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DESCRIPTION JP2010010791

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DESCRIPTION JP2010010791
To provide a speaker magnetic circuit having a substantially uniform magnetic flux density in the
amplitude region of a voice coil with a simple configuration, to provide a speaker with highquality sound characteristics, and to perform simple processing without complicated processing.
Manufacturing the above-mentioned speaker magnetic circuit. A speaker magnetic circuit
includes a magnet and a pole piece arranged as a magnetic pole, and the pole piece has a first
plate of a first outer diameter whose cross-sectional shape is formed in a rectangular shape. And
a second plate 5 of a second outer diameter larger than the first outer diameter concentrically
disposed on the first plate and having a rectangular cross-sectional shape, In the laminate 5, a
convex portion is formed on the outer peripheral side surface portion due to the difference in
outer diameter between the first plate and the second plate. [Selected figure] Figure 1
MAGNETIC CIRCUIT FOR SPEAKER, SPEAKER DEVICE, AND METHOD FOR MANUFACTURING
MAGNETIC CIRCUIT FOR SPEAKER
[0001]
The present invention relates to a speaker magnetic circuit, a speaker device, and a method of
manufacturing a speaker magnetic circuit.
[0002]
In a typical electrodynamic speaker, a voice coil is disposed in a magnetic gap formed in a
magnetic circuit, and when a signal current flows through the voice coil, a diaphragm joined to
the voice coil vibrates. Do.
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1
However, in a general loudspeaker, the amplitude of the voice coil has nonlinearity with respect
to the level of the signal current, and distortion may occur in the sound wave emitted from the
diaphragm. That is, when the driving force with respect to the amplitude of the vibration system
has nonlinearity, the sound radiated from the speaker may be distorted. One of the causes is that
when the voice coil is displaced along the axial direction in the magnetic gap of the magnetic
circuit, the magnetic flux density acting on the voice coil is not uniform. In detail, in a general
magnetic circuit, the magnetic flux density in the magnetic gap is a maximum value at the
reference position of the voice coil, and a lower value at a position displaced upward or
downward from the reference position. It is patterned. For this reason, in order for the speaker to
emit high-quality sound waves, the magnetic circuit needs to have a uniform magnetic flux
density formed in the voice coil amplitude region in the magnetic gap.
[0003]
A speaker magnetic circuit is known in which a magnetic gap is formed between an upper plate
disposed on a ring-shaped magnet and a pole piece, and the side surface of the upper plate facing
the pole piece is uneven. (See, for example, Patent Document 1). In this speaker magnetic circuit,
the unevenness of the upper plate makes the magnetic flux density in the magnetic gap uniform.
[0004]
Further, in the magnetic circuit described in Patent Document 2, a first plate in which the inner
peripheral portion is offset downward in the axial direction by press work, and the first plate are
disposed on the first plate, and the inner peripheral portion is in the axial direction The laminate
with the second plate, which is unevenly pressed upward by a press process, is disposed on the
annular magnet to achieve uniform magnetic flux density in the magnetic gap.
[0005]
Japanese Utility Model Application Publication No. 1-65592 Patent No. 3946047
[0006]
However, in the magnetic circuit described in Patent Document 1, when manufacturing the upper
plate, it is necessary to perform the concavo-convex processing such as cutting or undercutting
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on the side surface of the upper plate.
Further, in the magnetic circuit described in Patent Document 2, it is necessary to produce the
first and second plates of the above-described special shape by press processing.
Moreover, when producing the plate of the said special shape by press processing, there exist
problems, such as the comparatively low dimensional accuracy and comparatively high
processing cost.
[0007]
The present invention takes an example of the problem to address such a problem. That is, by
providing a speaker magnetic circuit with a substantially uniform magnetic flux density in the
amplitude region of the voice coil with a simple configuration, providing a speaker with highquality sound characteristics, and without performing complicated processing. It is an object of
the present invention to produce the above speaker magnetic circuit.
[0008]
In order to achieve such an object, the present invention at least comprises the configurations
according to the following independent claims.
[0009]
A speaker magnetic circuit according to the present invention includes a magnet and a pole piece
arranged as a magnetic pole, and the pole piece is a first plate of a first outer diameter whose
cross-sectional shape is formed in a rectangular shape. A laminate of a second plate of a second
outer diameter larger than the first outer diameter, the second plate being concentrically
disposed on the first plate and having a rectangular cross-sectional shape, The laminated body is
characterized in that a convex portion is formed on an outer peripheral side surface portion by a
difference between outer diameters of the first plate and the second plate.
[0010]
Further, a speaker magnetic circuit according to the present invention includes a magnet and an
annular top plate disposed as a magnetic pole, and the top plate has a first cross-sectional shape
formed into a rectangular shape and a first inner diameter of the first inner diameter. And a
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second plate of a second inner diameter smaller than the first inner diameter concentrically
disposed on the first plate and having a rectangular cross-sectional shape, The laminated body is
characterized in that a convex portion is formed on an inner peripheral side surface portion by a
difference in inner diameter between the first plate and the second plate.
[0011]
A speaker according to the present invention includes the above speaker magnetic circuit, a
frame, and a vibrator supported by the frame, and the vibrator is supported by the diaphragm
and the diaphragm. And a voice coil.
[0012]
An electronic device according to the present invention includes the above-described speaker.
[0013]
Further, a method of manufacturing a speaker magnetic circuit according to the present
invention is a method of manufacturing a speaker magnetic circuit including a magnet and a
laminate of a plurality of plates disposed as magnetic poles of the magnet, the cross-sectional
shape of which is rectangular. A first plate of a first outer diameter formed into a shape, and a
second plate of a second outer diameter larger than the first outer diameter of a cross-sectional
shape formed into a rectangular shape are laminated A jig having an inner peripheral shape
corresponding to the outer shape of the stack of the first plate and the second plate sandwiches
the side surface of the stack and the first plate and the second A second step of concentrically
arranging the first plate and the second plate and forming a convex portion on the outer
peripheral side surface portion of the laminate by the difference in outer diameter between the
first plate and the second plate. I assume.
[0014]
Further, a method of manufacturing a speaker magnetic circuit according to the present
invention is a method of manufacturing a speaker magnetic circuit including a magnet and a
laminate of a plurality of annular plates disposed as magnetic poles of the magnet, A first plate of
a first inner diameter formed into a rectangular shape, and a second plate of a second inner
diameter smaller than the first inner diameter, a cross-sectional shape of which is formed into a
rectangular shape And an outer peripheral jig corresponding to the inner diameter of the
laminate of the first plate and the second plate presses the inner surface of the laminate to form
the first plate and the second plate. And a second step of concentrically arranging the plates and
forming a convex portion on the inner peripheral side surface portion of the laminate by the
difference in the inner diameter of the first plate and the second plate. Do.
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[0015]
A speaker magnetic circuit according to the present invention includes a magnet and a pole piece
arranged as a magnetic pole, and the pole piece has a first plate of a first outer diameter whose
cross-sectional shape is formed in a rectangular shape, A laminate with a second plate of a
second outer diameter larger than the first outer diameter concentrically disposed on the first
plate and having a rectangular cross-sectional shape; A convex portion is formed on an outer
peripheral side surface portion by a difference in outer diameter between the first plate and the
second plate.
[0016]
In the speaker magnetic circuit, the pole piece is formed of a laminate of a first plate and a
second plate having different outer diameters.
The voice coil is axially and vibratably disposed in the vicinity of the radially outer periphery of
the laminate.
The laminate is formed in such a shape that the side facing the voice coil has a substantially
uniform magnetic flux density in the amplitude region of the voice coil.
Specifically, in the laminated body, a radial cross-sectional shape convex portion is formed on the
outer peripheral side surface portion by the difference in outer diameter between the first plate
and the second plate.
Therefore, it is possible to provide a magnetic circuit in which the magnetic flux density is
substantially uniform in the amplitude region of the voice coil.
[0017]
Further, a speaker magnetic circuit according to the present invention has a magnet and an
annular top plate arranged as a magnetic pole, and the top plate has a first inner diameter of a
first inner diameter whose cross-sectional shape is formed in a rectangular shape. A laminate
comprising a plate and a second plate concentrically disposed on the first plate and having a
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second inner diameter smaller than the first inner diameter formed in a rectangular shape in
cross section, and a laminate Is characterized in that a convex portion is formed on the inner
peripheral side surface portion by the difference in the inner diameter of the first plate and the
second plate.
[0018]
In the above speaker magnetic circuit, the top plate is formed of a laminate of a first plate and a
second plate having different inner diameters.
The voice coil is axially and vibratably disposed in the vicinity of the radially inner side of the
laminate.
The laminate is formed in such a shape that the side facing the voice coil has a substantially
uniform magnetic flux density in the amplitude region of the voice coil.
Specifically, in the laminated body, a radial cross-sectional shape convex portion is formed on the
inner peripheral side surface portion by the difference in the inner diameters of the first plate
and the second plate.
Therefore, it is possible to provide a magnetic circuit in which the magnetic flux density is
substantially uniform in the amplitude region of the voice coil.
[0019]
A speaker according to the present invention is characterized by including a magnetic circuit
including the above-described laminate, a frame, and a vibrator supported by the frame.
In detail, in the laminated body, the shape of the side surface facing the voice coil is formed such
that the magnetic flux density is substantially uniform in the amplitude region of the voice coil of
the vibrating body.
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[0020]
Since the speaker is formed such that the magnetic circuit has a substantially uniform magnetic
flux density in the amplitude region of the voice coil, the amplitude of the voice coil is
substantially linear with respect to the level of the signal current input to the voice coil. Have sex.
