JP6792277B2 - Transmitter and communication system - Google Patents

Description

The present invention relates to a transmitter for wirelessly transmitting a signal and a communication system using the transmitter.

Patent Document 1 below discloses an electronic drum pad for detecting vibration of a striking surface caused by striking by a sensor and outputting an electronic sound corresponding to the striking vibration. The electronic drum pad gives an output signal corresponding to the striking vibration to the sound source device. The sound source device outputs a sound corresponding to the striking vibration based on the output signal.

The electronic drum pad includes a piezoelectric element as a sensor for detecting impact vibration. The piezoelectric element is provided with a signal line for giving a detection signal to the sound source device. That is, in order to give an output signal to the sound source device, it is necessary to connect the electronic drum pad and the sound source device by a signal line so that the detection signal can be transmitted and received between them.

Japanese Unexamined Patent Publication No. 9-244633

The electronic drum pad may be used as a drum set by combining a plurality of (for example, about 10) electronic drum pads. In this case, it is necessary to connect all the signal lines extending from each of the plurality of electronic drum pads to the sound source device. Therefore, when assembling or disassembling as a drum set, a large number of signal lines must be connected or disconnected, which causes a problem that the wiring work of the signal lines becomes complicated.

In response to the above problem, it is conceivable to transmit and receive an output signal by wireless communication between the electronic drum pad and the sound source device. If the detection signal is transmitted and received by wireless communication, the wiring work of the signal line can be eliminated.
However, in this case, electric power for wireless transmission is required on the electronic drum pad side. In order to secure power for wireless transmission on the electronic drum pad side, it is conceivable to provide a storage battery for each electronic drum pad.

However, when a storage battery is provided, maintenance such as charging or replacement of the storage battery is required. That is, although the signal line wiring work can be omitted, maintenance work is required for each electronic drum pad. Therefore, it is not preferable to take a measure of providing a storage battery in each electronic drum pad.

Therefore, it is conceivable to use the output signal from the electronic drum pad as electric power.
In this case, the output signal is given to the transmitter as a signal to be transmitted, and is rectified and given to the transmitter as electric power.
At this time, the output signal represents the striking vibration of the electronic drum pad, and the signal obtained by rectifying the output signal indicates that the striking vibration of the electronic drum pad itself is accurate. Even if a signal obtained by rectifying the output signal is transmitted as an output signal, it is not possible to transmit a signal that accurately represents the striking vibration of the electronic drum pad.

Further, if the output signal from the electronic drum pad is to be directly given to the transmitter as a signal to be transmitted, the signal source of the output signal must be grounded in the same manner as the transmitter. In this case, the output signal is used. It is not preferable because full-wave rectification cannot be performed and the efficiency as a power source is lowered.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique capable of transmitting an accurate signal.

(1) The transmitter according to the present invention includes a transmission circuit for wirelessly transmitting an input signal and a power supply circuit for full-wave rectifying the input signal and supplying the input signal to the transmission circuit. The first signal line for giving the input signal to the power supply circuit from the signal source and the second signal line for giving the input signal to the transmission circuit as a transmission signal are electrically isolated and transmitted by the first signal line. It further includes a signal transmission unit that transmits the input signal to be electrically isolated to the second signal line.

According to the transmitter configured as described above, since the power supply circuit includes the signal transmission unit that transmits the input signal for transmitting the first signal line to the second signal line that is electrically isolated, the power supply circuit is the first signal. The input signal as a transmission signal can be given to the transmission circuit through the second signal line regardless of the full-wave rectification of the input signal transmitted on the line. As a result, it is possible to transmit an input signal with high accuracy.

(2) In the transmitter, it is preferable that the transmission circuit analog-modulates the input signal and wirelessly transmits the input signal.
In this case, for example, as compared with the case of wireless transmission by digital modulation, the delay due to processing such as modulation / demodulation associated with wireless transmission of the input signal can be suppressed as much as possible. Further, the power consumption required for modulation of the input signal can be suppressed as compared with the case of wireless transmission by digital modulation.

(3) Further, in the transmitter, the input signal used for generating electric power by the power supply circuit is preferably an output signal output by a conversion element that converts input energy into an electric signal.

(4) The transmitter is further provided with a connection terminal that can be connected to an output terminal to which the output signal output by the conversion element is given, and is connected to the output terminal to receive the output signal as the input signal. You may.
In this case, the connection terminal makes it possible to connect to a device equipped with an output terminal, and the output signal output by the conversion element provided in the device is received as an input signal and used as electric power, and the output signal is wirelessly transmitted. be able to.
Therefore, if the transmitter is connected to a device that does not have a function of transmitting a signal, the transmitter can wirelessly transmit an output signal output by the device, which cannot originally transmit the signal wirelessly.

(5) Further, the connection terminal can be connected to the output terminal to which the output signals from the plurality of conversion elements are given, and each of the output signals from the plurality of conversion elements is used as the input signal. When accepting, it is preferable that a plurality of the extraction unit, the transmission circuit, and the power supply circuit are provided corresponding to the plurality of conversion elements.
In this case, each of the output signals from the plurality of conversion elements received by the connection terminal can be used as electric power, and the plurality of output signals can be wirelessly transmitted.

(6) Further, when the input signal is an output signal output by a conversion element that converts input energy input to an electronic musical instrument into an electric signal by a performance operation, the extraction unit, the transmission circuit, and the power supply circuit. Is preferably provided inside the electronic musical instrument.

(7) Further, the transmitter according to the present invention includes a conversion element that converts vibration energy into an electric signal, a transmission circuit that wirelessly transmits an output signal of the conversion element as an input signal, and full-wave rectification of the input signal. A first signal line for supplying the input signal from the signal source of the input signal to the power supply circuit, and a power supply circuit for supplying the input signal to the transmission circuit, and a power supply circuit for supplying the input signal to the transmission circuit. The two signal lines are electrically isolated, and further include a signal transmission unit that transmits the input signal transmitted by the first signal line to the second signal line that is electrically isolated.

