JP2000333294A - Oval speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oval speaker which can brake the unnecessary 'struggle' of a diaphragm by installing a control means braking the movement occurring in the direction opposite to the driving direction of the oval vibration of a driving system at a prescribed position in the long diameter direction of the oval diaphragm. SOLUTION: Driving coils 18L and 18R are wound with projection parts 17L and 17R formed in positions facing a separate position 7 where 'struggle' occurs on the long diameter of the oval diaphragm 3 at the inclination part of a funnel-like frame 16 as yokes. A circular recess 25 is formed in a separate position, and disk-like small magnets 26L and 26R are inserted into the recess 25 and they are joined to the diaphragm 3. When sound signals are supplied to the driving coils 18L and 18R, the projection parts 17L and 17R being the yokes become S-poles and the S poles of the magnets 26L and 26R laminated on the recess 25 of the diaphragm 3 repel each other, so that the separation position 7 of the diaphragm 3 is made to move upward and the downward deformation of a node part which occurs by the swing of the diaphragm 3 in driving is forced to moved upward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an elliptical speaker, and more particularly, to an elliptical speaker configured to dampen shaking in the major axis direction of an elliptical diaphragm.

[0002]

2. Description of the Related Art Conventionally, elliptical speakers as shown in FIGS. 6A and 6B have been widely used for vehicles and the like.

In FIGS. 6 (A) and 6 (B), reference numeral 1 denotes a plan view and a partial cross-sectional view of an elliptical speaker as a whole. A magnetic circuit of a magnetic type is provided, an elliptical cone-shaped diaphragm 3 has a dome-shaped cap 4 at a center position, and a driving system such as a voice coil including a voice coil bobbin is provided below the cap 4. It is pivotally attached to the diaphragm 3 so as to be able to swing up and down in the magnetic gap of the circuit.

The outer periphery of the elliptical diaphragm 3 is adhered to the frame 2 by the gasket 5 via the elliptical edge 6.

[0005]

The cap 4 provided at the center of the elliptical diaphragm 3 in the elliptical speaker 1 described above.
When the major axis LD of the elliptical diaphragm 3 increases from the center position O, the amplitude of the drive system such as the voice coil provided at the center position does not correspond to the separation position 7 separated from the center position O by a predetermined distance. When the vibration of the diaphragm 3 or the vibration of the divided vibration region occurs, nodes and antinodes are generated in the diaphragm, and nodes and the like are generated at the separated position 7 as shown by the amplitude curve 8 in FIG. Sound was generated and the sound quality was degraded.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an elliptical speaker 1 capable of damping unnecessary "flurring" of a diaphragm 3 by effectively utilizing a conventional magnetic circuit. It is something to offer.

[0007]

A loudspeaker according to the present invention moves at a predetermined position in the major axis direction of an elliptical diaphragm driven by a driving system, in a direction opposite to the driving direction of the elliptical vibration of the driving system. A braking means for braking is provided.

According to the present invention, unnecessary vibration generated in the major axis direction of the elliptical diaphragm can be easily damped by using the magnetic path of the magnetic circuit and the voice coil of the drive system.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An elliptical speaker according to the present invention will be described below in detail with reference to FIGS. FIG. 1 (A) to (C)
FIG. 1 is a plan view showing one embodiment of an elliptical speaker according to the present invention;
FIG. 6 is a side sectional view and an enlarged view of a portion A in FIG. 1 (B), and portions corresponding to FIG. 6 are denoted by the same reference numerals.

1 (A) to 1 (C), the magnetic circuit of the elliptical speaker 1 of the present embodiment is of a magnetic shield type.
On the bottomed portion of the bottomed cylindrical shield case 10, for example, S.P. N and the magnetized first magnet 11 are joined, and the first magnet 11
A high-permeability member composed of a columnar center pole 12 having a T-shaped cross section and a disk-shaped yoke 13 is joined thereon.

A second magnet 14 serving as a main magnet is joined on the disc-shaped yoke 13 with an adhesive or the like. The second magnet 14 is, for example, N.P. It is magnetized with S and is magnetized opposite to the first magnet 11.

