JPH11275677A - Acoustoelectric transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an acoustic resistor which gives resistance to the air that is passing through by the sound pressure and then to improve the sound quality by forming the acoustic resistor by pressing a wire net, which is made of the woven metallic wires of a required thickness. SOLUTION: An acoustic resistor 21 made of a wire net 22 is used as a directed resistor which gives the resistance to the air passing through an opening 11 formed at a flange part 7a of a frame yoke 7, in order to give the backward sound pressure to a diaphragm 4 of a microphone unit 20. The net 22 is produced in a process, where the vertical and horizontal metal wire members 22a and 22b of comparatively large thickness are woven into a net, and this net is vertically pressed by the necessary pressure to increase the contact areas between both members 22a and 22b and to put them close to each other. Thus, the sound quality is Co improved-without giving the more than the required resistance in the middle and high band frequencies nor substantially generating vibrations of the net 22 itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic-electric conversion device such as a microphone, particularly a dynamic microphone.

[0002]

2. Description of the Related Art A vocal dynamic microphone, which is a kind of microphone as an acoustic-electrical conversion device, is generally used by hand and is configured as a unidirectional microphone. The structure is such that sound pressure from outside is also applied to a part of the rear side of the diaphragm.

As shown in FIG. 5, this conventional unidirectional dynamic microphone has a microphone unit comprising a diaphragm 4 on which a pot-shaped magnetic circuit 2, a voice coil 3 is mounted, an equalizer 5, and an air chamber 6. ing.

In the microphone unit 1, the pot-shaped magnetic circuit 2 is positioned at the center of a bottom surface 7b of a frame yoke 7 having a concave section and a flange 7a formed on the outer periphery, and penetrates in the central axis direction. A column-shaped upper side of the column 8 having the hole 8a is fixed to the N pole (or S pole), and the lower side is fixed to the S pole (or N pole). A ring-shaped plate having a stiffness ring 9 fitted to the inner periphery of the upper side to support the upper side of the magnet 8 and having a circular opening 10a at the mouth of the frame yoke 7 larger than the outer diameter of the magnet 8. 10 is fitted to form a magnetic gap g between itself and the magnet 8.

[0005] A plurality of openings 11 are formed in the flange portion 7a of the frame yoke 7, and a plurality of openings 12 are also formed in the bottom surface 7b. The opening 13 is formed in the stiffness ring 9 so as to communicate with the center through hole 8a, and the hollow portion of the frame yoke 7 is permeable.

A diaphragm 4 to which a voice coil 3 is attached is disposed on the upper side of the frame yoke 7 of the pot-shaped magnetic circuit 2 configured as described above, that is, on the front side. The diaphragm 4 has a diaphragm ring 14 mounted on the outer periphery thereof. The voice coil 3 is connected to the magnet 8 and the magnetic gap g of the plate 10 at the front side peripheral edge of the flange portion 7 a of the frame yoke 7 via the diaphragm ring 14.
It is joined in the state inserted in.

[0007] The equalizer 5 is covered from the front side of the diaphragm 4 to the outer peripheral surface side of the frame yoke 7, and an opening 15 is formed in a front part 5a of the equalizer 5 facing the diaphragm 4, and a peripheral part 5b is formed. The frame yoke 7 is formed to extend rearward from the outer periphery of the flange 7a.

The air chamber 6 is formed in a box shape by an elastic material such as rubber and is fitted and fixed to a rear portion of the frame yoke 7, and communicates with a hollow portion of the frame yoke 7 through an opening 12 in a bottom surface 7b. Have been. Although not shown, a lead wire is connected to the voice coil 3, and the lead wire is connected to an output terminal mounted outside the air chamber 6.

The opening side of the air chamber 6, that is,
A damper resistance paper 16 as an acoustic resistor is adhered to the lower surface of the bottom surface portion 7b of the frame yoke 7.

In the microphone unit configured as described above, when sound pressure due to sound from the front side or the like is applied to the diaphragm 4 through the opening 15 of the equalizer 5, the diaphragm 4 vibrates, and the vibration causes the voice coil 3 to move the magnetic circuit. 2 is reciprocated in the axial direction in the magnetic gap g, and a current proportional to the sound pressure flows through the voice coil 3, and is output through the lead wire to convert voice and the like into an electric signal. The vibration of the diaphragm 4 is caused by the air on the rear surface side of the diaphragm 4 being moved from the through hole 8a of the frame yoke 7 and the magnet 8 to the opening 12 of the bottom portion 7b by the sound pressure.
Through the damper resistance paper 16 which gives resistance to the passing air, and flows into and out of the air chamber 6 repeatedly.