(8) Further, the communication system according to the present invention acquires the output signal from the transmitter of the above (7) and the received signal obtained by receiving the radio signal transmitted by the transmitter, and obtains the output. It includes a receiver that supplies a signal to a sound source device that generates a signal representing an instrument sound based on the output signal.

(9) Further, the present invention comprises an electronic musical instrument including a conversion element that converts an input due to a performance operation into an electric signal, and a sound source device that generates a signal representing an instrument sound based on an output signal output by the conversion element. The transmitter according to (1) above, wherein the output signal output by the conversion element is given as an input signal, and a reception obtained by receiving a radio signal transmitted by the transmitter. It includes a receiver that acquires the output signal from the signal and feeds it to the sound source device.
According to the communication system having the above configuration, since the power supply circuit includes a signal transmission unit that transmits the input signal that transmits the first signal line to the second signal line in a state of being electrically isolated, the power supply circuit uses the first signal line. The input signal can be given to the transmission circuit as a transmission signal regardless of the full-wave rectification of the input signal to be transmitted. As a result, an input signal with high accuracy can be transmitted, and a signal with high accuracy can be transmitted and received.

(10) In the communication system, the electronic musical instrument is a plurality, the transmitter is a plurality corresponding to the plurality of the electronic musical instruments, and the receiver is a plurality of the transmitters from the received signal. A separation unit that separates a plurality of the corresponding output signals and a plurality of output terminals that output the plurality of the output signals to the sound source device may be provided.
In this case, since the separation unit separates the output signals of the plurality of transmitters from the received signals, it is possible to give the output signals of each electronic musical instrument corresponding to the plurality of transmitters to the sound source device. As a result, the sound source device can generate an electronic sound for each electronic musical instrument.

(11) Further, in the communication system, the transmission circuits of the transmitter perform wireless transmission using frequencies different from each other, and the separation unit is a plurality of transmitters corresponding to each of the plurality of transmitters from the received signal. The output signal may be frequency-separated, and the output terminal of the plurality of output terminals may be switched according to the frequency of the output signal.
In this case, the output signals corresponding to each of the plurality of transmitters can be easily separated by frequency separation. Further, the output terminal for outputting the output signal can be easily assigned to each of the plurality of transmitters.

(12) Further, when the separation unit stores a table in which the frequency of the output signal and the information for identifying the plurality of output terminals are registered in association with each other, the plurality of said parts are based on this table. It is preferable to switch which of the plurality of output terminals the output signal is output from.
In this case, if the above table is changed, it becomes easy to change the output terminal for outputting the output signal transmitted by each transmitter 8.

According to the present invention, it is possible to transmit an accurate signal.

It is a figure which shows the whole structure of the electronic drum set including the communication system which concerns on 1st Embodiment. It is an enlarged view which showed the part of an output jack and a transmitter. It is a block diagram which shows an example of a transmission part. (A) is a diagram showing an example of the waveform of the output signal output by the piezoelectric element due to the impact vibration of the drum pad 5, and (b) is a diagram after the rectifier circuit rectifies the output signal shown in FIG. 4 (a). It is a figure which shows an example of the waveform of. It is a figure which shows an example of the waveform of the DC power output by a series regulator. It is a block diagram which shows an example of a receiver. It is a block diagram which shows the structure of the separation part. It is a figure which shows an example of the table which a switching part stores. It is a figure which shows an example of the result of having measured the delay time from the piezoelectric element of an electronic drum output of an output signal to the time when a receiver outputs an output signal. It is a figure which shows the transmitter which concerns on the modification of 1st Embodiment. It is a figure which shows the security device including the communication system which concerns on 2nd Embodiment.

Hereinafter, preferred embodiments will be described with reference to the drawings.
[About the first embodiment]
[Overall system configuration]
FIG. 1 is a diagram showing an overall configuration of an electronic drum set including the communication system according to the first embodiment. In FIG. 1, the electronic drum set 1 is arranged so that one player can play a plurality of percussion instruments such as electronic drums 2, and includes a plurality of electronic drums 2, a synthesizer 3, and a speaker 4. ing.

The electronic drum 2 includes a circular plate-shaped drum pad 5 and a piezoelectric element 6 that converts an impact on the drum pad 5 into an electric signal (voltage signal). The surface 5a of the drum pad 5 constitutes a striking surface, and the surface 5a is struck by the player.
The piezoelectric element 6 is provided on the back surface side of the drum pad 5, generates electricity by the impact vibration generated in the drum pad 5, and outputs the generated electric signal as an output signal. The piezoelectric element 6 is configured by using, for example, a piezo element.
The drum pad 5 vibrates when the player strikes the drum pad 5 (playing motion). The piezoelectric element 6 outputs an output signal in response to this striking vibration. Therefore, the piezoelectric element 6 outputs an output signal in response to the player's striking action against the drum pad 5.
That is, the piezoelectric element 6 constitutes a conversion element that converts the input energy (vibration energy) input to the drum pad 5 by the striking operation into an electric signal.

Two piezoelectric elements 6 are provided for one drum pad 5. One of the two piezoelectric elements 6 provided on one drum pad 5 is provided substantially in the center of the drum pad 5, and outputs an output signal corresponding to the impact vibration generated in the central portion of the drum pad 5. To do. The other piezoelectric element 6 is provided at the edge of the drum pad 5, and outputs an output signal corresponding to the impact vibration generated at the edge of the drum pad 5.