A concentric disk-shaped plate 15 made of a metal having high magnetic permeability is joined to the first magnet 14.
The outer peripheral portion of the plate 15 is formed so as to be in contact with the cylindrical inner diameter of the shield case 10.

An elliptical funnel-shaped frame 16 pressed with metal or the like is fixed on the plate 15 with rivets or the like to form a magnetic circuit.

Cylindrical projections 17L and 17R are formed on the inclined portion of the funnel-shaped frame 16 at positions opposite to the separation position 7 on the major axis of the elliptical vibration plate 3 where "flickering" occurs.
The drive coils 18L and 18R are wound around the projections 17L and 17R as yokes, and the input terminals 19L and 19R are disposed near the projections 17L and 17R, and the tinsel wire 20L is formed.
, And 20R and voice coil lead wires 28L and 28R (see FIG. 1A), and are connected to a winding start and a winding end of a voice coil 23 described later.

In order to pivotally connect the diaphragm 3 and the voice coil 23 constituting the drive system to the above-described magnetic circuit, the voice coil 23 is wound around the tip of a cylindrical voice coil bobbin 22, and the inner diameter of the plate 15 and the center pole The voice coil bobbin 22 is inserted into the magnetic gap 21 formed between the outer diameters of the voice coil bobbin 12 through a spacer guide, and the inner diameter of the concentric damper 24 having a wave shape is attached to the upper outer diameter of the voice coil bobbin 22. Is fixed to the bottom of the frame 16 and the voice coil bobbin 22 including the voice coil 23 is pivotally mounted in the magnetic gap 21 so as to be vertically swingable.

Further, a through hole formed in the center of the diaphragm 3 formed in an elliptical cone shape is inserted into and joined to the upper end of the voice coil bobbin 22, and the outer periphery of the diaphragm 3 has an elliptical cross section. The dome-shaped edge 6 is adhered, and the outer periphery of the edge 6 is adhered on the longest and shortest apertures of the frame 16 via the elliptical gasket 5 to form the elliptical speaker 1.

At the separation position 7 caused by "flutter" at the time of driving on the major axis of the elliptical diaphragm 3 of this example, for example, a circular concave portion 25 (for attaching small disc-shaped magnets 26L and 26R). 1 (C) is formed, and small disc-shaped magnets 26L and 26R are inserted into the concave portions 25 so as to be joined to the diaphragm 3. As shown in FIG. 1C, the small magnets 26L and 26R are, for example, N.P. S, and the driving coils 18L and 18
When an acoustic signal is supplied to the voice coil 23 on R, the convex portions 17L and 17R constituting the yoke become S poles,
The lower poles of the small magnets 26L and 26R are configured to have the same polarity as the lower S pole and generate a repulsive force. Of course, the magnets 26L and 26R are selected to be small and lightweight so as not to increase the equivalent mass of the diaphragm 3. Therefore, since the mass of the oscillating portion of the diaphragm 3 is small, it is about 1/100 or less of the drive amplitude of the drive system.

The operation of the elliptical speaker having the above-described configuration will be described. When a positive signal of an acoustic signal is supplied to the input terminal 19L and a negative signal is supplied to the input terminal 17R, the driving coil 18L, the voice coil 23, The drive coils 18R are configured to be connected in series to an acoustic signal source.

Therefore, when an acoustic signal is supplied to the drive coils 18L and 18R, the projections 17L and 17L which become yokes are provided.
R is, for example, an S pole, and the S poles of the magnets 26L and 26R adhered to the recess 25 of the diaphragm 3 repel each other, thereby moving the separated position 7 of the diaphragm 3 upward. 6
As shown in (B), the vibration of the diaphragm 3 at the time of driving can be made to move upward so that the deformation of the node portion to the lower side is increased.

According to the above configuration, the small magnet 2
6L and 26R and two drive coils 18L and 18R wound on the frame are merely added, and there is no difficulty in manufacturing, and the vibration generated in the diaphragm 3 of the elliptical speaker 1 is reduced, and it is clear. It can reproduce a sound.

