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JPWO2013190836

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This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPWO2013190836
A magnet (102, 302, 402, 502) having at least one hole (108, 308, 408, 508, 708) and a plate
(103, 303, 403, 503) fixed to one pole face of the magnet And a magnetic circuit (107, 301, 401,
501) having a box-like yoke (101, 301, 401, 501) having an inner bottom surface fixed to the
other magnetic pole surface of the magnet, and a magnetic gap (107) formed by the plate and
the yoke. , 307, 507) and a diaphragm (104, 304, 404, 504) whose peripheral portion is joined
to the upper end of the voice coil. ), The gap between the voice coil and the plate, and the
magnetic field filled in at least one of the gap between the voice coil and the yoke. A speaker
(100, 203, 300, 400) comprising a fluid (110, 310, 410, 510, 610) and at least one means (108,
308, 411, 506, 708) for evenly distributing the magnetic fluid , 500, 700).
Speaker and apparatus provided with the same
[0001]
The present invention relates to the configuration of a speaker.
[0002]
BACKGROUND ART In recent years, with the demand for stylish appearance of TVs and mobile
devices, narrowing of the frame for thinning the outer frame around display devices has
progressed.
Therefore, in general, the shape of the speaker installed in the frame portion is required to be
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more elongated.
[0003]
However, in the case of an elongated speaker, the width in the short side direction is narrowed,
so that the width of the suspension for holding the diaphragm can not be sufficiently secured.
Therefore, the stiffness of the suspension is increased, and the lowest resonance frequency f0 of
the speaker is also increased. As a result, the characteristics of the low band are degraded, and a
problem occurs that the reproduction bandwidth is reduced. In order to address this problem,
Patent Document 1 proposes a conventional speaker that uses a magnetic fluid and a divided
suspension and does not reduce the reproduction bandwidth even if it is an elongated speaker.
[0004]
FIG. 22 (a) is a view showing a cross-sectional view of a speaker 600 using magnetic fluid and
divided suspensions in the conventional speaker in Patent Document 1, and FIG. 22 (b) is a
cutting line A- of FIG. 22 (a). It is the figure which looked at the speaker 600 in the arrow C
direction, when the speaker was disconnected by B. FIG. The speaker 600 includes a yoke 601, a
magnet 602, a plate 603, a diaphragm 604, suspensions 605a and 605b, a voice coil 606, a
sound hole 608, a rib 609, and a magnetic fluid 610. The magnet 602 has a front outer shape in
the form of a track, and is adhered to an inner bottom surface of a box-shaped yoke 601 whose
upper surface is open. The plate 603 has a front outer shape in the form of a track, and is
adhered to the upper surface of the magnet 602. A magnetic air gap 607 is formed between the
yoke 601 and the plate 603. Thus, the yoke 601, the magnet 602, and the plate 603 constitute a
magnetic circuit that forms the magnetic air gap 607. A sound hole 608 penetrating the yoke
601, the magnet 602, and the plate 603 along the central axis O is formed in the yoke 601, the
magnet 602, and the plate 603. The diaphragm 604 is formed with a plurality of ribs 609
parallel to the short side of the diaphragm 604. Suspensions 605 a and 605 b are provided on
the short side of the diaphragm 604 as a support that vibratably supports the diaphragm 604.
That is, no suspension is provided all around the diaphragm 604, and a plurality of independent
suspensions (divided suspensions) are provided in part of the suspension. The suspensions 605 a
and 605 b are made of the same material as the diaphragm 604, and are integrally formed with
the diaphragm 604. The voice coil 606 has a front outer shape and a front inner shape in the
form of a track, and is disposed in the magnetic air gap 607. The magnetic air gap 607 is filled
with the magnetic fluid 610 in addition to the voice coil 606. In the conventional speaker 600 in
Patent Document 1, the magnetic fluid 610 is filled only on the inner peripheral side of the voice
coil 606 in the magnetic gap 607.
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[0005]
According to the above configuration, the suspensions 605a and 605b that vibratably support
the diaphragm 604 are provided on the outer periphery of the diaphragm 604 and at mutually
different positions. Thus, even if the speaker is miniaturized, the stiffness and the minimum
resonance frequency of the speaker can be reduced by adjusting the width and thickness of the
suspensions 605a and 605b. Furthermore, by enclosing the magnetic fluid 610, it is possible to
suppress interference and rolling between sound waves generated on each surface of the
diaphragm 604. As described above, by using the loudspeaker 600 using the magnetic fluid 610
and the divided suspensions 605a and 605b, it is possible to improve the reduction of the
reproduction bandwidth, which is a problem with an elongated loudspeaker.
[0006]
International Publication No. 2009/066415 International Publication No. 2009/016743
[0007]
In the above-described conventional speaker 600, reduction of the reproduction bandwidth can
be suppressed by using the divided suspensions 605a and 605b and the magnetic fluid 610.
