JPH0624875Y2 - Electronic stringed instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an electronic stringed instrument, and more particularly to an electronic stringed instrument that discriminates a pitch designated by a performer by the operation of an ultrasonic signal.

<Prior Art> Generally, in an electronic stringed instrument, the position of the fret that is in contact with the string pressed by the player is determined, and the pitch of the musical tone to be generated is specified based on the determination result. The timing is detected to generate a musical tone of the specified pitch.

When determining the fret position in the sounding process of such an electronic stringed instrument, since the strings vibrate with a period corresponding to the string length when the strings are turned, the vibration of the strings is converted by an electromagnetic pickup into an electric signal of a waveform similar to the vibration of the strings. , Was made based on the peak spacing of the waveform.

However, in the case of converting the string vibration based on the above-mentioned string into an electric signal, it took a long time from the string to the generation of a musical sound, which gave an unnatural impression to the performer. In Japanese Patent Application No. 240138 of 1985, we proposed an electronic musical instrument that discriminates the fret position based on scanning by ultrasonic waves. Furthermore, in the patent application relating to the same application as this application, multiple reflection of ultrasonic signals generated by piezoelectric elements is proposed. The electronic stringed instrument capable of preventing the erroneous determination of the fret position due to the above has been disclosed. An electronic stringed instrument capable of eliminating the influence of this multiple reflection is a piezoelectric element supported by a vibration isolator capable of attenuating ultrasonic signals, and the vibration isolator has an attenuation coefficient capable of attenuating ultrasonic signals.

<Problems to be Solved by the Invention> Generally, the vibration isolator having a sufficient damping coefficient is a soft material, and the dimensional accuracy when forming the vibration isolator is low, and the piezoelectric element is a vibration isolator having a large dimensional error. When the instrument was carried, the contact position between the piezoelectric element and the string sometimes changed during the performance of the musical instrument. Since the electronic stringed instrument according to the above-mentioned patent application discriminates the fret position in contact with the string based on the round-trip time of the ultrasonic signal, such a change in the contact position results in a change in the distance between the piezoelectric element and the fret, which is extended. The round trip time changes. As a result, there is a problem in that, if the pitch is too great, the fret position is erroneously determined, and a musical tone with a pitch different from the pitch intended by the player is generated.

Therefore, an object of the present invention is to improve the mounting accuracy of the piezoelectric conversion element.

<Means for Solving Problems> The present invention is a string stretched over a musical instrument body, a piezoelectric conversion element for converting an electric signal into an ultrasonic signal, and a piezoelectric conversion element fixed on the musical instrument body. A bridge assembly supporting the piezoelectric conversion element so that the ultrasonic signal generated can be transmitted to the string, the bridge assembly comprising:
A bridge base fixed to the musical instrument body, a vibration isolator covering a part of the piezoelectric conversion element to attenuate an ultrasonic signal generated by the piezoelectric conversion element, and a space between the vibration isolation body and the bridge base. And a holder for interposing the piezoelectric conversion element at a predetermined position with respect to the string.

<Operation and Effect> In the electronic stringed instrument according to the above configuration, the vibration isolator is supported by the bridge base via the holder, and the volume of the vibration isolator is reduced. Therefore, even if an error occurs in the vibration isolator at the same rate as that of the conventional vibration isolator, the absolute value of the error becomes smaller than that in the prior art. Moreover, because the holder can be made of a material that has a higher dimensional accuracy than the vibration isolator, the dimensional error that occurs when the vibration isolator of the present invention and the holder are combined is smaller than the error that occurs with the conventional vibration isolator. Therefore, the mounting position of the piezoelectric conversion element supported by the bridge assembly including the holder and the vibration isolator does not easily change. as a result,
The contact position between the piezoelectric conversion element and the string becomes constant, and the distance between the contact position and the fret also maintains a preset value. Therefore, even if the position of the fret is determined based on the distance between the piezoelectric conversion element and the fret, the fret position is not erroneously determined, and the musical tone with the pitch intended by the player is always generated.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. Second
FIG. 1 is a side view of an embodiment, which is an application of the present invention to a six-string guitar. In the figure, reference numeral 1 denotes a musical instrument main body, and between the string winding 3 and the tailpiece 5 of the musical instrument main body 1, six strings 7 having different thicknesses,
9, 11, 13, 15, 17 are stretched in parallel with each other. In the neck portion of the instrument body 1, n frets 19, 21, ... Are planted at a right angle to the strings 7 to 17,
The frets 19, 21, ... Are located so as to be in contact with the six strings 7 to 17. Six electromagnetic pickups 23, 25, 27, 29, 3 are attached to the instrument body 1 on the tailpiece 5 side.
1, 33 and the bridge assembly 35 are fixed. The electromagnetic pickups 23 to 33 are provided corresponding to the strings 7 to 17, detect low-frequency vibration generated in the strings 7 to 17, and send a string signal ON to the tone generator 37.

On the other hand, the bridge assembly 35 includes six ceramic piezoelectric elements 39, 41, 43, 45, 4 as piezoelectric conversion elements.
7 and 49, and these piezoelectric elements 39 to 4
Reference numeral 9 generates an ultrasonic signal of about 450 KHz based on the electric pulse signal SCAN intermittently supplied from the fret position discriminating circuit 51, and the ultrasonic signal is applied to the corresponding strings 7 to 1
Communicate to 7. The ultrasonic signal transmitted to the strings 7 to 17 propagates through the strings 7 to 17, and the strings 7 to 17 are pressed toward the neck portion so that any one of the frets 19, 21, ...
When it comes into contact with, it is reflected by the frets 19, 21 ... This echo propagates again through the strings 7 to 17 toward the piezoelectric elements 39 to 49, and the echo reaching the piezoelectric elements 39 to 49 is converted into an electric signal DET having a waveform similar to the echo by the piezoelectric elements 39 to 49. To be done.