The speaker can emit sound waves with relatively little distortion from the diaphragm. That is, it
is possible to provide a speaker device with high-quality sound characteristics.
[0021]
Further, a method of manufacturing a speaker magnetic circuit according to the present
invention is a method of manufacturing a speaker magnetic circuit including a magnet and a
laminate of a plurality of plates disposed as magnetic poles of the magnet, the cross-sectional
shape of which is rectangular. A first plate having a first outer diameter formed into a shape and
a second plate having a second outer diameter larger than the first outer diameter having a
rectangular cross-sectional shape are stacked And a jig having an inner peripheral shape
corresponding to the outer shape of the laminate of the first plate and the second plate
sandwiching the side surface of the laminate to form the first plate and the second plate. And a
second step of concentrically arranging and forming a convex portion on an outer peripheral side
surface portion of the laminate by a difference in outer diameter between the first plate and the
second plate.
[0022]
Further, a method of manufacturing a speaker magnetic circuit according to the present
invention is a method of manufacturing a speaker magnetic circuit including a magnet and a
laminate of a plurality of annular plates disposed as magnetic poles of the magnet, A first plate of
a first inner diameter formed into a rectangular shape and a second plate of a second inner
diameter smaller than the first inner diameter formed into a rectangular shape in cross section A
jig having an outer peripheral shape corresponding to the inner diameter of the step and the
laminate of the first plate and the second plate presses the inner surface of the laminate so that
the first plate and the second plate are concentric. And a second step of forming a convex portion
on the inner peripheral side surface portion of the laminate by the difference of the inner
diameters of the first plate and the second plate.
[0023]
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In the method of manufacturing the speaker magnetic circuit, the first plate and the second plate
are stacked in a first step, and in the second step, the first plate and the second plate are
concentrically arranged by a jig. By arranging in a shape (centering), the laminate can be easily
manufactured.
By assembling the laminate (used as a magnetic pole), a magnet or the like, the speaker magnetic
circuit according to the present invention can be easily manufactured without performing
complicated processing.
[0024]
The speaker magnetic circuit according to the present invention and the speaker provided with
the magnetic circuit are, for example, audio devices such as headphones, speakers for vehicles,
speakers for mobile phones, speakers for personal computers, audio devices, speakers for
television broadcast receivers, etc. The present invention can be applied to electronic devices
such as in-vehicle devices, mobile phones, personal computers, television broadcast receivers,
and monitors.
Hereinafter, a method of manufacturing a speaker magnetic circuit, a speaker device, and a
speaker magnetic circuit according to an embodiment of the present invention will be described
with reference to the drawings.
[0025]
First Embodiment FIG. 1 is a view for explaining a speaker 1 adopting a speaker magnetic circuit
2 according to a first embodiment of the present invention. Specifically, FIG. 1 (A) is a crosssectional view of the speaker 1, and FIG. 1 (B) is a cross-sectional view of the speaker magnetic
circuit 2 shown in FIG. 1 (A). In FIG. 1 (B), the right half of the axial symmetry of the speaker
magnetic circuit 2 is omitted. FIG. 2A is a top view of a specific example of the speaker magnetic
circuit. FIG. 2B is a top view of another specific example of the speaker magnetic circuit.
[0026]
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As shown in FIG. 2A, the speaker 1 and the speaker magnetic circuit 2 according to the present
embodiment are formed in a circular shape when viewed from above. The speaker according to
the present invention is not limited to this form, and may be formed in a prescribed shape such
as a rectangular shape, an elliptical shape, a track shape, or a polygonal shape as shown in FIG. 2
(B), for example. .
[0027]
As shown in FIG. 1, the speaker 1 according to the first embodiment of the present invention
includes a magnetic circuit 2, a vibrating body 3, and a frame 4. The magnetic circuit 2 has a
magnet 21, a pole piece 22, and a yoke 23. The vibrating body 3 has a voice coil 31, a voice coil
bobbin 32, a diaphragm 33, an edge 34, a cap 35, and a damper 36. The pole piece 22
corresponds to an embodiment of the laminate according to the present invention. The magnet
21 corresponds to an embodiment of the magnet according to the present invention. The voice
coil 31 corresponds to an embodiment of a voice coil according to the present invention.
Hereinafter, each component of the speaker 1 will be described in detail.
[0028]
[Magnetic Circuit 2] The magnetic circuit 2 may be an inner magnet type magnetic circuit or an
outer magnet type magnetic circuit. The magnetic circuit 2 according to the present embodiment
is an internal magnet type magnetic circuit. The magnet 21 is formed in a flat plate shape having
a rectangular cross section. The magnet 21 is magnetized in the axial direction (the acoustic
radiation direction SD). As the magnet 21, permanent magnets, such as a neodymium system, a
samarium cobalt system, an alnico system, a ferrite system, a rare earth system magnet, etc. are
employable, for example.
[0029]
The pole piece 22 according to the present embodiment is formed of a ferromagnetic metal
material (magnetic material), and is disposed on the magnet 21 as a magnetic pole. The pole
piece 22 according to the present embodiment is constituted by a laminate 5 of a plurality of
metal plates. The laminated body 5 has a shape (concave / convex portion) such that the
magnetic flux density is substantially uniform in the vibration region of the voice coil 31 on the
side surface facing the voice coil 31, specifically the outer peripheral portion of the pole piece
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22. . The step and the width of the unevenness are appropriately defined so that the magnetic
flux density is substantially uniform in the vibration area of the voice coil 31.
[0030]
Specifically, the pole piece 22 (laminated body 5) has a first plate 221, a second plate 222, a
third plate 223, and a fourth plate 224. The third plate 223 corresponds to an embodiment of
the first plate of the first outer diameter according to the present invention. The fourth plate 224
corresponds to an embodiment of the second plate of the second outer diameter according to the
present invention. The first plate 221 corresponds to an embodiment of the third plate according
to the present invention.
[0031]
As shown in FIG. 1 (A) and FIG. 1 (B), the first plate 221 to the fourth plate 224 are formed in a
rectangular shape (flat plate shape) in cross-sectional shape (for example, radial direction crosssectional shape) There is. The first plate 221 is disposed on the magnet 21, the second plate 222
is disposed on the first plate 221, the third plate 223 is disposed on the second plate 222, and
the third plate 223 is disposed. A fourth plate 224 is disposed on top. Further, each of the first
plate 221 to the fourth plate 224 is concentrically stacked so that the central axes become the
same.
[0032]
As shown in FIG. 1A, in the present embodiment, the outer diameter P221 of the first plate 221
and the outer diameter P224 of the fourth plate 224 are substantially the same, and the outer
diameter of the second plate 222 P222 and the outer diameter P223 of the third plate 223 are
substantially the same. Further, the outer diameter P224 of the fourth plate 224 is larger than
the outer diameter P223 of the third plate. The outer diameter P222 of the second plate and the
outer diameter P223 of the third plate are larger than the outer diameter P21 of the magnet 21.
The outer diameter P221 of the first plate and the outer diameter P224 of the fourth plate are
larger than the outer diameter P21 of the magnet 21. In the present embodiment, the thickness
D221 of the first plate 221, the thickness D222 of the second plate 222, the thickness D223 of
the third plate 223, and the thickness D224 of the fourth plate 224 are substantially the same.
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[0033]
As shown in FIGS. 1A and 1B, in the laminate 5, at least two plates having the same shape as the
third plate 223 are stacked. Specifically, a second plate 222 having the same shape as the third
plate 223 is stacked. Further, as shown in FIG. 1A and FIG. 1B, the laminate 5 has a first plate
221 having the same shape as the fourth plate 224. The third plate 223 and the second plate
222 are disposed between the fourth plate 224 and the first plate 221.
[0034]
Further, in the laminated body 5, a convex portion is formed on the outer peripheral side surface
portion by the difference in outer diameter between the third plate 223 and the fourth plate 224.
Further, in the laminated body 5, a convex portion is formed on the outer peripheral side surface
portion due to the difference in outer diameter between the first plate 221 and the second plate
222. In the laminate 5, the uneven portion is formed on the outer peripheral side surface portion
due to the difference in outer diameter with the first plate 221 to the fourth plate 224.
[0035]
FIG. 3 is a cross-sectional view of a laminate according to an embodiment of the present
invention. The stacked body 5 is formed by stacking a plurality of ferromagnetic plates made of
metal. For example, as shown in FIG. 3, the metal plate constituting the laminate 5 may have a
surface layer SF provided with a metal layer (coating layer) subjected to surface processing such
as plating. The plates of the laminated body 5, for example, all or at least one of the first plate
221 to the fourth plate 224 have an inner layer NF and its surface layer ST. The laminate 5
shown in FIG. 3 is plated on the entire surface (front surface, back surface, side surface), and a
surface layer (covering layer) (SF) of a predetermined metal is formed. The inner layer NF of each
plate is made of, for example, a metal material such as iron or a magnetic material. The surface
layer SF of each plate is formed of, for example, a metal material different from the inner layer
NF, such as zinc, copper, or a magnetic material. Further, in the laminate 5 shown in FIG. 3, the
plates are stacked in a state in which the surface layer SF of the plate is bonded to all or part of
the surface layer of the adjacent plate. The lower plate 221 of the laminate 5 is disposed on the
magnet 21 via the surface layer SF.
