts the “communication distance D2” from the “distance D1” stored therein in advance to obtain the “distance (liquid level) D3 from the bottom surface of the container body 301 to the liquid surface”. calculate. Next, the control unit 11 calculates the internal volume of the liquid stored in the storage container 30 by multiplying the calculated “liquid level D3” by the “bottom area S1 of the container main body 301”. Next, the control unit 11 writes the ID information detected by the information detection unit 109 and the calculated liquid volume in the management information, and outputs the management information to the display device 40.

  Next, the display device 40 displays management information (ID information, liquid content) from the external transmission / reception device 10.

  Here, as shown in FIG. 15, when the internal volume of the liquid stored in the storage container 30 decreases, the floating member 302 in which the wireless transmission device 20 is installed descends. As a result, the distance between the external transmission / reception device 10 and the wireless transmission device 20 becomes long, so that the state of the reply signal received by the external transmission / reception device 10 deteriorates (the reception level decreases). Therefore, compared with the case of FIG. 12, the communication distance D2 calculated | required by the external transmission / reception apparatus 10 becomes long, and the calculated liquid content volume reduces. That is, the liquid content displayed on the display device 40 decreases.

<Effect>
As described above, the content of the contents stored in the storage container can be measured from the communication distance between the external transmission / reception device and the wireless transmission device. Moreover, the content accommodated in the storage container can be identified by acquiring the ID information. Thereby, the kind and content of the content accommodated in the storage container can be managed simultaneously.

  If the storage unit 21 of the wireless transmission device 20 stores the content information, the control unit 25 of the wireless transmission device 20 sends the content information together with the ID information to the return information (the source of the reply signal). It is also possible to write in the information). The content information is information about the content stored in the storage container 30 such as the type of content and the date of manufacture. In this case, if the content information is acquired together with the ID information by the information detection unit 109, the quality control can be performed simultaneously with the measurement of the liquid content.

  Further, the position where the transmission / reception coil L <b> 1 of the external transmission / reception device 10 is arranged is not limited to the upper part of the container 30. If the distance between the external transmission / reception device 10 and the wireless transmission device 20 is uniquely determined with respect to the change in the liquid level, the transmission / reception coil L1 of the external transmission / reception device 10 may be disposed beside the container 30. Absent.

  Of course, the transmission / reception systems of Modification 1 and Modification 2 can also be applied to this container management system.

  In addition, the amplitude level of the transmission signal from the external transmission / reception device 10 is determined when the distance from the wireless transmission device 20 is maximum (the housing container 30 becomes empty and the floating member 302 reaches the bottom surface of the container body 301). However, it is preferable that the wireless transmission device 20 is set so as to transmit a reply signal in response to the transmission signal. In this way, it is possible to determine whether the state of the return signal has deteriorated due to factors other than the communication distance (for example, device failure or communication failure due to radio wave shielding). Further, since it can be confirmed whether or not the receiving container 30 is mounted based on the presence / absence of a reply signal, the mounting confirmation component is not necessary.

  In this application example, the case where the cross-sectional area of the container main body 301 is constant is shown. However, if the relationship between the liquid level D3 and the volume of liquid contained is determined in advance, the cross-sectional area is not constant. May be.

<Installation location of IC tag>
As shown in FIG. 16, three wireless transmission devices 20-1, 20-2, and 20-3 may be arranged on the floating member 302. In this case, the external transmission / reception device 10 is based on the communication distance d1 with the wireless transmission device 20-1, the communication distance d2 with the wireless transmission device 20-2, and the communication distance d3 with the wireless transmission device 20-3. To measure the communication distance D2. According to this, even when the liquid level is inclined, the communication distance can be accurately measured. This is particularly effective when the container is attached to a portable electronic device.

<Variation 1 of the container>
In addition, as shown in FIG. 17, the same effect can be obtained when the storage container 30 </ b> A is used instead of the storage container 30 shown in FIG. 13. The storage container 30A includes a container main body 301A and a partition wall member 302A. The partition member 302A moves along the height direction of the container main body 301A according to the increase or decrease of the liquid stored in the container main body 301A. In addition, the transmission / reception coil L1 of the external transmission / reception device 10 is disposed at a position corresponding to the moving direction of the partition wall member 302A. Here, the transmission / reception coil L2 is disposed on the upper portion of the storage container 30A, which is on an extension line in the moving direction of the partition wall member 302A. Accordingly, the communication distance D2 can be measured even when the storage container 30A is tilted. Moreover, since airtightness can be ensured, it is possible to prevent the liquid as the contents from leaking to the outside or the outside air from entering the housing container 30A even when the housing container 30A is tilted.

<Modification 2 of the container>
Further, as shown in FIG. 18, the same effect can be obtained when the storage container 30 </ b> B is used instead of the storage container 30 shown in FIG. 12. The storage container 30B expands and contracts in accordance with an increase or decrease in the internal volume of the liquid stored in itself (see FIG. 19). Here, the storage container 30B expands and contracts in the height direction. The wireless transmission device 20 is installed on the extended line in the expansion / contraction direction (here, the upper surface of the storage container 30B) on the surface of the storage container 30B. The transmission / reception coil L1 of the external transmission / reception device 10 is disposed at a position corresponding to the expansion / contraction direction of the container 30B. Here, it arrange | positions above the container 30B which is on the extension line | wire of an expansion-contraction direction. According to this, even if the whole container management system inclines, the communication distance D2 can be measured. Further, since the wireless transmission device 20 is lightweight, the influence of the weight of the wireless transmission device 20 on the shape of the storage container 30B is small, and measurement errors can be reduced. Further, if the upper surface of the container 30B can be made substantially parallel to the external transmission / reception device 10, the communication distance D2 can be measured with high accuracy. Further, the storage container 30B may be entirely formed of the same members and materials, but the members and materials may be partially different. According to this, the degree of deformation in each part of the storage container 30B can be adjusted so that the upper surface of the storage container 30B is substantially parallel to the external transmission / reception device 10.

