JP2007228299A - Data transmission apparatus and data transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise the transmission speed compared with that using a piezoelectric element for generating compressional waves, and to improve the quality of the data transmission. <P>SOLUTION: A data processor circuit 10 generates transmission data and reads the contents of received data. A transmission circuit 11 converts the transmission data generated by the data processor circuit 10 into transmission signals of impulsive voltages, corresponding to bit series in the transmission circuit 11. A transmission element 1 has a structure of a heating body 23 laminated via an insulating layer 22 on a board 21 made of a radiative material, and locally changes the temperature of a medium contacted with the heating body 23, to generate a compressional wave according to the density change accompanying with the temperature change, when the heating body 23 is energized. The transmission signal outputted from the transmission circuit 11 is applied to the heating body 23 of the transmission element 1, to generate compressional wave corresponding to one cycle with sinusoidal variation in the density. Since there is no reverberation in transmission element 1, high-speed data transmission can be conducted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a data transmission apparatus and a data transmission system that perform data transmission using a dense wave propagating in a medium as a transmission medium.

  In general, a technique for performing data transmission using a sparse / dense wave is employed in a remote control device using ultrasonic waves as a transmission medium. It is also known to employ this technology for wireless data communication in information processing equipment (see, for example, Patent Document 1).

Patent Document 1 describes a data communication device that uses a piezoelectric element to transmit and receive a sound wave or an ultrasonic wave, which is a transmission medium. In particular, the frequency of a carrier wave at the time of transmission is set to a characteristic of the piezoelectric element. It is explained that it is desirable to match the resonance frequency.
JP-A-9-18377 (paragraph 0012-0014, FIG. 1)

  By the way, considering the impulse response of the piezoelectric element at a position 30 cm away when an impulse voltage is applied as shown in FIG. 9A, about 1 ms corresponding to the speed of sound as shown in FIG. 9B. Although it starts to rise later, the peak is reached after 3 to 4 wavenumbers, and the subsequent reverberation of several ms occurs. It takes 3 to 4 wave numbers to rise, and a very long reverberation occurs thereafter due to resonance of the piezoelectric element.

  Therefore, when a sparse wave such as a sound wave or an ultrasonic wave is generated using a piezoelectric element, and the carrier wave is digitally modulated in order to transmit data using this sparse wave as a transmission medium, a unit of time longer than the reverberation time is used. It is necessary to modulate the carrier wave. In other words, when using a sparse wave as a transmission medium for data transmission, if a piezoelectric element is used as the source of the sparse wave, the transmission rate is limited by the reverberation time, which makes it difficult to improve the transmission rate. Yes. In addition, since sparse waves due to reverberation are also transmitted during data transmission, reverberation may be mistaken for meaningful information, and there is a problem that the quality of data transmission deteriorates.

  The present invention has been made in view of the above-mentioned reasons, and the object thereof is to increase the transmission speed as compared with the case where a piezoelectric element is used for generation of a dense wave, and the quality of data transmission is high. A data transmission apparatus and a data transmission system are provided.

  According to the first aspect of the present invention, a transmission circuit that generates a transmission signal associated with a bit value of transmission data including a bit string, and a temperature of a medium in contact with the transmission signal when the transmission signal is given from the transmission circuit are locally changed. A transmission element that generates a dense wave corresponding to the transmission signal by thermal induction.

  According to this configuration, by using a transmission element that generates a dense wave by heat induction, reverberation due to the natural resonance frequency does not occur, and the time interval for generating the dense wave can be shortened compared to the piezoelectric element. it can. In other words, compared to the case where a piezoelectric element is used to generate a sparse / dense wave, it is possible to increase the transmission speed, and since noise components due to reverberation do not occur, transmission errors are reduced and data transmission quality is improved. .

  According to a second aspect of the invention, in the first aspect of the invention, the transmission circuit outputs an impulse voltage associated with a bit value of transmission data as a transmission signal.

  According to this configuration, since the transmission signal is in the form of an impulse, the transmission element is less likely to be thermally saturated, the time interval for transmitting the bit string in the transmission data can be shortened, and as a result, the data transmission speed can be increased. I can expect.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the transmission signal comprises a frequency component of 20 kHz or more.