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[0036]
In the laminated body 5 shown in FIG. 3, since a metal layer (coating layer) formed by surface
processing such as plating is formed on the surface layer SF of the plate, a relatively large heat
radiation effect can be obtained. . For example, when the speaker is driven, the metal layer
(coating layer) of the plate can release Joule heat by the voice coil 31 or the like by radiant heat,
and can suppress an increase in temperature in the magnetic circuit. In addition, since the metal
layer (covering layer) formed on the surface layer SF of each plate releases heat as radiant heat, it
is possible to prevent the magnet from becoming hot. In addition, generation of current
distortion (harmonic distortion) can be suppressed by generating an induced current in the metal
layer (coating layer) of the plate when driving the speaker, and the speaker can obtain good
acoustic characteristics. .
[0037]
As shown in FIGS. 1A and 1B, the yoke 23 is provided below the magnet 21 and is formed of, for
example, a material (magnetic material) such as iron, metal, or alloy. . That is, the magnet 21 is
provided on the yoke 23. Yoke 23 has a bottom surface portion 231 having a flat cross section, a
bent portion connecting outer peripheral side portion 232 having a shape extending axially
upward from the outer peripheral portion of bottom surface portion 231, and outer peripheral
side portion 232 and bottom surface portion 231. And H.233. The bottom portion 231, the outer
peripheral side portion 232, and the bent portion 233 are integrally formed. A top plate 24 is
provided at the upper end of the yoke 23. The top plate 24 is formed of a ferromagnetic metallic
material such as iron. The top plate 24 is formed in an annular shape, the inner diameter P 241
is larger than the outer diameter P 21 of the magnet 21, the outer diameter P 242 is
substantially the same as the outer diameter P 23 of the yoke 23, and the thickness D 24 is the
thickness of the laminate 5. It is formed to be substantially the same. In the said embodiment,
although the thickness of each plate is substantially the same, it is not restricted to this form. For
example, the thickness of each plate may be appropriately set so that the magnetic flux density in
the magnetic gap is substantially uniform.
[0038]
As shown in FIGS. 1 (A) and 1 (B), the magnetic circuit 2 is between the top plate 24 (one
magnetic pole) of the yoke 23 and the laminate 22 (the other magnetic pole) of the pole piece 22.
A cylindrical magnetic gap MG is formed in the axial direction. In detail, in the magnetic flux
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circuit 2, a first magnetic gap MG 1, a second magnetic gap MG 2, and a third magnetic gap MG
3 are formed between the yoke (top plate 24) and the pole piece 22. The first magnetic gap MG1
is defined between the top plate 24 and the first plate 221 at a first distance in the radial
direction. The second magnetic gap MG2 is defined at a second distance in the radial direction
between the top plate 24 and the second plate 222 (third plate 223). The third magnetic gap
MG3 is defined at a third distance in the radial direction between the top plate 24 and the fourth
plate 224. The first distance of the first magnetic gap MG1 is defined to be the same as the third
distance of the third magnetic gap MG3. The third distance of the third magnetic gap MG3 is
defined to be smaller than the second distance of the second magnetic gap MG2. Further, the
first distance of the first magnetic gap MG1 is defined to be smaller than the second distance of
the second magnetic gap MG2.
[0039]
As shown in FIG. 1B, in the laminate 5 according to the present embodiment, the length PS1
along the radial direction of the step between the third plate 223 and the fourth plate 224 is the
third magnetic. This is smaller than the third distance along the radial direction of the gap MG3.
The step between the third plate 223 and the fourth plate 224 is formed relatively small as
described above. In the present embodiment, the length along the radial direction of the step
between the first plate 221 and the second plate 222 is the same as the length PS1, and is along
the radial direction of the third magnetic gap MG3. Less than the third distance.
[0040]
The step between the third plate 223 and the fourth plate 224 is between the first magnetic gap
MG1, the second magnetic gap MG2 and the third magnetic gap MG3 and in the amplitude
region T31 of the voice coil 31. The magnetic flux density is formed to be substantially uniform.
Similarly, the step between the first plate 221 and the second plate 222 is between the first
magnetic gap MG1, the second magnetic gap MG2, the third magnetic gap MG3, and the
amplitude region of the voice coil 31. At T31, the magnetic flux density is formed to be
substantially uniform.
[0041]
Further, as shown in FIG. 1B, when the voice coil 31 is at rest, the upper end thereof is positioned
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at a position H31 which is substantially the same as or lower than the total height H5 of the
plurality of plates of the laminate 5 Is located in Further, the total height H5 of the plurality of
plates of the laminate 5 is defined to be substantially the same as the height H24 of the top plate
24. In addition, the top plate 24 is defined so that the lower surface thereof is located on a plane
substantially the same as or higher than the lower surface of the laminate 5.
[0042]
Vibrating Body 3 The vibrating body 3 is supported by the frame 4 as shown in FIGS. 1 (A) and 1
(B). As described above, the vibrating body 3 includes the voice coil 31, the voice coil bobbin
(voice coil support portion) 32, the diaphragm (first vibrating portion) 33, the edge (second
vibrating portion) 34, and the cap (third). A vibrating portion 35 and a damper 36 are provided.
[0043]
The voice coil 31 is loosely fitted in the magnetic gap MG of the magnetic circuit 2 so as to be
able to vibrate in the axial direction. Also, the voice coil 31 is supported by the diaphragm 33
directly or via the voice coil bobbin 32, for example. The voice coil bobbin 32 is formed in a
cylindrical shape, the voice coil 31 is provided near the lower end, the inner peripheral portion of
the diaphragm 33 is joined with an adhesive or the like near the upper end, and the damper is
near the upper end The inner circumferential portion 36 is joined by an adhesive or the like. The
diaphragm 33 is formed in, for example, a prescribed shape such as a dome shape, a cone shape,
a flat plate shape, or a circular shape. The diaphragm 33 which concerns on this embodiment is
formed in cone shape, as FIG. 1 (A) shows. The outer peripheral end of the diaphragm 33 is
vibratably joined near the upper end of the frame 4 via an edge 34. The diaphragm 33 may be
integrally formed with the edge 34 or may be formed of a separate member from the edge 34.
The edge 34 is formed in an annular shape, the inner peripheral portion is joined to the upper
end portion of the diaphragm 33, and the outer peripheral portion is joined to the frame 4. The
cap 35 is disposed in the vicinity of the central portion of the diaphragm 33 so as to cover the
front of the voice coil bobbin 32. The inner periphery of the damper 36 is joined to the voice coil
bobbin 32, and the outer periphery is joined to the frame 4, and the voice coil is supported so as
to be able to vibrate in the axial direction.
[0044]
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The frame 4 supports the vibrating body 3 and the magnetic circuit 2 as shown in FIG. 1 (A). The
frame 4 is formed, for example, in a substantially cone shape, the magnetic circuit is joined to the
lower flat portion, the diaphragm 33 is vibratably joined to the upper flat portion via the edge
34, and the damper 36 is joined to the middle flat portion. It is joined.
[0045]
FIG. 4A is a view for explaining the magnetic flux density in the magnetic gap of the speaker
magnetic circuit according to the embodiment of the present invention. FIG. 4B is a diagram for
explaining the magnetic flux density in the magnetic gap of the magnetic circuit according to the
comparative example. In the graphs shown in FIGS. 4A and 4B, the vertical axis represents the
magnetic flux density (B: unit T (Tesla)), and the horizontal axis represents the moving direction
(height) of the voice coil in the magnetic gap. Indicates the distance (L: unit (mm)) along the
direction. The range between the dotted lines on the horizontal axis (about 1.8 mm to 2.3 mm)
corresponds to the position of the voice coil at rest.
[0046]
As shown in FIG. 4B, in the magnetic circuit provided with the general pole piece according to the
comparative example, the magnetic flux density of the magnetic gap is near the center of the gap
(about 1.8 mm to 2.3 mm), The magnitude is not constant (non-uniform), and a local maximum of
magnetic flux density is formed at an intermediate position. For this reason, even for a relatively
small amplitude, the driving force generated in the voice coil changes non-linearly (specifically,
the linearity is relatively low). On the other hand, in the speaker magnetic circuit according to
one embodiment of the present invention, the pole piece is formed of a laminate of flat metal
members having different diameters, and as shown in FIG. A substantially uniform magnetic flux
density is obtained over the voice coil vibration region). Therefore, even when the speaker is
driven, the driving force generated in the voice coil linearly changes (specifically, the linearity is
relatively high). That is, the speaker 1 has relatively small distortion and high acoustic quality.
[0047]
FIG. 5 is a flowchart for explaining the method of manufacturing the speaker magnetic circuit 2
according to the embodiment of the present invention. FIG. 6A is a top view of the laminate 5 of
the speaker magnetic circuit 2 and the jig G, and FIG. 6B is a laminate 5 of the speaker magnetic
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circuit 2 shown in FIG. 6A. And a cross-sectional view of the jig G.
[0048]
A method of manufacturing the speaker magnetic circuit 2 will be described with reference to
FIGS. 5, 6A, and 6B. In step S1, as shown in FIG. 6 (A) and FIG. 6 (B), a plurality of plates (two
types of plates) are arranged in an overlapping manner. Specifically, the same as the first plate
221 having a rectangular cross section and the second plate 222 having a smaller outer diameter
than the first plate 221 and the second plate 222 by a manufacturing apparatus (not shown) The
third plate 223 having the outer diameter and the fourth plate 224 having the same outer
diameter as the third plate 223 are sequentially stacked.
