JP3475478B2 - Electric stringed instrument pickup device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric string instrument pickup apparatus suitable for application to an electric guitar or the like, and more particularly to an electric string instrument pickup apparatus capable of extracting a well-balanced stereo signal output.

[0002]

2. Description of the Related Art Conventionally, as a pickup device used for an electric stringed instrument such as an electric guitar, an electromagnetic type (eg, Japanese Patent Publication No. 62-33598), a piezoelectric type (eg, Japanese Utility Model Publication 6).
Various proposals have been made such as JP-A 1-46559 and JP-B-62-26797). In each of these pickup devices, a plurality of pickup devices are arranged in parallel corresponding to each string, and the vibration of each string is independently picked up, converted into an electric signal and amplified, and then produced by a speaker. . The prior art disclosed in Japanese Examined Patent Publication No. 62-33598 has a permanent magnet that is orthogonal to the direction of the magnetic circuit in order to obtain a clear tone peculiar to the guitar and a sound with a small attack and a long sustain to achieve a time-balanced sound. Anisotropic treatment is applied to the direction. Mitsuko Sho 61-
In the prior art disclosed in Japanese Patent No. 46559, in a case where a pickup device is molded in a string receiving member, in order to prevent the plus and minus electrodes from being short-circuited by the melted solder at the time of soldering work of the piezoelectric element, The joint portion of the electrode with the piezoelectric element is formed in a protrusion shape, and the other portion is separated from the piezoelectric element. In the prior art disclosed in Japanese Utility Model Publication No. 62-26797, in order to compensate for variations in output level due to differences between strings and to emphasize specific string vibration, the size and arrangement position of each piezoelectric element are set. It has been changed to have different characteristics.

Recently, a stereo-compatible pickup device has been proposed and implemented in order to enhance the playing effect. This is to give a feeling of expanse to those who perform and hear by having different sound sources on the left and right as in normal audio. 4 to 6 are a cross-sectional view of a string locking portion showing a conventional example of such a stereo-compatible pickup device, an exploded perspective view and a circuit diagram of the device. In these figures, 1 is a soundboard (front plate) forming a resonance drum of an electric guitar, and each string 2 is provided on a predetermined portion of the surface thereof.
A string receiving member 3 that supports (2A to 2F) is arranged via a lower piece 4. A pickup device 5 for converting the vibration of each string 2 into an electric signal is arranged between the string receiving member 3 and the lower piece 4.

The pickup device 5 includes a piezoelectric element 9 made of a piezoelectric ceramic arranged on a printed circuit board 6 with a positive electrode 8 interposed therebetween, and a common electrode 10 made of a metal plate closely fixed to the piezoelectric element 9. Etc. Piezoelectric element 9
Are divided into six in order to improve the isolation of vibration of each string 2, and are arranged in parallel so as to correspond to each string 2. For this reason, the positive electrode 8 also includes the piezoelectric elements 9A to 9F.
It is formed for each. Also, the first and third strings 2
Piezoelectric elements 9A and 9 for converting vibrations of A and 2C into electric signals
C plus electrodes 8A, 8C and the fourth and sixth strings 2
Piezoelectric elements 9D, 9 for converting vibrations of D, 2F into electric signals
F plus electrodes 8D and 8F are conductive portions 11 and 12, respectively.
Connected to each other by means of second and fifth strings 2B, 2
The piezoelectric elements 9B and 9E of E are independent of each other and are connected to the conductive portions 13 and 14, respectively. The conductors 11 and 13 have one core wire 1 of the two-core shield lead wire 15 on one side.
One end of each of 5a and 15b is connected, and these core wires 1
The other ends of 5a and 15b are connected to a mode changeover switch 16 such as a toggle switch. Conductive part 1
2 and 14 are the core wire 1 of the other two-core shield lead wire 17.
One ends of 7a and 17b are respectively connected, and these core wires 1
The other ends of 7a and 7b are the same as the mode changeover switch 16 described above.
Respectively connected to. Then, the mode changeover switch 16 connects the first and second speakers 18, 19 to the amplifier 2
0 and 21 are connected respectively. 22
Is a ground wire connected to the common electrode 10.