FIGS. 2A, 2B and 3 show other embodiments of the elliptical speaker and the magnetic circuit of the present invention.

FIGS. 2A and 2B are a plan view and a side sectional view showing another configuration of a magnetic circuit suitable for use in the speaker of the present embodiment. FIGS. It is the top view and side sectional drawing which show further another structure of the magnetic circuit suitable for use.

FIGS. 2A and 2B are FIGS.
A magnetic path using a normal external magnetic type magnetic circuit instead of the magnetic shield type as shown in FIG. 1C is improved to form a braking gap.

Referring to FIGS. 2A and 2B, the yoke 13a
Is a bottom portion 13b made of a substantially rectangular plate and a bottom portion 1 of the yoke.
Left and right yoke portions 13L and 13R extending upward from the left and right ends of 3b, and braking magnetic gap portions 27L and 27 protruding inward above the left and right yoke portions 13L and 13R.
Projection yokes 13c and 13d for forming R are formed. Furthermore, the bottom 13b is located at the center of the bottom 13b.
A columnar center pole 12 is erected integrally with b.

The bottom 13b of the yoke 13a is concentric with the N.C. The S and the magnetized magnet 14 are joined via an adhesive or the like so as to be concentric with the center pole 12, and the plate 15 a is joined onto the magnet 14 so as to form a predetermined magnetic gap 21.

In the plate 15a, a through hole 15b is formed in the center of an elliptical metal plate having a high magnetic permeability, and the center pole 12 is inserted into the through hole 15b to form a magnetic gap 21. A voice coil or the like which constitutes a driving unit of a normal vibration system is swingably pivoted in the gap 21.

The magnetic gaps 27L and 27R for braking are formed between the left and right arms 15L and 15R extending obliquely upward from the left and right ends of the rectangular plate 15a and the protruding yokes 13c and 13d.

The above-described braking magnetic gaps 27L and 27R
As will be described later, a braking coil such as an aluminum plate which is made swingable by the diaphragm 3 is interposed therebetween.

FIGS. 3A and 3B show still another magnetic circuit of the present embodiment. FIG. 2 (A), FIG. 2 (B)
The same reference numerals are given to portions corresponding to the magnetic circuit shown in FIG.

In the configuration shown in FIGS. 3A and 3B, the yoke 13 provided below the magnet 14 is formed as a disk-shaped portion similar to that described with reference to FIG. The column-shaped center pole 12 is erected at the center of the part,
A bottomed cylindrical yoke / cover 3 is provided on the lower surface of the disk-shaped portion.
0 is arranged, and the plate 15a is formed not in a square shape but in a disk shape.

At the left and right ends of the yoke and cover 30, cover arms 31L are formed by bending the upper end of the cylindrical yoke and cover 30 right and left at right angles, and further bending the upper end extended upward to the inside to form a protruding yoke. And a braking coil formed of an aluminum plate or the like as a braking member between the protruding yokes of the cover arms 31L and 31R and the braking magnetic gaps 27L and 27R formed between the left and right arms 15L and 15R of the plate 15a. Inserted.

FIGS. 4A and 4B show a plan view of a braking coil 33 as a braking member and cross-sectional views taken along lines AA 'and BB', respectively. Width 5
An aluminum plate having a thickness of about 0.3 mm and a thickness of about 0.3 mm is formed in a strip shape, and a rectangular punching portion 34 is formed near the upper side of the strip-shaped aluminum plate to form a wonton coil. A wide portion 33a formed below the punched portion 34 of the braking coil 33 indicates a portion to be inserted into the braking magnetic gaps 27L and 27R. In the case of FIG. 4B, a glue margin 33b is formed on the upper side of the strip portion along the inclination of the diaphragm 3. Such a braking coil 33 is connected to the magnetic gap 2 for braking.
7L and if brought into swing up and down in the 27R FIG. 4 (A), the braking short current I _S, such as shown in FIG. 4 (B) coil 33
Can flow inside.