[0049]
In step S2, a jig G having an inner peripheral shape corresponding to the outer shape of a stack
of a plurality of plates sandwiches the side surface of the stack 5, arranges the plates
concentrically, and the difference in the outer diameter of the plates Thus, a convex portion is
formed on the outer peripheral side surface portion of the laminate 5. The jig G has, for example,
two jigs G1 and G2 as shown in FIGS. 6 (A) and 6 (B). The jigs G1 and G2 are formed in a
semicircular arc shape when viewed from above, and are formed in a shape corresponding to the
outer diameter (outside surface) of the side surface of the laminate 5. The jigs G1 and G2 hold
the side surfaces of the stacked first plate 221 to fourth plate 224, whereby positioning is
performed such that the respective plates are concentrically stacked.
[0050]
In step S3, each plate is adhered and fixed by an adhesive or the like by the manufacturing
apparatus. In step S4, as shown in FIGS. 1A and 1B, the magnet 21 is disposed on the yoke 23,
the stacked body 5 is disposed on the magnet 21, and the outer periphery of the yoke 23 is
produced by the manufacturing apparatus. After the top plate 24 is disposed on the end and
positioned so that each component is at a prescribed position, it is fixed with an adhesive or the
like (completion of the magnetic circuit). In step S5, as shown in FIG. 1A, the frame 4 and the
vibrator 3 are positioned on the magnetic circuit 2, and then fixed by the manufacturing
apparatus. The manufacturing apparatus can easily manufacture the speaker 1 employing the
speaker magnetic circuit 2 and the speaker magnetic circuit 2 according to the present invention
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16
by performing the above steps. That is, for example, the method of manufacturing the speaker
magnetic circuit according to the present invention does not require the manufacturing
apparatus to use the jig G (G1, G2) without performing the complicated processing of making the
side surface of the flat top plate uneven. The speaker magnetic circuit 2 can be easily
manufactured with high accuracy by stacking the first plate 221 to the fourth plate 224 and
positioning and fixing the same in a prescribed position. The jig G (G1, G2) is not limited to the
embodiment described above. Jig G should just be able to laminate each plate 221-224
concentrically. The shape of the jig, the manufacturing process using the same, and the like may
be appropriately set.
[0051]
As described above, the speaker magnetic circuit 2 according to the present embodiment
includes the magnet 21 and the pole piece 22 disposed as a magnetic pole. The pole piece 22 is a
stack 5 of a plurality of plates, specifically, a first plate 221 having a rectangular cross-sectional
shape, a second plate 222 having a rectangular cross-sectional shape, and a cross section A
stacked body 5 is configured in which a third plate 223 having a rectangular shape and a fourth
plate 224 having a rectangular cross-sectional shape are sequentially stacked. The fourth plate
224 has an outer diameter larger than the outer diameter of the third plate 223. The second
plate 222 has an outer diameter substantially the same as that of the third plate 223. The first
plate has an outer diameter substantially the same as the fourth plate. The said laminated body 5
is formed in the outer peripheral side part with the convex part (uneven part) by the difference of
the outer diameter of each plate. Therefore, the speaker magnetic circuit 2 has a substantially
uniform magnetic flux density in the vicinity of the radially outer side of the laminate 5 and in
the amplitude region of the voice coil 31. Further, the speaker 1 provided with the speaker
magnetic circuit 2 has a substantially uniform magnetic flux density in the amplitude region of
the voice coil 31, so when the speaker is driven, the voice coil 31 is displaced along the axial
direction Even in this case, the driving force acting on the voice coil 31 has linearity with respect
to the displacement of the voice coil, and can emit a sound wave with relatively little distortion.
That is, it is possible to provide the speaker 1 having high-quality sound characteristics.
[0052]
Second Embodiment FIG. 7 is a cross-sectional view of a speaker magnetic circuit 2B according to
a second embodiment of the present invention. In FIG. 7, the right half of the axial symmetry of
the magnetic circuit 2B is omitted. Description of the same configuration as the speaker magnetic
circuit 2 and the speaker 1 according to the first embodiment will be omitted.
12-04-2019
17
[0053]
The magnetic circuit 2 according to the first embodiment is an internal magnet type magnetic
circuit, and the pole piece 22 on the magnet 21 is formed of the laminate 5. As shown in FIG. 7,
the magnetic circuit 2B according to the second embodiment is an internal magnet type magnetic
circuit, and an annular top plate 24 is disposed at the upper end of the yoke 23B. The top plate
24 is composed of a laminate 5B of a plurality of plates according to the present invention.
Specifically, as shown in FIG. 7, the yoke 23B includes a bottom portion 231, an outer peripheral
side portion 232, and a bent portion 233, which are integrally formed. The magnet 21B is
disposed on the bottom surface portion 231 of the yoke 23B, and the pole piece 22B having a
rectangular cross-sectional shape in the radial direction is disposed on the magnet 21B. A top
plate 24B is disposed at the upper end of the outer peripheral side portion 232 of the yoke 23B.
[0054]
As shown in FIG. 7, the top plate 24B (laminate 5) has a first plate 241, a second plate 242, a
third plate 243, and a fourth plate 244. The third plate 243 corresponds to an embodiment of
the first plate of the first inner diameter according to the present invention. The fourth plate
244B corresponds to an embodiment of the second plate of the second inner diameter according
to the present invention. The first plate 241B corresponds to an embodiment of the third plate
according to the present invention.
[0055]
As shown in FIG. 7, the first plate 241 to the fourth plate 244 are formed in an annular shape,
and a cross-sectional shape (for example, a radial cross-sectional shape) is formed in a
rectangular shape (flat plate shape). A second plate 242 is disposed on the first plate 241, a third
plate 243 is disposed on the second plate, and a fourth plate 244 is disposed on the third plate
243. The first plate 241 to the fourth plate 244 are concentrically stacked so that their central
axes are the same.
[0056]
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18
Further, as shown in FIG. 7, each of the first plate 241 to the fourth plate 244 is formed so that
the outer diameter is substantially the same as the outer diameter of the yoke 23. The inner
diameter P241 of the first plate 241 and the inner diameter P244 of the fourth plate 244 are
substantially the same, and the inner diameter P242 of the second plate 242 and the inner
diameter P243 of the third plate 243 are substantially the same. The inner diameter P244 of the
fourth plate 244 is smaller than the inner diameter P243 of the third plate. The inner diameter P
242 of the second plate and the inner diameter P 243 of the third plate are larger than the outer
diameter P 21 of the magnet 21. Further, the inner diameter P241 of the first plate and the inner
diameter P244 of the fourth plate are larger than the outer diameter P21 of the magnet 21. In
the present embodiment, the thickness D241 of the first plate 241, the thickness D242 of the
second plate 242, the thickness D243 of the third plate 243, and the thickness D244 of the
fourth plate 244 are substantially the same. In the said embodiment, although the thickness of
each plate is substantially the same, it is not restricted to this form. For example, the thickness of
each plate may be appropriately set so that the magnetic flux density in the magnetic gap is
substantially uniform.
[0057]
As shown in FIG. 7, in the laminate 5 </ b> B, at least two plates having the same shape as the
third plate 243 are stacked. Specifically, a second plate 242 having the same shape as the third
plate 242 is stacked. Further, as shown in FIG. 7, the laminate 5 has a first plate 241 having the
same shape as the fourth plate 244. The third plate 243 and the second plate 242 are disposed
between the fourth plate 244 and the first plate 241.
[0058]
Further, in the laminated body 5B, a convex portion is formed on the inner peripheral side
surface portion by the difference in the inner diameter of the third plate 243 and the fourth plate
244. Further, in the laminated body 5B, a convex portion is formed on the inner peripheral side
surface portion due to the difference in the inner diameter of the first plate 241 and the second
plate 242. In the laminated body 5 </ b> B, the uneven portion is formed on the inner peripheral
side surface portion by the difference of the inner diameters with the first plate 241 to the fourth
plate 244.
[0059]
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19
As shown in FIG. 7, in the magnetic circuit 2B, a cylindrical magnetic gap MG is formed in the
axial direction between the top plate 24B (one magnetic pole) of the yoke 23B and the pole piece
22B (other magnetic pole). ing. Specifically, in the magnetic circuit 2, a first magnetic gap MGB1,
a second magnetic gap MGB2, and a third gap MBG3 are formed between the yoke (top plate
24B) and the pole piece 22B. The first magnetic gap MGB1 is defined at a first distance in the
radial direction between the pole piece 22B and the first plate 241B. The second magnetic gap
MGB2 is defined at a second distance in the radial direction between the pole piece 22B and the
second plate 242 (third plate 243). The third magnetic gap MGB3 is defined at a third distance in
the radial direction between the pole piece 22B and the fourth plate 244. The first distance of the
first magnetic gap MGB1 is defined to be the same as the third distance of the third magnetic gap
MGB3. The third distance of the third magnetic gap MGB3 is defined to be smaller than the
second distance of the second magnetic gap MGB2.
[0060]
As shown in FIG. 7, in the stacked body 5B, the length PS3 along the radial direction of the step
between the third plate 243 and the fourth plate 244 is along the radial direction of the third
magnetic gap MGB3. Less than the third distance. In the present embodiment, the length along
the radial direction of the step between the first plate 241 and the second plate 242 is the same
as the length PS3 and is along the radial direction of the third magnetic gap MG3. Less than the
third distance.
[0061]
The step between the third plate 243 and the fourth plate 244 is a magnetic flux between the
first magnetic gap MGB1, the second magnetic gap MGB2 and the third magnetic gap MGB3 and
in the amplitude region of the voice coil 31. The density is formed to be substantially uniform.