However, the above-described conventional speaker 600 does not have a configuration
considered in regard to uniformly distributing the magnetic fluid 610 in the magnetic gap 607.
Therefore, in a speaker using an elongated shape like the above-mentioned conventional speaker
600, in some cases, the magnetic fluid 610 is partially concentrated, and an air gap is formed in
the magnetic gap 607 between the voice coil 606 and the plate 603. As a result, there has been a
problem of causing rolling and deterioration of low frequency characteristics.
[0008]
The speaker in the present disclosure includes a magnetic circuit including a magnet, a plate
fixed to one of the magnetic pole surfaces of the magnet, and a box-like yoke having an inner
bottom surface fixed to the other magnetic pole surface of the magnet, A voice coil disposed so
as to be vertically vibrated in a magnetic gap formed by a plate and the yoke, a diaphragm having
a peripheral edge portion joined to an upper end of the voice coil, and a gap between the voice
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coil and the plate A magnetic fluid filled in at least one of the voice coil and the gap of the yoke is
provided, and at least one means for evenly distributing the magnetic fluid is provided.
[0009]
In the speaker according to the present disclosure, a magnetic circuit including a magnet, a plate
fixed to one magnetic pole surface of the magnet, and a box-like yoke having an inner bottom
surface fixed to the other magnetic pole surface of the magnet. A voice coil disposed so as to be
vertically vibrateable in a magnetic gap formed by the plate and the yoke, a diaphragm having a
peripheral edge portion joined to an upper end of the voice coil, and the voice coil and the plate
A magnetic fluid filled in at least one of the gap and the gap between the voice coil and the yoke,
wherein the shape of the inner edge of the outer magnetic pole of the magnetic circuit with
respect to the voice coil and the magnetic circuit with respect to the voice coil The shape of the
outer edge of the inner magnetic pole means two substantially straight portions facing each
other in top view and two curved portions facing each other, The curved portion has a convex
shape on the side, and the gap between the inner edge of the outer magnetic pole and the outer
edge of the inner magnetic pole is formed by the substantially straight portions with each other
and the curved portions with each other. The interval is characterized in that it is smaller
between each other's curved portions than between each other's substantially straight portions.
[0010]
According to the present disclosure, since the magnetic fluid can be uniformly distributed in the
magnetic gap, generation of an air gap in the magnetic gap can be suppressed, whereby low-pass
characteristics due to sound leakage can be suppressed. Degradation and rolling can be
prevented.
[0011]
FIG. 1 is a cross-sectional view of a loudspeaker according to the present disclosure.
FIG. 2 is a diagram showing the difference in magnetic flux density distribution between the
conventional loudspeaker and the loudspeaker according to the present disclosure.
FIG. 3 is a partially enlarged view of a conventional speaker and a speaker according to the
present disclosure.
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FIG. 4 is a cross-sectional view of a loudspeaker according to a modification of the present
disclosure. FIG. 5 is a front external view of a flat-screen television equipped with the speaker
according to the present disclosure. FIG. 6 is a cross-sectional view of another loudspeaker
according to the present disclosure. FIG. 7 is a cross-sectional view of yet another loudspeaker
according to the present disclosure. FIG. 8 is a cross-sectional view of yet another loudspeaker
according to the present disclosure. FIG. 9 is a top view of yet another loudspeaker according to
the present disclosure. FIG. 10 is a cross-sectional view of the speaker of FIG. FIG. 11 is a view
showing the arrangement of the lead-out portion. FIG. 12 is a diagram showing the holding state
of the magnetic fluid. FIG. 13 is a diagram showing the distribution of magnetic flux. FIG. 14 is a
cross-sectional view of yet another loudspeaker according to the present disclosure. FIG. 15 is a
top view of the speaker of FIG. FIG. 16 is a top view of yet another loudspeaker according to the
present disclosure. FIG. 17 is a cross-sectional view of the speaker of FIG. FIG. 18 is a diagram for
describing a speaker array according to the present disclosure. FIG. 19 is a partial cross-sectional
view of an inner-ear headphone according to the present disclosure. FIG. 20 is a diagram for
explaining a portable information terminal according to the present disclosure. FIG. 21 is a
diagram for explaining a video and audio information terminal according to the present
disclosure. FIG. 22 is a structural sectional view of a conventional speaker. FIG. 23 is a structural
cross-sectional view of the speaker disclosed in Patent Document 1. As shown in FIG. FIG. 24 is a
structural cross-sectional view of the speaker disclosed in Patent Document 2. As shown in FIG.