The electronic drum 2 further includes an output jack 7 which is an output terminal. The output jack 7 is connected to two piezoelectric elements 6 via a signal line, and output signals from the two piezoelectric elements 6 are given.
A transmitter 8 is connected to the output jack 7. The transmitter 8 has a function of receiving an output signal from the piezoelectric element 6 given to the output jack 7 and wirelessly transmitting the signal.

FIG. 2 is an enlarged view showing a portion of the output jack 7 and the transmitter 8. FIG. 2 shows an enlarged view of the electronic drum 2a (FIG. 1), which is one of the plurality of electronic drums 2. The other electronic drum 2 has the same configuration as the electronic drum 2a.

The transmitter 8 is attached to the outside of the electronic drum 2. The transmitter 8 includes two transmitters 12 (12a, 12b) mounted on the substrate 9. Of the two transmission units 12, one transmission unit 12a is given an output signal from the piezoelectric element 6a, and the other transmission unit 12b is given an output signal from the piezoelectric element 6b.
Both transmission units 12 are given output signals from different piezoelectric elements 6 to perform wireless transmission. Therefore, both transmission units 12 wirelessly transmit signals different from each other.

The board 9 is provided with a connection plug 10 which is a connection terminal. The connection plug 10 is formed so that it can be inserted into a hole 7a provided in the output jack 7.
The transmitter 8 is attached to the outside of the electronic drum 2 by inserting the connection plug 10 into the hole 7a of the output jack 7.
Both transmitters 12 are connected to the connection plug 10. Both transmitters 12 are connected to the output jack 7 by inserting the connection plug 10 into the hole 7a of the output jack 7.
The connection plug 10 receives the output signals from the two piezoelectric elements 6 through the output jack 7, and gives the output signals from the two piezoelectric elements 6 to the two transmission units 12.
The output jack 7 and the connection plug 10 connect the piezoelectric element 6a and the transmission unit 12a, and also connect the piezoelectric element 6b and the transmission unit 12b.

In this way, the connection plug 10 can be connected to the output jack 7, and receives an output signal output from the piezoelectric elements 6a and 6b and given to the output jack 7.
The output signal received by the connection plug 10 is processed by the transmitter 8 (both transmitting units 12) as an input signal and wirelessly transmitted.

Returning to FIG. 1, the synthesizer 3 has a function as a sound source device that generates sound in response to a signal given from the outside. A receiver 11 for receiving a radio signal wirelessly transmitted by the transmitter 8 is connected to the synthesizer 3.
The receiver 11 receives the wireless signal from the transmitter 8, performs processing related to wireless communication such as amplification and demodulation on the received received signal, and receives the received signal from the electronic drum 2 (transmitter 12). The output signal is acquired, and the acquired output signal is given to the synthesizer 3.
That is, the transmitter 8 and the receiver 11 give the output signal output by the electronic drum 2 to the synthesizer 3 by wireless communication.

The synthesizer 3 generates a musical instrument sound signal representing a musical instrument sound based on an output signal from the electronic drum 2 given via the transmitter 8 and the receiver 11.
The synthesizer 3 gives the generated musical instrument sound signal to the speaker 4. The speaker 4 outputs a musical instrument sound based on a given musical instrument sound signal.

As described above, the output signal of the electronic drum 2 is output in response to the striking vibration of the drum pad 5 generated by the striking operation by the player. That is, when the player hits the drum pad 5 and plays, the electronic drum 2 outputs an output signal according to the playing operation. The output signal is given to the synthesizer 3 through the transmitter 8 and the receiver 11. The synthesizer 3 generates a musical instrument sound signal in response to a hit on the drum pad 5, and the speaker 4 outputs the musical instrument sound from the musical instrument sound signal.
As described above, the drum set 1 outputs the musical instrument sound produced by the performance from the speaker 4.

Further, the transmitter 8 and the receiver 11 constitute a communication system in which the electronic drum 2 which is an electronic musical instrument and the synthesizer 3 which is a sound source device are connected by wireless communication.

[Communication system configuration]
FIG. 3 is a block diagram showing an example of the transmission unit 12. Although the description will be focused on one transmission unit 12 in FIG. 3, the other transmission units 12 have the same configuration.
As shown in FIG. 3, the transmission unit 12 includes a separation circuit 15, a series regulator 16, a transmission circuit 17, and a transmission antenna 18.

The separation circuit 15 has a function of separating an output signal given from the piezoelectric element 6 into a signal for giving to the transmission circuit 17 as power and a signal for giving to the transmission circuit 17 as a transmission signal which is a signal to be transmitted. doing.

The separation circuit 15 includes a transformer 20 and a rectifier circuit 21.
The rectifier circuit 21 is composed of a full-wave rectifier circuit using a diode bridge, and has a function as a power supply circuit that rectifies the output signal of the piezoelectric element 6 and supplies the rectified signal to the transmission circuit 17 as power. ..
The input ends 21a and 21b of the rectifier circuit 21 are connected to both ends of the piezoelectric element 6 by the first signal line 27. The output signal of the piezoelectric element 6, which is the signal source of the output signal, is given to the rectifying circuit 21 as an input signal through the first signal line 27. Of the output ends 21c and 21d of the rectifier circuit 21, one of the output ends 21c is connected to the series regulator 16. The other output end 21d is grounded. The rectifier circuit 21 applies the generated DC power to the series regulator 16.

FIG. 4A is a diagram showing an example of the waveform of the output signal output by the piezoelectric element 6 due to the impact vibration of the drum pad 5, and FIG. 4B is a diagram for rectifying the output signal shown in FIG. 4A. It is a figure which shows an example of the waveform after the circuit 21 rectified. In FIGS. 4A and 4B, the vertical axis represents voltage and the horizontal axis represents time.
The voltage of the output signal of the piezoelectric element 6 changes between positive and negative as shown in FIG. 4A, but it can be seen that the output signal is rectified by the rectifier circuit 21 as shown in FIG. 4B.

