JP2000183828A - Vibration communication system by means of piezoelectric element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To desirably decrease the number of components of a communication system, used for small-sized electronic equipment, so as to facilitate the electronic equipment main body small-sized and lower the cost secondarily and to lower the power consumption of small-sized portable equipment to realize long-time operation by a battery power source. SOLUTION: The communication system has on its transmission side a data modulating means 1, a piezoelectric element driving means 2 which is connected to the voltage output of the data modulating means 1, and the piezoelectric element 3 which is driven by the piezoelectric element driving means 2 and on its reception side a piezoelectric element and a data demodulating means 6 which inputs a voltage from the piezoelectric element, propagates the pressure vibration generated by the piezoelectric element 3 having received the voltage output of the modulating means 1 of the transmission-side system to the piezoelectric element of the reception-side system through a transmission medium which can propagate the pressure vibration or a vibration transmission part 14 which efficiently transmits a frequency component used to communicate the piezoelectric element vibration to the transmission medium, and converts the vibration into a voltage signal by the piezoelectric element of the reception-side system and demodulates it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is characterized in that communication is performed by using a piezoelectric element as a means for converting a voltage signal and a pressure vibration signal through pressure vibration, thereby reducing the number of parts and reducing the size. It is necessary, and is useful for small electronic devices that need to realize low power consumption at relatively low communication speeds, especially small portable devices that already have a piezoelectric element for various notification sound outputs, The present invention relates to providing a communication system in which a piezoelectric element for utterance and a piezoelectric element used for communication can be shared, and the number of newly added components can be further reduced, which is very effective.

[0002]

2. Description of the Related Art FIGS. 2 and 3 show conceptual block diagrams of a conventional communication system using a radio wave and a communication system using a wire, respectively. The circuit scale and the number of components will be described, and the operation will be described.

[0003] The configuration will be described first when the communication system using radio waves shown in FIG. 2 is applied to a small portable device.

A communication system using radio waves includes a carrier generation means 9 and a data modulation means 7 for a transmission system.
And the antenna driving means 8 and the antenna 10. For the receiving system, the antenna 10 and the data demodulating means 11 are provided.
Consisting of In a system having a bidirectional communication function, a transmitting antenna and a receiving antenna are shared, and both a modulating unit and a demodulating unit are provided.

The operation is as follows.

The transmitting system receives data to be transmitted from the transmission data input terminal 103 and inputs the data to the data modulating means 7. The data modulating means 7 performs a desired modulation operation on the input transmission data and the carrier wave clock signal 104 generated by the carrier wave generating means 9, and the generated signal is mainly amplified by the antenna driving means 8. The signal is output to the antenna 10 and emitted from the antenna 10 as an electromagnetic wave 105.

It should be noted here that a carrier must have a frequency of at least several tens KHz in order to secure the electric field strength on the receiving side. For example, the information transmission speed of communication is low. Even in a sufficient case, the frequency handled by the circuit cannot be lowered, and it is difficult to reduce the power consumption.

Next, in the receiving system, the antenna 10 receives the electromagnetic wave 105 in the space as a current. The current signal is demodulated by the data demodulating means 11 to extract information sent from the transmitting system. Regarding the circuit scale, each of the data modulation means 7 and the data demodulation means 11 requires several tens of elements, and tends to be relatively large. In addition, there are large elements that cannot be formed in the IC such as the coil of the data demodulation unit 11 and the antenna 10, and the number of parts is not small. This is disadvantageous for small portable equipment that requires a small size and space for mounting components is small, and when applying to a small portable equipment such as a wristwatch, it is necessary to secure a place to mount the antenna itself. Is difficult. In addition, there is also a problem that the mounting cost tends to increase irrespective of the function because the antenna is often a part of the exterior.

Next, the configuration will be described first when the wired communication system shown in FIG. 3 is applied to a small portable device.

[0010] The wired communication system comprises a transmission level adjusting means 12 and a transmission line connection connector 13 for the transmission side system, and a transmission line connection connector 13 and a waveform shaping means 15 for the reception side system. Further, a transmission line 14 having connectors connected to both ends is required as a transmission line. In general, a connector which is a component of the transmitting means and a connector of the receiving means are shared.

The operation is as follows.