[0012]
The present disclosure includes a magnetic circuit including a magnet, a plate fixed to one
magnetic pole surface of the magnet, and a box-like yoke having an inner bottom surface fixed to
the other magnetic pole surface of the magnet, and the plate A voice coil disposed so as to be
vertically vibrateable in a magnetic gap formed by the yoke, a diaphragm having a peripheral
edge portion joined to an upper end of the voice coil, a gap between the voice coil and the plate,
The first speaker includes a magnetic fluid filled in at least one of a voice coil and a gap between
the yokes and at least one means for evenly distributing the magnetic fluid. The present
disclosure also includes a magnetic circuit including a magnet, a plate fixed to one of the
magnetic pole surfaces of the magnet, and a box-like yoke having an inner bottom surface fixed
to the other magnetic pole surface of the magnet, A voice coil disposed so as to be vertically
vibrated in a magnetic gap formed by a plate and the yoke, a diaphragm having a peripheral edge
portion joined to an upper end of the voice coil, and a gap between the voice coil and the plate A
shape of an inner edge of an outer magnetic pole of the magnetic circuit with respect to the voice
coil, and an inner magnetic pole of the magnetic circuit with respect to the voice coil. The shape
of the outer edge of each is two substantially straight portions facing each other in top view, and
two curved portions facing each other, each having a convex shape on the outside. And a gap
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between the inner edge of the outer magnetic pole and the outer edge of the inner magnetic pole
is formed by the substantially straight portions with each other and the curved portions with
each other, and the distance between the gaps is the distance between the outer portions. It
includes a second speaker smaller between the curved portions and between the substantially
straight portions.
[0013]
Thereby, since the magnetic fluid can be uniformly distributed in the magnetic gap, generation of
air gaps in the magnetic gap can be suppressed, whereby deterioration of low frequency
characteristics due to sound leakage or It is possible to prevent rolling.
[0014]
In addition, as another aspect of the first speaker, it is possible to adopt the following
configuration.
[0015]
For example, as the means, a sound hole may be provided so as to penetrate the plate and the
magnet.
Further, for example, the sound holes may be formed by combining respective openings of the
same shape formed in each of the plate and the magnet.
Also, for example, when viewed in the through axis direction of the sound hole, a point closest to
the outer periphery of the plate from the center of gravity of the sound hole is taken as a first
point, and the shortest distance between the first point and the outer periphery of the sound hole
A first distance, and a point furthest from the center of gravity of the sound hole to the outer
periphery of the plate is a second point, and a shortest distance between the second point and
the outer periphery of the sound hole is a second distance The first distance may be less than the
second distance. As a result, the magnetic flux distribution can be equalized by adjusting the
distance to realize uniform distribution of the magnetic fluid.
[0016]
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In addition to the above, the following configuration may be mentioned as a method for making
the magnetic flux distribution uniform by adjusting the distance. For example, as the means, a
plurality of sounds provided so as to penetrate through the plate, the magnet, and the yoke by
combining respective openings of the same shape formed in the plate, the magnet, and the yoke,
respectively. It may have a hole. Further, for example, the sound hole may be provided at least at
a portion where the magnetic flux density is high. For example, the outer peripheral shape of the
horizontal cross section of the magnet is a track shape, and the sound hole is a track shape when
viewed in the penetrating axis direction, and the position where the magnetic flux density of the
magnetic flux passing through the outer periphery of the linear portion of the magnet is reduced
May be provided. Also, for example, as the means, the voice coil may be adjusted in shape so as
to evenly distribute the magnetic fluid in the gap. Further, for example, sound holes are provided
so that the respective openings of the same shape formed in each of the plate, the magnet, and
the yoke are combined to penetrate the plate, the magnet, and the yoke. The third point is a point
closest to the outer periphery of the plate from the center of gravity of the sound hole when
viewed in the through axis direction of the sound hole, and the shortest distance between the
third point and the voice coil is a third Third distance, where the fourth point is the point furthest
to the outer periphery of the plate from the center of gravity of the sound hole, and the fourth
distance is the shortest distance between the fourth point and the voice coil, the third distance It
may be a fourth distance. Further, for example, an auxiliary magnet provided outside the voice
coil may be provided as the means. For example, the horizontal cross-sectional shape of the voice
coil may be a track shape, and the auxiliary magnet may be provided on the outer periphery in
the short side direction of the voice coil so as to have the same curvature radius as the plate
outer periphery. It is also possible to configure an AV device including a television, a mobile
phone, a smartphone, a tablet terminal, an earphone, and a hearing aid provided with the
speaker.
[0017]
Moreover, it is also possible to take the following structures as another aspect of a 2nd speaker.
For example, the shape of the magnetic circuit may be any of a track shape and a substantially
rectangular shape in top view. Also, for example, the yoke may have at least two slit portions in
the curved portion which allow the lead wire of the voice coil to pass through the magnetic
circuit. This prevents contact with other members of the voice coil lead wire, and further makes
the magnetic fluid evenly distributed by making the magnetic gap width of the notched portion
narrower than the other portions, resulting in high efficiency and high linearity. A small speaker
can be provided. The following are mentioned as a concrete mode of a slit part. For example, the
slit portion may be a notch extending to the upper end of the yoke. Also, for example, the slit
portion may be a through hole provided on the side wall of the yoke so as to have a
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predetermined clearance above and below the vibration range of the lead wire. An inner-ear
headphone, a portable information terminal, and a tablet type video and audio information
terminal provided with the speaker can be configured.