(Application example 2 of this embodiment)
<Configuration>
FIG. 20 shows a configuration of a fuel cell system to which the transmission / reception system according to the present embodiment is applied. The fuel cell system includes a container 30, a wireless transmission device 20, a fuel cell unit 50, and an electronic device 60. In this system, the fuel cell unit 50 generates power using the aqueous methanol solution stored in the storage container 30 as fuel, and the electronic device 60 is driven by the power of the fuel cell unit 50 and manages the aqueous methanol solution stored in the storage container 30. . The electronic device 60 is, for example, a notebook personal computer.

[Container 30]
The storage container 30 stores a methanol aqueous solution. The storage unit 21 of the wireless transmission device 20 provided in the floating member 302 stores methanol information as content information in addition to the ID information. The methanol information is information relating to the aqueous methanol solution stored in the storage container 30, such as the concentration of the aqueous methanol solution. The reply signal includes methanol information in addition to the ID information.

[Fuel cell unit 50]
The fuel cell unit 50 includes a power generation unit 500 and an external transmission / reception device 10. The power generation unit 500 includes a fuel supply pump 501, a DMFC power generation cell 502, and a voltage conversion circuit 503.

  The fuel supply pump 501 sucks out the methanol aqueous solution from the container 30 and supplies the sucked methanol aqueous solution to the power generation cell 502. The power generation cell 502 generates power using the aqueous methanol solution supplied from the fuel supply pump 501. The voltage conversion circuit 503 converts the electric power generated by the power generation cell 502 into a voltage suitable for the electronic device 60 and supplies the converted electric power to the electronic device 60.

  The information detection unit 109 of the external transmission / reception device 10 detects methanol information in addition to the ID information.

  The controller 11 calculates the internal volume of the aqueous methanol solution stored in the storage container 30 based on the determined communication distance. In addition, the control unit 11 outputs management information in which the ID information and methanol information detected by the information detection unit 109 and the calculated content of the aqueous methanol solution are written to the electronic device 60 instead of the measurement result information. Further, the control unit 11 outputs a remaining amount decrease signal to the electronic device 60 when the content of the aqueous methanol solution stored in the storage container 30 becomes equal to or less than the specified amount.

[Electronic device 60]
The electronic device 60 includes a control microcomputer 601 and a display unit 602. The control microcomputer 601 receives management information from the external transmission / reception device 10 and outputs the management information to the display unit 602. Further, when the control microcomputer 601 receives the remaining amount decrease signal from the external transmission / reception device 10, it outputs a warning display command.

  The display unit 602 displays management information (ID information, methanol information, content of methanol aqueous solution) from the control microcomputer 601. Further, when receiving a warning display command from the control microcomputer 601, the display unit 602 displays a remaining amount reduction notification image. The remaining amount decrease notification image is an image for notifying that the remaining amount of the aqueous methanol solution is small, such as “the remaining amount of fuel“ low ””.

<Operation>
Next, the operation of the fuel cell system shown in FIG. 20 will be described.

  When the power generation operation by the fuel cell unit 50 is started, various signals (transmission signal, reply signal) are exchanged between the external transmission / reception device 10 and the wireless transmission device 20 to control the external transmission / reception device 10. The unit 11 periodically obtains the communication distance D2. Moreover, the control part 11 calculates the content volume of the methanol aqueous solution accommodated in the storage container 30 based on the calculated | required communication distance. Next, the control unit 11 writes the ID information and methanol information detected by the information detection unit 109 and the obtained volume of the aqueous methanol solution in the management information, and periodically outputs the management information to the electronic device 60. Thereby, the management information (ID information, methanol information, content of methanol aqueous solution) displayed on the display unit 602 of the electronic device 60 is periodically updated.

  Further, when the control unit 11 determines that the calculated internal volume of the aqueous methanol solution is equal to or less than the specified amount, the control unit 11 outputs a remaining amount decrease signal to the control microcomputer 601. Therefore, “remaining amount“ low ”” is displayed on the display unit 602. Thereby, it is possible to prompt the user of the electronic device 60 to change the fuel or refill the fuel.

<Effect>
As described above, the content of the aqueous methanol solution can be measured from the communication distance between the external transmission / reception device and the wireless transmission device. Moreover, the methanol aqueous solution accommodated in the container can be identified by acquiring the methanol information. Thereby, the kind and content volume of methanol aqueous solution can be managed simultaneously.

  In addition, by referring to the methanol information as the contents information, it is possible to prevent erroneous use of aqueous methanol solutions having different specifications. In other words, the content information displayed on the display unit 602 can include information on conformity / nonconformity of the content with respect to the fuel cell system.