The transmitting system receives data to be transmitted from the transmission data input terminal 107 and inputs the data to the transmission level adjusting means 12. The transmission level adjusting means 12 adjusts the voltage signal reflecting the input data to an amplitude necessary and sufficient for communication and outputs the adjusted signal to the connector 13. The voltage waveform transmitted to the receiving system via the transmission line 14 via the connector 13 is input to the waveform shaping means 15 via the connector of the receiving system. The waveform shaping unit 15 converts the input voltage signal into a voltage that can be handled by a logic circuit and outputs the converted voltage.

The circuit scale can be realized on a very small scale if the communication standards for both transmission and reception are correctly followed.

[0014] However, communication requires a transmission line on which a connector is mounted, and the inability to communicate unless the transmission line is carried poses a serious problem for portable equipment and the like. Also,
A connector for connecting the transmission line is also required in the main body of the portable device, and when mounted on a small portable device such as a wristwatch, the size of the connector becomes a problem similarly to an antenna in wireless communication. Furthermore, transmission lines and connectors
Another drawback is that the cost is relatively high.

[0015]

In the communication means to be added to a small electronic device, it is difficult to reduce the size of the main body of the portable device due to the large number of components in a conventional communication system using radio waves, and the power consumption is reduced. However, there is a major problem in that a wired communication system has to carry a transmission line necessary for communication. Although not mentioned in the prior art, a communication system using infrared rays still has problems in that the number of parts is large and the power consumption is large.

In a communication system used for a small electronic device, it is desirable that the number of parts be small in order to facilitate downsizing of the electronic device body and, secondarily, to reduce the cost. It was pointed out that realizing low power consumption in order to achieve long-term operation with a battery power supply was an issue.

[0017]

In order to solve the above-mentioned problems, the present invention employs a communication system having the following configuration.

The transmitting side has data modulating means, a piezoelectric element driving means connected to a voltage output of the data modulating means, and a piezoelectric element driven by the piezoelectric element driving means. A data demodulator having a piezoelectric element as a voltage input, and receiving a voltage output of a modulating means of a transmitting system, generating a pressure oscillation generated by the piezoelectric element, a transmission medium capable of transmitting the pressure oscillation, or a pressure oscillation. Propagation to the piezoelectric element of the receiving system through the transmission medium that can propagate and the vibration transmitting unit that efficiently transmits the frequency component used for the communication of the piezoelectric element vibration to the transmission medium, and is converted into a voltage signal by the piezoelectric element of the receiving system A communication system characterized by performing demodulation.

The configuration and operation of a vibration communication system using a piezoelectric element according to the present invention will be described below with reference to the block diagram of FIG.

First, components and operations required for communication of the transmitting system will be described.

The components for communication on the transmitting side are:
Transmission data input terminal 101 for inputting transmission data
Data modulation means 1 for modulating data by an arbitrary modulation method, piezoelectric element driving means 2 for receiving a modulation output and converting the data into a voltage signal capable of driving a piezoelectric element,
And a piezoelectric element 3. The data modulating means 1 modulates the transmission data by an arbitrary modulation method prearranged with the receiving system. Piezoelectric element driving means 2
Converts the modulation output of the modulating means into a voltage signal capable of driving the piezoelectric element, and drives the piezoelectric element 3. The piezoelectric element 3 is continuously deformed by the AC component of the voltage signal, and generates vibration.

Next, a medium or the like for transmitting the pressure vibration generated by the piezoelectric element on the transmitting side to the piezoelectric element on the receiving side will be described. As a medium for transmitting pressure vibration, any medium that can transmit pressure vibration at a frequency during communication can be used as a transmission medium. In addition to this, a vibration transmitting unit 4 for efficiently transmitting a frequency component used for communication of piezoelectric element vibration to a transmission medium.
May be connected between the piezoelectric element 3 and the transmission medium 5 in some cases.

Normally, the transmission medium 5 uses the housing itself on which the transmitting and receiving systems are mounted, or air. Further, as the vibration transmitting unit 4, for example, an attachment or the like in which the surface of the piezoelectric element mounting unit opposite to the surface on which the piezoelectric element is mounted is brought into contact with the housing is exemplified. As a result, vibration can be efficiently transmitted to the housing.

The components and operation of the receiving system required for communication will be described.