  According to this configuration, since no frequency component in the audible range is included in the transmission signal, no noise is generated during data transmission.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, a capacitor serving as an auxiliary power source is connected in parallel to a DC power source that supplies a transmission signal to the transmitting element.

  According to this configuration, when a current having a large peak value is passed through the transmitting element in a short time, the shortage of the current capacity of the DC power supply can be compensated for by the charge of the capacitor. Therefore, a small DC power supply having a small capacity is used. Even in this case, it is possible to secure a current to be applied to the transmitting element.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the transmitting element includes a substrate made of a heat dissipating material, a heat insulating layer laminated on the substrate, and a heat insulating layer on the substrate. The heating element is laminated, and Joule heat is generated in the heating element by the transmission signal.

  According to this configuration, Joule heat generated when the heating element of the transmitting element is energized is transmitted to the medium without escaping to the substrate side due to the presence of the heat insulating layer, so that input power can be efficiently converted into a dense wave. In addition, since the heat transferred to the heat insulating layer is dissipated through the substrate, which is a heat dissipating material, the temperature of the heat insulating layer does not rise, and the overall heat capacity can be reduced. As a result, the time interval for energizing the heating element can be shortened, and the data transmission can be speeded up.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, a receiving element including a microphone that receives a sparse wave generated by a transmitting element and outputs a reception signal, and a reception output from the receiving element. And a receiving circuit for extracting a bit string from the signal.

  According to this configuration, the configuration on the receiving side can be realized at low cost by receiving the sparse / dense wave with the receiving element using the microphone.

  According to a seventh aspect of the invention, in the sixth aspect of the invention, the receiving element is characterized in that a wavelength region including a peak wavelength of the dense wave output from the transmitting element is more sensitive than other wavelength regions. .

  According to this configuration, since the receiving element is highly sensitive to sparse and dense waves, it is possible to take a long distance for data transmission.

  In the invention of claim 8, in the invention of claim 6 or claim 7, the transmitting element and the receiving element are housed in one container, and the container acoustically separates the transmitting element and the receiving element from each other. It is characterized by comprising a separate storage chamber.

  According to this configuration, it is possible to suppress the sneak wave from the transmitting element to the receiving element, and therefore, it is possible to reduce unnecessary components received by the receiving element during the period when the sparse wave is being output, and to transmit data. Can improve the quality.

  According to a ninth aspect of the present invention, in the sixth to eighth aspects of the present invention, a plurality of the transmitting elements and the receiving elements are provided in the same number, and each transmitting element and each receiving element are associated with each other on a one-to-one basis. It is arranged that data transmission of transmission data composed of different bit strings is performed between a transmission element and a reception element that are arranged and correspond to each other.

  According to this configuration, a plurality of bits can be transmitted in parallel at the same time, and the data transmission speed can be improved by parallel transmission as compared to serial transmission.

  A tenth aspect of the present invention is a data transmission system comprising a plurality of the data transmission devices according to any one of the sixth to ninth aspects, wherein data transmission is performed between the data transmission devices. To do.

  According to this configuration, data transmission is performed between the data transmission apparatuses using the dense wave as a transmission medium, so that the possibility of interception is reduced as compared with the case where radio waves are used as the transmission medium.

  In the invention of claim 11, in the invention of claim 10, the data transmission device includes an ID holding unit having unique identification information, an ID adding unit for adding identification information to the transmission data, and a reception signal. An ID collating unit that collates the identification information to be identified with the identification information held in the ID holding unit, and receives data when a prescribed result is obtained by the ID collating unit.

  According to this configuration, since the data transmission device that performs data transmission is identified using the identification information, data transmission is not established between data transmission devices that are not associated with each other, and data integrity in data transmission is reduced. Get higher.

  According to a twelfth aspect of the present invention, in the tenth aspect of the invention, the other transmitting element and receiving element are acoustically coupled to each other with respect to two data transmitting apparatuses that perform data transmission among the data transmitting apparatuses. It is characterized by.

  According to this configuration, since the transmitting element and the receiving element are acoustically coupled between the two data transmission apparatuses, data transmission is possible without using identification information between the specific data transmission apparatuses. is there.