  Further, in the fuel cell system for electronic devices, the container 30 is relatively small. Here, since the floating member 302 provided with a wireless transmission device (for example, a wireless tag) can be manufactured with a size of about several millimeters square, it can also be used for a small container 30. That is, it can be applied to a small container.

  In addition, it is possible to replace conventional components for content management (liquid level measurement using the conductivity and dielectric constant of contents or reflection of ultrasonic waves) with a small and lightweight wireless transmission device. It becomes. As a result, fuel information of the fuel cell system (fuel concentration, characteristics of contents, number of cartridge recycles, etc.) can be stored, and at the same time, sharing as a component for managing the internal capacity can be realized. In this way, an excellent effect of reducing the size and weight of the storage container can be obtained. In addition, since the conventional components for the internal volume management method are not necessary, the space for storing the fuel can be increased. Thereby, prolonged operation of the fuel cell system can be realized.

  In addition, although methanol aqueous solution was mentioned as an example as a fuel, it is not restricted to methanol, Liquids, such as a solution which melt | dissolved borohydride in alkaline aqueous solution, can also be used as fuel instead of methanol.

  Further, information regarding the liquid level measured periodically may be stored in the external transmission / reception device 10 and the wireless transmission device 20. Further, the expected remaining driving time of the fuel cell system can be obtained from the stored liquid level information and the measured elapsed time.

  Further, the transmission / reception systems of Modification 1 and Modification 2 can also be applied to this fuel cell system. Moreover, it may replace with the storage container 30 shown in FIG. 19, and may provide the storage container shown in FIG.17 and FIG.18.

  The transmission / reception system of the present embodiment can be applied not only to a fuel cell system but also to a system that is easily within the scope of those skilled in the art. For example, it can be used to store liquids, such as storage containers for petroleum fuel (for example, kerosene, gasoline), fuel tanks for automobiles, storage containers for edible seasonings, oil, soup, liquor, etc. It is. As a large one, it can be used in a crude oil storage tank having a floating lid.

  Further, the present invention can be applied to cases other than the case where the content is a liquid (for example, a case where a solid is stored like rice bran). In this case, as the container, for example, a form as shown in FIGS. 17 and 18 is preferable. Moreover, in the form shown in FIG.17 and FIG.18, even when the content is a gas, it is applicable.

(Application example 3 of this embodiment)
<Configuration>
FIG. 21 shows a configuration of an infusion management system to which the transmission / reception system according to the present embodiment is applied. The infusion management system includes an infusion pack 71, an infusion stand 72, a wireless transmission device 20, an external transmission / reception device 10, an information transmission device 73, and a display device 40. This infusion management system is applied to an infusion pack used for infusion at a medical site such as a hospital.

[Infusion pack 71]
The infusion pack 71 stores the infusion. A floating member 302 is floating on the liquid level of the infusion contained in the infusion pack 71.

[Infusion stand 72]
The infusion stand 72 includes a support column 72a that extends substantially vertically from the installation surface, and a pack attachment 72b that protrudes from the tip of the support column 72a. The infusion pack 71 is attached to the attachment hook of the pack attachment portion 72b.

[Wireless transmission apparatus 20]
The wireless transmission device 20 is installed on the surface of the floating member 302 that floats in the infusion pack 71. The storage unit 21 of the wireless transmission device 20 stores infusion information as content information in addition to the ID information. Infusion information is, for example, information on infusion, such as the type, concentration, volume, expiration date of use, information on infusion pack containers, etc. The reply signal includes infusion information in addition to the ID information.

[External transmission / reception device 10]
The transmission / reception coil L1 of the external transmission / reception device 10 is disposed at a position corresponding to the moving direction of the floating member 302 in a state where the infusion pack 71 is attached to the infusion stand 72. Here, the transmission / reception coil L1 is disposed on the pack attachment portion 72b of the infusion stand 72, which is on the extension line in the moving direction of the floating member 302.

  Moreover, the information detection part 109 of the external transmission / reception apparatus 10 detects infusion information in addition to ID information. The control unit 11 calculates the internal volume of the infusion contained in the infusion pack 71 based on the determined communication distance. The control unit 11 stores in advance a content correspondence table created based on the relationship between the communication distance and the content of the infusion. In the internal capacity correspondence table, a plurality of internal capacity and a plurality of communication distances are associated. In the internal capacity correspondence table, the internal capacity corresponding to the communication distance decreases as the communication distance increases. Instead of the measurement result information, the control unit 11 outputs the measurement result information in which the ID information and the infusion information detected by the information detection unit 109 and the calculated infusion volume are written to the information transmission device 73.

  Moreover, the control part 11 will output the residual amount reduction signal to the information transmission apparatus 73, if the content volume of infusion is below a regulation amount. Further, the control unit 11 stores in advance patient information, which is information related to the patient, such as the type of infusion to be administered to the patient, and the infusion information detected by the information detection unit 109 and the patient information stored in itself. If they do not match, a warning signal is output to the information transmission device 73.

[Information transmission device 73]
The information transmission device 73 transmits various signals (management information, remaining amount reduction signal, warning signal) from the external transmission / reception device 10 to the display device 40. Here, when the information transmission device 73 and the display device 40 communicate wirelessly, a frequency that does not interfere with the communication between the external transmission / reception device 10 and the wireless transmission device 20 may be employed. Communication between the information transmission device 73 and the display device 40 may be performed by wire.