[0018]
(Findings Obtained from the Prior Art) In the conventional speaker 600, the magnetic fluid 610
is concentrated in part because the configuration is not taken into consideration in uniformly
distributing the magnetic fluid 610 in the magnetic gap 607. The problem of ending up occurs.
The inventor of the present application has found that the cause of the concentration of the
magnetic fluid in part is that the shape of the speaker is an elongated shape. In the elongated
speaker, the magnetic flux density in the magnetic air gap curve becomes uneven. For example,
in the conventional speaker 600, the voice coil 606 and the plate 603 forming the magnetic gap
607 have a track shape (a shape formed of two parallel line segments and two curves connecting
opposing ends of the lines) However, since the magnetic flux in the curved portion of the
magnetic air gap 607 is diffused more than that in the straight portion, the magnetic flux density
in the curved portion of the magnetic air gap 607 is lower than that in the straight portion. For
this reason, in some cases, the magnetic fluid will be partially concentrated, and an air gap is
formed in the magnetic gap 607 between the voice coil 606 and the plate 603, causing rolling
and deterioration of the low frequency characteristics. . The present disclosure solves these
found problems.
[0019]
Hereinafter, embodiments of the present disclosure will be described with reference to the
drawings. The embodiments described below each show a preferable specific example of the
present disclosure. Numerical values, shapes, materials, components, arrangement positions and
connection forms of components, steps, order of steps, and the like described in the following
embodiments are merely examples, and are not intended to limit the present disclosure. The
present disclosure is limited only by the claims. Therefore, among the components in the
following embodiments, components not described in the independent claim indicating the
highest concept of the present disclosure are not necessarily required to achieve the problems of
the present disclosure, It is described as constituting a preferred embodiment. In addition, the
same code | symbol is attached | subjected to the same element and description may be
abbreviate | omitted.
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[0020]
Embodiment 1 A cross-sectional view of a loudspeaker 100 according to the present disclosure is
shown in FIG. In the following description, as indicated by the arrow on the right side of FIG. 1A,
the vertical direction is defined with the upper side of the sheet vertically upward and the lower
side of the sheet vertically downward. The horizontal direction is a direction orthogonal to the
vertical direction. Further, in the description of FIG. 1, the “vibration direction” indicates the
same direction as the vertical direction. FIG. 1 (a) is a vertical cross-sectional view of the speaker
100, and FIG. 1 (b) is a view in the direction of arrow C when the speaker is cut along the cutting
line AB in FIG. 1 (a). FIG. The speaker 100 includes a yoke 101, a magnet 102, a plate 103, a
diaphragm 104, suspensions 105a and 105b, a voice coil 106, a sound hole 108, and a magnetic
fluid 110. A magnetic air gap 107 is formed by the yoke 101, the magnet 102, and the plate 103.
The voice coil 106 and the magnetic fluid 110 are disposed in the magnetic air gap 107. Each
configuration will be described below.
[0021]
The yoke 101 has a box-like shape with an open upper surface, and an opening end has a trackshaped opening at the center of the bottom and forms a part of the sound hole 108. Two parallel
line segments form two parallel line segments of the track shape, and two curved line portions
curved in an arc shape so that two curved lines connecting opposite ends of the line segments
are convex outward doing. That is, the long side of the opening of the yoke 101 is linear, and the
short side is curvilinear. Also, the yoke 101 is made of a magnetic material.
[0022]
The outer periphery of the horizontal cross section of the magnet 102 has a track shape. The
magnet 102 has an opening at the center and forms a part of the sound hole 108. The shape of
the opening of the magnet 102 is the same as the shape of the opening provided in the yoke
101. Also, the magnet 102 is bonded to the inner bottom surface of the yoke 101 so that the
position of the opening matches the position of the opening of the yoke 101. The magnetizing
direction of the magnet 102 is magnetized in the same direction as the vibration direction of the
diaphragm 104.
[0023]
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The plate 103 has a track shape at the outer periphery of the horizontal cross section. Similar to
the yoke 101 and the magnet 102, the plate 103 has an opening at the center and forms a part
of the sound hole 108. The shape of the opening of the plate 103 is also the same as the shape of
the opening provided in the yoke 101. Further, the plate 103 is fixed by adhesion or the like on
the upper surface of the magnet 102 which forms one of the magnetic pole surfaces so that the
position of the opening matches the position of the opening of the magnet 102. The lower
surface forming the other magnetic pole surface of the magnet 102 is fixed to the inner bottom
surface of the yoke 101 by adhesion or the like as described above. The magnetic fluid 110 is in
contact with the outer periphery of the plate 103. The plate 103 is made of a magnetic material.