  According to the configuration of the present invention, since a transmitting element that generates a dense wave by heat induction is used, reverberation due to the natural resonance frequency does not occur as in the case of using a piezoelectric element, and a time interval for generating a dense wave is set. There is an advantage that it can be shortened as compared with the piezoelectric element. As a result, it has the advantage that the transmission speed can be increased compared to the case where a piezoelectric element is used for the generation of the dense wave, and the generation of transmission errors is reduced because no noise component due to reverberation occurs. It has the advantage that the quality of transmission is high.

(Embodiment 1)
The present embodiment is a data transmission apparatus that performs data transmission using a sparse / dense wave as a transmission medium, and includes a data processing circuit 10 that generates transmission data and reads the contents of reception data, as shown in FIG. .

  Transmission data generated by the data processing circuit 10 is input to the transmission circuit 11 and converted into a transmission signal for driving the transmission element 1. The transmission data generated by the data processing circuit 10 is data in which a bit string of a digital value is associated with a rectangular wave pulse string. For example, the H level of the rectangular wave is associated with “1” of the transmission data, and L The level corresponds to “0” of the transmission data.

  The transmission circuit 11 outputs an impulse voltage as a transmission signal to the transmission element 1. To generate a transmission signal that is an impulse voltage from a rectangular wave, for example, from a rectangular wave input using a one-shot circuit that differentiates the rising edge of the rectangular wave or uses the rising edge of the rectangular wave as a trigger Alternatively, a rectangular wave with a short time width may be generated. In the case of adopting this type of configuration, as shown in FIG. 2, if a capacitor C1 serving as an auxiliary power source is connected in parallel to a DC power source DC that applies a voltage to the transmitting element 1, an inrush current is supplied to the heating element 23. Even when such a large current flows, the shortage of the charge amount can be compensated for by the charge of the capacitor C1, so that the voltage drop of the DC power source DC can be prevented. The switch SW1 in FIG. 2 is opened and closed by a transmission signal, and generates a dense wave by energizing the transmission element 1 from the DC power source DC when turned on.

  Moreover, as shown in FIG. 3, the structure which applies an impulse-like voltage to the transmission element 1 using charging / discharging of the capacitor | condenser C2 is also employable. The circuit shown in FIG. 3 transmits the electric charge of the capacitor C2 after charging the capacitor C2 with a constant current smaller than the current of the constant current source Is using a Widdler type current mirror circuit composed of two transistors Q1 and Q2. It is configured to flow through the element 1, and is configured such that charging / discharging of the capacitor C2 is switched by a changeover switch SW2 connected to the capacitor C2. That is, when the capacitor C2 is connected to the a side by the changeover switch SW2, the capacitor C2 is charged. Since the charging current of the capacitor C2 is kept constant, the charge amount of the capacitor C2 is determined by the charging time.

  On the other hand, when the changeover switch SW2 is connected to the b side after the capacitor C2 is charged, the charge charged in the capacitor C2 flows to the transmission element 1, and a density wave of energy corresponding to the amount of charge accumulated in the capacitor C2 is generated in the transmission element 1. Generated. That is, by managing the charging time of the capacitor C2, the energy of the dense wave generated by the transmitting element 1 can be managed. Since the change-over switch SW2 requires high-speed switching, an analog switch is used, and the current waveform flowing through the transmission element 1 includes the charge amount of the capacitor C2, the resistance value of the heating element 23, and the on-resistance of the change-over switch SW2. And determined by

  If this configuration is adopted, a current having a large peak value can be caused to flow through the transmitting element 1 by adjusting the amount of charge when the capacitor C2 is charged. ) Can transmit dense waves. In other words, it is possible to generate a dense wave that is excellent in straightness and reaches far away.

  The transmission element 1 used in the present embodiment has a form called a heat-induced pressure wave generator or a heat-induced acoustic wave radiating element. An example of the structure of the transmission element 1 is shown in FIG. As shown, a heat insulating layer 22 made of porous silicon is formed on one surface of a substrate 21 made of single crystal silicon, and a heating element 23 made of tungsten is provided on the heat insulating layer 22. Signal terminals 24 are provided at both ends of the heating element 23, respectively. The material shown here is only an example, and a material with high heat dissipation may be selected as the substrate 21. Other materials can be selected as long as the function of each part is satisfied.