[Display device 40]
The display device 40 is installed in a hospital room or a nurse station. The display device 40 displays management information (ID information, infusion information, infusion volume) from the information transmission device 73. Further, when the display device 40 receives the remaining amount reduction signal from the information transmission device 73, the display device 40 displays a remaining amount reduction notification image. In addition, when receiving a warning signal from the information transmission device 73, the display device 40 displays an infusion nonconformity notification image. The infusion solution non-conformity notification image is an image notifying that the infusion pack is not correctly assigned to the patient, for example, “infusion pack non-conformity”.

<Operation>
Next, the operation of the infusion management system shown in FIG. 21 will be described.

  When the infusion pack 71 is attached to the infusion stand 72, various signals (transmission signals, reply signals) are exchanged between the external transmission / reception device 10 and the wireless transmission device 20, and the external transmission / reception device 10 is controlled. The unit 11 periodically obtains the communication distance. Moreover, the control part 11 calculates | requires the content volume of the infusion accommodated in the infusion pack 71 based on the calculated | required communication distance. For example, the control unit 11 detects the internal capacity corresponding to the communication distance from the internal capacity correspondence table stored in itself. Next, the control unit 11 writes the ID information and the infusion information detected by the information detection unit 109 and the obtained infusion volume in the management information, and periodically outputs the management information to the information transmission device 73.

  Next, the information transmission device 73 transmits the management information from the external transmission / reception device 10 to the display device 40. Thereby, the management information (ID information, infusion information, infusion volume) displayed on the display device 40 is periodically updated.

  Moreover, if the control part 11 of the external transmission / reception apparatus 10 determines with the content volume of the calculated | required infusion being below a regulation amount, it will output a residual amount reduction signal. Therefore, “remaining amount“ low ”” is displayed on the display device 40. Thereby, attention of drip exchange can be urged.

  Further, when the control unit 11 determines that the patient information stored in advance in itself does not match the infusion information detected by the information detection unit 109, the control unit 11 outputs a warning signal. Therefore, “not compatible with infusion pack” is displayed on the display device 40. Thereby, attention of drip incompatibility can be urged.

<Effect>
As described above, the type and content of the infusion contained in the infusion pack can be managed simultaneously. Moreover, since the remaining amount of the infusion pack assigned to each patient can be managed, the timing of infusion exchange for many patients can be grasped. In this case, the information transmission device 73 and the display unit 40 may communicate with each other wirelessly, and the display device 40 may be carried by a nurse or doctor as being small and portable. This frees nurses and doctors from the troublesome work associated with running out of infusion. Further, by referring to the infusion information as the contents information, it is possible to collate whether or not the infusion is suitable for the patient. Therefore, it is possible to prevent a medical error such as injecting the wrong infusion to the patient. In other words, the contents information displayed on the display device 40 can include information on conformity / nonconformity of the contents with respect to the infusion management system.

  Moreover, since the floating member 302 provided with the wireless transmission device can be manufactured with a size of about several millimeters square, it can also be used for a small infusion pack 71. That is, it can be applied to a small infusion pack.

  The display device 40 may emit a warning sound together with the remaining amount reduction notification image and the infusion nonconformity notification image. Moreover, you may provide the alarm device which emits a warning sound separately.

  In this application example, the example using the internal capacity correspondence table is shown, but the internal capacity corresponding to the communication distance may be obtained using a calculation formula.

  Each device (external transmission / reception device 10, information transmission device 73, etc.) installed on the infusion stand 72 may be a type in which power is supplied from an outlet or a cordless type using a rechargeable battery. good.

  Furthermore, in this application example, an infusion pack used for infusion is given as an example, but the infusion in this application example includes blood. That is, the present invention can also be applied to a blood transfusion pack used for blood transfusion. In this case, if the storage unit 21 of the wireless transmission device 20 stores information related to blood type, it is possible to manage the remaining amount of blood for blood transfusion and blood type.

(Application example 4 of this embodiment)
<Configuration>
Next, a paper management system to which the transmission / reception system according to the present embodiment is applied will be described. The paper management system manages printer paper accommodated in the printer.

  FIG. 22 is an external view of the printer 80. This paper management system includes an external transmission / reception device 10, a wireless transmission device 20, a paper feed tray 81, and a printer main body 82. The printer main body 82 is formed with a concave tray storage portion 800. The paper feed tray 81 is inserted into the tray storage unit 800 and stored in the tray storage unit 800.

[Paper Tray 82]
FIG. 23 is a schematic cross-sectional view of the paper feed tray 81. The paper feed tray 81 includes a rectangular box-shaped tray main body 801, a rectangular paper feed plate 802, and an elastic body (for example, a spring) 803 as an urging member. The sheet feeding plate 802 is disposed inside the tray main body 801 (specifically, the upper portion of the bottom surface 801a of the tray main body 801), and the printer paper is placed thereon. The spring 803 is connected between one end of the paper feed plate 802 and one end of the bottom surface 801 a of the tray main body 801 in the insertion direction of the paper feed tray 81. Due to the restoring force of the spring 803, one end of the sheet feeding plate 802 is biased in a direction away from the bottom surface 801 a of the tray body 801.