Returning to FIG. 3, the series regulator 16 adjusts the signal separated and rectified by the separation circuit 15 to a constant voltage and gives it to the transmission circuit 17. The series regulator 16 adjusts the voltage of the rectified signal so that it becomes a predetermined voltage set as the power applied to the transmission circuit 17.
For example, the series regulator 16 of this embodiment gives a signal adjusted to about 1.8V to the transmission circuit 17.

FIG. 5 is a diagram showing an example of a signal waveform output by the series regulator 16. In FIG. 5, the vertical axis represents voltage and the horizontal axis represents time.
As shown in FIG. 5, it can be seen that the series regulator 16 can output a signal having a substantially constant voltage at about 1.8 V.

Returning to FIG. 3, the transformer 20 has a function of acquiring the output signal of the piezoelectric element 6 transmitted by the first signal line 27 in a state of being electrically isolated and giving it to the transmission circuit 17.
Both ends of the primary coil of the transformer 20 are connected to both ends of the piezoelectric element 6. The output signal of the piezoelectric element 6 is applied to the primary coil as an input signal. One end of the secondary coil of the transformer 20 is connected to the transmission circuit 17 by the second signal line 22, and the other end is grounded. When an output signal from the piezoelectric element 6 is given to the primary coil, the secondary coil of the transformer 20 outputs a transformed output signal with reference to 0 V according to the output signal.
The transformer 20 transmits the transformed output signal to the second signal line 22 and gives it to the transmission circuit 17.

Here, a first signal line 27 for connecting the piezoelectric element 6 and the rectifying circuit 21 and giving an output signal to the rectifying circuit 21, and a second signal line 22 for giving the output signal to the transmitting circuit 17 as a transmission signal. Is electrically isolated, and the transformer 20 transmits the output signal transmitted by the first signal line 27 to the electrically isolated second signal line 22.
Therefore, the output signal as a transmission signal is transmitted through the second signal line 22, regardless of whether the rectifying circuit 21 full-wave rectifies the output signal (input signal) of the piezoelectric element 6 that transmits the first signal line 27. It can be given to the circuit 17. That is, since the second signal line 22 and the transmission circuit 17 are insulated from the piezoelectric element 6 and the rectifier circuit 21, the output signal transmitted by the second signal line 22 can be given to the transmission circuit 17 as it is, and further. , The transmission circuit 17 can wirelessly transmit the output signal transmitted by the second signal line 22 as it is. As a result, the transmission circuit 17 can transmit an output signal with high accuracy.

As described above, the separation circuit 15 transmits as a signal for giving the output signal given from the piezoelectric element 6 to the transmission circuit 17 as power by the transformer 20 and the rectifier circuit 21 and as a transmission signal which is a signal to be transmitted. Separated from the signal to be given to the circuit 17.

The transmission circuit 17 performs FM modulation (analog modulation) on the output signal given from the separation circuit 15. A branch path 23 extending from the output end of the series regulator 16 is connected to the second signal line 22. A first resistor 24 is connected to the branch path 23. Further, a branch path 26 to which the second resistor 25 is connected is connected to the second signal line 22. One end of the branch path 26 is connected to the second signal line 22, and the other end is grounded. A predetermined bias voltage is applied to the output signal given to the second signal line 22 by the branch path 23, the branch path 26, the first resistor 24, and the second resistor 25.

The transmission circuit 17 can perform wireless transmission by applying the signal rectified from the separation circuit 15 as electric power.
The transmission circuit 17 performs FM modulation on the output signal given as a transmission signal through the second signal line 22. The transmission circuit 17 gives an FM-modulated output signal to the transmission antenna 18.
The transmitting antenna 18 radiates the FM-modulated output signal given from the transmitting circuit 17 into space as a radio signal.
As a result, the transmitter 8 (transmitter 12) wirelessly transmits the output signal of the piezoelectric element 6.
For example, the transmission circuit 17 of the present embodiment is configured to FM-modulate a carrier wave of several hundred MHz by an output signal.

According to this embodiment, the transmitter 8 and the electronic drum 2 can wirelessly transmit an accurate output signal (input signal) without including a storage battery or the like. As a result, it is possible to easily transmit signals without performing complicated work such as wiring work of signal lines for output signals and maintenance work of storage batteries and the like.

Further, the transmitter 8 is provided with a connection plug 10 which is connectable to an output jack 7 to which an output signal output by the piezoelectric element 6 is given, is connected to the output jack 7, and receives an output signal as an input signal. As a result, the transmitter 8 can be connected to a device provided with an output jack 7 such as an electronic drum 2, and receives an output signal output by the piezoelectric element 6 provided in the device as an input signal to receive electric power. It can be generated and the output signal can be transmitted wirelessly.
Therefore, if the transmitter 8 is connected to a device such as an electronic drum 2 that does not have a function of transmitting a signal, the transmitter 8 can wirelessly transmit an output signal output by a device that cannot originally wirelessly transmit the signal. it can.

Further, the connection plug 10 of the transmitter 8 of the present embodiment can be connected to the output jack 7 to which the output signals from the two piezoelectric elements 6a and 6b are given, and the output from the two piezoelectric elements 6a and 6b. It is configured to accept each signal as an input signal. Therefore, the transmitter 8 is provided with a plurality of transmitter units 12 corresponding to the two piezoelectric elements 6a and 6b.
Therefore, each of the output signals by the two piezoelectric elements 6a and 6b received by the connection plug 10 can be used as electric power, and a plurality of output signals can be wirelessly transmitted.