FIG. 5 is a side sectional view of a speaker using the magnetic circuit described with reference to FIGS. 2A and 2B. Parts corresponding to the speaker described in detail in FIG. And a duplicate description is omitted.

In FIG. 5, the frame 16 is mounted on the left and right yokes 13L and 13R, and the "flutter" caused by the swing on the major axis of the elliptical diaphragm 3 facing the braking magnetic gaps 27L and 27R of the magnetic circuit. The braking coil 33 is adhered to the node where "" occurs, and the wide portion 33a of the braking coil 33 is pivotally attached to the braking magnetic gap portions 27L and 27R so as to be vertically swingable.

When an acoustic signal is supplied to the input terminal 19 by the above-described speaker, the diaphragm 3 is driven vertically by the acoustic signal supplied to the voice coil 23 via the tinsel wire 20. At this time, the separation position 7 in the major axis direction of the elliptical diaphragm 3
Is pressed upward at the center position of the elliptical diaphragm 3, and is pushed down, for example, by the vibration of the diaphragm 3. Therefore, the wide portion 33a of the braking coil 33 is provided with a fuco current (eddy current) according to the framing right hand rule in order to cut off the magnetic flux from the north pole to the south pole in the braking magnetic gaps 27L and 27R. Occurs.
Since the force due to the electromagnetic induction serves as a force for pushing up the diaphragm 3 and acts as a force for braking or canceling the force for pushing down the diaphragm 3, the operation at the inflection point of the node or the diaphragm is reversed. It is possible to make correction so as to push back.

In FIG. 5, one ordinary second magnet 1 is used.
4 has been described, but as described with reference to FIG. 1B, the lower side of the yoke 13 and the bottom 13 of the yoke 13a.
By adding the first magnet 11 for cancellation between B, it is possible to make it a magnetic-shield type. In this case, the magnetic flux density of the braking magnetic gaps 27L and 27R depends on the magnetic flux of the canceling first magnet 11, so that
Although it is about 00 Gauss, such a configuration can be sufficiently used to drive the braking coil 33.

[0037]

According to the loudspeaker of the present invention, in a loudspeaker having a narrow diaphragm which is long in a long diameter direction like an elliptical loudspeaker, a vibration in a long diameter direction different from the movement of the center portion of the diaphragm of the voice coil portion. Unnecessary movement of the plate can be braked or canceled by a simple magnetic circuit, and clear sound can be reproduced, thereby improving sound quality. Also, the braking means effectively utilizes the conventional magnetic circuit to form a braking magnetic gap,
This has the effect of obtaining a speaker that is simple and easy to assemble.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of a speaker of the present invention.

FIG. 2 is a plan view and a side sectional view of a magnetic circuit of the present invention.

FIG. 3 is a plan and side sectional view of another magnetic circuit of the present invention.

FIG. 4 is an explanatory diagram of a braking coil according to the present invention.

FIG. 5 is a side sectional view of the speaker of the present invention.

FIG. 6 is a plan view of a conventional elliptical speaker.

[Explanation of symbols]

1 ‥‥ elliptical speaker, 3 ‥‥ diaphragm, 17L, 17R
{Protrusion, 18L, 18R} Drive coil, 26L, 2
6R ‥‥ magnet, 27L, 27R 磁 気 magnetic gap for braking, 33 ‥‥ braking coil

Continued on the front page (72) Inventor Kenji Tokushige 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5D012 BA06 BB03 BB04 BB05 BD03

Claims (3)

[Claims] A control means is provided at a predetermined position in a major axis direction of an elliptical diaphragm driven by a drive system for braking a movement of the drive system in a direction opposite to a drive direction of the elliptical vibration. An elliptical speaker comprising: 2. The elliptical speaker according to claim 1, wherein the braking means is fixed to a frame, and includes a coil connected in series with a voice coil of the driving system and a magnet fixed to the elliptical diaphragm. . 3. An elliptical speaker according to claim 1, wherein said braking means comprises a magnetic gap formed in a plate of a magnetic circuit and a braking coil fixed to said elliptical diaphragm.