JPH0631953B2 - Electronic stringed instrument - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic stringed instrument, and more particularly to sound generation control means for setting a sound generation duration of a musical sound.

(Prior Art) Conventionally, in this type of electronic string instrument, the position of the fret with which the string pressed by the player is in contact is determined, and the pitch of the musical sound to be produced is specified based on the determination result.
The timing of the crossed strings is detected to generate a musical tone of the specified pitch for a predetermined time.

The control of the sounding duration of such a conventional electronic stringed instrument is based on the detection of the plucked string, and as shown in FIG. The electric signal S1 having a waveform similar to the string vibration is converted (FIG. 6 (a)). The electric signal S1 is amplified by the amplifier 5 and then supplied to the peak hold circuit 7.
The output S2 of the peak hold circuit 7 is compared with the threshold value Vth in the comparison circuit 9 (FIG. 6 (b)). The comparison circuit 9 outputs the output S3 when the output voltage of the peak hold circuit 7 becomes equal to or higher than the threshold value Vth. Is shifted to a low level (FIG. 6 (c)). The tone generation circuit (not shown) is a comparison circuit 9
Since the generation of the musical sound is continued while the output S3 of (1) is at a low level, the tone generation duration of the musical sound is controlled by the output of the comparison circuit 9.

(Problems to be Solved by the Invention) In the above-described conventional electronic string instrument, since the sounding duration time is controlled based on the string vibration generated in the string 1 at the time of stringing, the string vibration is attenuated and the peak hold circuit 7 When the output voltage became less than the threshold value Vth, the sound generation was stopped. However, in the performance of a stringed instrument, there is a case where it is desired to continue sounding for a long time, and the above-mentioned conventional example cannot meet such a demand, and there is a problem that a playing technique is limited.

In order to solve the above-mentioned difficulties, there is one in which the player continues to produce sound until the player touches the string after the stringing and the touch sensor detects the capacity of the human and stops the sounding.
Such a touch sensor has a problem in that it is easily affected by the dryness of the skin and the like, and it is difficult to distinguish it from the operation of pressing the string when the pitch is specified, which causes a malfunction.

Therefore, an object of the present invention is to make it possible to accurately control the sounding duration of an electronic stringed instrument.

(Means for Solving Problems) The present invention relates to a string stretched over a musical instrument body, an ultrasonic signal generated based on a first electric signal, and the ultrasonic signal is supplied to the string. Second based on the constant frequency component of
A means for generating an electric signal and a means for supplying the first electric signal to the means, and a second means within a predetermined time after supplying the first electric signal.
It is characterized in that a sounding control means is provided for enabling the continuation of musical tone generation when an electric signal is received, and for generating a musical tone stop command when the second electric signal is not received within the predetermined time. .

(Operation and Effect) In the electronic stringed instrument according to the above configuration, the ultrasonic signal is generated based on the first electric signal supplied from the sound generation control means, and the ultrasonic signal is transmitted to the string. This ultrasonic signal propagates through the strings, and if the player wishes to keep sounding and does not touch the strings, a second electric signal is generated based on the constant frequency component of the ultrasonic waves. The second electric signal is supplied to the sound generation control means, and the sound generation control means discriminates the intention of the player based on the first electric signal and the second electric signal to enable the sound generation of the musical sound. On the other hand, if the player touches the string with an ultrasonic signal absorber, for example, a finger in order to stop the sound generation of the musical sound, the ultrasonic signal transmitted to the string is attenuated and the second electric signal is not generated. . Therefore,
When the second electric signal is not received within a predetermined time from the supply of the first electric signal, it can be determined that the intention of the sound generation is stopped, and the sound generation control means stops the generation of the musical sound.

