JPH0617198Y2 - Electric musical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electric musical instrument, and particularly, to generate a musical tone corresponding to string vibration.

[Prior art]

Conventionally, as the above electric musical instrument, for example, Japanese Patent Publication No.
Some are disclosed in Japanese Patent Publication. This is done by arranging a plurality of electrically conductive strings so that they cross the magnetic field generated by the magnetic field generator during vibration, grounding one end of each string, and connecting the other end of each string to the waveform correction circuit and amplification device, respectively. When connected and each string vibrates and crosses the magnetic field, the current induced in the strings is supplied to the amplification device via the waveform correction circuit, and a musical tone is generated according to the frequency and amplitude of the string vibration. Is.

[Problems to be solved by the invention]

In such an electric musical instrument, when a certain string is played, a current is induced in another string, so-called crosstalk occurs. Such crosstalk becomes a problem particularly when a musical tone is newly generated based on the electric current induced in the strings, such as a guitar synthesizer.

The reason why this crosstalk occurs is as follows. For example, in FIG. 4, assume that the frets of strings A and B are pressed simultaneously. It should be noted that one ends of the strings A and B are grounded by a conductive nut, and the other ends thereof are used as output terminals and are respectively connected to loads. The equivalent circuit of FIG. 4 is shown in FIG. In the figure, Z _a is the impedance between the 5 fret of the string A and the output terminal, Z ′ _a is the impedance between the 5 fret of the string A and the nut, and Z _b is the 5 fret of the string B and the output terminal. impedance between, Z _'b is the impedance between the 5 Furetsuto and nuts strings B. I'm holding down 5 fret strings A and B at the same time,
Z _{'a, Z' b} are connected in parallel. The fret is made of a metal with good workability and wear resistance, and is electrically conductive. In this state, when a pluck is made between the five frets of the string B and the bridge, an electromotive force E is generated as shown in FIG. Z _oa , Z _ob
Is the impedance of the load connected to the output terminal. i _b is a current flowing through the impedance of the load due to the electromotive force E, and a voltage E _b is generated at Z _ob . Rewriting FIG. 6 results in FIG. 7. In the figure, i _b flowing through Z _ob is _divided into i _a , i ′ _a , and i ′ _b . i _a is Z
_a , Z _oa , and a voltage E _a is generated at Z _oa . This is crosstalk.

[Means for solving problems]

To prevent crosstalk, as shown in FIG. 8 Z _a
And a series circuit of a _{Z oa, Z 'a, Z} ' may be shorted to either _b. As a result, i _b flows through the short circuit and Z
_No current flows in _a and Z _oa, and no voltage occurs in Z _oa . Therefore, in this device, each fret is grounded. Accordance connexion, strings as described above A, the pressing certain Furetsuto simultaneously in _{B, Z 'a, Z'} b are short-circuited, _{i b} is _Z 'a, _Z' flow _b, it does not flow in the _{Z oa} . It is conceivable that each fret is made of an insulating material, but there is currently no suitable one in terms of workability, wear resistance, price, and the like.

〔Example〕

In FIG. 1, reference numeral 2 is a body, and the body 2 is provided with an elongated neck portion 4. A tuning winding screw 6 is provided at the tip of the net portion 4, and a bridge 8 is provided at the rear end of the body 2. A string 10 made of a conductive material is provided between the winding screw 6 and the bridge 8.

The body 2 is provided with a magnetic field generator 12. This magnetic field generating unit 12 is provided for each string as shown by arrows A and B in FIG.
The permanent magnet 14 has a double structure in order to generate a magnetic field across 10 and to make the magnetic field uniform at the position of each string 10.

A nut 16 is provided in the vicinity of each tuning screw 6 of the neck portion 4 in contact with each string 10. This nut 16
Is made of a conductive metal such as Shinchi Yu. This nut
Frets 18 are provided in order from 16 toward the body 2 side. These frets 18 are all made of conductive metal.

In the net part 4, from the nut 16 toward the body 2 side,
For example, a ground wire 20 which is a copper splint wire is buried. The ground wire 20 includes a nut 16 and each fret 18
Are respectively welded or soldered. Therefore,
When one of the strings 18 of each string 10 is pressed, the ground wire 20 short-circuits between the nut 16 of the string 10 and the pressed fret 18. The end of each string 10 on the bridge 8 side is connected to a processing circuit (not shown) provided for each string 10. A ground wire 20 is connected to the ground side of each of these processing circuits.

The equivalent circuit of the device constructed as described above is the same as that shown in FIG. Therefore, crosstalk does not occur even when the same fret of a plurality of strings 10 is pressed.

In the above embodiment, the magnetic field generating unit 12 has the dual structure of the permanent magnet 14, but only one permanent magnet 14 may be provided. Although the permanent magnet is used, an electromagnet may be used instead of the permanent magnet to control the current flowing through the electromagnet to adjust the volume. Although the impedance of the ground wire 20 is ignored in the above description, the ground wire 20 is actually used.
There is also impedance. However, the string 10 is made of steel, the ground wire 20 has a lower resistance value than the string 10,
If the copper wire is thick enough, the impedance of the ground wire 20 can be ignored.

〔effect〕

As described above, according to the present invention, the configuration is adopted in which the conductive frets provided for a plurality of conductive strings that are interposed in a magnetic field and generate an electric signal by themselves are grounded. Therefore, even with a simple structure, it is possible to prevent crosstalk from occurring even if a plurality of strings are simultaneously pressed and at least one string is played.

[Brief description of drawings]

FIG. 1 is a partially omitted perspective view of an embodiment of an electric musical instrument according to the present invention, FIG. 2 is a schematic view of a magnetic field generating portion of the embodiment, and FIG. 3 is a partially omitted vertical sectional view of a neck portion of the embodiment. FIG. 4 is a schematic diagram showing a neck portion of a conventional electric musical instrument, FIGS. 5 to 7 are circuit diagrams for explaining the reason why crosstalk occurs in the conventional electric musical instrument, and FIG. 8 is an electric musical instrument according to the present invention. 6 is a diagram for explaining the operation of FIG. 10 …… Strings, 12 …… Magnetic field generator, 16 …… Nuts, 18 …… Flets, 20 …… Ground wires.

Claims (1)

[Scope of utility model registration request] 1. A magnetic field generating section for generating a magnetic field, a plurality of electrically conductive strings which output an electric signal self-induced by vibrating in the magnetic field and whose one end is grounded, and to these strings. An electric musical instrument comprising a conductive fret and grounding the fret.