[Wireless transmission apparatus 20]
The wireless transmission device 20 is set at one end of the paper feed plate 802 in the insertion direction of the paper feed tray 81. The storage unit 21 of the wireless transmission device 20 stores sheet information as content information in addition to the ID information. The paper information is information relating to the printer paper such as the type and size of the printer paper. Note that the reply signal includes paper information in addition to the ID information.

[Printer body 81]
FIG. 24 is a schematic cross-sectional view of the printer main body 82. The printer main body 82 includes an external transmission / reception device 10 and a display unit 804.

[External transmission / reception device 10]
The transmission / reception coil L1 of the external transmission / reception device 10 is disposed at a position corresponding to the moving direction of the sheet feeding plate 802. Here, the transmission / reception coil L1 is installed on the upper surface portion 800a of the tray storage portion 800, which is an extension line in the moving direction of one end portion of the sheet feeding plate 802.

  The information detection unit 109 of the external transmission / reception device 10 detects paper information in addition to the ID information. The control unit 11 obtains the number of printer papers stored in the paper feed tray 81 based on the obtained communication distance. The control unit 11 stores in advance a number correspondence table created based on the relationship between the communication distance and the number of printer sheets. In the number correspondence table, a plurality of sheets and a plurality of communication distances are associated with each other. In the number correspondence table, the longer the communication distance, the larger the number of sheets corresponding to the communication distance. Further, the control unit 11 outputs, to the display unit 804, management information in which the ID information detected by the information detection unit 109 and the sheet information and the calculated number of sheets are written instead of the measurement result information.

  In addition, the control unit 11 outputs a remaining amount decrease signal to the display unit 401 when the obtained number of sheets is equal to or less than the specified amount.

  The display unit 804 displays management information (ID information, paper information, the number of sheets) from the external transmission / reception device 10. In addition, when the display unit 804 receives the remaining amount decrease signal from the external transmission / reception device 10, the display unit 804 displays a remaining amount decrease notification image (for example, the remaining amount “low”).

<Operation>
Next, the operation by the paper management system will be described.

  When the paper feed tray 81 is stored in the tray storage recess 800 of the printer main body 82, various signals (transmission signals, reply signals) are exchanged between the external transmission / reception device 10 and the wireless transmission device 20, and the external The control unit 11 of the transmission / reception device 10 periodically obtains a communication distance. Further, the control unit 11 obtains the number of printer papers stored in the paper feed tray 81 based on the obtained communication distance. For example, the control unit 11 detects the number of sheets corresponding to the communication distance from the number correspondence table. Next, the control unit 11 writes the ID information and paper information detected by the information detection unit 109 and the obtained number of sheets in the management information, and periodically outputs the management information to the display unit 804. The management information displayed on the display unit 804 is periodically updated.

  Here, when the number of printer sheets stored in the sheet feed tray 81 decreases, one end of the sheet feed plate 802 moves upward of the tray body 801 (that is, the upper surface of the tray storage recess 800 by the restoring force of the spring 803). Part 800a). Therefore, the state of the reply signal from the wireless transmission device 20 is improved. Thereby, the communication distance D2 calculated | required by the external transmission / reception apparatus 10 becomes short, and the calculated number of sheets reduces. That is, the number of sheets displayed on the display device 804 is reduced.

  If the control unit 11 of the external transmission / reception device 10 determines that the obtained number of sheets is equal to or less than the specified amount, the control unit 11 outputs a remaining amount reduction signal. Therefore, “remaining amount“ low ”” is displayed on the display unit 804. Thereby, it is possible to prompt the user to replenish paper. Note that the display unit 804 may emit a warning sound together with the remaining amount decrease signal.

<Effect>
As described above, the type and number of sheets stored in the sheet feed tray can be managed simultaneously. If the paper information is displayed on the display screen of the personal computer, it is possible to prevent the paper having different sizes from being specified when printing from the personal computer.

  In addition, since a wireless transmission device (for example, a wireless tag) can be manufactured with a size of about several millimeters square, it can be mounted in an arbitrary space in a paper feed tray.

  In this application example, an example using the number correspondence table is shown, but the number of sheets corresponding to the communication distance may be obtained using a calculation formula.

(Application example 5 of this embodiment)
<Configuration>
Next, an ink management system to which the transmission / reception system according to the present embodiment is applied will be described. This ink management system manages ink contained in an ink cartridge built in an ink jet printer.

  FIG. 25A is an external view of an inkjet printer. A cartridge holder portion 91 is formed in the printer main body 90. This ink management system includes an external transmission / reception device 10, a wireless transmission device 20, a cartridge holder 91, and an ink cartridge 92. FIG. 25B is an external view of the cartridge holder portion 91. The ink cartridge 92 is attached in the cartridge holder portion 91. FIG. 26 is a schematic cross-sectional view of the cartridge holder 91 and the ink cartridge 92.

[Ink cartridge 92]
The ink cartridge 92 stores ink. In addition, a floating member 302 floats on the liquid level of the ink stored in the ink cartridge 92.

[Wireless transmission apparatus 20]
The wireless transmission device 20 is installed on the surface of the floating member 302. The storage unit 21 of the wireless transmission device 20 stores ink information as content information in addition to the ID information. Ink information is information about ink, such as the color and type of ink, for example. The return signal includes ink information in addition to the ID information.