Similarly, the step between the first plate 241 and the second plate 242 is between the first
magnetic gap MGB1, the second magnetic gap MGB2, and the third magnetic gap MGB3, and the
amplitude region of the voice coil 31. The magnetic flux density is formed so as to be
substantially uniform.
[0062]
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20
Further, as shown in FIG. 7, when the voice coil 31 is at rest, the upper end portion thereof is
disposed at a position H31 having substantially the same height as the total height of the
plurality of plates of the laminate 5B. Further, the total height H5 of the plurality of plates of the
laminate 5 is defined to be substantially the same as or lower than the height 22B of the pole
piece 22B. In addition, the pole piece 22B is defined so that the lower surface thereof is located
substantially on the same plane or higher than the lower surface of the laminate 5.
[0063]
The respective constituent elements (oscillator, frame, etc.) of the speaker employing the speaker
magnetic circuit 2B are substantially the same as those of the first embodiment, and thus the
description thereof is omitted.
[0064]
FIG. 8 is a flowchart for explaining the method of manufacturing the speaker magnetic circuit 2B
according to the embodiment of the present invention.
FIG. 9 is a cross-sectional view of the laminated body of the speaker magnetic circuit 2B and the
jig G.
[0065]
Description is abbreviate | omitted about steps similar to the manufacturing method of the
speaker magnetic circuit which concerns on 1st Embodiment regarding the manufacturing
method of the speaker magnetic circuit 2B of the said structure. In step S1, a plurality of plates
(two types of plates) are stacked and arranged. In detail, according to the manufacturing
apparatus (not shown), the annular first plate 241, the second plate 242 having a larger inside
diameter than the first plate 241, and the third plate 243 having the same inside diameter as the
second plate 242. , And the fourth plate 244 having substantially the same inner diameter as the
third plate 243 are sequentially stacked.
[0066]
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21
In step S2, a jig G having an inner peripheral shape corresponding to the outer shape of the
laminate 5B of a plurality of plates sandwiches the side surface of the laminate 5B, and arranges
the respective plates concentrically to make a difference in inner diameter of the plates. As a
result, convex portions (concave and convex portions) are formed on the inner peripheral side
surface portions of the laminate 5B. The jig G has, for example, two jigs G11 and G21 as shown in
FIG. The jigs G11 and G21 are formed in a substantially semicircular arc shape when viewed
from above, and have a sectional shape corresponding to the inner diameter (inner side surface)
of the side surface of the laminate 5 (first plate 241 to fourth plate 244) Is formed. The jigs G11
and G21 press the inner side surfaces of the stacked first to fourth plates 241 to 244 to position
the respective plates so as to be concentrically stacked. Moreover, since the outer diameter of
each plate 241-244 of the laminated body 5B which concerns on this embodiment is the same
magnitude | size, for example, two jigs in which the cross-sectional shape along the axis was
formed in a semicircular arc shape are The side surfaces of the stacked body 5B may be held.
The manufacturing apparatus (not shown) can easily perform center positioning of each plate by
the steps S1 and S2. The manufacturing apparatus manufactures the above-mentioned layered
product 5B by carrying out adhesion fixation of a plurality of plates with adhesives etc. after
positioning. Next, as shown in FIG. 7, the manufacturing apparatus arranges the magnet 21B, the
pole piece 22B, and the laminate 5B on the yoke 23B, and fixes them with an adhesive or the like.
The speaker magnetic circuit 2B according to the present embodiment is manufactured by the
method of manufacturing the magnetic circuit. Next, the manufacturing apparatus assembles the
magnetic circuit 2B, the frame, and the vibrating body to produce a speaker.
[0067]
As described above, the speaker magnetic circuit 2B according to the present embodiment is an
internal magnet type magnetic circuit, and the magnet 21B disposed at the center of the yoke
23B and the pole piece 22B disposed on the magnet 21B. , And an annular top plate 24B
disposed as a magnetic pole on the outer peripheral side 232 of the yoke. The annular top plate
24B constitutes a laminate 5B of the first plate 241 to the fourth plate 244 defined to have a
second inner diameter larger than the first inner diameter or the first inner diameter. In the
laminated body 5 </ b> B, convex portions (concave and convex portions) are formed on the
inner peripheral side surface portion due to the difference in the inner diameter of each plate.
Therefore, the speaker magnetic circuit 2B has a substantially uniform magnetic flux density in
the vicinity of the radially inner side of the laminate 5B of the top plate 24B and in the amplitude
region of the voice coil 31.
[0068]
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22
In the speaker 1 provided with the speaker magnetic circuit 2B, since the magnetic flux density is
formed substantially uniformly in the amplitude region of the voice coil 31, when the voice coil
31 is displaced along the axial direction at the time of driving the speaker Even in this case, the
driving force acting on the voice coil 31 has linearity with respect to the displacement of the
voice coil, and can emit a sound wave with relatively little distortion.
[0069]
In addition, by stacking the annular plates and positioning the jig, the laminate 5B can be easily
manufactured.
Further, by arranging the laminate 5B as a top plate on the yoke 23B, the speaker magnetic
circuit 2B according to the present invention can be easily manufactured.
[0070]
Third Embodiment FIG. 10 is a cross-sectional view of a speaker magnetic circuit 2C according to
a third embodiment of the present invention. In FIG. 10, the right half of the axial symmetry of
the magnetic circuit axis 2C is omitted. The description of the same configuration as the first
embodiment and the second embodiment will be omitted.
[0071]
As shown in FIG. 10, the speaker magnetic circuit 2C is an external magnetic side magnetic
circuit, and includes an annular magnet 21C, a yoke 23C, and a top plate 24B. The yoke 23C has
a flat bottom portion 231C, and a convex pole 234C projecting upward in the axial direction at a
central portion. In the yoke 23C according to the present embodiment, the bottom portion 231C
and the pole 234C are integrally formed of a metal material (magnetic material) or the like.
[0072]
The top plate 24B is disposed on the magnet 21C. The top plate 24B constitutes a laminate 5B of
12-04-2019
23
each plate. The laminate 5B is substantially the same as the laminate 5B of the magnetic circuit
2B according to the second embodiment, and thus the description thereof is omitted.
[0073]
The speaker magnetic circuit 2C according to the present embodiment is an external magnet type
magnetic circuit, and the top plate 24B is disposed as a magnetic pole on the annular magnet
21C. The top plate 24B is formed of a laminate 5 of a plurality of plates of a second inner
diameter larger than the first inner diameter or the first inner diameter, and a convex portion
(concave / convex portion) is formed on the inner peripheral side surface portion ing. Therefore,
the speaker magnetic circuit 2C has a substantially uniform magnetic flux density in the vicinity
of the radially inner side of the laminate 5B of the top plate 24B and in the amplitude region of
the voice coil 31.
[0074]
Fourth Embodiment FIG. 11 is a cross-sectional view of a speaker magnetic circuit 2D according
to a fourth embodiment of the present invention. In FIG. 11, the right half of the axial symmetry
of the magnetic circuit 2D is omitted. The description of the same configuration as that of the
first to third embodiments is omitted.
[0075]
As shown in FIG. 11, the speaker magnetic circuit 2D is an internal magnet type magnetic circuit.
The magnetic circuit 2D includes a yoke 23B, a magnet 21B, a pole piece 22 (laminated body 5),
and a top plate 24B (laminated body 5B). For example, the yoke 23B, the magnet 21B, and the
top plate 24B (laminated body 5B) are substantially the same as the components of the second
embodiment shown in FIG. 7, and the pole piece 22 (laminated body 5) is illustrated in FIG. A)
Since it is substantially the same as the pole piece 22 (laminated body 5) of the first embodiment
shown in FIG. 1 (B), the description thereof is omitted.
[0076]
The speaker magnetic circuit 2D is an internal magnet type magnetic circuit, and the pole piece
22 is composed of the laminate 5 and the top plate 24B is composed of the laminate 5B. Density
12-04-2019
24
is formed.
[0077]
Fifth Embodiment FIG. 12 is a cross-sectional view of a speaker magnetic circuit 2E according to
a fifth embodiment of the present invention.
In FIG. 12, the right half of the axial symmetry of the magnetic circuit axis 2E is omitted. The
description of the same configuration as that of the first to fourth embodiments is omitted.
[0078]
As shown in FIG. 12, the speaker magnetic circuit 2E is an external magnet type magnetic circuit.
The magnetic circuit 2D includes a yoke 23B, a magnet 21B, a pole piece 22 (laminated body 5),
and a top plate 24B (laminated body 5B). For example, the annular magnet 21C and the top plate
24B (laminate 5B) are substantially the same as the components of the fourth embodiment
shown in FIG. 10, and the pole piece 22 (laminate 5) is shown in FIG. Since the pole piece 22
(stacked body 5) shown in FIG. 1 (B) is substantially the same, the description thereof is omitted.
The yoke 23E has substantially the same shape as the yoke 23C shown in FIG. 10, but in detail,
the top surface of the pole piece 22 in the central portion is defined to be at the same height as
the top surface of the top plate 24. .
[0079]
The speaker magnetic circuit 2E is an external magnet type magnetic circuit, and since the pole
piece 22 is composed of the laminate 5 and the top plate 24 is composed of the laminate 5, the
magnetic gap has a substantially uniform magnetic flux density. It is formed.
[0080]
Sixth Embodiment FIG. 13 is a cross-sectional view of a speaker magnetic circuit 2F according to
a sixth embodiment of the present invention.
12-04-2019
25
In FIG. Q13, the right half of the axial symmetry of the magnetic circuit 2F is omitted. The
description of the same configuration as the first to fifth embodiments is omitted.