As described above, the electronic stringed instrument according to the present invention discriminates the intention of the performer through the ultrasonic signal. Therefore, there is no influence of the dry state of the finger and the frequency component for generating the second electric signal is appropriately set. If selected, the intention display regarding the continuation of the pronunciation can be distinguished from the intention display when the pitch is specified, and it is possible to set the pronunciation continuation time without malfunction.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. In this embodiment, the present invention is applied to a six-string guitar, and reference numeral 1 indicates a musical instrument body. The instrument body 1 is provided with a string winding 3 and a tail piece 5, and between the string winding 3 and the tail piece 5, six strings 7, 9, 11, 13, 15 having different thicknesses are provided. 17 is stretched. The strings 7 to 1 are attached to the neck of the musical instrument body 1.
The n-th fret 19, 21, ... Is planted almost at right angles to the 7, and the fret 19 is a 0 fret which is always in contact with the strings 7 to 17, and the fret 21 ,. It is separated from the strings 7 to 17 and is pressed when the pitch is specified and comes into contact with the strings 7 to 17. A bridge assembly 23 is fixed to the instrument body 1 on the tailpiece 5 side, and the bridge assembly 23 supports ceramic piezoelectric elements 25 to 35. Each of the piezoelectric elements 25 to 35 has the above 6
The piezoelectric elements 25 to 35, which are in direct contact with the strings 7 to 17 of the book, are supplied from the sound generation control circuit 37.
A high frequency ultrasonic signal is generated based on the drive pulse P1 as an electric signal, and the high frequency ultrasonic signal is transmitted to the corresponding strings 7 to 17. The high-frequency ultrasonic signal transmitted to the strings 7 to 17 propagates through the strings 7 to 17 toward the frets 19, 21, ..., And when the string is open, it is reflected by the 0 fret 19 to generate an echo. When the player presses the strings 7 to 17 toward the neck in order to specify the pitch of a musical tone, the echo is generated by being reflected by the frets 21. Either fret 1
The echoes reflected by 9, 21, ... Propagate the strings 7 to 17 toward the piezoelectric elements 25 to 35, and the piezoelectric element 25 is transmitted when the player's right hand does not touch the strings 7 to 17.
Through 35, and converted into the reflected signal S1 as the second electric signal. Note that the signal processing thereafter is performed by a separate circuit for each of the strings 7 to 17, but in the following description, only the echo generated with respect to the string 7 will be described.

The reflection signal S1 is supplied in parallel to the tone generation control circuit 37 and the fret position determination circuit 39, and the fret position determination circuit 39 generates an echo based on the time interval between the drive pulse P1 and the predetermined frequency component of the reflection signal S1. Fret 1
.. are discriminated from the frets 19, 21, ..
The tone pitch signal TP representing the tone pitch corresponding to is sent to the tone generator 41. As a result, the tone generator 41
In response to the cross string signal ON detected by the electromagnetic pickup 43 (45 to 53), a tone signal having a pitch represented by the tone pitch signal TP is supplied to the sound system 43 to generate a tone.

On the other hand, when the tone generation control circuit 37 receives the reflection signal S1 within the generation period of the drive pulse P1, the tone generation control circuit 37 supplies the tone generation signal CON to the tone generator 41 based on the constant frequency component different from the predetermined frequency component. As a result, the tone generator 41 continuously supplies the tone signal to the sound system 43 to continue the tone generation.

However, when the player desires to stop the generation of musical sound and touches the string 7 near the electromagnetic pickup 43 with his right hand, the echoes generated by the frets 19, 21, ... Are attenuated and the reflected signal S1 is not generated. As a result, the tone generation control circuit 37 does not send the tone generation continuation signal CON to the tone generator 41, and the tone generator 41 stops the tone signal transmission. As described above, in the above-described embodiment, since the musical tone is continuously produced until the performer touches the strings 7 to 17 after the stringing, the performer can arbitrarily set the duration of the musical tone, and the musical tone can be changed. Rich musical expression became possible.

Next, the configuration and operation of the sound generation control circuit 37 will be described in detail. FIG. 2 is a block diagram showing the configuration of the tone generation control circuit 37, and FIG. 3 is a waveform diagram of the tone generation control circuit 37. The pulse generation circuit 101 uses a 1 KHz pulse signal P
11 is generated, and when the pulse signal P11 shifts to a high level at time t1, the monostable multivibrator 10
3 generates a drive pulse P1 having a narrow pulse width, and this pulse P1 is amplified by the constant current amplifier 105 and then supplied to the piezoelectric element 25. As a result, the piezoelectric element 25 generates an ultrasonic signal and supplies it to the string 7. After that, the piezoelectric element 25 continues to vibrate for a certain period of time, and the noise N resulting from this self-vibration is supplied to the muting circuit 107, but at the time t1, the monostable multivibrator 10 is provided.
9 supplies the one-shot pulse P12 that shifts to a high level during the duration of the noise N to the muting circuit 107 and maintains the muting circuit 107 in the off state, so that the noise N is cut off.