[External transmission / reception device 10]
The transmission / reception coil L1 of the external transmission / reception device 10 is disposed at a position corresponding to the moving direction of the floating member 302. Here, the transmission / reception coil L1 is disposed on the upper portion of the cartridge holder portion 91 which is on an extension line in the movement direction.

  The information detection unit 109 of the external transmission / reception device 10 detects ink information in addition to the ID information. The control unit 11 obtains the internal volume of the ink stored in the ink cartridge 92 based on the obtained communication distance. In addition, the control unit 11 outputs management information in which the ID information and ink information detected by the information detection unit 109 and the obtained ink content are written, instead of the measurement result information, to the display unit 901.

  In addition, the control unit 11 outputs a remaining amount decrease signal to the display unit 901 when the ink content is equal to or less than the specified amount.

  The display unit 901 displays management information (ID information, ink information, ink content) from the external transmission / reception device 10. In addition, when the display unit 901 receives the remaining amount decrease signal from the external transmission / reception device 10, the display unit 901 displays a remaining amount decrease notification image (for example, the remaining amount “low”). Note that the display unit 901 may emit a warning sound together with the remaining amount decrease signal.

<Operation>
Next, the operation by the ink management system will be described.

  When the ink cartridge 92 is housed in the cartridge holder 91, various signals (transmission signal, reply signal) are exchanged between the external transmission / reception device 10 and the wireless transmission device 20, and the external transmission / reception device 10 The control part 11 calculates | requires a communication distance regularly. Further, the control unit 11 obtains the internal volume of the ink stored in the ink cartridge 92 based on the obtained communication distance. Next, the control unit 11 writes the ID information and ink information detected by the information detection unit 109 and the obtained ink content in the management information, and periodically outputs the management information to the display unit 901. Management information displayed on the display unit 901 is periodically updated.

  If the control unit 11 of the external transmission / reception device 10 determines that the obtained ink content is equal to or less than the specified amount, the control unit 11 outputs a remaining amount decrease signal. Therefore, “remaining amount“ low ”” is displayed on the display unit 901. Thereby, replacement of the ink cartridge can be urged.

<Effect>
As described above, the type and content of ink stored in the ink cartridge can be managed simultaneously.

  In addition, the floating member 302 provided with a wireless transmission device (for example, a wireless tag) can be manufactured with a size of about several millimeters square, and thus can be mounted inside a small ink cartridge.

  In addition, in each of the application examples of the present embodiment described above, the transmission / reception systems of Modification Examples 1 and 2 can naturally be applied.

  As described above, the present invention can detect the position of the wireless transmission device, so that the present invention can be applied to a container management system for managing the content of contents stored in a predetermined storage container, or a paper feed tray. This is useful as a paper management system for managing the stored printer paper.

The block diagram which shows the whole structure of the transmission / reception system by embodiment of this invention. The block diagram which shows the internal structure of the external transmission / reception apparatus shown in FIG. The block diagram which shows the internal structure of the transmission signal supply part shown in FIG. The block diagram which shows the internal structure of the decoding part and signal state detection part which were shown in FIG. The block diagram which shows the internal structure of the wireless transmission apparatus shown in FIG. The block diagram which shows the internal structure of the decoding part shown in FIG. The block diagram which shows the internal structure of the reply signal supply part shown in FIG. The graph which shows the relationship between a reception level and communication distance. The figure which shows an example of an amplification degree corresponding | compatible table. (A) The graph which shows the relationship between communication S / N and communication distance. (B) A graph showing the relationship between error rate and communication S / N. (C) A graph showing the relationship between the number of error corrections and the communication distance. The figure which shows an example of an error location number corresponding | compatible table. The figure which shows an example of an amplitude level corresponding | compatible table. The figure which shows the structure of the container management system to which the transmission / reception system shown in FIG. 1 is applied. The figure which shows the example of installation of the wireless transmission apparatus in the floating member shown in FIG. The figure for demonstrating the case where the liquid in the storage container shown in FIG. 13 decreases. The figure which shows the example of installation of the wireless transmission apparatus in the floating member shown in FIG. The figure which shows the modification of the storage container shown in FIG. The figure which shows the modification of the storage container shown in FIG. The figure for demonstrating the case where the liquid in the storage container shown in FIG. 18 decreases. The figure which shows the structure of the fuel cell system to which the transmission / reception system shown in FIG. 1 is applied. The figure which shows the structure of the infusion management system to which the transmission / reception system shown in FIG. 1 is applied. FIG. FIG. 6 is a schematic cross-sectional view of a paper feed tray. FIG. 3 is a schematic cross-sectional view for explaining the configuration of the paper management system. (A) External view of printer. (B) External view of cartridge holder. The figure for demonstrating the structure of an ink management system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 External transmission / reception apparatus 20 Wireless transmission apparatus 11, 25 Control part 12 Transmission signal supply part 13, 22 Transmission / reception part 14, 24 Decoding part 15 Signal state detection part 21 Storage part 23 Voltage generation part 26 Reply signal supply part 101,204 Encoding processing unit 102, 205 Error correction code addition unit 103 Transmission data generation unit 104, 207 Modulation circuit 105 Reception amplification circuit 106, 201 Demodulation circuit 107, 202 Error correction circuit 108, 203 Decoding processing unit 109 Information detection unit 110 Amplification Degree calculation unit 111 Error location counting circuit 206 Transmission data generation unit 30, 30A, 30B Container 301, 301A Container body 302 Floating member 302A Partition member 40 Display device 50 Fuel cell unit 500 Power generation unit 501 Fuel supply pump 502 DMFC power generation cell 503 Voltage conversion circuit 60 Electronic device 601 control Control microcomputer 602 Display unit 71 Infusion pack 72 Infusion solution stand 80, 90 Printer 81 Paper feed tray 82 Printer main body 800 Tray storage recess 801 Tray main body 802 Paper feed plate 803 Energizing members 804, 901 Display unit 91 Cartridge holder unit 92 Ink cartridge