When the mode selector switch 16 is set to the stereo mode I state in such a configuration, the vibrations of the first, second, and third strings 2A, 2B, and 2C are sounded from the first speaker 18 as electric sounds. While the fourth, fifth, sixth
The vibrations of the strings 2D, 2E, and 2F are sounded as electric sounds from the second speaker 19. On the other hand, mode switch 1
When 6 is switched to stereo mode II, the first, third, fifth
While the vibrations of the strings 2A, 2C, 2E of No. 2 are generated as electric sounds from the first speaker 18, the strings 2B, 2B, 2
The 2D and 2F vibrations are sounded as electric sounds from the second speaker 19. In this case, as a method of connecting the piezoelectric element 9, a connection other than the above connection, for example, connection between the piezoelectric elements of the first, fifth and sixth strings and the piezoelectric elements of the second, third and fourth strings can be considered. However, there is a feeling of strangeness, and the connection described above is actually sufficient.

[0006]

By the way, in such a conventional stereo-compatible pickup device, the piezoelectric elements 9 having the same size are taken into consideration in consideration of moldability, commonality, and the like.
Since A to 9F are used, there is a problem that the sound output balance is not good. That is, generally, in the case of a piezoelectric element, the relationship between the signal voltage to be extracted and the capacitance (C) is expressed by the following equation. Q = C · V, where Q is the charge (strength of vibration of the string), C is the capacitance of the piezoelectric element, and V is the signal voltage. V = Q / C, V
Is inversely proportional to C, and increases as the thickness of the piezoelectric element increases.
Further, C is proportional to the area of the electrode bonding surface of the piezoelectric element. Therefore, the sum of C of the piezoelectric elements 9A and 9C of the first and third strings and the sum of C of the piezoelectric elements 9D and 9F of the fourth and sixth strings are the piezoelectric elements 9B of the second and fifth strings. Since it is larger than C of 9E, when the strings are played with the same strength, the signal output of the 1st, 3rd strings and the 4th, 6th strings drop, and the overall output balance deteriorates. In practice, BaTiO 3 is used as the material of the piezoelectric element 9.
₃ (barium titanate), PbTiO ₃ —PbZrO ₃
When using a piezoelectric ceramic such as (lead zirconate titanate),
Since the piezoelectric ceramic is very hard, even if it is divided for each string, the string vibration easily propagates to the adjacent piezoelectric element and is averaged, so the poor output balance tends to be inconspicuous, but still Since the outputs of the second and fifth strings having a small C were too high, the outputs between the strings could not be perfectly balanced. Further, since the string vibration propagates through the piezoelectric element, there is a problem that sound separation is poor, in other words, stereo effect is poor.

Therefore, as a method for solving such a problem, for example, the vibration of all strings is individually picked up by a piezoelectric element, an amplifier circuit is provided in front of the mode changeover switch, and an output level is adjusted by a volume control. By adopting the above method, it is possible to compensate the variation in the output level, but in that case, the circuit becomes complicated, the cost becomes high, and the number of lead wires increases.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to take out a well-balanced output signal to improve the stereo performance effect and to separate the sound. An object of the present invention is to provide a pickup device for an electric stringed instrument, which is improved in performance.

[0009]

In order to achieve the above object, the invention according to claim 1 is arranged in a string receiving member for supporting the strings in correspondence with each string, and the vibration of the strings is converted into an electric signal. In a pick-up device for an electric string instrument, which comprises a plurality of piezoelectric elements for conversion, the piezoelectric elements of the first and third strings are also electrically connected to each other, and the piezoelectric elements of the fourth and sixth strings are electrically connected to each other. Connected to make the capacitances of the piezoelectric elements of the second and fifth strings substantially equal, and to add the capacitances of the piezoelectric elements of the first and third strings and the piezoelectric elements of the fourth and sixth strings. The sum of the capacities is set to be substantially equal to the capacities of the piezoelectric elements of the second and fifth strings.

A second invention is characterized in that, in the invention described in claim 1, the piezoelectric element of each string is integrally molded.

A third invention is characterized in that, in the invention described in claim 2, a vibration propagation preventing groove is formed at a boundary portion between adjacent piezoelectric elements.

