JPH0631951B2 - Electronic stringed instrument - Google Patents

Description

Description: TECHNICAL 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 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 is detected to generate a musical tone of the specified pitch.

When determining the fret position in the pronunciation process of such an electronic stringed instrument, the strings vibrate at a period corresponding to the length of the strings when the strings are turned. However, it was done based on the peak interval 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 1985, Japanese Patent Application No. 240138, an electronic musical instrument was proposed in which the fret position was determined based on ultrasonic scanning. In the electronic stringed instrument disclosed in Japanese Patent Application No. 240138 of 1985, an electric signal is converted into an ultrasonic signal by a piezoelectric element, the ultrasonic signal is transmitted to the string, and the ultrasonic signal is transmitted to contact the string. The fret position is determined based on the time required until the echo reflected by the fret is received.

<Problems to be Solved by the Invention> The electronic stringed instrument disclosed in Japanese Patent Application No. 240138 of 1985 mentioned above has a fret position based on the time required from the transmission of an ultrasonic signal to the reception of an echo of the ultrasonic signal. Since it was discriminated, the piezoelectric element had to generate an electric signal capable of discriminating the echoes reflected by the frets. However, in general, an ultrasonic signal travels in all directions if a propagation medium is present, and is reflected when the propagation medium is in contact with substances having different densities to generate an echo. Also, ultrasonic waves propagate not only in the strings but also in a bridge supporting a piezoelectric element, and an echo is generated by a substance in contact with the bridge, such as a body of a guitar. Since the echo reflected by the body or the like is also converted into an electric signal by the piezoelectric element, there is a possibility that the position of the fret may be erroneously determined unless it can be distinguished from the echo reflected by the fret.

Therefore, it is an object of the present invention to provide a bridge assembly that can eliminate unwanted echoes.

<Means for Solving Problems> The present invention relates to a string stretched on a musical instrument body, a piezoelectric conversion means for converting an electric signal into an ultrasonic signal and an echo of the ultrasonic signal into an electric signal, A bridge assembly fixed to the instrument body and supporting the piezoelectric conversion means so that an ultrasonic signal generated by the piezoelectric conversion means can be transmitted to the string, and the string fixed to the instrument body and contacted by the strings. A plurality of frets for generating echoes of the ultrasonic signals propagating through the strings when the bridge assembly carries the piezoelectric transducer means and attenuates the ultrasonic signals generated by the piezoelectric transducer means. The point is to have a swing body.

<Operation and Effect> In the electronic stringed instrument according to the above configuration, when an ultrasonic signal is generated based on an electric signal supplied by the piezoelectric conversion means, the ultrasonic signal is transmitted from the piezoelectric conversion means to the string, and It propagates through the vibration proof body. The ultrasonic signal transmitted to the strings is reflected by the frets to generate an echo when the strings are in contact with the frets, and propagates again toward the piezoelectric conversion means through the strings. On the other hand, since the ultrasonic signal propagating through the vibration isolator is attenuated according to the attenuation characteristic of the vibration isolator, the ultrasonic signal is reflected by an object of different density in contact with the vibration isolator, for example, the instrument body, Even if an echo occurs, the amplitude of the echo becomes significantly smaller than the amplitude of the echo that occurs even when reflected by the frets. as a result,
The electric signal generated by the piezoelectric conversion means contains a remarkably large amount of echo components generated by the frets, and the fret that generated the echo can be easily discriminated based on the electric signal.

<Example> An example of the present invention will be described below with reference to the drawings. First
The figure is a side view of one embodiment, and this one embodiment applies 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, and detect a low-frequency vibration generated in the strings 7 to 17 when the strings 7 to 17 are stringed to turn the string signal ON. Send to 37.

On the other hand, the bridge assembly 35 includes six ceramic piezoelectric elements 39, 41, 43, 45, 4 as piezoelectric converting means.
7 and 49, and these piezoelectric elements 39 to 4
Reference numeral 9 generates an ultrasonic wave signal of about 450 KHz based on the electric pulse signal SCAN intermittently supplied from the fret position discriminating circuit 51 and transmits the ultrasonic wave signal to the corresponding strings 7 to 17. 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 in contact with .., it is reflected by the frets 19, 21, .. The 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 configuration of the bridge assembly 35 will be described below.
The following is a description with reference to FIGS. 2 and 3 are a front view and a plan view of the bridge assembly 35, and the bridge assembly 35 is the instrument body 1.
It has a bridge base 105 supported by a pair of studs 101, 103 that are planted in the. The bridge base 105 has a pair of holes 107 and 109 penetrating in the vertical direction of FIG. 2 at both ends thereof, and the pair of studs 101 and 103 are slidable in the holes 107 and 109, respectively. Has been inserted into. Nuts 111 and 113 are screwed onto the pair of studs 101 and 103, respectively, and sliding of the bridge base 105 downward in FIG. 2 is restricted by these nuts 111 and 113. In the middle portion of the bridge base 105, holes 115, 117, 119, 121, 123 having a substantially square cross section are formed.
125 is formed, and the vibration isolator 127, 129, 131, 133, 135, 137 is formed in each of the holes 115 to 125.
Has been inserted. As shown in detail in FIG. 4, each of the vibration isolator 127 to 137 holds the piezoelectric element 39 and the like in a slit 139 formed in the central portion thereof.
The upper ends of the left side of the vibration isolator 127 to 137 in FIG. 4 are chamfered, so that the strings 7 and the like extending from the piezoelectric element 39 and the like toward the string winding 3 have the piezoelectric element 39 and the like protruding from the instrument body 1. Nevertheless, it does not come into contact with the vibration isolator 127 or the like. On the other hand, a protrusion 141 is formed on the upper right end surface of the vibration isolator 127 to 137 in FIG.
1 is in contact with each string 7 etc. As a result, the piezoelectric element 39
Although the ultrasonic signal transmitted from the etc. to the string 7 etc. also propagates to the tail piece 5 side of the string 7 etc., it is not attenuated by these projections 141 and does not generate a sufficient echo.