Claims (29)

An external transmission / reception device that communicates with a wireless transmission device that transmits a return signal having a predetermined amplitude level when receiving a transmission signal,
A transmission signal supply unit for supplying the transmission signal;
A transmission / reception unit for transmitting a transmission signal supplied by the transmission signal supply unit and receiving a return signal from the wireless transmission device;
A signal state detection unit for detecting a state of a reply signal received by the transmission / reception unit;
An external transmission / reception device comprising: a control unit that obtains a communication distance between the transmission / reception unit and the wireless transmission device based on a signal state detected by the signal state detection unit. In claim 1,
A reception amplification unit that amplifies the amplitude level of the reply signal received by the transmission / reception unit to a predetermined level;
The signal state detection unit obtains the amplification degree of the reply signal by the reception amplification unit,
The said control part calculates | requires the said communication distance based on the amplification degree calculated | required by the said signal state detection part, The external transmission / reception apparatus characterized by the above-mentioned. In claim 2,
The control unit has a correspondence table in which a plurality of amplification degrees and a plurality of communication distances are associated one-to-one, and corresponds to the amplification degree obtained by the signal state detection unit from the correspondence table. An external transmission / reception apparatus, wherein a communication distance is detected. In claim 2,
The control unit calculates the communication distance by performing a predetermined calculation based on a relationship between the amplification degree of the reply signal and the communication distance with respect to the amplification degree obtained by the signal state detection unit. An external transmission / reception device characterized by the above. In claim 1,
The signal state detection unit counts the number of error locations occurring in the reply signal received by the transmission / reception unit,
The external transmission / reception apparatus, wherein the control unit obtains the communication distance based on the number of error locations counted by the signal state detection unit. In claim 5,
The control unit has a correspondence table in which a plurality of error locations and a plurality of communication distances are associated one-to-one, and the number of error locations counted by the signal state detection unit from the correspondence table An external transmission / reception apparatus characterized by detecting a communication distance according to the frequency. In claim 5,
The control unit calculates the communication distance by executing a predetermined calculation based on a relationship between the number of error parts of the return signal and the communication distance with respect to the number of error parts counted by the signal state detection unit. An external transmission / reception device characterized by: In claim 1,
The signal state detection unit measures an amplitude level of a reply signal received by the transmission / reception unit,
The said transmission part calculates | requires the said communication distance based on the amplitude level measured by the said signal state detection part, The external transmission / reception apparatus characterized by the above-mentioned. In claim 8,
The control unit has a correspondence table in which a plurality of amplitude levels and a plurality of communication distances are associated one to one, and corresponds to the amplitude level measured by the signal state detection unit from the correspondence table. An external transmission / reception apparatus, wherein a communication distance is detected. In claim 8,
The control unit calculates the communication distance by executing a predetermined calculation based on a relationship between the amplitude level of the reply signal and the communication distance with respect to the amplitude level measured by the signal state detection unit. An external transmission / reception device characterized by the above. A transmission / reception system in which a wireless transmission device communicates with an external transmission / reception device that transmits a transmission signal,
The wireless transmission device includes:
A first transmission / reception unit for receiving a transmission signal from the external transmission / reception device;
When the transmission signal is received by the first transmission / reception unit, a return signal supply unit that supplies a return signal having an amplitude level corresponding to the amplitude level of the transmission signal,
The first transmission / reception unit further transmits a reply signal supplied by the reply signal supply unit,
The external transmission / reception device is:
A transmission signal supply unit for supplying the transmission signal;
A second transmission / reception unit that transmits a transmission signal supplied by the transmission signal supply unit and receives a return signal from the wireless transmission device;
A signal state detection unit for detecting a state of a reply signal received by the second transmission / reception unit;
A transmission / reception system comprising: a control unit that obtains a communication distance between the first transmission / reception unit and the second transmission / reception unit based on a signal state detected by the signal state detection unit. In claim 11,
The external transmission / reception device is:
A reception amplification unit that amplifies the amplitude level of the reply signal received by the second transmission / reception unit to a predetermined level;
The signal state detection unit obtains the amplification degree of the reply signal by the reception amplification unit,
The said control part calculates | requires the said communication distance based on the amplification degree calculated | required by the said signal state detection part, The transmission / reception system characterized by the above-mentioned. In claim 11,
The signal state detection unit counts the number of error locations occurring in the reply signal received by the second transmission / reception unit,
The said control part calculates | requires the said communication distance based on the number of error locations counted by the said signal state detection part, The transmission / reception system characterized by the above-mentioned. In claim 11,
The signal state detection unit measures an amplitude level of a reply signal received by the second transmission / reception unit,
The said control part calculates | requires the said communication distance based on the amplitude level measured by the said signal state detection part, The transmission / reception system characterized by the above-mentioned. In claim 12 or claim 14,
The reply signal supply unit generates a reply signal having an amplitude level corresponding to the amplitude level of the transmission signal received by the first transmitting / receiving unit and having a section in which the amplitude level is constant, and the generated reply A transmission / reception system characterized by supplying a signal. In claim 11,
