JPH0624880Y2 - Electronic stringed instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an electronic stringed instrument, and more particularly to an electronic stringed instrument that determines a pitch designated by a performer by scanning 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.

In the discrimination of the fret position in the sounding process of such an electronic stringed instrument, since the strings vibrate at a period corresponding to the string length at the time of turning, the string vibration is converted into an electric signal of a waveform similar to this by an electromagnetic pickup, and the It was done 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, an electronic musical instrument for discriminating the fret position based on scanning with ultrasonic waves was proposed, and in a patent application (hereinafter referred to as a prior application) filed on March 25, 1986, a piezoelectric element. Disclosed is an electronic stringed instrument capable of preventing erroneous determination of the fret position due to multiple reflections of ultrasonic signals generated in the above. 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> However, in general, a vibration isolator having a sufficient damping coefficient is a soft material, and the vibration isolator itself is easily deformed. When the cover is carried, the piezoelectric element collapses due to the force from the string, and the contact position between the piezoelectric element and the string may change during the performance of the musical instrument. In this case, since the electronic stringed instrument according to the prior 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 is caused between the piezoelectric element and the fret. The distance changes, and the round trip time changes. As a result, in extreme cases, 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 prevent the piezoelectric conversion element from collapsing and prevent the fret position from being erroneously determined.

<Means for Solving Problems> The present invention relates to a string stretched on a musical instrument body, a piezoelectric conversion element that is pressed against the string and converts an electric signal into an ultrasonic signal, and is fixed to the musical instrument body. An electronic stringed instrument having a bridge assembly supporting the piezoelectric conversion element, wherein the bridge assembly includes the piezoelectric conversion element and attenuates an ultrasonic signal generated by the piezoelectric conversion element. And a fall prevention body having a rigidity higher than that of the vibration isolator and abutting against a part of the piezoelectric conversion element.

<Operation and Effect> In the electronic stringed instrument according to the above configuration, the fall prevention body having rigidity higher than that of the vibration isolation body is brought into contact with a part of the piezoelectric conversion element,
Since the collapse prevention body is supported by the bridge assembly, even if a large force acts on the piezoelectric conversion element from the strings, the piezoelectric conversion element does not fall down and the mounting position of the piezoelectric conversion element does not 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 discriminated based on the distance between the piezoelectric conversion element and the fret, there is no fear of erroneous discrimination of the fret position, and the musical tone of 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. First
1 to 3 are views showing an embodiment of the present invention, in which the present invention is applied to a six-string guitar.

In FIG. 1, reference numeral 1 denotes a musical instrument body, and between the string winding 3 and the tailpiece 5 of the musical instrument body 1, six strings 7A, 7B, ... Is stretched over. String 7A on the neck of the instrument body 1
..N-numbered frets 19 and 2 approximately at right angles to this
1, ... are planted, and frets 19, 21, ...
Are arranged below the six strings 7A so as to be able to contact them. 6 on the instrument body 1 (body) on the tailpiece 5 side
The individual electromagnetic pickups 23A, 23B, ... And the bridge assembly 35 are fixed at a predetermined distance. The electromagnetic pickups 23A ... Are provided corresponding to the respective strings 7A .. When the strings 7A ..
Detects low-frequency vibrations generated in .. and sends a string signal ON to the tone generator 37.

On the other hand, the bridge assembly 35 supports six ceramic piezoelectric elements 39A, 39B, ... As piezoelectric conversion elements, and these piezoelectric elements 39A ... Are intermittently fed from the fret position determination circuit 51. An ultrasonic wave signal of about 450 KHz is generated based on the electric pulse signal SCAN supplied to, and the ultrasonic wave signal is transmitted to each corresponding string 7A. The ultrasonic signals transmitted to the strings 7A ...
.., and when the strings 7A ... are pressed toward the neck and are in contact with any of the frets 19, 21, ..., They are reflected by the frets 19, 21 ,. Generate. This echo is again piezoelectric element 39A
.. propagating through the strings 7A ... toward the piezoelectric element 39A.
Is converted into an electric signal DET having a waveform similar to that of the echo.

The fret position determination circuit 51 uses the electric pulse signal SC
The frets 19, 21, which are in contact with the strings 7A, ...
.. is discriminated, and a pitch signal representing the pitch corresponding to the frets 19, 21, ... Contacting the strings 7A ... Is supplied to the tone generator 37 based on the discrimination result. 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, sends the musical tone signal to the sound system 53 to generate a musical tone of a predetermined pitch. Let

Next, the detailed configuration of the bridge assembly 35 will be described below.
The following is a description with reference to FIGS.

FIG. 2 is a cross-sectional view of the bridge assembly 35. The bridge assembly 35 has a metal bridge base 103. The bridge base 103 is a pair of stud bolts that are planted in the musical instrument body 1. It is supported by 101. The bridge base 103 has a pair of holes (not shown) penetrating vertically in FIG. 2 at both ends thereof.
The pair of studs 101 are slidably inserted into these holes, respectively. The pair of studs 101
A nut 105 is screwed onto each of them, and sliding of the bridge base 103 in the downward direction in FIG. 2 is restricted by these nuts 105. Further, the height position of the bridge base 103 can be adjusted by these nuts 105.

A hole 1 having a substantially square cross section is formed in the middle of the bridge base 103.
07 are formed corresponding to the strings 7A ...
Holders 109 are inserted and fixed in 07.