A point (first point) closest to the outer periphery of the plate 108 from the center of gravity of
the sound aperture 108 in the plate 103 seen in the through axis direction of the sound aperture
108 is P, and the point between the point P and the outer periphery of the sound aperture 108 A
shortest distance is LP (first distance), and a point (second point) farthest from the center of
gravity of the sound hole 108 to the outer periphery of the plate 103 in the plate 103 is Q, and a
point between the point Q and the outer periphery of the sound hole 108 When the shortest
distance is LQ (second distance), there is a relation of LP <LQ. The sound hole 108 may be
formed only by the opening of the plate 103 and the opening of the magnet 102. In this case, at
least the opening of the plate 103 and the opening of the magnet 102 in the yoke 101. There is
no opening provided to fit the
[0024]
The outer peripheral shape of the horizontal cross section of the diaphragm 104 is a track shape.
That is, the long side of the diaphragm 104 is linear and the short side is curved. The diaphragm
104 is made of the same material as the suspension 105a and the suspension 105b, and the
curved portion is integrally formed on the suspension 105a and the suspension 105b and
adhered. The diaphragm 104 may not be integrally formed with the suspensions 105a and 105b,
or may not be made of the same material. Further, the upper end of the voice coil 106 is joined to
the bottom surface outer peripheral portion of the peripheral portion of the diaphragm 104 by
adhesion or the like. Further, as shown in FIG. 1A, a plurality of ribs 109 parallel to the short side
of the diaphragm 104 may be formed. The presence of the ribs 109 can suppress resonance in
the audible band.
[0025]
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The suspension 105 a and the suspension 105 b are bonded to the diaphragm 104 and the yoke
101. The sides to which the suspensions 105 a and 105 b are bonded to the diaphragm 104
have a curved shape. Further, the sides on which the suspensions 105a and 105b are bonded to
the yoke 101 have a linear shape. The plurality of suspensions 105a and 105b are collectively
referred to as a divided suspension because they are bonded to only a part (curved portion)
without covering the entire periphery of the diaphragm. Further, the vertical cross-sectional
shape of the suspension 105a and the suspension 105b is non-linear. The diaphragm 104 is
vibratably held by this shape. In addition, the vertical cross-sectional shape of the suspension
105a and the suspension 105b may be a shape that is convex downward in the vibration
direction as shown in FIG. 1A, or may be a shape that is convex upward. The shapes of the
suspension 105 a and the suspension 105 b are not limited to these. For example, the side
bonded to the yoke 101 may have a curved shape. In this case, of course, the side to be bonded
to the suspension 105 a and the suspension 105 b of the yoke 101 has a curved shape.
[0026]
The voice coil 106 has a horizontal cross-sectional shape that is a track shape and a threedimensional shape that is a tubular shape. The upper end in the vertical direction of the voice coil
106 is bonded to the bottom outer periphery of the diaphragm 104. Further, the lower end in the
vertical direction of the voice coil 106 is disposed in the magnetic air gap 107. The magnetic
fluid 110 is in contact with the lower end in the vertical direction and the inner periphery of the
voice coil 106. Thus, the voice coil 106 is arranged in the magnetic gap 107 so as to be able to
vibrate in the vertical direction.
[0027]
The sound holes 108 (means for evenly distributing the magnetic fluid) are constituted by
openings of the same shape provided in the yoke 101, the magnet 102 and the plate 103
respectively. The shape of the sound hole 108 is a track shape seen in the through axis direction
as shown in FIG. 1 (b).
[0028]
The magnetic fluid 110 fills the space on the outer periphery of the plate 103 and the inner
periphery of the voice coil 106 without any gap. Generally, the magnetic fluid 110 may be filled
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in at least one of the gap between the voice coil 106 and the plate 103 and the gap between the
voice coil 106 and the yoke 101.
[0029]
The operation of the speaker 100 configured as described above will be described. When an
electrical signal is input to the voice coil 106, the voice coil 106 vibrates according to Fleming's
left-hand rule. Since the voice coil 106 is bonded to the diaphragm 104, sound waves are
generated from the diaphragm 104. At this time, since the suspensions 105a and 105b are
partially adhered to the diaphragm 104 without surrounding the entire circumference of the
diaphragm 104, the stiffness of the suspensions 105a and 105b is equal to the stiffness of the
suspension surrounding the general circumference of the diaphragm. It will be much lower than
that. Thereby, the lowest resonance frequency can be reduced, and the reduction of the
reproduction bandwidth can be suppressed.