A storage container for storing predetermined contents;
The communication distance changes according to the increase or decrease of the contents,
The said control part calculates | requires the content of the said predetermined content based on the calculated | required communication distance, The transmission / reception system characterized by the above-mentioned. In claim 11,
A container main body in which a predetermined content that is liquid is stored;
A floating member that floats on the liquid level of the predetermined content stored in the container main body,
The wireless transmission device is installed on the surface of the floating member,
The transmission / reception system, wherein the control unit of the external transmission / reception device obtains an internal volume of a predetermined content stored in the container main body based on the obtained communication distance. In claim 11,
A container body for storing predetermined contents;
A partition member that is arranged inside the container main body and moves in accordance with an increase or decrease in the content of the predetermined content stored in the container main body,
The wireless transmission device is installed on the partition member,
The transmission / reception system, wherein the control unit of the external transmission / reception device obtains an internal volume of a predetermined content stored in the container main body based on the obtained communication distance. In claim 11,
The container further includes a container body in which the predetermined contents are stored and the outer shape expands and contracts according to the increase or decrease of the contents,
The wireless transmission device is installed on the surface of the container body,
The transmission / reception system, wherein the control unit of the external transmission / reception device obtains an internal volume of a predetermined content stored in the container main body based on the obtained communication distance. In any one of claims 17, 18, and 19,
A fuel cell unit that generates electric power for driving the electronic device;
The container body contains liquid fuel for a fuel cell,
The fuel cell unit includes a power generation unit that generates electric power using the liquid fuel stored in the storage container body,
The transmission / reception system, wherein the control unit of the external transmission / reception device calculates an internal volume of the liquid fuel stored in the storage container body based on the determined communication distance. In claim 11,
An infusion container for containing a predetermined infusion; and
A floating member floating on the liquid surface of the predetermined infusion contained in the infusion container;
A container mounting stand for mounting the infusion container, and
The wireless transmission device is installed on the surface of the floating member,
The transmission / reception system, wherein the control unit of the external transmission / reception device obtains the internal volume of a predetermined infusion contained in the infusion container based on the obtained communication distance. In claim 11,
A paper feed tray for storing printer paper,
A printer main body having a tray storage unit in which the paper supply tray is inserted and stores the paper supply tray;
The paper feed tray includes a paper feed tray main body, a paper feed plate disposed inside the paper feed tray main body and on which the printer paper is placed, and a bottom surface of the paper feed tray main body in the insertion direction of the paper feed tray. An urging member that connects one end of the sheet feeding plate and one end of the sheet feeding plate and urges the sheet feeding plate in a direction away from the bottom surface of the tray body,
The wireless transmission device is installed at one end of the sheet feeding plate,
The transmission / reception system, wherein the control unit of the external transmission / reception device obtains the number of printer papers stored in the paper feed tray based on the obtained communication distance. In claim 11,
An ink cartridge containing predetermined ink;
A floating member that floats on the surface of the ink contained in the ink cartridge;
A cartridge holder formed in the printer main body and accommodated in the ink cartridge;
The wireless transmission device is installed on the surface of the floating member,
The transmission / reception system, wherein the control unit of the external transmission / reception device obtains an internal volume of ink stored in the ink cartridge based on the obtained communication distance. In any one of claims 16 to 20,
The wireless transmission device further includes:
A storage unit for storing content information that is information about the content;
When the transmission signal is received by the first transmission / reception unit, the response signal supply unit supplies the response signal based on the content information stored by the storage unit,
The external transmission / reception device further includes:
An information detection unit for detecting the content information from the reply signal received by the second transmission / reception unit;
A transmission / reception system comprising: a display unit configured to display at least one of content content obtained by the control unit and content information detected by the information detection unit. A transmission / reception method executed between an external transmission / reception device and a wireless transmission device,
Step (A) in which the external transmission / reception device transmits a transmission signal;
A step (B) in which the wireless transmission device receives the transmission signal and transmits a reply signal having a predetermined amplitude level in response to the received transmission signal;
Step (C) in which the external transmission / reception device receives the reply signal;
Detecting the state of the reply signal received in step (C) (D);
A transmission / reception method comprising: (E) obtaining a communication distance between the external transmission / reception device and the wireless transmission device based on the signal state detected in the step (D). In claim 25,
The step (D) includes a step (a) for amplifying the amplitude level of the reply signal received in the step (C) to a specified level, and a step (b) for obtaining the amplification level of the amplitude level in the step (a). Including
In the step (E), the communication distance is obtained based on the amplification degree obtained in the step (b). In claim 25,
In the step (D), the number of error locations occurring in the reply signal received in the step (C) is counted,
In the step (E), the communication distance is obtained based on the number of error locations counted in the step (D). In claim 25,
In the step (D), the amplitude level of the reply signal received in the step (C) is measured,
In the step (E), the communication distance is obtained based on the amplitude level measured in the step (D). In claim 26 or claim 28,
In the step (B), the wireless transmission device generates a reply signal having a predetermined amplitude level and a section in which the amplitude level is constant, and transmits the generated reply signal. Transmission / reception method.

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