Then, this microphone unit 1
Diaphragm 4 to form a unidirectional microphone
The sound pressure from outside is also applied to a part of the rear side. That is, sound pressure is applied to a portion near the outer periphery, which is a part on the rear surface side of the diaphragm 4, through the opening 11 formed in the flange portion 7 a of the frame yoke 7.

When the air permeability of the opening 11 of the flange portion 7a is good, the diaphragm 4 is easily vibrated, and the microphone becomes a speed type and becomes bidirectional. A directional resistance paper 17 made of non-woven paper or the like as an acoustic resistor that gives resistance to the air passing through 11 is attached to constitute a unidirectional microphone.

A microphone unit 18 of another conventional unidirectional dynamic microphone shown in FIG.
In the above, instead of the directional resistance paper 17 in the microphone unit 1 shown in FIG.
Is used.

That is, the directional resistance foam 19 is made of a foamed resin material and has a required thickness and is formed in a ring shape having the same inner diameter as the outer diameter of the frame yoke 7.
Is inserted into the outer peripheral side of the frame yoke 7 and the flange portion 7a
A sound pressure is applied to the diaphragm 4 in a state where resistance is given to the air passing through the opening 11 by covering the outer peripheral surface side of the foam body 19 with the peripheral surface portion 5b of the equalizer 5 by abutting and sticking to the rear surface side. A unidirectional microphone is constructed in such a manner as to be able to perform the operation.

[0015]

In the microphone unit of the conventional unidirectional dynamic microphone configured as described above, the air passing through an opening for applying an external sound pressure to the rear surface of the diaphragm is not affected by air. Directional resistance paper made of non-woven paper or the like, or directional resistance foam formed of a foamed resin material is used as an acoustic resistance material for providing resistance. Unnecessary resistance results in excessive absorption of sound, making it difficult to achieve a relaxed sound quality.

The present invention has been made in view of the above, and an object of the present invention is to significantly improve the sound quality of an acoustic-electric conversion device, particularly, a unidirectional dynamic microphone.

[0017]

According to the present invention, there is provided an acoustic-to-electrical conversion device for providing a resistance to air passing through an opening disposed opposite to a diaphragm by sound pressure. Is formed by pressing a wire mesh formed by weaving a metal wire having a required thickness.

Further, in this configuration, an acoustic resistor provided in an opening for applying a sound pressure from the outside to a required portion on the rear side of the diaphragm is formed by pressing a wire net formed by weaving a metal wire. is there.

Further, in the above structure, the metal mesh formed by pressing is formed by pressing at least the contact portions of the metal wires with a required contact surface to form an acoustic resistor. is there.

The sound-to-electric converter thus constructed has improved sound quality without giving excessive resistance at middle and high frequency bands and hardly generating vibrations in the wire netting itself.

[0021]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS.

In this embodiment, the acoustic-electric conversion device according to the present invention is configured as a unidirectional dynamic microphone, and FIG. 1 shows a microphone unit.

Since the microphone unit of this embodiment is substantially the same as the microphone unit shown in FIGS. 5 and 6, the corresponding members are denoted by the same reference symbols and redundant description is omitted. .

In FIG. 1, reference numeral 20 indicates the entire microphone unit of this embodiment.
In this microphone unit 20, an acoustic resistor 21 for giving resistance to passing air is formed by a wire mesh.

In a normal wire netting, a metal wire is woven and formed. Therefore, when this wire netting is used as it is as the acoustic resistor 21, when a sound pressure is applied to the wire netting, the metal wire is vibrated by the sound pressure. Although a phenomenon such as noise occurs due to vibration, sound quality is impaired. In this embodiment, a wire mesh is formed by pressing at a required pressure.

That is, in this embodiment, as shown in FIG. 3A, the vertical and horizontal metal wires 22a and 22b constituting the wire mesh 22 are woven by using relatively thick wires, and the wire mesh is placed on the upper and lower surfaces. By pressing at a required pressure from the direction, the contact area between the vertical and horizontal metal wires 22a and 22b is increased and the metal wires 22a and 22b are brought into close contact with each other to form the wire mesh 22 shown in FIG. 3B. Vibration of the vertical and horizontal metal wires 22a and 22b is remarkably reduced, and the press of the metal wires 22a and 22b narrows the mesh interval to pass through the wire mesh 22, as shown in FIG. An acoustic resistor 21 capable of giving a required resistance to air is formed.