[0030]
Further, since the sound holes 108 are designed to uniformly distribute the magnetic fluid 110
on the outer surface of the plate 103, the magnetic fluid 110 can be uniformly distributed in the
magnetic gap formed inside the voice coil 106. .
[0031]
The result of having compared the magnetic flux density distribution of the plate side surface in a
conventional structure and this indication in FIG. 2 is shown.
2 corresponds to a position within the distance X along the plate periphery between the position
X0 of the point P and the position X1 of the point Q, as the horizontal axis is indicated by the
arrow in FIG. 1 (b), the vertical axis Indicates the height of the magnetic flux density. The result
of the magnetic flux density distribution in the conventional configuration is shown by a solid
line, and the result of the magnetic flux density distribution of the present disclosure is shown by
a dotted line. According to FIG. 2, in the conventional configuration, the distribution of the
magnetic flux density is uneven due to the influence of the sound hole and the magnetic air gap
curve, but in the present disclosure, the magnetic flux density distribution in the magnetic air gap
is constant. Since the sound holes are designed, the distribution of magnetic flux density is
uniform as compared with the conventional configuration. Therefore, in the present disclosure,
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the magnetic fluid 110 can be uniformly distributed on the side surface of the plate 103.
[0032]
Here, the reason why the distribution of magnetic flux density becomes uniform will be described
by providing the sound holes 108 as shown in the present disclosure. FIG. 3 (a) shows an
enlarged part of the conventional speaker 600, and FIG. 3 (b) shows an enlarged part of the
speaker 100 in the present disclosure. As shown in FIG. 3A, in the conventional speaker, the
magnetic flux density in the linear portion of the track shape is high, and the magnetic flux
density in the curved portion is low. On the other hand, in the present disclosure of FIG. 3 (b), the
magnetic flux density in the linear portion is reduced by the formation of the sound holes 108.
Accordingly, the distribution of magnetic flux density becomes uniform. The distribution of the
magnetic flux density can be made uniform by providing such a sound hole, for example, at a
location where the magnetic flux density becomes relatively high assuming that there is no sound
hole. When the track-shaped magnet is provided as in the speaker 100, for example, a sound hole
is provided at a position where the magnetic flux density of the magnetic flux penetrating the
outer periphery of the linear portion of the magnet is reduced. For the above reasons, in the
speaker 100 in the present disclosure, the magnetic fluid 110 is not partially concentrated as in
the conventional speaker 600. As a result, no gap is created in the space on the outer periphery
of the plate 103 and the inner periphery of the voice coil 106, so the space under the sound hole
108 and the diaphragm 104 is kept sealed by the magnetic fluid. That is, leakage of the sound
generated in the lower space of the divided suspension from the space under the sound hole 108
and the diaphragm 104 is suppressed. That is, it is possible to prevent the deterioration of the
low frequency characteristics and the rolling due to the sound leakage.
[0033]
Furthermore, the sound holes 108 are designed to uniformly distribute the magnetic fluid 110
on the outer surface of the plate 103, so that the magnetic fluid 110 can be injected without bias
when injecting the magnetic fluid into the magnetic circuit in the assembly stage. it can.
Therefore, adhesion of the magnetic fluid 110 to the inner side surface of the yoke 101 can be
suppressed.
[0034]
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Furthermore, regarding the sound waves radiated from the sound holes 108, in the present
disclosure, the sound holes 108 are provided so as to extend in the long side direction, so the
sound waves radiated from the center and the end of the diaphragm 104 interfere due to the
path difference. Can be prevented. As a result, even if the speaker 100 has an elongated shape,
sound waves can be emitted without impairing the high-frequency characteristics that are
susceptible to interference due to the path difference.
[0035]
Next, a speaker device 700 which is a modified example of the present disclosure will be
described using FIG. 4. The difference between the speaker device 700 and the speaker device
100 is a sound hole 708. The sound hole 708 is one in which three circular holes are arranged.
By forming the hole with such a shape, the magnetic fluid 110 can be easily designed, and the
magnetic fluid 110 can be uniformly distributed in the magnetic air gap formed inside the voice
coil 106. The number of holes is not limited to three. Here, as described with reference to FIG. 3,
in the case of a track-shaped speaker, the location where the nonuniformity of the magnetic flux
density significantly occurs is near the boundary between the linear portion and the curved
portion, and the linear portion near this (high magnetic flux density A sound hole may be
provided at a position where the magnetic flux density is reduced at the point). That is, the
present disclosure can also be applied to shapes other than the track shape (for example, shapes
such as rectangles and shapes other than circular). Even in such a case, the sound hole may be
designed so as to reduce the magnetic flux density at the portion where the magnetic flux density
is high at the portion where the nonuniformity of the magnetic flux density is significantly
generated.