[0012]

In the present invention, the piezoelectric elements of the second and fifth strings are independent of each other, and the piezoelectric elements of the first, third strings and the piezoelectric elements of the fourth, sixth strings are electrically connected to each other. It is connected to the. The capacitances of the piezoelectric elements of the second and fifth strings are substantially equal, and the sum of the capacitances of the piezoelectric elements of the first and third strings and the sum of the capacitances of the piezoelectric elements of the fourth and sixth strings are: It is substantially equal to the capacitance of the piezoelectric elements of the second and fifth strings. Therefore, the signal voltages of the first, third and fourth and sixth strings become substantially equal to the signal voltages of the second and fifth strings, compensating for variations in the output level.

The piezoelectric elements corresponding to the respective strings are integrally molded to facilitate the manufacturing and assembling work. Further, the vibration propagation preventing groove provided at the boundary between the piezoelectric elements adjacent to each other prevents the string vibration from propagating through the piezoelectric element and being averaged. Therefore, the sound can be easily separated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is an exploded perspective view showing an embodiment of a pickup device for an electric stringed instrument according to the present invention.
It should be noted that, in the figure, the same components as those in FIGS. 4 to 6 are designated by the same reference numerals, and the description thereof will be omitted. In the figure, piezoelectric elements 9A to 9F arranged in parallel on the printed circuit board 6 corresponding to the strings 2A to 2F are polymer piezoelectric materials such as polyvinylidene fluoride (PVDF) or synthetic rubber or synthetic resin. Piezoelectric material for the second and fifth strings 2B and 2E, which is made of a polymer composite piezoelectric material (eg, chloroprene rubber + lead zirconate titanate) in which dielectric ceramic powder is uniformly mixed with the polymer material and is formed into a chip shape. The elements 9B and 9E are independently connected to the conductive portions 13 and 14, respectively, and the piezoelectric elements 9A and 9C of the first and third strings 2A and 2C and the piezoelectric element 9D of the fourth and sixth strings 2D and 2F. , 9F are electrically connected to each other by conductive parts 11 and 12, respectively. The piezoelectric elements 9A to 9F have the same thickness and different sizes, and the first, third, fourth and sixth piezoelectric elements 9A, 9C, 9D and 9F are the second and fifth piezoelectric elements.
The size of the piezoelectric elements 9B and 9E is about half. Therefore, the first, third, fourth and sixth piezoelectric elements 9A, 9
The electrode bonding area of C, 9D, 9F is about half the electrode bonding area of the second and fifth piezoelectric elements 9B, 9E, in other words, the capacitance C is 1/2, and the first, first 3rd string 2A, 2
Sum of capacitances C ₁ and C ₃ of piezoelectric elements 9A and 9C of C and capacitance C of piezoelectric elements 9D and 9F of fourth and sixth strings 2D and 2F
The sum of ₄ , C ₆ is the capacitance C of the second and fifth strings 2B, 2E.
₂ and C ₅ (C ₂ ≈C ₅ ≈C ₁ + C ₃ ≈C ₄
+ C ₆ ). In this case, the piezoelectric elements 9A to 9F may have any shape as long as they satisfy the above conditions, and may have, for example, a circular shape. The other structure is the same as that of the conventional device shown in FIGS.

As described above, in the pickup device according to the present invention, the electrode bonding areas of the first, third, fourth and sixth piezoelectric elements 9A, 9C, 9D and 9F are set to the second and fifth piezoelectric elements. 9B and 9E, the size of the electrode bonding area is approximately 1/2, and the piezoelectric elements 9A of the first and third strings 2A and 2C are
The sum of the capacitances C ₁ and C ₃ of 9C and the fourth and sixth strings 2D,
The sum of the capacitances C ₄ and C ₆ of the 2F piezoelectric elements 9D and 9F becomes approximately equal to the capacitances C ₂ and C _{5 of} the second and fifth strings 2B and 2E (up to an allowable range of about ± 20%). Therefore, when each of the strings 9A to 9F is played with the same strength, the signal voltages V thereof are substantially equal, and a well-balanced signal output can be taken out as an electric guitar. Further, in the present invention, the piezoelectric elements 9A to 9F are made of a material that is softer than a piezoelectric ceramic, such as a polymeric piezoelectric material such as polyvinylidene fluoride (PVDF) or a polymeric material such as synthetic rubber or synthetic resin. Since it is made of polymer composite piezoelectric material, etc., in which porcelain powder is uniformly mixed, the ratio of vibration of each string transmitted to other piezoelectric elements via each piezoelectric element is smaller than that of piezoelectric ceramics. The separation is good, clear sound is obtained, and the stereo performance effect can be improved.