[0081]
As shown in FIG. 13, the speaker magnetic circuit 2F is an internal magnet type magnetic circuit.
The magnetic circuit 2F includes a magnet 21F and a plurality of stacked bodies 5 (51F, 52F)
which sandwich the magnet 21F in the axial direction. The laminate 51 is disposed as a top plate
(magnetic pole), and the laminate 52 is disposed as a bottom plate (magnetic pole). The yoke 23F
is formed in a substantially cylindrical shape, the magnet 21F and the stacked body 5 (51F, 52F)
are disposed inside, and the radially inner side is directed toward the stacked body 5 (51F, 52F)
in the inner peripheral portion B) having a plurality of protrusions 231F and 232F extending.
Similar to the first embodiment, magnetic gaps GM of different distances are provided between
the yoke 23F and the plurality of stacks 5, specifically between the yoke 23F and the stack 51F,
and between the yoke 23F and the stack 52F. It is formed. In each of the magnetic gaps GM, a
voice coil (not shown) is disposed so as to be able to vibrate in the axial direction.
[0082]
The speaker magnetic circuit 2F is a so-called two gap type internal magnetic type magnetic
circuit, and the laminate 5 (51F) is provided as a magnetic pole. Therefore, the space between the
yoke 23F and the laminate 51F, and the yoke 23F and A substantially uniform magnetic flux
density is formed at each magnetic gap between the laminate 52F. Therefore, the speaker
adopting the magnetic circuit 2F has high-quality sound characteristics.
[0083]
Seventh Embodiment FIG. 14 is a cross-sectional view of a speaker 1K employing a speaker
magnetic circuit 2K according to a seventh embodiment of the present invention. The description
of the same configuration as in the first to sixth embodiments is omitted. As shown in FIG. 14, the
speaker 1 </ b> K includes a magnetic circuit 2 </ b> K, a vibrator 3, and a frame 4. The vibrating
body 3 and the frame 4 are substantially the same as the vibrating body 3 and the frame 4
according to the first embodiment shown in FIGS. 1 (A) and 1 (B), and thus the description
thereof is omitted. The magnetic circuit 2K is an internal magnet type magnetic circuit, and
includes a magnet 21, a pole piece 22, and a yoke 23K. The magnet 21 and the pole piece 22 are
12-04-2019
26
substantially the same as the magnet 21 and the pole piece 22 according to the first embodiment
shown in FIGS. 1 (A) and 1 (B), and thus the description thereof is omitted. The yoke 23 K is
disposed below the magnet 21. In detail, the yoke 23K has a bottom surface portion 231K on
which a convex portion is formed, an outer peripheral side surface portion 232K, and a flat platelike top plate 24K extending radially outward from the upper portion of the outer peripheral side
surface portion 232K. . The bottom surface portion 231K, the outer peripheral side surface
portion 232K, and the top plate 24K are integrally formed of a metal material (magnetic
material) or the like.
[0084]
The speaker magnetic circuit 2K has a substantially uniform magnetic flux density in the
amplitude region of the voice coil 31 because the pole piece 22 is formed of the laminate 5. The
speaker 1K including the speaker magnetic circuit 2K has high-quality sound characteristics.
[0085]
Eighth Embodiment FIG. 15 is a cross-sectional view of a speaker magnetic circuit 2N according
to an eighth embodiment of the present invention. The description of the same configuration as
in the first to seventh embodiments is omitted. The speaker magnetic circuit 2N shown in FIG. 15
is an internal magnet type magnetic circuit, and includes a magnet 21, a pole piece 22, and a
yoke 23N. The magnet 21 and the pole piece 22 are substantially the same as the magnet 21 and
the pole piece 22 according to the first embodiment shown in FIGS. 1 (A) and 1 (B), and thus the
description thereof is omitted. The yoke 23N is disposed below the magnet 21. In detail, the yoke
23N has a bottom surface portion 231N and a substantially cylindrical outer peripheral side
surface portion 232N. Further, the yoke 23N is bent between the bottom surface portion 231N
and the outer peripheral side surface portion 232N from the outer peripheral portion of the
bottom surface portion 231N axially downward (opposite to the sound radiation direction SD)
and radially outward. It has the bending part 238N extended and joined to the lower end part of
the outer peripheral side part 232N. The bent portion 238N and the bottom portion 231N are
integrally formed of a metal material (magnetic material) or the like.
[0086]
The speaker magnetic circuit 2N has the substantially uniform magnetic flux density in the
12-04-2019
27
amplitude region of the voice coil because the pole piece 22 is formed of the laminate 5. The
speaker provided with the speaker magnetic circuit 2N has high-quality sound characteristics.
[0087]
Ninth Embodiment FIG. 16 is a cross-sectional view of a speaker magnetic circuit 2S according to
a ninth embodiment of the present invention. The description of the same configuration as that
of the first to eighth embodiments is omitted. The speaker magnetic circuit 2S shown in FIG. 16
is an internal magnet type magnetic circuit, and includes a magnet 21, a pole piece 22, and a
yoke 23S. As shown in FIG. 16, the yoke 23S has a bottom surface portion 231S in which a
convex portion 235S is formed at the central portion, and a substantially cylindrical outer
peripheral side surface portion 232S. The bottom surface portion 231S and the outer peripheral
side surface portion 232S are integrally formed of, for example, a metal material (magnetic
material) or the like. The outer peripheral side surface portion 232S is formed with a bent end
portion 2321S whose upper end portion is bent radially inward (toward the laminate 5). A
magnetic gap is formed between the bent end portion 2321 S and the stacked body 5. A voice
coil is disposed in the magnetic gap.
[0088]
The speaker magnetic circuit 2S has a substantially uniform magnetic flux density in the
amplitude region of the voice coil because the pole piece 22 is formed of the laminate 5. The
speaker provided with the speaker magnetic circuit 2S has high-quality sound characteristics.
[0089]
Tenth Embodiment FIG. 17 is a cross-sectional view of a speaker magnetic circuit 2R according to
a tenth embodiment of the present invention. The description of the same configuration as in the
first to ninth embodiments is omitted. The speaker magnetic circuit 2R shown in FIG. 17 is an
internal magnet type magnetic circuit, and includes a magnet 21, a pole piece 22, and a yoke
23R. The yoke 23R is disposed below the magnet 21. Specifically, it has a bottom portion 231R
in which a yoke 23R and a central hole 239R are formed, and a substantially cylindrical outer
peripheral side portion 232R. In addition, the yoke 23R has a bent portion 233R that connects
the bottom surface portion 231R and the outer peripheral side surface portion 232R. The
thickness T233R of the bent portion 233R is smaller than the thickness of the outer peripheral
12-04-2019
28
side surface portion 232R or the bottom surface portion 231R. Further, as shown in FIG. 17, in
the yoke 23R, the speaker frame 4R is joined to the portion where the thickness is small. In the
outer peripheral side surface portion 232R, an inclined surface portion is formed at an outer
peripheral side corner portion of the upper end portion. The bottom surface portion 231R, the
outer peripheral side surface portion 232R, and the bending portion 233R are integrally formed
of, for example, a metal material (magnetic material) or the like.
[0090]
Since the pole piece 22 of the speaker magnetic circuit 2R is formed of the laminate 5, the
speaker magnetic circuit 2R has a substantially uniform magnetic flux density in the amplitude
region of the voice coil. The speaker provided with the speaker magnetic circuit 2R has highquality sound characteristics.
[0091]
Eleventh Embodiment FIG. 18 is a cross-sectional view of a speaker magnetic circuit 2T
according to an eleventh embodiment of the present invention. The description of the same
configuration as in the first to tenth embodiments is omitted. FIG. 18 is a cross-sectional view of
the speaker magnetic circuit 2J according to the comparative example.
[0092]
The speaker magnetic circuit 2T shown in FIG. 18 is an internal magnet type magnetic circuit,
and includes a magnet 21, a pole bead 22T, and a yoke 23N. The yoke 2N is substantially the
same as the yoke 2N according to the eighth embodiment shown in FIG.
[0093]
The pole piece 22T shown in FIG. 18 has a first plate 221T, a second plate 222, a third plate
223, and a fourth plate 224. The pole piece 22T constitutes a laminate 5T of a first plate 221T to
a fourth plate 224. The first plate 221T has an outer diameter smaller than the outer diameter of
the second plate 222 (third plate 223). Further, the outer diameter of the first plate 221T is
12-04-2019
29
larger than the outer diameter of the magnet 21. The second plate 222 to the fourth plate 224
are substantially the same as the second plate 222 to the fourth plate 224 according to the first
embodiment shown in FIGS. 1A and 1B. I omit explanation. Specifically, as shown in FIG. 18, in
the laminate 5T according to the present embodiment, the outer diameter of the third plate 223
(second plate 222) is smaller than that of the fourth plate 224, and the third plate is used. The
outer diameter of the first plate 221T is smaller than 223 (second plate 222). That is, the
laminate 5T is formed such that the outer diameter of each plate differs stepwise along the axial
direction.
[0094]
For example, as shown in FIG. 19, the speaker magnetic circuit 2J according to the comparative
example has a pole piece 22J formed in a flat plate shape. In the magnetic circuit 2J, of the
magnetic flux in the magnetic gap between the yoke 23N and the pole piece 22J, the magnetic
flux (leakage flux) leaking from the lower end of the pole piece 22J to the yoke 23N is relatively
large.