Next, materials and the like of the vibration isolator 127 to 137 will be described. It is sufficient for the vibration isolators 127 to 137 to attenuate mechanical vibrations of about 450 KHz. For that purpose, the damping coefficient needs to be a predetermined value or more. In this embodiment, the hardness is JIS 30 to 70 degrees. I am using chloroprene.

Next, the operation of the above embodiment will be described. During the performance
The fret position determination circuit 51 intermittently sends the electric pulse signal SCAN to the piezoelectric elements 39 to 49, and the piezoelectric elements 39 to 49 generate ultrasonic signals based on the electric pulse signal SCAN. The ultrasonic signals generated by the piezoelectric elements 39 to 49 are transmitted to the strings 7 to 17 as described above, and the frets 19 and 2 contacting the strings 7 to 17 are contacted.
It is reflected by 1, ... And generates an echo. On the other hand, the ultrasonic signal transmitted to the vibration isolator 127 to 137 propagates in the vibration isolator 127 to 137, but is also attenuated in the process and the echo generated by being reflected by the bridge base 105 is also vibration-isolated. Since it is further attenuated in the process of propagating through the bodies 127 to 137, it is significantly attenuated when it reaches the piezoelectric elements 39 to 49 again. As a result, fret 1
The amplitude of the electric signal DET generated by the echoes generated at 9, 21, ... Is significantly larger than the amplitude of the electric signal DET generated by the echo generated at the bridge base 105, and the fret position determination circuit 51 determines this amplitude difference. Based on this, it is possible to easily separate the echoes generated by being reflected by the frets 19, 21 ,.

Further, in the above-mentioned embodiment, the piezoelectric elements 39 to 49 are directly connected to the strings 7.
Since they are in contact with the strings 7 to 17, the ultrasonic signal can be efficiently transmitted to the strings 7 to 17. The piezoelectric element 3
When another member is interposed between the strings 9 to 49 and the strings 7 to 17, it is necessary to make the mass as small as possible. When the mass is large, the member is sufficiently vibrated. It is not possible, and in particular, it is difficult to convert the echo reflected by the frets 19, 21, ... To the electric signal DET.

Further, in the above-described embodiment, since the vibration absorbers 127 to 137 are always interposed between the piezoelectric elements 39 to 49 and the bridge base 105, any one of the piezoelectric elements 39 to 49 is not included.
The ultrasonic signal generated in 1 is sufficiently attenuated before reaching the other piezoelectric elements 39 to 49, and the adjacent piezoelectric elements 39 to 49 are
Based on the ultrasonic signal generated in
・ Do not erroneously determine the position of.

[Brief description of drawings]

 1 is a side view showing an embodiment of the present invention, FIG. 2 is a front view of a bridge assembly, FIG. 3 is a plan view of the bridge assembly, and FIG. 4 is a sectional view of the bridge assembly. DESCRIPTION OF SYMBOLS 1 ... Instrument main body, 7 to 17 ... string, 19, 21, ... Fret, 35 ... Bridge assembly, 39 to 49 ... Piezoelectric conversion means (piezoelectric element), 127 to 137 ... Vibration isolator.

Claims (3)

[Claims] 1. A string stretched over a main body of a musical instrument, piezoelectric conversion means for converting an electric signal into an ultrasonic signal and an echo of the ultrasonic signal into an electric signal, and the piezoelectric element fixed to the main body of the musical instrument. A bridge assembly that supports the piezoelectric converting means so that the ultrasonic signal generated by the converting means can be transmitted to the strings, and an ultrasonic wave that is fixed to the instrument body and propagates through the strings when the strings are in contact with each other. In an electronic stringed instrument having a plurality of frets for generating signal echoes, the bridge assembly has a vibration isolator that carries the piezoelectric conversion means and attenuates ultrasonic signals generated by the piezoelectric conversion means. An electronic stringed instrument characterized by that. 2. The electronic stringed instrument according to claim 1, wherein the piezoelectric conversion means is in direct contact with the string. 3. The string comprises a plurality of strings substantially parallel to each other, and the piezoelectric conversion means has a plurality of piezoelectric elements respectively corresponding to the plurality of strings. The piezoelectric element is formed by the vibration isolator. The electronic stringed instrument according to claim 1, wherein the electronic stringed instruments are isolated from each other.