  In this transmission element 1, when the voltage applied to the signal terminal 24 is controlled to change the current supplied to the heating element 23, the density of the medium (generally air) in contact with the heating element 23 changes locally due to Joule heat. It generates a dense wave by using Therefore, when an impulse-like voltage is generated from the transmission circuit 11 and applied to the signal terminal 24 as described above, one cycle of sparse / dense waves whose density changes in a sine wave shape can be generated. Since the transmission element 1 is configured to generate a dense wave by energizing the heating element 23, it is thermally saturated when a pulsed voltage of a rectangular wave is repeatedly applied at short time intervals, and the heating element 23 is energized. However, there is a possibility that a thermal change does not occur and a dense wave cannot be generated. However, by setting the transmission signal as an impulse voltage, thermal saturation is unlikely to occur, and the time interval during which the impulse voltage is applied Can be shortened, and high-speed data transmission becomes possible.

  Here, since the heat insulating layer 22 is in contact with one surface of the heating element 23, the short-term Joule heat generated in the heating element 23 is less likely to escape to the substrate side within a short period in which the heat is generated. Heat from the heating element 23 can be efficiently transferred to the medium in contact with the heating element 23, and the heat transmitted from the heating element 23 to the heat insulating layer 22 in a short period thereafter is made of a material with high heat dissipation. Heat is quickly radiated through the substrate 20. That is, the heat capacity of the portion that changes in temperature due to the generation of Joule heat of the transmitting element 1 is the heat capacity 23 and the heat insulating layer 22 where the temperature changes in a short period when Joule heat is generated. The transmission element 1 is cooled without waiting for a long time after the application of the voltage to the heating element 23 is stopped, so that it is possible to generate a dense wave even if the voltage application is repeated. Even when the generated Joule heat is not completely dissipated and a part of the Joule heat remains in the heating element 23, the heat is constantly radiated from the heat insulating layer 22 to the substrate 21 side. Thus, a density wave is formed in the medium in contact with the heating element 23 due to the temperature change of the heating element 23 corresponding to the Joule heat applied next. Therefore, the shortest cycle in which the voltage application can be repeated depends on the heat capacity of the transmission element 1, the Joule heat generated by the heating element 23, the ambient temperature, and the like, but the shortest cycle of repetition at room temperature is on the order of μs. The transmission element 1 can be created.

  An example of the operation of the transmitting element 1 is shown in FIG. When a transmission signal having an impulse voltage as shown in FIG. 4A is applied to the transmission element 1, a dense wave is generated as shown in FIG. 4B. Similar to the piezoelectric element, an impulse-shaped dense wave having a single wave number rises about 1 ms from the voltage application corresponding to the speed of sound, and substantially no reverberation occurs as is apparent from FIG. 4B. That is, when an impulse voltage is applied, a pulsed dense wave having a time width similar to that of the impulse voltage can be generated. In addition, when a transmission signal whose voltage changes with the passage of time is given to the signal terminal 24, a dense wave whose pressure changes according to the voltage change can be generated. For example, if an impulse voltage is applied at a repetition frequency of 20 kHz or higher, it is possible to generate an ultrasonic wave as a dense wave. However, in this embodiment, an impulse signal composed of frequency components of 20 kHz or higher is used as the transmission signal.

  When the transmission element 1 having the above configuration is used, it is not necessary to consider 3 to 4 wave numbers and reverberation until reaching a peak, and therefore, the time interval between bits constituting transmission data is shortened as compared with the case of using a piezoelectric element. can do. In other words, when the piezoelectric element is employed, the next bit cannot be transmitted during the time of 3 to 4 wave numbers until the peak and the reverberation time, whereas the transmission element 1 of the present embodiment substantially reverberates. Therefore, the next bit can be transmitted without waiting for the time of 3 to 4 wave numbers and the reverberation time as in the case of using a piezoelectric element, and as a result, the time interval between bits is shortened, The transmission speed can be improved. Further, since reverberation does not occur, the quality of data transmission is improved. In other words, transmission data can be easily extracted on the receiving side.

  By the way, the receiving element 2 which consists of a microphone is used for the reception of dense waves. The receiving element 2 preferably has a configuration that does not have a natural resonance frequency, and it is preferable to use a condenser microphone instead of a microphone using a piezoelectric element. However, the receiving element 2 has a sensitivity characteristic capable of receiving the dense wave output from the transmitting element 1. In other words, the receiving element 2 is employed in which the wavelength region including the peak wavelength of the density wave generated by the transmitting element 1 is more sensitive than the other wavelength regions.