When the echo reaches the piezoelectric element 25 and the reflected signal S1 is formed at time t2, the reflected signal S1 is supplied to the muting circuit 107. Since the one-shot pulse P12 has already shifted to the low level at time t2, the reflected signal S1 passes through the muting circuit 107 and is amplified by the amplifier 111. Subsequently, the reflected signal S1 is supplied to the peak hold circuit 115 through the high-pass filter 113 that allows the constant frequency component to pass therethrough, and then is compared with a predetermined threshold value Vth by the comparison circuit 117. The comparison circuit 117 sends to the tone generator 41 a tone generation continuation signal CON that shifts to the high level during the period from time t3 to t4 when the output voltage of the peak hold circuit 115 becomes equal to or higher than the threshold value Vth. The tone generation continues while the tone generator 41 receives the tone generation continuation signal CON regularly. In this embodiment, the number of piezoelectric elements may be smaller than in other embodiments described later, and the structure can be simplified.

Next, another embodiment of the present invention will be described with reference to FIG. In the structure of the other embodiment, the same components as those of the above-mentioned one embodiment are designated by the same reference numerals and detailed description thereof will be omitted.
In the other embodiment, the means for generating the ultrasonic signal and the second electric signal is constituted by the transmitting piezoelectric elements 201, 203 ... And the receiving piezoelectric elements 211 to 221. The transmitting piezoelectric elements 201, 203 are It is provided corresponding to each of the frets 19, 21, .... Each of these piezoelectric elements 201, 203
Is supplied with a drive pulse P31 as the first electric signal from the pulse generation circuit 223 to generate an ultrasonic signal, and when the string is open, the ultrasonic signal is transmitted from the 0th fret 19 to the strings 7 to 17. On the other hand, when the strings 7 to 17 are pressed by the neck portion in order to specify the pitch of the musical sound, the strings 7 to 17 come from the frets 21, which are in contact with the pressed strings 7 to 17. The ultrasonic signal is transmitted to.

The ultrasonic signal thus transmitted to the strings 7 to 17 propagates through the strings 7 to 17 toward the piezoelectric elements 211 to 221, and is converted into the low frequency signal S11 as the second electric signal by the pressure transmitting elements 211 to 221. Followed by amplifier 235
After being amplified by, it is supplied to the low pass filter 237. The low pass filter 237 cuts off the high frequency pulse used to determine the fret position, and the low frequency signal S11 is generated.
Is passed through and supplied to the comparator 239. The comparator 239 compares the low frequency signal S11 with a predetermined threshold value Vth and shifts its output to a high level while the voltage of the low frequency signal S11 is equal to or higher than the threshold value Vth. This high level output causes the monostable multivibrator 241 to generate a sound continuation signal CON.
To the tone generator 41. The pulse circuit 223, the amplifier 235, the low-pass filter 237, the comparator 239, and the monostable multivibrator 241 together constitute a tone generation control circuit 243.

The above-described one embodiment and the other embodiments are examples in which the present invention is applied to an electronic stringed instrument that determines the position of the fret specified by the player based on the propagation time of the ultrasonic signal. It may be applied to an electronic string instrument in which the vibration frequency of a string is detected by an electromagnetic pickup and the frets in contact with the string are determined based on the detection result. Further, the means for generating the ultrasonic signal and the second electric signal may be constituted by an element utilizing the magnetic field phenomenon.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a block diagram showing a sounding control circuit of one embodiment, FIG. 3 is a waveform diagram of the sounding control circuit, and FIG. FIG. 5 is a side view showing another embodiment, FIG. 5 is a block diagram showing an electric circuit of a conventional example, and FIG. 6 is a waveform diagram of the conventional example. 1 ... Instrument body, 7 to 17 ... strings, 19, 21, ... Frets, 25 to 35 ... Means (piezoelectric element) for generating ultrasonic signals etc., 37 ... Sound control means, (Sound control circuit ) 201, 203, ... Means for generating ultrasonic signals, etc., 211 to 221 ... (Piezoelectric element) 243 ... Sound generation control means, (Sound generation control means). P1 ... First electric signal, (driving pulse), S1, S11 ... Second electric signal, (reflection signal, low-frequency signal)

Claims (2)

[Claims] 1. A string stretched over a musical instrument body, an ultrasonic signal is generated based on a first electric signal and is supplied to the string, and a second string is generated based on a constant frequency component of the ultrasonic signal. A means for generating an electric signal, and supplying the first electric signal to the means, and when the second electric signal is received within a predetermined time after the supply of the first electric signal, it is possible to continue to produce a musical sound An electronic stringed instrument comprising: a tone generation control means for instructing to stop the tone generation of a musical tone when the second electric signal is not received within the time. 2. The electronic stringed instrument according to claim 1, wherein the ultrasonic signal for generating the second electric signal is an echo of the ultrasonic signal based on the first electric signal.