As described above, the transmitter 8 has two transmitters 12, and the transmitter 8 is also provided on another electronic drum 2. Therefore, the transmission unit 12 of each transmitter 8 provided on each electronic drum 2 may wirelessly transmit during a period in which they overlap each other.
Here, if each transmission unit 12 wirelessly transmits using carriers having the same frequency during a period in which they overlap each other, interference will occur with each other, and the receiver 11 that receives the interference may not be able to take out the original output signal. Sex arises. Therefore, each transmission unit 12 performs wireless transmission using different carrier frequencies (different occupied bandwidths).

FIG. 6 is a block diagram showing an example of the receiver 11.
As shown in FIG. 6, the receiver 11 includes a receiving antenna 30, an RF circuit 31, an analog-to-digital converter (ADC) 32, and a separation unit 33.
The receiving antenna 30 has a function of receiving a radio signal transmitted by the transmitter 8. As described above, the transmitters 12 of each transmitter 8 may wirelessly transmit during periods of overlap with each other. Therefore, the receiving antenna 30 duplicately receives the radio signals transmitted by the plurality of transmitting units 12.
The receiving antenna 30 gives the received radio signal to the RF circuit 31 as a receiving signal.

The RF circuit 31 has a function of amplifying the received signal given from the receiving antenna 30 and converting the frequency of the received signal to a lower frequency. The RF circuit 31 supplies the frequency-converted received signal to the analog-digital converter 32 (hereinafter, also referred to as ADC 32) connected to the subsequent stage.
The frequency of the received signal is several hundred MHz, which is the carrier frequency of the wireless signal wirelessly transmitted by the transmitter 8. The RF circuit 31 frequency-converts a received signal having a frequency of several hundred MHz to, for example, several to several tens of MHz.

The ADC 32 converts a received signal, which is an analog signal given from the RF circuit 31, into a digital signal. The ADC 32 gives the received signal converted into a digital signal to the separation unit 33 in the subsequent stage.

The separation unit 33 separates a plurality of output signals corresponding to each transmission unit 12 from the reception signal given from the ADC 32.
The separation unit 33 is provided with an output plug 35, which is connected to the synthesizer 3 via the output plug 35. The separation unit 33 gives a plurality of separated output signals to the synthesizer 3 through the output plug 35.

FIG. 7 is a block diagram showing the configuration of the separation unit 33.
In FIG. 7, the separation unit 33 includes a fast Fourier transform (FFT: Fast Fourier Transform) 40, a switching unit 41, and a demodulation unit 42.

The fast Fourier transformer 40 (hereinafter, also referred to as FFT40) separates a plurality of output signals corresponding to each transmission unit 12 from the received signal.
Here, the received signal may include a plurality of output signals wirelessly transmitted using different carrier frequencies.
Therefore, the FFT 40 performs a fast Fourier transform on the received signal given from the ADC 32, and frequency-separates a plurality of output signals included in the received signal.
The FFT 40 gives a plurality of output signals separated from the received signal to the switching unit 41 in the subsequent stage.
The switching unit 41 gives a plurality of output signals given from the FFT 40 to the demodulation unit 42 in the subsequent stage.

The plurality of output signals separated by the FFT 40 have been frequency-converted by the RF circuit 31, but are still in an FM-modulated state. Therefore, the demodulation unit 42 demodulates the FM-modulated plurality of output signals given from the switching unit 41, and acquires the demodulated plurality of output signals.

The demodulator 42 includes a first FM demodulator 43a, a second FM demodulator 43b, a third FM demodulator 43c, a fourth FM demodulator 43d ..., a first AM demodulator 43e, a second AM demodulator 43f, and so on. It includes a plurality of analog demodulators 43.

For example, when one of a plurality of output signals is given by the switching unit 41, the first FM demodulator 43a performs FM demodulation on the given output signal. The first FM demodulator 43a gives the FM demodulated output signal to the output plug 35.

The receiver 11 of the present embodiment includes a plurality of output plugs 35. Each output plug 35 is configured to receive output signals from the two demodulators 43 and output the output signals from the two received demodulators 43.

The first FM demodulator 43a is connected to the first output plug 35a, which is one of the plurality of output plugs 35, and gives an output signal to the first output plug 35a.

Further, when one of a plurality of output signals is given from the switching unit 41, the second FM demodulator 43b performs FM demodulation on the given output signal. The second FM demodulator 43b is connected to the first output plug 35a, and gives the FM demodulated output signal to the first output plug 35a.
Further, the third FM demodulator 43c and the fourth FM demodulator 43d perform FM demodulation on the given output signal when one of the plurality of output signals is given by the switching unit 41. The third FM demodulator 43c and the fourth FM demodulator 43d are connected to the second output plug 35b, and give the FM demodulated output signal to the second output plug 35b.

Further, the first AM demodulator 43e and the second AM demodulator 43f perform AM demodulation on the given output signal when one of the plurality of output signals is given by the switching unit 41. The first AM demodulator 43e and the second AM demodulator 43f are connected to the third output plug 35c, and give the AM demodulated output signal to the third output plug 35c.

In this way, when an output signal is given from the switching unit 41, each analog demodulator 43 gives an analog demodulated output signal to one output plug 35 connected in advance among the plurality of output plugs 35.

Further, since the plurality of analog demodulators 43 include both an FM demodulator that demodulates FM and an AM demodulator that demodulates AM, the demodulation can be performed according to the modulation method of the separated output signal.

Here, the switching unit 41 distributes a plurality of output signals given from the FFT 40 to any of the analog demodulators 43.
The switching unit 41 outputs a plurality of output signals to each analog demodulator 43 based on a table stored in advance by the switching unit 41 as to which of the plurality of analog demodulators 43 the plurality of output signals is given. Switch to which of the distribution.