In this embodiment, the wire net 22 formed in this manner is used as the acoustic resistor 21 of the microphone unit 20. That is, in the microphone unit 20 according to this embodiment, FIG.
As shown in FIG.
The wire mesh 22 described above is used as the acoustic resistor 21 in place of the damper resistance paper 16 and the directional resistance paper 17 provided in the first embodiment.

In particular, in this embodiment, the directional resistance which gives resistance to the air passing through the opening 11 formed in the flange portion 7a of the frame yoke 7 in order to apply a sound pressure from behind to the diaphragm 4 of the microphone unit 20. Acoustic resistor 21 formed by wire mesh 22 described above as a body
The required directional resistance can be obtained by using
It can be seen that the directional resistance at the mid-band frequency is lower than that of the conventional directional resistance paper made of nonwoven paper or the like indicated by the broken line a as shown by the frequency characteristic shown in FIG. Be improved.

In this experiment, only the directional resistance was examined, but the sound pressure from the front side of the diaphragm 4 of the microphone unit 20 caused the bottom surface 7b of the frame yoke 7 to move.
By using the acoustic resistor 21 formed of the above-described wire mesh 22 as the damper resistor 26 that provides resistance to the air passing through the side opening 12, a sound with a better sound can be reproduced.

Next, a method of assembling the microphone of this embodiment will be described. First, a method of manufacturing the microphone unit 20 will be described.

The voice coil 3 is bonded to the diaphragm 4 to which the diaphragm ring 14 is attached by using an adhesive using a jig (not shown). After the adhesive is dried, the diaphragm 4 is fixed together with the voice coil 3 to the jig. Remove more.

Next, the magnet 8 is placed in the frame yoke 7.
And the stiffness ring 9 are adhered with an adhesive and dried. The frame yoke 7 has a horizontal flange 7
a is formed, and a plurality of openings 1 are formed in the flange portion 7a.
1 are formed, and a plurality of openings 12 are also formed in the bottom surface portion 7b. The magnet 8 has a columnar shape having a through hole 8a in the central axis direction, and has an N pole (or S pole) on the upper side,
The lower side is magnetized to the S-pole (or N-pole), and the stiffness ring 9 has a vertical mounting surface portion 9a formed on the outer periphery thereof, which has substantially the same diameter as the inner periphery of the frame yoke 7, and the inner periphery of which has the magnet 8 And a plurality of openings 13 are formed in the plane portion 9b.

The magnet 8 is placed on the center of the bottom surface 7b of the frame yoke 7 thus formed, and the through hole 8a
Is connected to the center opening 12a of the opening 12 and adhered by an adhesive, and the stiffness ring 9 is fitted to the magnet 8 on the inner peripheral side toward the inside of the opening of the frame yoke 7 and adheres to the mounting surface 9a. It is dried by bonding with an agent. A ring-shaped plate 10 having a circular opening 10a having a diameter larger than the outer diameter of the magnet 8 is fitted and fixed to the inner periphery of the opening of the frame yoke 7 to form a magnetic gap g between the ring 8 and the magnet 8. .

On the other hand, the diaphragm 4 to which the voice coil 3 is adhered is adhered and fixed in the equalizer 5. The equalizer 5 is formed in a substantially lid shape by a front surface portion 5a and a peripheral surface portion 5b. A plurality of openings 15 are formed in the front surface portion 5a, and the diaphragm 4 is provided inside the equalizer 5 via a diaphragm ring 14. The diaphragm ring 14 is fitted and fixed to the inside of the peripheral surface 5b of the equalizer 5 by bonding with an adhesive. After drying the adhesive, equalizer 5
Is fitted to the front side of the frame yoke 7 and the diaphragm 4
The voice coil 3 adhered to the frame y is inserted into the aforementioned magnetic gap g on the frame yoke 7 side, and the peripheral surface 5b of the equalizer 5 is inserted.
Is fixed to the peripheral surface of the flange portion 7a of the frame yoke 7 with an adhesive.

After the adhesive is dried, the lead wire (not shown) of the voice coil 3 is fixed to the output terminal (not shown) by soldering, and the lead wire is fixed with the adhesive. After the adhesive is dried, the magnetic circuit is magnetized.

Thereafter, an acoustic resistor 21 as a damper resistor formed by the above-described wire mesh 22 is adhered to the back surface of the bottom surface 7b where the opening 12 of the frame yoke 7 is formed by an adhesive. As the damper resistor, a conventional damper resistor paper made of nonwoven paper or the like may be used.