The components for communication in the receiving system include the piezoelectric element 3 and data demodulating means 6 for demodulating data from the voltage signal from the piezoelectric element 3. The piezoelectric element 3 converts the pressure vibration transmitted from the transmission medium 5 via the vibration transmission unit 4 into a voltage waveform. Data demodulation means 6 demodulates data from this voltage waveform. From the data demodulation means 6, data having the same content as the transmitted data is obtained at the reception data output terminal 102.

As described above, in the communication system using the piezoelectric element of the present invention, there are few large-sized components such as antennas which are difficult to be integrated into ICs, and the piezoelectric element which is the only necessary large-sized functional part. Since it can be used for generating a normal notification sound, a large-sized component is not newly required for various conventional systems having a function of generating a sound using a piezoelectric element.

When the communication information transmission speed is low enough, unlike the wireless communication, each component can be operated at a low frequency, so that low power consumption is easy.

As described above, a communication system using a piezoelectric element has a smaller number of large-sized components that are difficult to be integrated into an IC than other wireless communication systems or wired communication systems. At the same time, cost reduction is possible. In addition, when the information transfer rate of communication is low enough, it is possible to reduce the power consumption by operating each component at a low frequency compared to other wireless communication systems. It is suitable for the communication function.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, in which amplitude modulation is applied as a modulation method and applied to a wristwatch. That is, a block diagram showing the configuration of the system in FIG. 4, a cross-sectional view of the wristwatch mounted state in FIG. 5, a modulation waveform diagram in FIG. 6, a conceptual diagram of a main circuit configuration of the transmission side system in FIG. FIG. 10 shows voltage waveforms, a conceptual diagram of a main circuit configuration of the receiving-side system in FIG. 9, and main voltage waveforms in FIG.

In the description, the transmitting side system and the receiving side system are separated for simplicity. However, in practice, both the modulation side and the demodulation side systems are mounted on the same wristwatch, and the piezoelectric element is shared for transmission and reception. Enables half-duplex communication.

As a transmission medium of the vibration, a glass surface which is a part of a housing of each of the transmission and reception systems is used, and the vibration is propagated in a state where the glass surfaces are in contact with each other. As the vibration transmitting unit that transmits vibration to the glass surface, the housing itself and the vibration transmitting column that has both ends in contact with the piezoelectric element and the glass surface are used. This can also be used as a part necessary for driving the hands of the timepiece.

The configuration example of the system on the transmitting side is as follows.

The transmission side system has a transmission enable signal 109 and a transmission data signal 111 as inputs, a 1-bit read pulse 110 as output, and a vibration by a piezoelectric element.
1/6 frequency dividing means 17, inverter circuit 18 for performing logical inversion, amplitude modulating means 19, signal amplitude adjusting means 20
, A piezoelectric element driving unit 21, an output impedance adjusting unit 22, and a piezoelectric element 23.

The operation of the transmitting system in the embodiment is as follows.

First, the modulation method in the embodiment will be described with reference to FIG.

The modulation method in the embodiment is a kind of amplitude modulation as is apparent from the correspondence between the piezoelectric element driving waveform in FIG. 6, that is, the modulation waveform and the transmission data. In the embodiment, a waveform consisting of eight pulses of 6.5 KHz and a ground power supply potential section having a length corresponding to eight pulses of 6.5 KHz is also associated with data '1'. Also, a ground power supply potential section having a length corresponding to 16 6.5 KHz pulses is associated with data '0'.

The reason why the voltage waveform corresponding to the data "1" has a section having no pulse is that the piezoelectric element vibrating by eight pulses takes several ms until the vibration is attenuated even if the pulse is stopped. This is because time is required. If the next data is sent after the vibration is sufficiently attenuated, demodulation on the receiving side becomes easy.

The reason why 6.5 KHz is used as the carrier frequency is that the resonance frequency of the piezoelectric element used in the embodiment is 6.5 KHz, so that the transmission and reception are also easy, and the frequency is experimentally determined. used.

In order to generate such a modulated waveform, the transmitting system performs the following operation. Note that the input signal is positive logic, and the latch operation of each latch circuit in FIG. 7 is performed at the rising edge of the clock input of each latch circuit. The functions of the terminals of the latch circuit are as follows: CK is clock input, D is data input, Q is output,
RB is a negative logic reset input. The function of each terminal of the 1/16 frequency divider circuit is that CK is a clock input, Q is an output,
RB is a negative logic reset input. Further, the correspondence between the transmission data and the transmission data signal is such that data “1” is at the voltage logic level “H” and data “0” is at the voltage logic level “H”.
L '.