FIG. 8 is a diagram showing an example of a table stored in the switching unit 41.
In FIG. 8, in the table, the frequency of the output signal, the information for specifying the analog demodulator 43, and the information for specifying the output plug 35 are registered in association with each other. Information for identifying the analog demodulator 43 is registered in the "demodulator" column in FIG. 8, but in FIG. 8, it is referred to as "first FM demodulator", "second FM demodulator", and the like. It is abbreviated. In addition, information for identifying the output plug 35 is registered in the "output destination" column, but in FIG. 8, it is abbreviated as "first output plug", "second output plug", and the like. ing.

In this table, the frequency of the output signal, the analog demodulator 43 to which the output signal of that frequency is given, and the output plug 35 are registered in association with each other.

For example, when an output signal having a frequency of f1 is given to the switching unit 41, the switching unit 41 gives an output signal having a given frequency of f1 to the first FM demodulator 43a. Since the first FM demodulator 43a is connected to the first output plug 35a, the output signal demodulated by the first FM demodulator 43a is given to the first output plug 35a and output from the first output plug 35a. ..

When an output signal having a frequency of f3 is given to the switching unit 41, the switching unit 41 gives an output signal having a given frequency of f3 to the third FM demodulator 43c. Since the third FM demodulator 43c is connected to the second output plug 35b, the output signal demodulated by the third FM demodulator 43c is given to the second output plug 35b and output from the second output plug 35b. ..

When an output signal having a frequency of f5 is given to the switching unit 41, the switching unit 41 gives an output signal having a given frequency of f5 to the first AM demodulator 43e. Since the first AM demodulator 43e is connected to the third output plug 35c, the output signal demodulated by the first AM demodulator 43e is given to the third output plug 35c and output from the third output plug 35c. ..

In this way, the switching unit 41 distributes the plurality of output signals given from the FFT 40 to which of the analog demodulators 43 and outputs from which of the plurality of output plugs 35 is determined by the frequency of the output signal. Switch accordingly.
In this way, by switching according to the frequency of the output signal, the output plug 35 that outputs the output signal can be easily assigned to each transmitter 8 (transmitter 12).

Further, by setting the frequency of the output signal in association with the modulation method, it is possible to switch from a plurality of analog demodulators 43 to a demodulator suitable for the target output signal, and appropriately according to the modulation method. It can be demodulated.

The frequency of the output signal used by the switching unit 41 for switching the output plug 35 that outputs each output signal is the frequency after the frequency is converted by the RF circuit 31.
Therefore, the frequency of the output signal corresponding to each transmitter 8 after the frequency is converted by the RF circuit 31 is grasped in advance. The contents registered in the above table are set based on the frequency of the output signal corresponding to each transmitter 8 after frequency conversion.

Returning to FIG. 7, the plurality of output plugs 35 are inserted into the plurality of input jacks 13 provided on the synthesizer 3 and connected to the synthesizer 3. Each input jack 13 is configured to be able to receive output signals from two demodulators 43 given from the output plug 35.
The synthesizer 3 generates an instrument sound signal based on a plurality of output signals given from the plurality of input jacks 13.

The synthesizer 3 generates an instrument sound signal for each output signal given to each of the plurality of input jacks 13 (13a, 13b, 13c ...).

For example, it is assumed that the frequency of the output signal corresponding to the transmission unit 12a (FIG. 2) after frequency conversion by the RF circuit 31 is f1.
In this case, the output signal corresponding to the transmission unit 12a is given to the first FM demodulator 43a by the switching unit 41 according to the table (FIG. 8), and is output from the first output plug 35a.
Therefore, the output signal corresponding to the transmission unit 12a is given to the input jack 13a of the synthesizer 3 through the first output plug 35a.

Further, it is assumed that the frequency of the output signal corresponding to the transmission unit 12b (FIG. 2) after frequency conversion by the RF circuit 31 is f2.
In this case, the output signal corresponding to the transmission unit 12b is given to the second FM demodulator 43b by the switching unit 41 according to the table (FIG. 8), and is output from the first output plug 35a.
Therefore, the output signal corresponding to the transmission unit 12b is given to the input jack 13a of the synthesizer 3 through the first output plug 35a.

As described above, the transmission units 12a and 12b wirelessly transmit the output signals of the piezoelectric elements 6a and 6b (FIG. 2) based on the performance of the electronic drum 2a.
Therefore, the output signal output by the electronic drum 2a is output from the first output plug 35a.

In this case, the synthesizer 3 is given an output signal from the electronic drum 2 through an input jack 13a to which the first output plug 35a is connected. As a result, the synthesizer 3 generates an instrument sound signal corresponding to the electronic drum 2a.
Further, the other electronic drums 2 are the same as the electronic drums 2a, and the synthesizer 3 is given an output signal from the other electronic drums 2 through the input jack 13, and the synthesizer 3 responds to each electronic drum 2. Generates an instrument sound signal.

The output jack 7 (FIG. 2) of the electronic drum 2 and the input jack 13 of the synthesizer 3 can be connected by wire, for example, by a signal line.
However, in the present embodiment, the electronic drum 2 and the synthesizer 3 are connected by wireless communication by connecting the transmitter 8 and the receiver 11 instead of the signal line.

The system of this embodiment is between an electronic drum 2 provided with a piezoelectric element 6 that converts an input due to a performance operation into an electric signal, and a synthesizer 3 that generates an instrument sound signal based on an output signal output by the piezoelectric element 6. In the communication system of the above, the synthesizer acquires an output signal from a transmitter 8 in which an output signal output by the piezoelectric element 6 is given as an input signal and a received signal obtained by receiving a radio signal transmitted by the transmitter 8. It is provided with a receiver 11 for giving to 3.

According to this configuration, since the transmitter 8 can wirelessly transmit the output signal with high accuracy as described above, the communication system as a whole can also transmit and receive the signal with high accuracy.