  When the reception element 2 detects the density wave, the reception element 2 outputs a reception signal that is an electrical signal corresponding to the density wave, and this reception signal is given to the reception circuit 12. The receiving circuit 12 extracts a bit string of received data from the received signal and passes it to the data processing circuit 10. The data processing circuit 10 verifies the bit string of the received data and requests retransmission if there is a transmission error.

  As shown in FIG. 5, the transmitting element 1 and the receiving element 2 are accommodated in a container 3 constituting a data transmission apparatus. The container 3 is formed with a first storage chamber 3a for storing the transmitting element 1 and a second storage chamber 3b for storing the receiving element 2, and the first storage chamber 3a and the second storage chamber 3b are separated from each other by a partition 3c. Separated by The partition wall 3 c is formed so as to prevent a sparse wave from entering between the transmitting element 1 and the receiving element 2. That is, the transmitting element 1 and the receiving element 2 are acoustically separated by the partition wall 3c.

  If the container 3 is formed in a connector shape, it is possible to perform data transmission by acoustically coupling the transmitting element 1 and the receiving element 2 between other data transmission apparatuses. In addition, if one of the two data transmission devices for data communication is configured as a card-like responder, and the other data transmission device is configured as an interrogator for the card, contactless Read / write data on the transponder.

(Embodiment 2)
In the configuration exemplified as the first embodiment, since each of the transmitting element 1 and the receiving element 2 is provided, there is one transmission path for data transmission, and serial transmission for transmitting data of 1 bit at a time is performed. ing. In contrast, the present embodiment exemplifies a configuration in which the transmission speed of data transmission is higher than that of the first embodiment by performing parallel transmission in which a plurality of bits of data are transmitted simultaneously.

  That is, in this embodiment, as shown in FIG. 6, a plurality of transmission elements 1 and a plurality of reception elements 2 are provided. In this configuration, each transmitting element 1 and each receiving element 2 need to correspond one-to-one, and data transmission cannot be performed normally if the positions of the transmitting element 1 and the receiving element 2 are shifted. . Further, when the distance between the transmitting element 1 and the receiving element 2 is increased, the dense wave generated by the transmitting element 1 is diffused and mixed with the dense wave from different transmitting elements 1 (crosstalk between bit strings occurs). . Therefore, the present embodiment is a configuration that is applied when the transmitting element 1 and the receiving element 2 are arranged close to each other, and is used only within a range in which crosstalk does not occur in the dense wave from each transmitting element 1. be able to. When the distance between the transmitting element 1 and the receiving element 2 is increased, a horn is attached to the transmitting element 1 to enhance directivity, and the frequency component of the dense wave generated from the transmitting element 1 has a high frequency component. It is desirable to improve the straightness of the sparse wave so as to be included. Other configurations and operations are the same as those of the first embodiment.

(Embodiment 3)
Each of the above-described embodiments has been described assuming that two data transmission apparatuses perform data transmission on a one-to-one basis. However, in this embodiment, as illustrated in FIG. A case will be described. In this case, each data transmission device A needs to have unique identification information so that each data transmission device A can recognize which data transmission device A has received the data. Further, when data is transmitted from the data transmission apparatus A by a sparse / dense wave, it is necessary to add identification information to the transmission data. Each data transmission device A is configured to collate the identification information added to the received data with the unique identification information and receive the data when the received identification information has a prescribed relationship with the unique identification information. Is done. The specified relationship means that the result of applying a predetermined rule for the received identification information and possessed identification information becomes a predetermined result. For example, when both identification information matches including.

  That is, as shown in FIG. 8, an ID holding unit 10a that holds identification information, an ID adding unit 10b that adds identification information to transmission data, and ID information extracted from the received signal are stored in the data processing circuit 10. The ID collation part 10c collated with the identification information currently hold | maintained at the holding | maintenance part 10a is provided. The ID holding unit 10a is configured by a DIP switch or a non-volatile memory, and different identification information is set for each data transmission apparatus A.