[0095]
On the other hand, since the speaker magnetic circuit 2T according to the eleventh embodiment
of the present invention is formed so that the outer diameter of each plate of the multilayer body
5T differs stepwise along the axial direction, the leakage flux is reduced. can do. The speaker
magnetic circuit 2T has a substantially uniform magnetic flux density in the amplitude region of
the voice coil. The speaker provided with the speaker magnetic circuit 2T has high-quality sound
characteristics.
[0096]
Twelfth Embodiment FIG. 20 is a cross-sectional view of a speaker magnetic circuit 2U according
to a twelfth embodiment of the present invention. The description of the same configuration as
the ninth embodiment and the eleventh embodiment will be omitted. The speaker magnetic
circuit 2U shown in FIG. 20 is an internal magnet type magnetic circuit, and includes a magnet
21, a pole bead 22T, and a yoke 23R. The magnetic circuit 2U is obtained by providing the pole
piece 22T (laminated body 5T) shown in FIG. 18 in the magnetic circuit 2R according to the tenth
embodiment shown in FIG.
12-04-2019
30
[0097]
Since the speaker magnetic circuit 2U is formed so that the outer diameters of the plates of the
laminate 5T differ stepwise along the axial direction, the leakage magnetic flux can be reduced.
In addition, the speaker magnetic circuit 2U has a substantially uniform magnetic flux density in
the amplitude region of the voice coil. The speaker provided with the speaker magnetic circuit
2U has high-quality sound characteristics.
[0098]
Thirteenth Embodiment FIG. 21 is a cross-sectional view of a speaker 1V employing a speaker
magnetic circuit 2V according to a thirteenth embodiment of the present invention. The speaker
1V shown in FIG. 21 has a magnetic circuit 2V, a vibrator 3G, and a frame 4G. The magnetic
circuit 2V is an internal magnet type magnetic circuit. The magnetic circuit 2V includes a magnet
21G, a substantially flat yoke 23G formed below the magnet 21G, and a pole piece 22T disposed
on the magnet 21.
[0099]
The pole piece 22T is composed of a laminate 5T of a plurality of plates. The pole piece 22T
(laminated body 5T) is substantially the same as the pole piece 22 (laminated body 5) according
to the first embodiment shown in FIGS. 1 (A) and 1 (B), and therefore the description thereof is
omitted. In the vibrating body 3G, the outer peripheral portion of the dome-shaped diaphragm
33G is vibratably joined to the frame 4G via an edge 34G. The voice coil 31 is vibratably
supported along the axial direction in the vicinity of the outer peripheral portion of the
diaphragm 33G. The frame 4G is formed to extend radially outward from the outer peripheral
portion of the yoke 23G and to be bent in the acoustic radiation direction SD. The frame 4G
supports the magnetic circuit 2V and the vibrator 3G.
[0100]
Since the speaker magnetic circuit 2V is formed so that the outer diameter of each plate of the
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laminate 5T differs stepwise along the axial direction, the leakage magnetic flux can be reduced.
In addition, the speaker magnetic circuit 2V has a substantially uniform magnetic flux density in
the amplitude region of the voice coil. The speaker 1V having the speaker magnetic circuit 2V
has high-quality sound characteristics. Fourteenth Embodiment FIG. 22 is a cross-sectional view
of a speaker 1G employing a speaker magnetic circuit 2G according to a fourteenth embodiment
of the present invention. The description of the same configuration as that of the first to
thirteenth embodiments is omitted. As shown in FIG. 22, the speaker 1G includes an externalmagnet type magnetic circuit 2G, a vibrator 3G, and a frame 4G. The magnetic circuit 2G has an
annular magnet 21G, a substantially flat plate-like yoke 23G provided below the magnet 21G,
and an annular top plate 24B disposed on the magnet 21. The top plate 24B is formed of a
laminate 5B. In the vibrating body 3G shown in FIG. 22, an outer peripheral portion of a domeshaped diaphragm 33G is vibratably joined to a frame 4G with an edge 34G. The voice coil 31 is
vibratably supported along the axial direction in the vicinity of the outer peripheral portion of the
diaphragm 33G. The frame 4G is formed to extend radially outward from the outer peripheral
portion of the yoke 23G and to be bent in the acoustic radiation direction SD. The frame 4G
supports the magnetic circuit 2G and the vibrator 3G. The top plate 24B shown in FIG. 22 has a
first plate 241, a second plate 242, a third plate 243, and a fourth plate 244. The top plate 24B
constitutes a laminate 5B of the first plate 241 to the fourth plate 244. The first plate 241 has an
outer diameter smaller than the outer diameter of the second plate 242 (third plate 243).
Further, the outer diameter of the first plate 241 is larger than the outer diameter of the magnet
21G. The second plate 242 to the fourth plate 244 are substantially the same as the second plate
242 to the fourth plate 244 according to the second embodiment shown in FIG. Specifically, as
shown in FIG. 22, in the laminate 5 </ b> B according to the present embodiment, the outer
diameter of the third plate 243 (second plate 242) is smaller than that of the fourth plate 244,
and the third plate The outer diameter of the first plate 241 is smaller than that of the second
plate 242 (second plate 242).
That is, the laminate 5B is formed such that the outer diameter of each plate differs stepwise
along the axial direction.
[0101]
As a comparative example, in the speaker magnetic circuit in which the top plate 24B is formed
of a single member, the magnetic flux of the magnetic gap between the yoke 23G and the top
plate 24B leaks to the yoke 23G from the lower end of the top plate 24B. Magnetic flux (leakage
flux) is relatively large. On the other hand, since the speaker magnetic circuit 2G according to the
fourteenth embodiment of the present invention is formed so that the outer diameter of each
plate of the laminate 5B differs stepwise along the axial direction, the above-mentioned leakage
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flux is reduced can do. In addition, the speaker magnetic circuit 2G has a substantially uniform
magnetic flux density in the amplitude region of the voice coil. The speaker 1G provided with the
speaker magnetic circuit 2G has high-quality sound characteristics.
[0102]
Fifteenth Embodiment FIG. 23 is a cross-sectional view of a speaker magnetic circuit 2L
according to a fifteenth embodiment of the present invention. The description of the same
configuration as in the first to fourteenth embodiments is omitted. The speaker magnetic circuit
2L shown in FIG. 23 is an internal magnet type magnetic circuit, and includes a magnet 21, a
pole piece 22, and a yoke 23L. The pole piece 22 is composed of a laminate 5. The magnet 21
and the pole piece 22 are substantially the same as the magnet 21G and the pole piece 22T
shown in FIG. As shown in FIG. 23, the yoke 23L has a substantially flat bottom portion 231L and
a side portion 232L that is bent obliquely forward from the outer peripheral portion of the
bottom portion 231L in the axial direction (sound radiation direction SD). Have. A magnetic gap
is formed between the upper end of the side surface portion 232L of the yoke 23L and the pole
piece 22, and a voice coil (not shown) is disposed in the magnetic gap.
[0103]
Since the speaker magnetic circuit 2L is formed so that the outer diameters of the plates of the
pole piece 22 differ stepwise along the axial direction, the leakage magnetic flux can be reduced.
In addition, the speaker magnetic circuit 2L has a substantially uniform magnetic flux density in
the amplitude region of the voice coil. The speaker provided with the speaker magnetic circuit 2L
has high-quality sound characteristics.
[0104]
Sixteenth Embodiment FIG. 24 is a cross-sectional view of a speaker magnetic circuit 2M
according to a sixteenth embodiment of the present invention. The description of the same
configuration as the first to fifteenth embodiments is omitted. The speaker magnetic circuit 2M
shown in FIG. 24 is an external magnet type magnetic circuit, and has an annular magnet 21G, an
annular top plate 24B disposed on the magnet 21G, and a yoke 23M. The top plate 24B is
composed of a laminate 5B. The magnet 21G and the top plate 24B are substantially the same as
the magnet 21G and the top plate 24B shown in FIG. As shown in FIG. 24, the yoke 23M has a
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bottom portion 231M in which a convex portion 235M having a shape protruding toward the
axial direction front (the acoustic radiation direction SD) is formed at the central portion. The
convex portion 235M is formed, for example, by subjecting a flat metal plate to a pressing
process.
[0105]
Since the speaker magnetic circuit 2M is formed so that the outer diameter of each plate of the
top plate 24B differs stepwise along the axial direction, the leakage magnetic flux can be
reduced. In addition, the speaker magnetic circuit 2M has a substantially uniform magnetic flux
density in the amplitude region of the voice coil. The speaker provided with the speaker magnetic
circuit 2M has high-quality sound characteristics.
[0106]
Seventeenth Embodiment FIG. 25 is a cross-sectional view of a speaker magnetic circuit 2W
according to a seventeenth embodiment of the present invention. The description of the same
configuration as that of the thirteenth embodiment shown in FIG. 20 will be omitted. The speaker
magnetic circuit 2W shown in FIG. 25 is an internal magnet type magnetic circuit, and includes a
magnet 21, a repelling magnet 215, a pole piece 22T (laminated body 5T), an upper plate 220,
and a yoke 23R. As shown in FIG. 25, the pole piece 22T (laminated body 5T) is disposed on the
magnet 21, the repelling magnet 215 is disposed on the pole piece 22T (laminated body 5T), and
the top plate 220 is disposed on the repelling magnet 215. It is arranged. That is, the speaker
magnetic circuit 2W includes the two magnets 21 and the repelling magnet 215 which are
disposed so as to sandwich the stacked body 5T. The magnet 21 and the repelling magnet 215
are magnetized in mutually opposite directions along the axial direction. Further, as shown in
FIG. 25, the yoke 23R is disposed below the magnet 21. The yoke 23R has a cylindrical outer
peripheral side portion.