These holders 109 are made of a material having high rigidity and high dimensional accuracy, such as metal or plastic. Therefore, the bridge base 103 and the holder 109 are fitted with each other with extremely high accuracy.
The holder 109 is composed of a lower holder 109A fitted to the bridge base 103 and an upper holder 109B joined to the lower holder 109A by a boss 110.

The upper holder 109B is formed with substantially rectangular holes 111 opening toward the strings 7A ... (Upward), and the rectangular plate-shaped piezoelectric elements 39A ... , So that the width direction thereof extends in a direction orthogonal to the extending direction of the strings 7A.
The plate thickness direction of 9A coincides with the extending direction of the strings 7A). Further, a liquid sealing agent 113 made of a silicone polymer is injected and solidified in the hole 111. That is, most of the piezoelectric elements 39A ... Are covered (enclosed) by the sealing agent 113 in the hole 111, and the upper end portion thereof is the upper holder 109B.
It projects from and is pressed against the strings 7A. As such a sealing agent, RT manufactured by Shin-Etsu Chemical Co., Ltd.
There is a V series, and the hardness in the solidified state can be selectively changed. As a result, by appropriately selecting the hardness in the solidified state and adapting it to the attenuation of the ultrasonic signal, the vibration isolator 113 can be configured by this sealing agent. Therefore, the rigidity of the upper holder 109B (anti-tilt body) is higher than that of the vibration isolator 113.

Here, as shown in FIG. 3, on the side wall of the hole 111 of the upper holder 109B (side wall parallel to the extending direction of the strings 7A),
Recesses 114 having a rectangular cross section are formed to engage with both ends of the piezoelectric elements 39A. That is, a part of the piezoelectric elements 39A ... Abuts directly on the upper holder 109B to prevent its fall.

The upper surface of the upper holder 109B on the left side in FIG. 2 is chamfered to prevent the strings 7A ... Further, elastic projections 115 are attached to the upper holder 109B on the right upper surface in FIG. 2, and these projections 115 come into contact with the strings 7A ...
The transmission of ultrasonic signals to the side is prevented.

Next, the operation of this 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 elements 39A ...
When the piezoelectric element 39A is supported on the string 7A ...
・ Can be fixed in place with respect to. Further, in this case, since the piezoelectric elements 39A ... Are partially supported by directly contacting the inner wall of the recess 114 of the upper holder 109B, even if the force from the strings 7A. The elements 39A ... themselves are prevented from falling.
Further, since the volume of the vibration isolator 113 is small, the amount of deformation of the vibration isolator 113 is also small. Therefore, from these results, these piezoelectric elements 39A ... Will not fall down or move greatly during the performance, so that the frets are not moved. Position discriminating circuit 51
Can accurately discriminate the frets that come into contact with the strings 7A, and will not generate an undesired musical tone.

Next, another embodiment will be described with reference to FIG.

In FIG. 4, the same components as those of the above-mentioned embodiment are designated by the same reference numerals and detailed description thereof will be omitted. In this embodiment, a pair of protrusions 116 are formed on the front side wall of the hole 111 in the direction orthogonal to the extending direction of the strings 7A ... It is in contact with a part. Therefore, even if a force from the strings 7A ... Is applied to the piezoelectric elements 39A ..., The protrusions 116 prevent the piezoelectric elements 39A. The sealing agent (vibration isolator) 113 covers (encloses) most of the piezoelectric elements 39A ... And elastically supports them, as in the case described above. Further, other actions are similar to those of the above-mentioned embodiment, and will be omitted.

Next, FIG. 5 shows still another embodiment of the present invention.

As shown in the figure, in this embodiment, one projection 118 is formed in the center of the front side wall of the hole 111 in the direction orthogonal to the extending direction of the strings 7A ... 11
8 is brought into contact with a part of the piezoelectric elements 39A .... The protrusion 118 is arranged immediately below the string 7A. Therefore, the strings 7A ... Are pressed and the piezoelectric elements 39A ...
Even when a force for tilting the piezoelectric elements 39A ... Is applied in the plate thickness direction, the projection 118 penetrates a part of the vibration isolator 113 and the piezoelectric element 39A.・ Because it supports, the fall is prevented.
The rest of the configuration and operation are similar to those of the above-mentioned embodiment, and will be omitted.

[Brief description of drawings]

FIG. 1 is a side view showing an electronic stringed instrument according to an embodiment of the present invention, FIG. 2 is a sectional view showing the bridge assembly, FIG. 3 is a plan view of the bridge assembly, and FIG. FIG. 5 is a plan view showing a bridge assembly of another embodiment, and FIG. 5 is a plan view showing a bridge assembly of still another embodiment. 1 ... Instrument body, 7A, 7B ... String, 35 ... Bridge assembly, 39A, 39B, ... Piezoelectric conversion element (piezoelectric element), 109B ... Upper holder (tilt prevention body) 113 ... Vibration isolator .

Claims (1)

[Scope of utility model registration request] 1. A string stretched over a main body of a musical instrument, a piezoelectric conversion element which is pressed against the string to convert an electric signal into an ultrasonic signal, and a bridge which is fixed to the main body of the musical instrument and supports the piezoelectric conversion element. An electronic stringed instrument including an assembly, wherein the bridge assembly includes a vibration isolator that encloses the piezoelectric conversion element and attenuates an ultrasonic signal generated by the piezoelectric conversion element, and a vibration isolation body that is higher than the vibration isolation body. An electronic stringed instrument having rigidity and a fall-preventing body that comes into contact with a part of the piezoelectric conversion element.