[0036]
Next, an example in which the speaker of the present disclosure is mounted on a flat-screen
television will be described. FIG. 5 is a diagram showing the configuration of a flat-screen
television equipped with the speaker of the present disclosure. Here, FIG. 5 is a front external
view of the flat-screen television. In the figure, reference numeral 201 denotes a set case, 202
denotes a display unit such as a PDP, liquid crystal or organic EL, and 203 denotes a speaker.
The speakers 203 are provided inside set housings on both sides of the display unit 202. As the
speaker 203, any of the speakers 100, 300, 400, 500, and 700 in the present disclosure can be
adopted.
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[0037]
The operation of the flat-screen television configured as described above will be described.
Although not shown here, when the acoustic signal processed by the signal processing unit is
input to the left and right speakers 203, the sound is reproduced from the speaker 203. The
speaker 203 has an elongated shape in accordance with the narrow frame design of the
television, but since the sound hole is designed so that the magnetic flux density on the outer
surface of the plate is constant, the magnetic gap formed by the magnetic coil by the voice coil
and the plate Since they are uniformly distributed in the interior, a thin-screen television
excellent in bass reproduction can be realized in a state in which the reduction of low frequency
characteristics and the rolling by air holes are suppressed. In the present disclosure, the speakers
are disposed at both ends of the display unit, but the number of speakers and the installation
position thereof are not limited.
[0038]
A cross-sectional view of a loudspeaker 300 according to the present disclosure is shown in FIG.
In the same manner as described above, the vertical direction, the horizontal direction, and the
vibration direction are defined. 6 (a) is a vertical cross-sectional view of the speaker 300, and FIG.
6 (b) is a diagram showing the speaker 300 in the direction of arrow C when the speaker 300 is
cut along the cutting line AB in FIG. 6 (a). It is the figure which looked at. The speaker 300
includes a yoke 301, a magnet 302, a plate 303, a diaphragm 304, suspensions 305a and 305b,
a voice coil 306, a sound hole 308, and a magnetic fluid 310. A magnetic air gap 307 is formed
by the yoke 301, the magnet 302 and the plate 303. The voice coil 306 and the magnetic fluid
310 are disposed in the magnetic air gap 307. The point of difference from the speaker 100 is
that a bonded magnet is used for the magnet 302 and a sound hole 308. Hereinafter, regarding
the operation of the speaker 300, a configuration different from that of the speaker 100 will be
described.
[0039]
The point at which the voice coil 306 vibrates and a sound wave is generated from the
diaphragm 304 is the same as the speaker 100. A significant difference from the speaker 100 is
that a bonded magnet is used for the magnet 302 (means for evenly distributing the magnetic
fluid). Here, the bonded magnet is a flexible magnet obtained by crushing the magnet and
kneading it into rubber or plastic, and is a magnet having a high degree of design freedom in
11-05-2019
15
shape and magnetization direction. Therefore, by using a bonded magnet, the magnetic flux
density can be designed to evenly distribute the magnetic fluid 310 in the magnetic air gap
formed inside the voice coil 306. Therefore, it is not necessary to provide a sound hole shaped
like the speaker 100, and the same effect as the conventional sound hole can be obtained. That
is, it is possible to suppress the occurrence of the air gap between the plate 303 and the voice
coil 306 due to the deviation of the magnetic fluid, and to prevent the deterioration of the low
frequency characteristics and the rolling due to the sound leakage.
[0040]
Furthermore, since the magnetic fluid 310 can be injected without bias when the magnetic fluid
310 is injected into the magnetic circuit in the assembly stage, adhesion of the magnetic fluid
310 to the inner side surface of the yoke 301 can be suppressed. Furthermore, bonded magnets
are easy to process. Therefore, the sound hole 308 can be freely designed so that the sound wave
emitted from the sound hole 308 does not cause the interference of the sound wave emitted
from the center and the end of the diaphragm at the time of molding, thereby suppressing the
interference due to the path difference. Can. Therefore, it is easy to form a sound hole by a
plurality of circular holes as in the speaker 700 of FIG. 4. By forming the sound holes by the
plurality of circular holes, it is possible to emit a sound wave without impairing the
characteristics of the high region susceptible to the interference due to the path difference even
if the speaker is elongated.
[0041]
Thus, in the present disclosure, it is possible to adopt an aspect in which a magnet capable of
freely changing the magnetic flux density in the magnetic gap is adopted as the magnet.
[0042]
A cross-sectional view of a loudspeaker 400 according to the present disclosure is shown in FIG.
In the same manner as described above, the vertical direction, the horizontal direction, and the
vibration direction are defined. 7 (a) is a vertical cross-sectional view of the speaker 400, and FIG.
7 (b) is a diagram showing the speaker 400 in the direction of arrow C when the speaker 400 is
cut along the cutting line AB in FIG. 7 (a). It is the figure which looked at. The speaker 400
includes a yoke 401, a magnet 402, a plate 403, a diaphragm 404, suspensions 405a and 405b,
11-05-2019
16
a voice coil 406, a sound hole 408, a magnetic fluid 410, and an auxiliary magnet 411. The point
different from the speaker 100 is that the auxiliary magnet 411 is provided. Hereinafter, with
respect to the operation of the speaker 400, a configuration different from that of the speaker
100 will be described.