2 and 3 are a perspective view and a front view of a piezoelectric element showing another embodiment of the present invention. In this embodiment, all the piezoelectric elements 9A to 9F are made of a polymer piezoelectric material such as polyvinylidene fluoride (PVDF) or a polymer composite material in which dielectric ceramic powder is uniformly mixed with a polymer material such as synthetic rubber or synthetic resin. The vibration propagation preventing groove 30 is integrally formed of a material or the like, and at one of the electrode bonding surfaces, for example, the positive electrode side bonding surface, at the boundary portion between the piezoelectric elements adjacent to each other.
Is formed.

In the piezoelectric element 9 having such a structure, all the piezoelectric elements 9A to 9F are integrally formed, so that the production and the mounting work on the printed circuit board 6 are easy. In this case, since the piezoelectric elements 9A to 9F are formed continuously, the string vibration is more likely to propagate and the sound separation is inferior than the case where they are formed individually, but the piezoelectric element 9 itself is made of a soft material. Since it is formed and the vibration propagation preventing groove 30 is provided between the piezoelectric elements, the string vibration propagating between them is very small, and there is no problem in practical use. Since a piezoelectric ceramic is extremely hard and brittle, it is generally impossible to integrally form all piezoelectric elements.

[0018]

As described above, in the pickup device for an electric stringed instrument according to the present invention, the sizes of the piezoelectric elements are made different, and the piezoelectric elements of the first and third strings are electrically connected to each other. And the piezoelectric elements of the sixth string are also electrically connected to each other, the piezoelectric elements of the second and fifth strings are independent of each other, and their capacities are made substantially equal to each other. Since the sum of the capacities and the sum of the capacities of the piezoelectric elements of the fourth and sixth strings are set to be substantially equal to the capacities of the second and fifth strings, each of the strings when the string is played with the same strength The output voltages can be made substantially equal, and a well-balanced signal output can be taken out. Therefore, it is not necessary to adjust the variation of the output in a circuit manner, a good stereo performance effect can be obtained, and the structure can be simplified and the cost can be provided at a low cost.

Further, according to the present invention, since the piezoelectric element of each string is integrally molded, the piezoelectric element can be manufactured and attached easily and easily. Further, since the vibration propagation preventing groove is formed in the boundary portion of the integrally formed piezoelectric element, the propagation of the string vibration is slight, and the sound separability is not impaired in practical use.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a pickup device for an electric stringed instrument according to the present invention.

FIG. 2 is a perspective view of a piezoelectric element showing another embodiment of the present invention.

FIG. 3 is a front view of the piezoelectric element.

FIG. 4 is a cross-sectional view of a string locking portion of a conventional electric guitar.

FIG. 5 is an exploded perspective view of a conventional pickup device.

FIG. 6 is a circuit diagram of a conventional pickup device.

[Explanation of symbols]

1 ... Sound board, 2 ... String, 3 ... String receiving member, 4 ... Lower piece, 5 ... Pickup device, 6 ... Printed circuit board, 8 ... Positive electrode,
9 ... Piezoelectric element, 10 ... Common electrode, 11-14 ... Conductive part,
15 ... 2-core shielded lead wire, 16 ... Mode changeover switch, 17 ... 2-core shielded lead wire, 30 ... Vibration propagation preventing groove.

Claims (3)

(57) [Claims] 1. A pickup device for an electric stringed musical instrument, comprising: a plurality of piezoelectric elements for converting the vibrations of the strings into electric signals, which are respectively arranged on a string receiving member for supporting the strings. The piezoelectric elements of the third string are electrically connected to each other, and the piezoelectric elements of the fourth and sixth strings are also electrically connected to each other, and the capacitances of the piezoelectric elements of the second and fifth strings are substantially equal. In addition, the sum of the capacitances of the piezoelectric elements of the first and third strings and the sum of the capacitances of the piezoelectric elements of the fourth and sixth strings are approximately equal to the capacitances of the piezoelectric elements of the second and fifth strings. An electric stringed instrument pickup device characterized by being set equally. 2. The pickup device for an electric stringed instrument according to claim 1, wherein the piezoelectric element of each string is integrally molded. 3. The pickup device for an electric stringed instrument according to claim 2, wherein a vibration propagation preventing groove is formed at a boundary between adjacent piezoelectric elements.