Further, in the present embodiment, there are a plurality of electronic drums 2, a plurality of transmitters 8 corresponding to the electronic drums 2 (two for each of the electronic drums 2), and a plurality of receivers 11 from the received signal. It is provided with a separation unit 33 for separating a plurality of output signals corresponding to each of the transmitters 8 and a plurality of output plugs 35 as a plurality of output terminals for outputting the plurality of output signals to the synthesizer 3.
Since the separation unit 33 separates the output signals of the plurality of transmitters 8 from the received signals, the output signals of the electronic drums 2 corresponding to the plurality of transmitters 8 can be given to the synthesizer 3. As a result, the synthesizer 3 can generate musical instrument sounds for each electronic drum 2.

Further, the switching unit 41 included in the separation unit 33 stores the above table (FIG. 8), and distributes a plurality of output signals given from the FFT 40 based on this table to any of the analog demodulators 43. Since it is configured to switch which of the plurality of output plugs 35 outputs, by changing this table, the output plug 35 for outputting the output signal transmitted by each transmitter 8 is changed. Can be easily performed.

Further, in the system of the present embodiment, from the time when the player hits the electronic drum 2 and the output signal is output from the piezoelectric element 6 until the player reaches the synthesizer 3 via wireless communication and the musical instrument sound is output. Therefore, if a delay occurs, it is possible that the player's performance may be hindered.

In this regard, in the present embodiment, the transmission circuit 17 of the transmission unit 12 performs FM modulation (analog modulation) on the output signal extracted from the output signal and wirelessly transmits it to the receiver 11, so that, for example, digital modulation In comparison with the above, the delay due to the processing such as modulation / demodulation accompanying the wireless transmission of the output signal can be suppressed as much as possible. Therefore, it is possible to prevent a large delay from occurring between the time when the player hits the electronic drum 2 and the time when the musical instrument sound is output.

FIG. 9 shows an example of the result of measuring the delay time from the output signal output by the piezoelectric element 6 of the electronic drum 2 to the output signal output by the receiver 11 using the electronic drum set 1 of the present embodiment. It is a figure which shows. In the figure, the waveform shown on the upper side is the waveform of the output signal of the piezoelectric element 6, and the waveform shown on the lower side is the waveform of the output signal output by the receiver 11. Both waveforms are shown to coincide in timing along the time axis.

As shown in the figure, in this measurement result, the delay time from the output signal of the piezoelectric element 6 to the output of the corresponding output signal by the receiver 11 was 900 microseconds.
Generally, a delay of 1 millisecond or more is considered to affect the player's performance, but in the electronic drum set 1 of the present embodiment, the delay is suppressed to be smaller than 1 millisecond, which affects the player's performance. It can be seen that the delay is suppressed to the extent that it is not given.

Further, in the present embodiment, since the transmission circuit 17 of the transmission unit 12 is configured to wirelessly transmit by analog modulation, the power consumption required for modulation of the output signal can be suppressed as much as possible.

In the above embodiment, the case where the transmission circuit 17 wirelessly transmits by FM modulation is shown, but it may be configured to wirelessly transmit by AM modulation.
In this case, the output signal that is AM-modulated and wirelessly transmitted is given to the first AM demodulator 43e or the second AM demodulator 43f by the switching unit 41.

Further, in the above embodiment, the case where the transmitter 8 includes two transmitters 12 is shown, but it is sufficient that the transmitter 8 includes at least one transmitter 12, and the transmitter 8 includes three or more transmitters 12. May be.

Further, in the above embodiment, the case where the transmitter 8 is attached to the outside of the electronic drum 2 is illustrated. For example, as shown in FIG. 10, the outer frame 14 of the electronic drum 2 to which the drum pad 5 is attached The transmitter 8 may be fixed to the inner peripheral surface 14a, and the transmitter 8 may be provided inside the electronic drum 2.

[About the second embodiment]
FIG. 11 is a diagram showing a security device including a communication system according to a second embodiment. In FIG. 11, the security device 50 is a device that detects and notifies the opening and closing of the sliding door 60.
In the security device 50, a large number of magnets 51 fixed to the upper rail 60a of the sliding door 60, a detection coil 52, a notification device 53, a transmitter 8 to which the detection coil 52 is connected, and a notification device 53 are connected. The receiver 11 is provided.

The magnets 51 are arranged at equal intervals along the opening / closing direction of the sliding door 60, and move integrally with the sliding door 60.
The detection coil 52 is fixed to the upper side of the upper rail 60a of the sliding door 60, and is arranged at a position capable of facing a large number of magnets 51 moving in the opening / closing direction of the sliding door 60.
When the sliding door 60 moves by opening and closing, the magnets 51 arranged at equal intervals along the opening and closing direction sequentially move to positions facing the detection surface 52a of the detection coil 52 and pass through.

The detection coil 52 generates an induced current due to a change in the magnetic field generated by the movement of the magnet 51. That is, when the sliding door 60 is opened and closed and the magnet 51 moves, the detection coil 52 generates an induced current and outputs an electric signal as an output signal. Therefore, when the sliding door 60 is opened and closed, the detection coil 52 outputs an output signal as the detection result.

The output signal of the detection coil 52 is given to the transmitter 8 as an input signal.
The transmitter 8 and the receiver 11 of the present embodiment have the same configuration as the transmitter 8 and the receiver 11 shown in the first embodiment.
Therefore, the transmitter 8 wirelessly transmits the output signal and gives it to the receiver 11.
The receiver 11 gives the output signal transmitted from the transmitter 8 to the notification device 53.
The notification device 53 notifies the opening / closing of the sliding door 60 in response to this output signal.

Also in the case of the present embodiment, the transmitter 8 uses the rectified output signal of the detection coil 52, which is an input signal, as power, and wirelessly transmits the output signal given as the transmission signal. Therefore, the transmitter 8 and the detection A signal can be transmitted wirelessly without the coil 52 including a storage battery or the like. As a result, it is possible to easily transmit signals without performing complicated work such as wiring work of a signal line for outputting an output signal and maintenance work of a storage battery or the like.