[0107]
The speaker magnetic circuit 2W has the substantially uniform magnetic flux density in the
amplitude region of the voice coil because the pole piece 22T is formed of the laminate 5.
Further, as shown in FIG. 25, since the repelling magnet 215 is disposed on the laminated body 5
in the speaker magnetic circuit 2W, the leakage flux to the outside of the magnetic circuit is
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relatively small. In addition, since the upper plate 220 is disposed on the repelling magnet 215,
the magnetic circuit for speakers 2W has a smaller leakage flux. In addition, the speaker
provided with the speaker magnetic circuit 2W has high-quality sound characteristics.
[0108]
Eighteenth Embodiment FIG. 26 is a cross-sectional view of a speaker 1Y employing a speaker
magnetic circuit 2Y according to an eighteenth embodiment of the present invention. The
description of the same configuration as the first to seventeenth embodiments will be omitted.
The speaker 1Y shown in FIG. 26 has a magnetic circuit 2Y, a vibrating body 3Y, and a frame 4Y.
The magnetic circuit 2Y includes a magnet 21, a pole piece 22 (laminated body 5), and a
repulsive magnet 215. The vibrating body 3Y has a voice coil 31, a voice coil bobbin 32Y, a
diaphragm 33Y, an edge 34Y, a cap 35Y, and a damper 36Y.
[0109]
In the magnetic circuit 2Y, the pole piece 22 (stacked body 5) is disposed on the magnet 21, and
the repulsive magnet 215 is disposed on the pole piece 22 (stacked body 5). Since this pole piece
22 (laminated body 5) is substantially the same as the pole piece 22 (laminated body 5) shown,
for example, in FIGS. 1 (A) and 1 (B), the description will be omitted.
[0110]
As shown in FIG. 26, in the frame 4Y, a convex portion 45Y is formed at the center. The magnet
21 is disposed on the convex portion 45Y. In the frame 4Y, the diaphragm 33Y is vibratably
joined to the upper flat portion via the edge 34Y, and the damper 36Y is joined to the middle flat
portion. The cap 35Y is arranged in the vicinity of the central portion of the diaphragm 33Y so as
to cover the front of the voice coil bobbin 32Y.
[0111]
The speaker magnetic circuit 2Y has the substantially uniform magnetic flux density in the
amplitude region of the voice coil because the pole piece 22 is formed of the laminate 5. Further,
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in the speaker magnetic circuit 2Y, since the repelling magnet 215 is disposed on the laminate 5,
the leakage flux to the outside of the magnetic circuit is relatively small. Further, in the magnetic
circuit 2Y, the magnet 21 is disposed on the convex portion 45Y of the frame 4Y, and the yoke is
not required. For this reason, the magnetic circuit 2Y has a relatively simple structure and is
relatively lightweight. In addition, the speaker 1Y including the speaker magnetic circuit 2Y has
high-quality sound characteristics.
[0112]
FIG. 27A is a view showing an electronic device (mobile phone) 100 according to a first specific
example in which the speaker device 1 according to an embodiment of the present invention is
adopted. FIG. 27B is a view showing an electronic device (headphones) 100A according to a
second specific example in which the speaker device 1 according to an embodiment of the
present invention is adopted. FIG. 27C is a diagram showing an electronic device (monitor) 100B
according to a third specific example in which the speaker device 1 according to an embodiment
of the present invention is adopted.
[0113]
An electronic device (mobile phone) 100 according to a first specific example of the present
invention has the above-mentioned speaker device 1 in the mobile phone 100 as shown in FIG.
27 (A). An electronic device (headphones) 100 according to a second specific example of the
present invention has the above-mentioned speaker device 1 in the mobile phone 100 as shown
in FIG. 27 (B). An electronic device (monitor) 100B according to the first specific example of the
present invention has the above-mentioned speaker device 1 in the mobile phone 100 as shown
in FIG. 27 (C). The electronic device according to the present invention is not limited to the above
embodiment, and the speaker device according to the present invention may be mounted on
various electronic devices.
[0114]
As described above, the speaker magnetic circuit according to the present invention includes the
magnet 21 and the pole piece arranged as the magnetic pole, and the pole piece 22 has the first
cross-sectional shape formed in a rectangular shape. A first plate of outer diameter, and a second
plate of a second outer diameter larger than the first outer diameter concentrically disposed on
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the first plate and having a rectangular cross-sectional shape In the amplitude region of the voice
coil, since the convex portion is formed on the outer peripheral side portion due to the difference
between the outer diameters of the first plate and the second plate, which constitute the
laminated body 5. A speaker magnetic circuit having a substantially uniform magnetic flux
density can be provided. In addition, by adopting the magnetic circuit, it is possible to provide a
speaker with high-quality sound characteristics. In addition, as described above, the speaker
magnetic circuit can be easily manufactured without complicated processing.
[0115]
The present invention is not limited to the above embodiment. For example, the embodiments
may be combined. Moreover, the shape of the side part of a laminated body is not restricted to
the form mentioned above. It may be any shape as long as the magnetic flux density is uniform in
the amplitude region of the voice coil. Moreover, in the said embodiment, although each plate of
a laminated body is respectively substantially the same thickness, it is not restricted to this form.
The number and thickness of the plates may be appropriately defined so that the magnetic flux
density is uniform in the amplitude region of the voice coil.
[0116]
It is a figure for demonstrating the speaker 1 which employ | adopted the speaker magnetic
circuit 2 which concerns on 1st Embodiment of this invention, FIG. 1 (A) is sectional drawing of
the speaker 1, FIG. 1 (B) is FIG. It is sectional drawing of the magnetic circuit 2 for speakers
shown by (A). (A) is a top view of one specific example of a speaker magnetic circuit, (B) is a top
view of another specific example of a speaker magnetic circuit. It is sectional drawing of the
laminated body which concerns on one Embodiment of this invention. (A) is a figure for
demonstrating the magnetic flux density in the magnetic gap of the speaker magnetic circuit
which concerns on one Embodiment of this invention, (B) is the magnetic flux density in the
magnetic gap of the magnetic circuit which concerns on a comparative example. It is a figure for
demonstrating. It is a flowchart for demonstrating the manufacturing method of the speaker
magnetic circuit 2 which concerns on one Embodiment of this invention. (A) is a top view of the
laminate 5 and the jig G of the speaker magnetic circuit 2, (B) is a cross section of the laminate 5
of the speaker magnetic circuit 2 and the jig G shown in (A) FIG. It is sectional drawing of the
speaker magnetic circuit 2B which concerns on 2nd Embodiment of this invention. It is a
flowchart for demonstrating the manufacturing method of the speaker magnetic circuit 2B which
concerns on one Embodiment of this invention. It is a sectional view of a layered product and jig
G of speaker magnetic circuit 2B. It is a cross-sectional view of a speaker magnetic circuit 2C
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according to a third embodiment of the present invention. It is sectional drawing of the speaker
magnetic circuit 2D which concerns on 4th Embodiment of this invention. It is sectional drawing
of the speaker magnetic circuit 2E which concerns on 5th Embodiment which concerns on this
invention. It is sectional drawing of the speaker magnetic circuit 2F which concerns on 6th
Embodiment of this invention. It is sectional drawing of the speaker 1K which employ | adopted
the speaker magnetic circuit 2K which concerns on 7th Embodiment of this invention. It is
sectional drawing of the speaker magnetic circuit 2N which concerns on 8th Embodiment of this
invention. It is sectional drawing of the speaker magnetic circuit 2S which concerns on 9th
Embodiment of this invention. It is sectional drawing of the magnetic circuit 2R for speakers
which concerns on 10th Embodiment of this invention. It is sectional drawing of the speaker
magnetic circuit 2T which concerns on 11th Embodiment of this invention. It is sectional drawing
of the speaker magnetic circuit 2J which concerns on a comparative example. It is sectional
drawing of the magnetic circuit 2U for speakers which concerns on 12th Embodiment of this
invention. It is sectional drawing of the speaker 1V which employ | adopted the speaker
magnetic circuit 2V which concerns on 13th Embodiment of this invention. It is sectional
drawing of the speaker 1G which employ | adopted the speaker magnetic circuit 2G which
concerns on 14th Embodiment of this invention. It is sectional drawing of the magnetic circuit 2L
for speakers which concerns on 15th Embodiment of this invention. It is sectional drawing of the
speaker magnetic circuit 2M which concerns on 16th Embodiment of this invention.
It is sectional drawing of the speaker magnetic circuit 2W which concerns on 17th Embodiment
of this invention. It is sectional drawing of the speaker 1Y which employ | adopted the speaker
magnetic circuit 2Y which concerns on 18th Embodiment of this invention. (A) is a figure which
shows the electronic device (mobile telephone) 100 which concerns on the 1st specific example
which employ | adopted the speaker apparatus 1 which concerns on one Embodiment of this
invention, (B) is a speaker which concerns on one embodiment of this invention It is a figure
showing electronic equipment (headphones) 100A concerning the 2nd example which adopted
device 1 and (C) is an electronic equipment (the 3rd example according to which the speaker
apparatus 1 concerning one embodiment of the present invention is adopted ( It is a figure which
shows monitor 100B.
Explanation of sign
[0117]
Reference Signs List 1 speaker 2 magnetic circuit 3 vibrator 4 frame 5 laminated body 21
magnet 22 pole piece 23 yoke 24 top plate 31 voice coil 32 voice coil bobbin 33 diaphragm 34
edge 35 cap 36 damper 100 electronic device
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