The flange portion 7 of the frame yoke 7
b, an acoustic resistor 21 formed between the outer peripheral surface of the frame yoke 7 and the inner peripheral surface of the peripheral surface 5b of the equalizer 5 and formed by the above-described wire mesh 22 as a directional resistor.
Are bonded with an adhesive.

After the damper resistor and the directional resistor are bonded to the frame yoke 7 side, the air chamber 6 formed in a box shape by an elastic material such as rubber is fitted to the back side of the frame yoke 7. Then, it is fixed with an adhesive, and communicates with the inside of the frame yoke 7 through the opening 12 in the bottom surface 7b.
A flange 6 a is formed on the outer peripheral surface side of the air chamber 6.

Through the above manufacturing steps, the microphone unit 20 is completed. This microphone unit 20
The microphone 30 is assembled by incorporating a head grill 31 and a grip 32 into which a wind screen formed of, for example, a foam is inserted. In assembling the microphone 30, the microphone unit 2
The microphone unit 20 is immovably incorporated by sandwiching the flange 6a of the zero air chamber 6 between the head grill 31 and the grip 32. It should be noted that the on-grip with a microphone wire that is normally used
An off switch is attached by a screw or the like, and an output terminal of the microphone unit 20 is fixed to a lead wire led out from above the grip 32 by soldering.

The embodiment of the present invention has been described above.
The present invention is not limited to this embodiment,
Various changes can be made without departing from the spirit of the present invention.

For example, the shape and the like of each member can be arbitrarily changed according to the shape and the like of the entire microphone.
Further, as the metal wire of the wire mesh forming the damper resistor, which is an acoustic resistor, and the directional resistor, a wire having a relatively large tensile strength, such as an iron wire, a stainless steel wire, or an aluminum wire, which can be pressed can be used. Things. Also,
The material for forming the air chamber is not limited to rubber, but may be a synthetic resin material having elasticity.

The present invention is not limited to microphones, but can be applied to various sound-to-electric conversion devices.

[0043]

As described above, according to the sound-electricity conversion device of the present invention, an acoustic resistor which gives resistance to air passing through an opening formed opposite to a diaphragm by sound pressure is formed by weaving a metal wire. Since the formed wire mesh is formed by pressing, the metal wires forming the wire mesh are pressed against each other with a large contact area without giving excessive resistance at middle and high frequency bands, and are pressed into contact with each other. As a result, vibrations are hardly generated, and therefore, sound quality can be improved and sound-to-electric conversion can be performed well.

Further, the acoustic resistor can be formed easily by pressing a wire mesh formed by weaving a metal wire, so that the cost is hardly increased as compared with the conventional one, and the acoustic resistor can be used in the entire apparatus. It is also advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a microphone unit as an example of the device of the present invention.

FIG. 2 is a perspective view of a part of a wire net as an acoustic resistor applied to the microphone unit shown in FIG.

FIG. 3 is an explanatory view for producing the acoustic resistor (wire mesh) shown in FIG. 2;

FIG. 4 is a frequency characteristic diagram of the device of the present invention.

FIG. 5 is a sectional view of a conventional microphone unit.

FIG. 6 is a sectional view of a conventional microphone unit.

[Explanation of symbols]

2 magnetic circuit, 3 voice coil, 4 diaphragm, 5 equalizer, 6 air chamber, 7 frame yoke, 7a flange, 8 magnet, 11
{Aperture, 12} Aperture, 20} Microphone Unit, 21} Acoustic Resistor, 22} Wire Mesh, 22a, 22
b ‥‥ Metal wire

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiichi Yoshida 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Takashi Hamada 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] An acoustic resistor for providing resistance to air passing through an opening disposed opposite to a diaphragm by sound pressure is formed by pressing a metal net formed by weaving a metal wire having a required thickness. An acoustic-to-electrical conversion device characterized by the above-mentioned. 2. The acoustic-electric conversion device according to claim 1, wherein an acoustic resistor provided in an opening for applying an external sound pressure to a required portion on the rear side of the diaphragm is formed by weaving the metal wire. An acoustic-electrical conversion device characterized by being formed by pressing a metal net to be formed. 3. The acoustic-electrical conversion device according to claim 1, wherein the acoustic resistor formed by pressing a wire mesh formed by weaving the metal wire has at least a contact portion between the metal wires. An acoustic-electrical conversion device characterized by being pressed and pressed with a required contact surface.