JP2000354289A - Loudspeaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in a characteristic due to split resonance at a specific frequency of a cone in a cone type speaker, to make an area occupancy of the cone large and to facilitate its assembling. SOLUTION: A cylindrical voice coil bobbin is fitted to an inner circumference 21j arranged coaxially with an outer circumference 21o of a diaphragm (cone) 21A of nearly conical shape, a voice coil wound on the coil bobbin is inserted to a gap, and a cone edge is fitted fully to the frame. The heights of two points 21p, 21q of the inner circumference symmetrical with respect to a center axis of the cone are set to h2, h3 (<h2) and the height is continuously changed over the entire circumference of the cone to change a half apex angle from a θ2 to a θ3 (θ2<θ3) and to change the length of a generating line over the entire circumference so that the split resonance frequency is distributed. A peak in an output sound pressure frequency characteristic is suppressed and reproduction sound quality can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cone-shaped speaker.

[0002]

2. Description of the Related Art Cone-shaped speakers that emit sound waves directly from a substantially conical diaphragm (cone) are widely used.

For example, as shown in FIG. 3, in a general cone-shaped speaker 10, in the case of an external magnet type, a front side of a ring-shaped magnet 11 (a radiating side of a sound wave is called a front side in this specification). And the back side (the side opposite to the sound wave emission side is referred to as the back side in this specification).
And a plate 12 and a yoke 1 made of a magnetic material such as iron.
3 is attached.

A center pole 14 is integrally formed at the center of the yoke 13 on the front side. Then, a magnetic circuit having a gap (magnetic gap) 15 between the outer peripheral surface of the center pole 14 and the inner peripheral surface of the plate 12 is formed. A center pole 14 is provided on the front side of the plate 12.
The frame 16 is mounted coaxially with the frame.

On the other hand, a substantially conical diaphragm (cone) 21 is disposed in front of the plate 12. The outer peripheral edge 24 of the cone 21 is attached to the outer peripheral edge of the frame 16. In a state where the voice coil 23 wound around the cylindrical voice coil bobbin 22 is inserted into the gap 15, the inner peripheral edge of the cone 21 and the voice coil bobbin 22 are joined and attached.

[0006] The frame 16 and the voice coil bobbin 22 are connected via a damper 25.

[0007]

In a conventional cone-shaped speaker as described above, as shown in FIG.
1 outer circumference 21o (outer diameter do) and voice coil bobbin 2
The cone 21 is concentric with the inner circumference 21i (inner diameter di) of the cone 21 and has a circular shape perpendicular to the center axis of the voice coil bobbin 22.

The height (depth) h1 between the edge portion and the inner peripheral edge of the cone 21 is the same over the entire circumference, and
The half-vertical angle θ1 of 1 and the length of the corresponding generatrix are the same over the entire circumference.

For this reason, there has been a problem that split resonance occurs in the diaphragm at a frequency unique to the speaker, which tends to cause a peak, thereby deteriorating the reproduced sound quality.

In order to eliminate the deterioration of reproduced sound quality due to the split resonance as described above, the shape of the diaphragm is not coaxial with the voice coil. There is a speaker equipped with a so-called oblique cone, which is cut in a diagonal plane.

[0011] In these eccentric cone speakers and oblique cone speakers, the distance to the periphery of the diaphragm is not uniform, so that split resonance at the natural frequency does not occur, and deterioration of reproduced sound quality is eliminated.

However, in an eccentric cone speaker,
When using a non-circular frame, assembly is difficult,
When a circular frame is used, there is a problem that the area occupation ratio of the cone becomes small and efficiency is poor.

Further, in the oblique cone speaker, the voice coil has a non-cylindrical shape, which causes a problem that assembly is difficult.

In view of the above, the present invention prevents deterioration of characteristics due to split resonance at a natural frequency of a generally conical diaphragm, and has a large area occupancy of the diaphragm.
An object of the present invention is to provide a speaker that can be easily assembled.

[0015]

According to a first aspect of the present invention, there is provided a speaker according to the first aspect of the present invention, wherein a cylindrical voice coil bobbin is joined to the voice coil bobbin at an inner peripheral edge and an outer peripheral edge of the voice coil bobbin is provided. And a diaphragm having a shape in which the height of the outer peripheral edge and the joint portion with the voice coil bobbin continuously changes.

In the loudspeaker according to the first aspect of the present invention, the area occupancy of the diaphragm is large, the assembling is easy, and the length of the generatrix of the diaphragm changes over the entire circumference, so that the speaker is divided. Since the resonance frequency is dispersed, the peak of the output sound pressure frequency characteristic is suppressed, and the reproduced sound quality is improved.

Further, the speaker according to the second aspect of the present invention
2. The speaker according to claim 1, wherein an abutting ridge line between the inner peripheral edge of the diaphragm and the voice coil bobbin is substantially the same as an outer shape of a cross section cut at a plane obliquely intersecting a center axis of the voice coil bobbin. It is characterized by being a shape.

In the loudspeaker according to the second aspect of the present invention, the reproduced sound quality is improved due to the dispersion of the resonance frequency, and the shape of the contact ridge line between the diaphragm and the voice coil bobbin is relatively simplified. Dies can be easily manufactured.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a speaker according to the present invention will be described below with reference to FIGS.

FIG. 1 shows the overall configuration of an embodiment of the present invention.
FIG. 2 shows the configuration of the main part. In these figures, the parts corresponding to those in FIGS. 3 and 4 are denoted by the same reference numerals.