The concept of the operation from the start of the modulation operation to the end of the modulation at the voltage logic level, that is, the generation of the modulation logic signal of FIG.
Taking the transmission operation in the order of 1 "0" as an example, a description will be given using a conceptual diagram of a main circuit configuration of the transmission side system in FIG. 7 and main voltage waveforms in FIG. Note that a start bit '1' for a synchronous operation on the receiving side is added to the head of the transmission data. That is, the data to be transmitted is '1''1''0' as a whole.

First, the reset of each latch circuit in FIG. 7 is released by the rise of the transmission enable signal, and the modulation operation starts. It is assumed that the first-bit data to be transmitted at this stage has been input to the transmission data signal terminal 114.

When the reference clock signal rises eight times after the rise of the transmission enable signal, the output Q of the 1/16 frequency divider 38 goes high, thereby causing the latch circuit 39 to output the transmission data signal. The voltage logic level at terminal 114 is output to output terminal Q. In the example '
An “H” level corresponding to “1” is output. As a result, the reference clock signal, the output of the latch circuit 39, and 1
The output of the 1/6 frequency divider 38 and the output of the AND circuit 40 connected to the three input terminals, that is, the modulation logic signal 118, are output before the output of the 1/16 frequency divider falls. Eight 6.5 KHz identical to the reference clock signal
A pulse is output. This is shown in FIG.

Due to the fall of the output of the 1/16 frequency divider 38, no pulse appears in the output of the modulation logic signal. Further, the output of the 1-bit read pulse terminal 117 rises. By this operation, an “H” level corresponding to the next 1-bit transmission data “1” appears at the transmission data signal terminal.

When the reference clock signal rises eight more times, the output of the 1/16 frequency divider, that is, the data clock rises again. Up to this point, the first 1-bit data modulation operation has been completed. FIG. 8 shows a state where a waveform corresponding to “1” is generated as a modulation logic signal.

1 bi at the rise of the data clock
When the modulation operation at the t-th voltage logic level ends,
The modulation operation of the second bit has started.

As in the case of the first bit, "H" of the transmission data signal terminal 114 is latched, and as a result, a pulse equivalent to eight reference clocks and "L" of the same time are output to the modulation logic signal terminal 118. You. That is, the modulation waveform corresponding to the data “1” is output once again.

The generation of the modulation waveform corresponding to the transmission data '1' of the second bit ends at the rising edge of the data clock, and the generation of the modulation waveform corresponding to the transmission data '0' of the third bit starts at the same time.

The transmission data signal is latched by the latch circuit 39 at the rise of the data clock. However, since the transmission data signal is "L", the modulation logic signal terminal 118
Is not output and remains at 'L'.

After all, the modulation logic signal terminal 118 remains "L" until the 16 reference clocks rise from the start of the third bit modulation operation, and the transmission data "
This means that a modulation waveform corresponding to 0 'has been obtained.

The modulation operation at the voltage logic level is performed by the above operation. Hereinafter, description will be made again with reference to FIG.

The modulation system further includes a signal amplitude adjusting means for converting a modulation signal of a voltage logic level into a voltage amplitude suitable for driving the piezoelectric element, and a piezoelectric element driving means for mainly amplifying electric power for driving the piezoelectric element. And output impedance adjusting means for equalizing the input impedance of the piezoelectric element as a load and the impedance on the driving side to prevent the modulation waveform from being distorted, thereby generating a final voltage modulation waveform and driving the piezoelectric element.

The modulation operation has been described above. Next, mainly with reference to FIG. 5, in order to propagate vibration generated in the piezoelectric element of the transmitting system to the piezoelectric element of the receiving system,
The vibration transmission unit and the transmission medium will be described.

FIG. 5 is a sectional view showing a contact state of the transmitting system and the receiving system in the communication state of the embodiment. Since the embodiment is applied to a wristwatch,
The structure is as shown in the figure. The drawing shows a state in which the display surfaces of the wristwatches, that is, the glass surfaces 31 are in contact with each other to propagate vibrations and communicate.