The fret position discriminating circuit 51 uses the electric pulse signal SCA.
Frets 19 and 21, which are in contact with the strings 7 to 17, based on the time from the transmission of N to the reception of the electric signal DET
. Is supplied to the tone generator 37 based on the result of the determination, and a pitch signal representing the pitch corresponding to the frets 19, 21, ... Contacting the strings 7 to 17 is supplied. As a result, the tone generator 37 forms a musical tone signal based on the supplied pitch signal, and when the chord signal ON is supplied,
The musical tone signal is sent to the sound system 53 to generate a musical tone having a predetermined pitch.

Next, the detailed structure of the bridge assembly 35 will be described.
It will be described below with reference to the drawings. FIG. 1 is a sectional view of the bridge assembly 35.
Reference numeral 5 has a metal bridge base 103 supported by a pair of studs 101 that are planted in the musical instrument body 1. The bridge base 103 has a pair of holes (not shown) penetrating in the vertical direction in FIG. 1 at both ends thereof, and the pair of studs 101 are slidable in these holes. Has been inserted. A nut 105 is screwed onto each of the pair of studs 101, and sliding of the bridge base 103 in the downward direction in FIG. 1 is restricted by these nuts 105. A hole 107 having a substantially square cross section is formed in the middle portion of the bridge base 103.
The holders 109 are inserted and fixed in the holes 107, respectively. These holders 109 are formed of a material having high dimensional accuracy such as metal or plastic (preferably a material having rigidity having a larger elastic coefficient than that of the vibration isolator). Therefore, the bridge base 103 and the holder 109 are fitted with each other with extremely high accuracy. Grooves 111 that open toward the strings 7 to 17 are formed in the holder 109, and the piezoelectric elements 39 to 4 are formed in these grooves 111.
9 is loosely inserted. Further, a liquid sealing agent made of a silicon polymer is injected into the groove 111 and solidified. As such a sealing agent, there is RTV series manufactured by Shin-Etsu Chemical Co., Ltd., and the hardness in a solidified state can be selectively changed. As a result, the hardness in the solidified state is appropriately selected and adapted to the attenuation of the ultrasonic signal.
Can be configured. The upper left end of the holder 109 in FIG. 1 is chamfered so that the strings 7 to 17 do not come into contact with each other. Further, elastic protrusions 115 are attached to the holder 109 at the upper right end in FIG. 1, and these protrusions 115 contact the strings 7 to 17 to propagate the ultrasonic signal to the tailpiece 5 side. Is being prevented.

The operation of the above-described embodiment will be described. As described above, since the assembly accuracy of the bridge base 103 and the holder 109 is extremely high and the vibration isolator 113 is easily formed, the piezoelectric element 3
When 9 to 49 are supported by the bridge assembly 35, the piezoelectric elements 39 to 49 can be fixed in place. Further, since the volume of the vibration isolator 113 is small, the amount of deformation of the vibration isolator 113 is also small. Therefore, since the piezoelectric elements 39 to 49 do not move during the performance, the fret position discriminating circuit 51 contacts the strings 7 to 17. Frets can be accurately discriminated, and musical tones with an undesired pitch are not generated.

Next, another embodiment will be described with reference to FIG. In FIG. 3, the same components as those of the above-described embodiment are designated by the same reference numerals and detailed description thereof will be omitted. In another embodiment hole 107
A spacer 121 made of chloroprene rubber having a JIS hardness of 30 to 70 is inserted in the lower part of, and a metal or plastic holder 123 is inserted thereon. Grooves 125 are formed in the holder 123,
Piezoelectric elements 39 to 49 are loosely inserted in the groove 125, and a vibration isolator 113 of a sealing agent is injected and solidified. In the other embodiment, the protrusion 127 can be formed integrally with the holder 123, which facilitates the formation of the protrusion 127.

[Brief description of drawings]

FIG. 1 is a sectional view showing a bridge assembly according to an embodiment of the present invention, FIG. 2 is a side view of the embodiment, and FIG. 3 is a sectional view showing a bridge assembly of another embodiment. 1 ... Instrument body, 7 to 17 ... strings, 35 ... Bridge assembly, 39 to 49 ... Piezoelectric conversion element (piezoelectric element), 103 ... Bridge base, 109 ... Holder, 113 ... Vibration isolator .

Claims (2)

[Scope of utility model registration request] 1. A string stretched over a musical instrument body, a piezoelectric conversion element for converting an electric signal into an ultrasonic signal, and an ultrasonic signal generated by the piezoelectric conversion element which is fixed to the musical instrument body and which is generated by the piezoelectric conversion element. In an electronic stringed instrument that includes a bridge assembly that supports the piezoelectric conversion element so that the bridge base fixed to the instrument body and a part of the piezoelectric conversion element. A vibration isolator for attenuating an ultrasonic signal generated by the piezoelectric conversion element, and a holder interposed between the vibration isolation body and the bridge base to position the piezoelectric conversion element at a predetermined position with respect to the string. An electronic stringed instrument characterized by having. 2. The utility model registration claim according to claim 1, wherein the holder has a groove opening toward the chord, and the vibration isolator is made of a curable liquid material inserted into the groove. Electronic stringed instrument.