  In the configuration of the present embodiment, data transmission is possible only between the data transmission devices A defined by the rules described above, and a combination of the data transmission devices A capable of data transmission can be determined. As in the case of entering / leaving management using the data transmission device A, it can be used for applications that require verification of identification information. In addition, the identification information is used for recognizing which data transmission apparatus A the received dense wave is transmitted among three or more data transmission apparatuses A. In order to prevent the leakage of information more reliably, a high-level encryption technology that cannot be easily decrypted may be used. Other configurations and operations are the same as those of the first embodiment.

  In the configuration of each of the embodiments described above, since a sparse wave is used as a transmission medium for data transmission, there is no possibility of causing a malfunction in the medical device as in the case of using a radio wave as the transmission medium. That is, non-contact data transmission at a medical site becomes possible. In addition, since data transmission is performed in a non-contact manner, it can be applied to a non-contact type IC card or used as an interface for computer data input / output.

It is a block diagram which shows Embodiment 1 of this invention. It is a principal part circuit diagram same as the above. It is a principal part circuit diagram same as the above. It is operation | movement explanatory drawing of the transmission element used for the same as the above. It is principal part sectional drawing same as the above. It is a block diagram which shows Embodiment 2 of this invention. It is a schematic block diagram which shows Embodiment 3 of this invention. It is a block diagram same as the above. It is operation | movement explanatory drawing of the transmission element using a piezoelectric element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission element 2 Reception element 3 Body 3a 1st storage chamber 3b 2nd storage chamber 10a ID holding | maintenance part 10b ID addition part 10c ID collation part 11 Transmission circuit 12 Reception circuit 21 Board | substrate 22 Heat insulation layer 23 Heat generating body A Data transmission device C1 Capacitor DC DC power supply

Claims (12)

  Corresponding to the transmission signal by the thermal induction that locally changes the temperature of the medium that is in contact with the transmission circuit that generates the transmission signal corresponding to the bit value of the transmission data consisting of the bit string and the transmission circuit A data transmission device comprising: a transmission element that generates a sparse / dense wave.   The data transmission apparatus according to claim 1, wherein the transmission circuit outputs an impulse voltage associated with a bit value of transmission data as a transmission signal.   3. The data transmission apparatus according to claim 1, wherein the transmission signal includes a frequency component of 20 kHz or more.   4. The data transmission device according to claim 1, wherein a capacitor serving as an auxiliary power source is connected in parallel to a DC power source that supplies a transmission signal to the transmission element. 5.   The transmission element includes a substrate made of a heat radiating material, a heat insulating layer laminated on the substrate, and a heating element laminated on the substrate via the heat insulating layer, and generates Joule heat in the heating element by the transmission signal. The data transmission apparatus according to claim 1, wherein the data transmission apparatus is a data transmission apparatus.   A receiving element comprising a microphone that receives a density wave generated by a transmitting element and outputs a received signal, and a receiving circuit that extracts a bit string from the received signal output from the receiving element. 6. The data transmission device according to any one of items 5.   7. The data transmission apparatus according to claim 6, wherein the receiving element has a higher sensitivity in a wavelength region including a peak wavelength of the dense wave output from the transmitting element than in other wavelength regions.   7. The transmission device and the reception device are accommodated in one container, and the container includes separate storage chambers that acoustically separate the transmission element and the reception element from each other. 8. The data transmission device according to 7.   The same number of the transmitting elements and the receiving elements are provided, each transmitting element and each receiving element are arranged in a one-to-one correspondence, and different bit strings between the corresponding transmitting elements and receiving elements The data transmission apparatus according to any one of claims 6 to 8, wherein data transmission of transmission data comprising:   A data transmission system comprising a plurality of data transmission apparatuses according to any one of claims 6 to 9, wherein data transmission is performed between the data transmission apparatuses.   The data transmission device includes an ID holding unit having unique identification information, an ID adding unit that adds identification information to the transmission data, and identification information held in the ID holding unit. The data transmission system according to claim 10, further comprising: an ID collating unit that collates the data, and receiving data when a prescribed result is obtained by collation by the ID collating unit.   The data transmission system according to claim 10, wherein the two transmission elements that perform data transmission among the data transmission apparatuses are acoustically coupled to the other transmission element and reception element.

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