The piezoelectric element 32 has a thin circular shape, and is closely mounted on the inner surface of the back cover 33 opposite to the glass surface 31.

The mechanical vibration generated by the piezoelectric element 32 mainly propagates to the back cover 33 on which the piezoelectric element is mounted. This finally reaches the glass surface 31 where the transmission side system and the reception side system are in contact via the watch housing 34 and the like. However, since the vibration is absorbed by the rubber packing 35 and the like between the back cover 33 and the watch housing 34, the vibration transmitted to the glass surface is weak. For this reason, a vibration transmitting column 36 having both ends in contact with the piezoelectric element and the glass surface is provided for efficiently transmitting vibration to the glass surface.

In this case, the vibration transmitting column 36 corresponds to the vibration transmitting section, and the glass surface 31 corresponds to the transmission medium.

Note that the vibration transmitting column 36 is
Is transmitted to the glass surface 31 and also functions to drive the time hand 37. As can be seen from this example, the vibration transmitting unit and the transmission medium may be anything as long as they can transmit vibration during communication, and do not require special components. This also contributes to minimizing an increase in the number of components and an increase in cost due to the addition of the communication function.

Next, an outline of the configuration of the receiving side system is shown in FIG.
And the concept of the main operation of demodulation will be described with reference to FIGS. 9 and 10. The correspondence between the received data and the received data signal and the operation of each latch circuit are the same as those described in the description of the transmission system.

As shown in FIG. 4, the receiving system in the embodiment comprises a piezoelectric element 24, an amplitude modulation waveform demodulating means 25, a waveform shaping means 26, a data sampling means 27, a timing control means 28, 6.5K
It comprises a Hz reference clock generating means 29 and a delay means 30.

First, a description will be given of a process until the vibration propagated to the piezoelectric element becomes a demodulated signal at an analog level.

The potential difference generated between the piezoelectric element terminals greatly changes depending on the vibration amplitude. When the transmitting system and the receiving system are in contact with each other, the potential difference is about several tens of mV to several hundred mV. The amplitude modulation waveform demodulating means 25 has a function of removing the noise component and amplifying the voltage amplitude since the noise component having many other frequency components is also included in the propagation process. That is, it has amplification and filter means inside.

The voltage waveform sufficiently amplified around the 6.5 KHz frequency component is then converted to the amplitude modulated waveform demodulating means 25.
Is detected by the double-wave rectifier circuit of
z fifth order Chebyshev flow pass filter, and 400
The signal is demodulated as an analog signal by a low-pass filter of Hz.

The voltage waveform demodulated by the amplitude modulation waveform demodulating means 25 contains many 400 Hz frequency components in the section corresponding to “1”, and has almost no AC component in the section corresponding to “0”. When this is converted into a signal of a logic voltage level by the waveform shaping means 26, it becomes 'H' in a section having a large AC component of 400 Hz and 'L' in a section having a small AC component. The voltage waveform at this time is the logic signal after the waveform shaping in FIG.

Hereinafter, the concept of the operation performed until the reception data signal is extracted from the waveform-shaped signal obtained by shaping the analog demodulated signal by the waveform shaping means will be described with reference to FIGS. 9 and 10. It is assumed that, in the voltage logic level waveform after the waveform shaping, only in the section corresponding to the data “1”,
It is assumed that an H 'level pulse is generated and remains'L' in a section corresponding to data '0'. It is also assumed that the pulse width of the “H” level in the data “1” section is longer than eight reference clock signal pulses.

First, although not shown in FIG. 10, it is necessary to raise a reception enable signal to set a reception state.

In this receiving state, when the signal after waveform shaping rises for the first time, that is, when start bit '
The demodulation operation starts when 1 'is detected.

First, the latch circuit 42 performs a latch operation at the rise of the waveform after the waveform shaping, and the sampling start signal rises. The sampling timing is determined at the first rising edge of the reference clock signal thereafter.

That is, when the reference clock signal rises after the rising of the sampling start signal, the 1/16 frequency dividing circuit 44 in FIG. 9 starts operating, and after eight generations of the reference clock signal from this point, the sampling of the first bit is performed. Will be performed. That is, the output of the 1/16 frequency divider becomes a sampling signal, and the waveform after waveform shaping is sampled at the rising edge. Thereafter, the sampling operation is performed every 16 reference clock signal pulses from the first sampling.