[Other]
The present invention is not limited to the above embodiments.
In the first embodiment, the case where the communication system is applied to the electronic drum set 1 is shown, but it is also applied to other electronic musical instruments such as electric guitars that need to be connected to a sound source device or the like by a signal line. Can be done.

Further, in the first embodiment, the case where FM modulation and AM modulation are adopted as the analog modulation method of the transmitter 8 is illustrated, but other analog modulation such as phase modulation can be adopted.

Further, in the first embodiment, the case where the piezoelectric element 6 is used as the conversion element for converting the input input energy into an electric signal is shown. For example, a photovoltaic cell (solar cell) for converting light energy into an electric signal. May be used as a conversion element, or a Peltier element that converts heat energy into an electric signal may be used as a conversion element.

1 Electronic drum set 2, 2a Electronic drum 3 Synthesizer 4 Speaker 5 Drum pad 5a Surface 6, 6a, 6b Piezoelectric element 7 Output jack 7a Hole 8 Transmitter 9 Board 10 Connection plug 11 Receiver 12, 12a, 12b Transmitter 13 , 13a Input jack 14 Outer frame 14a Inner peripheral surface 15 Separation circuit 16 Series regulator 17 Transmission circuit 18 Transmission antenna 20 Transformer 21 Demodulation circuit 22 Line 23 Branch path 24 1st resistance 25 2nd resistance 26 Branch path 30 Reception antenna 31 RF circuit 32 Digital converter 33 Separation part 35 Output plug 35a 1st output plug 35b 2nd output plug 35c 3rd output plug 40 High-speed Fourier converter 41 Switching part 42 Demodulator 43 Analog demodulator 43a 1st FM demodulator 43b 2nd FM demodulator 43c 3rd FM demodulator 43d 4th FM demodulator 43e 1st AM demodulator 43f 2nd AM demodulator 50 Security device 51 Magnet 52 Detection coil 52a Detection surface 53 Notification device 60 Sliding door 60a Upper rail

Claims (11)

A conversion element that converts input energy into an electrical signal,
A transmission circuit that wirelessly transmits the output signal of the conversion element as an input signal,
A power supply circuit that full-wave rectifies the input signal and supplies it to the transmission circuit,
A transformer with a primary coil and a secondary coil,
A signal line connecting the conversion element and the power supply circuit, the first signal line for giving the input signal from the conversion element to the power supply circuit, and a first signal line for giving the input signal to the transmission circuit as a transmission signal. The two signal lines are transmitters that are electrically isolated by the transformer by connecting the first signal line to the primary coil and connecting the second signal line to the secondary coil. The transmitter according to claim 1, wherein the transmitter circuit analog-modulates the input signal and wirelessly transmits the input signal. The invention according to claim 1 or 2, further comprising a connection terminal which is connectable to an output terminal to which the output signal output by the conversion element is given, is connected to the output terminal, and receives the output signal as the input signal. Transmitter. The connection terminal can be connected to the output terminal to which the output signals from the plurality of conversion elements are given, and receives each of the output signals from the plurality of conversion elements as the input signal.
The transmitter according to claim 3, wherein a plurality of the transmitter circuit and the power supply circuit are provided corresponding to the plurality of the conversion elements. The conversion element is a conversion element that converts the input energy input to the electronic musical instrument by the performance operation into an electric signal.
The transmitter according to any one of claims 1 to 3, wherein the transmitter circuit and the power supply circuit are provided inside the electronic musical instrument. A conversion element that converts vibration energy into an electrical signal,
A transmission circuit that wirelessly transmits the output signal of the conversion element as an input signal,
A power supply circuit that full-wave rectifies the input signal and supplies it to the transmission circuit,
A transformer with a primary coil and a secondary coil,
A signal line connecting the conversion element and the power supply circuit, the first signal line for giving the input signal from the conversion element to the power supply circuit, and a first signal line for giving the input signal to the transmission circuit as a transmission signal. The two signal lines are transmitters that are electrically isolated by the transformer by connecting the first signal line to the primary coil and connecting the second signal line to the secondary coil. The transmitter according to claim 6 and
A receiver that acquires the output signal from a received signal obtained by receiving a radio signal transmitted by the transmitter and gives the acquired output signal to a sound source device that generates a signal representing an instrument sound based on the output signal. And, a communication system equipped with. A communication system between an electronic musical instrument provided with a conversion element that converts an input due to a performance operation into an electric signal, and a sound source device that generates a signal representing a musical instrument sound based on an output signal output by the conversion element.
The transmitter according to claim 1, wherein the output signal output by the conversion element is given as an input signal.
A communication system including a receiver that acquires the output signal from a received signal obtained by receiving a radio signal transmitted by the transmitter and supplies the output signal to the sound source device. There are a plurality of electronic musical instruments.
There are a plurality of transmitters corresponding to the plurality of electronic musical instruments.
The receiver includes a separation unit that separates a plurality of output signals corresponding to the plurality of transmitters from the received signal, and a plurality of output terminals that output the plurality of output signals to the sound source device. The communication system according to claim 8. The transmitter circuits of the transmitter perform wireless transmission using frequencies different from each other.
The separation unit frequency-separates a plurality of output signals corresponding to the plurality of transmitters from the received signal, and outputs the plurality of output signals from any of the plurality of output terminals. The communication system according to claim 9, wherein the signal is switched according to the frequency of the output signal. The separation unit stores a table in which the frequency of the output signal and information for identifying the plurality of output terminals are registered in association with each other, and the plurality of output signals are stored in the plurality of output signals based on the table. The communication system according to claim 10, wherein the output terminal is switched from which of the output terminals the output terminal is used.