In the speaker 10A of the embodiment shown in FIG.
A plate 12 made of a magnetic material such as iron and a yoke 13 are attached to the front side and the back side of the ring-shaped magnet 11, and the outer peripheral surface of the center pole 14 integrated with the center of the front surface of the yoke 13 and the plate A magnetic circuit having a gap 15 between itself and the inner peripheral surface is formed. A frame 16 is mounted on the front surface of the plate 12 coaxially with the center pole 14.

On the other hand, in front of the plate 12, a substantially conical diaphragm (cone) 21A is provided. An edge 24 of the outer peripheral edge of the cone 21A is attached to the outer peripheral edge of the frame 16, and the voice coil 23 wound around the cylindrical voice coil bobbin 22 is inserted into the gap 15 while the cone 21A is inserted. The voice coil bobbin 22 and the inner peripheral edge of 21A are joined and attached.

The frame 16 and the voice coil bobbin 22 are connected via a damper 25.

The configuration described above is the same as the conventional example shown in FIG. 3 except for the shape of the cone 21A.

In this embodiment, as shown in FIG.
The shape of the cone 21A is set such that the height between the outer peripheral edge of the cone 21A, that is, the edge on the edge portion 24 side, and the joint between the cone 21A and the voice coil bobbin 22 is different at each position in the circumferential direction of the cone 21A Differently, they have a continuously changing shape.

That is, as shown in FIG.
A outer peripheral edge 21o (outer diameter do) and inner peripheral edge 21j (inner diameter d
The height of the point 21p where the height with i) is the maximum is defined as h2,
Further, the height of a point 21q where the height of the outer peripheral edge 21o (outer diameter do) and the inner peripheral edge 21j (inner diameter di) of the cone 21A is minimum is defined as h3. In this example, the position of the point q is the point 21
The position of the inner peripheral edge 21j different from P by 180 degrees is set.

The shape of the cone 21A is
By continuously changing the height from h2 to h3 over the entire circumference of 1A, the inner peripheral edge 21j of the cone 21A, which is the contact ridge line with the voice coil bobbin 22, is positioned with respect to the center axis of the voice coil bobbin. And the half apex angle changes from θ2 to θ3 (θ
2 <θ3). Corresponding to the half apex angles θ2 to θ3, the length of the generatrix of the cone 21A also changes over the entire circumference.

For example, in the case of a full-range (all-band) speaker having a diameter of about 10 cm, θ2 = 45 ° and θ3 = 60
Set to about ゜.

According to the set range of the half apex angles θ2 to θ3, the frequency of the split resonance as described above is dispersed, so that the peak of the output sound pressure frequency characteristic is suppressed to, for example, about 3 dB, and the reproduction is performed. The sound quality is improved, and the frequency characteristics and the sound quality can be controlled to some extent.

In this embodiment, the frame 16
Since the cone 21A is disposed over the entire area of the front end of the horn, the efficiency and appearance are good, and the voice coil 23 is wound around the cylindrical voice coil bobbin 22. Easy.

Further, in this embodiment, the cone 21
The height of the outer peripheral edge 21o and the inner peripheral edge 21j of the
Since the half vertex angle is changed from θ2 to θ3 over the entire circumference of 1A by changing from h2 to h3, it is easy to manufacture a cone mold.

The height of the cone 21A (h2 to h2)
The change in h3) and the half apex angle (θ2 to θ3) may or may not be linear with respect to the azimuth in a cylindrical coordinate system having the central axis as the z-axis.

In the above-described embodiment, as shown in FIG. 2, the inner circumference 21j of the cone 21A whose half apex angle is changed from θ2 to θ3 obliquely intersects the central axis of the voice coil bobbin 22. At the same time, it has a shape that is cut along a curved surface perpendicular to the paper surface.

However, the shape of the cone 21A is not limited to such a shape. The height of the cone 21A is h over the entire circumference of the cone in a specific radial direction of the substantially conical cone.
By changing from 2 to h3, a relatively simple shape (not shown), such as a cross section obliquely intersecting the center axis of the voice coil bobbin 22 and cutting the plane perpendicular to the paper surface, can be used. In this case, the production of the cone mold is further facilitated, and the frequency of the split resonance is dispersed and the reproduced sound quality is improved, as in the above-described embodiment.
Effects such as good efficiency and appearance, and easy assembly are achieved.

[0035]

As described above, according to the first aspect of the present invention, the area occupancy of the diaphragm is large, the assembly is easy, and the peak of the output sound pressure frequency characteristic is suppressed.
Playback sound quality is improved.

According to the second aspect of the present invention, the reproduced sound quality is improved and the manufacture of the mold for the diaphragm is facilitated.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of a speaker according to the present invention.

FIG. 2 is a sectional view showing a configuration of a main part of the embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration example of a conventional speaker.

FIG. 4 is a sectional view showing a configuration of a main part of a conventional example.

[Explanation of symbols]

10A speaker, 11 magnet, 12 plate, 13 yoke, 14 center pole, 15 gap (magnetic gap), 16 frame, 21A cone (diaphragm), 21j inner circumference of cone, 22 ... Voice coil bobbin, 23 ... voice coil, 24 ... cone edge,
25: damper, h1 to h3: height (depth) of cone, θ
1 to θ3: Half apex angle of cone

Claims (2)

[Claims] A cylindrical voice coil bobbin, which is joined to the voice coil bobbin at an inner peripheral edge, and an outer peripheral edge is concentric with the voice coil bobbin;
A speaker comprising: a diaphragm having a shape in which a height between the outer peripheral edge and a joint with the voice coil bobbin is continuously changed. 2. The loudspeaker according to claim 1, wherein a ridge line abutting between an inner peripheral edge of said diaphragm and said voice coil bobbin has a cross section cut along a plane obliquely intersecting a center axis of said voice coil bobbin. A speaker having substantially the same shape as an outline.