In the signal of the voltage logic level after the waveform shaping,
In the section corresponding to the data "1", the amplitude modulation waveform demodulating means operates so that an "H" section of eight reference clocks or more is generated. For this reason, when the waveform is returned to the beginning and the waveform-shaped waveform rises first and then the waveform-shaped waveform is sampled after the generation of the reference clock signal 8, the sampled signal becomes “H”. No.

Thereafter, sampling is performed every 16 reference clock signals, the waveform is shaped and the data is continuously demodulated. In the example shown in FIG. 10, the same three bits of “1”, “1”, and “0” as the transmitted data are obtained in time series. For the purpose of notifying that an 1-bit data has been received to an external circuit that uses the received data, a delay is applied to the sampling signal,
It is a received signal. This is shown in FIG.

In the embodiment, communication through vibration using a piezoelectric element can be realized by the above method.

It should be noted here that neither the transmission / reception system nor the communication medium requires an antenna or a dedicated external connection component. This prevents the system from increasing in size and, secondly, allows the addition of a communication function while keeping the cost down.

The communication speed in the embodiment is approximately 400 bits / sec, which is low as the information transmission speed, but sufficient for some applications. Even in such a case, in the conventional wireless communication, the carrier wave is several tens KHz.
Although a frequency of several hundred KHz has to be used, which increases the power consumption. However, according to the means of the present invention, the power consumption can be kept to the minimum necessary.

The communication means for a small portable device using a piezoelectric element according to the present invention can be configured with a minimum number of large parts which are difficult to be integrated as described above. It is advantageous. Also, when the information transmission speed is low, unlike other communication means of the related art, it is possible to suppress power consumption in proportion to the decrease in the information transmission speed, which is advantageous for a system operating on a battery power supply. This is particularly effective for small portable devices such as wristwatches.

[0075]

According to the communication means for a small portable device using the piezoelectric element of the present invention as described above, the number of large parts which are difficult to be integrated into an IC is small compared to other wireless communication means or wire communication means. Therefore, the system can be easily reduced in size, and at the same time, the cost can be reduced. In addition, when the communication information transfer rate is low enough, it is possible to reduce the power consumption by operating each component at a low frequency as compared with other wireless communication means, and generally operate on battery power. This is advantageous for systems and the like, and is particularly effective for small portable devices such as watches.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration concept of a communication system according to the present invention.

FIG. 2 is a block diagram showing a configuration of a communication system using a conventional radio wave.

FIG. 3 is a block diagram showing a configuration of a conventional wired communication system.

FIG. 4 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 5 is an actual sectional view of a wristwatch to which a communication system is applied according to an embodiment of the present invention;

FIG. 6 is a modulation waveform diagram.

FIG. 7 is a conceptual diagram of a main circuit configuration of a transmission side system.

FIG. 8 is a main voltage waveform of a transmission side system.

FIG. 9 is a conceptual diagram of a main circuit configuration of a receiving-side system.

FIG. 10 shows main voltage waveforms of the receiving system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Data modulation means 2 Piezoelectric element driving means 3 Piezoelectric element 4 Vibration transmission part 5 Transmission medium 6 Data demodulation circuit 39 Latch circuit 40 AND circuit 41 Inverter circuit 42 Latch circuit 43 Latch circuit 45 Latch circuit

Claims (1)

[Claims] The transmitting system includes a data modulating means,
A piezoelectric element driving means connected to the voltage output of the data modulation means, and a piezoelectric element driven by the piezoelectric element driving means; the receiving system includes a piezoelectric element; and a data demodulation means using the piezoelectric element as a voltage input. Communication of the piezoelectric element vibration with a transmission medium capable of transmitting the pressure vibration, or a transmission medium capable of transmitting the pressure vibration, the pressure vibration generated by the piezoelectric element in response to the voltage output of the modulation unit of the transmission side system. A piezoelectric element characterized in that a frequency component used for transmission is transmitted to a piezoelectric element of a receiving system through a vibration transmission unit that efficiently transmits the frequency component to a transmission medium, and is converted into a voltage signal by the piezoelectric element of the receiving system and demodulated. A vibration communication system using elements.