[0043]
The point at which the voice coil 406 vibrates and a sound wave is generated from the
diaphragm 404 is the same as the speaker 100. A large difference from the speaker 100 is that
the auxiliary magnet 411 (means for evenly distributing the magnetic fluid) is bonded to both
ends of the yoke 401 in the short side direction. Since the auxiliary magnet 411 is adjusted in
size and shape so that the magnetic fluid 410 is held uniformly on the outer surface of the plate
403, the magnetic fluid 410 is evenly distributed in the magnetic gap formed inside the voice coil
406. It can be distributed. As a result, it is possible to suppress the occurrence of an air gap
between the plate 403 and the voice coil 406 due to the deviation of the magnetic fluid 410, and
it is possible to prevent the low frequency characteristics from deteriorating and rolling due to
sound leakage.
[0044]
Furthermore, since the magnetic fluid 410 can be injected without bias when the magnetic fluid
410 is injected into the magnetic circuit in the assembly stage, adhesion of the magnetic fluid
110 to the inner surface of the yoke 401 can be suppressed. Further, in the present disclosure,
the auxiliary magnet 411 can increase the magnetic flux density of the magnetic gap curve that
is lacking with respect to the curve of the magnetic gap 407. Therefore, the magnetic flux density
distribution can be made uniform without any decrease in efficiency.
[0045]
A cross-sectional view of a loudspeaker 500 according to the present disclosure is shown in FIG.
In the same manner as described above, the vertical direction, the horizontal direction, and the
vibration direction are defined. FIG. 8A is a vertical cross-sectional view of the speaker 500, and
FIG. 8B is a diagram showing the speaker 500 in the direction of arrow C when the speaker 500
is cut along the cutting line AB in FIG. 8A. It is the figure which looked at. The speaker 500
includes a yoke 501, a magnet 502, a plate 503, a diaphragm 504, suspensions 505a and 505b,
11-05-2019
17
a voice coil 506, a sound hole 508, and a magnetic fluid 510. A different point from the speaker
100 is the shape of the voice coil 506. The operation of the speaker 500 will be described below
with reference to a configuration different from that of the speaker 100.
[0046]
The point at which the voice coil 506 vibrates and a sound wave is generated from the
diaphragm 504 is the same as the speaker 100. A large difference from the speaker 100 is that
the voice coil 506 (means for evenly distributing the magnetic fluid) is used in accordance with
the distribution of the magnetic fluid 510 and deformed. Specifically, in FIG. 8B, the magnetic
flux density in the region E of the linear portion of the track is higher than the region D of the
curved portion of the track. The width w2 of the magnetic air gap 507 is set wide. This condition
is generally the third point (corresponding to the point R in FIG. 8) which is the point closest to
the outer periphery of the plate from the center of gravity of the sound hole when viewed in the
through axis direction of the sound hole. The third distance (corresponding to the width w2 in
FIG. 8) is the shortest distance between them, and the fourth point (corresponding to the point S
in FIG. 8) is the point farthest from the center of gravity of the sound hole to the outer periphery
of the plate. When the shortest distance between the point and the voice coil is a fourth distance
(corresponding to the width w1 in FIG. 8), the third distance> the fourth distance. With such a
configuration, the voice coil 506 has a shape that matches the distribution of the magnetic fluid
510, even if the magnetic fluid 510 is unevenly distributed on the outer surface of the plate 503.
It is possible to suppress the occurrence of air gaps in the magnetic air gaps 507 formed on the
inner side, and to prevent deterioration and rolling of the low frequency characteristics due to
sound leakage. In the present disclosure, the long side direction of the voice coil 506 is
deformed, but any deformation may be applied as long as the deformation conforms to the
distribution of the magnetic fluid.
[0047]
Second Embodiment Next, a description will be further given of a speaker capable of uniformly
distributing a magnetic fluid in a magnetic gap. Further, the following description also relates to
the improvement of the production efficiency and the efficiency improvement of a small-sized
and bass-reproducible speaker. In addition, the code | symbol of each member in the following
description shall be independent of the thing of FIGS. 1-8, FIG.
[0048]
11-05-2019
18
2. Description of the Related Art In recent years, the demand for high-quality earbud headphones
has increased due to the spread of portable information terminals and the spread of life styles for
viewing video and music by individuals. The shape of the ear canal in which the in-ear
headphones are inserted varies depending on the user, so a small speaker with a high degree of
freedom in housing design is required to improve the wearing feeling of more users. Moreover, in
the speaker mounted on the portable information terminal main body, it is required that the
frequency band in which the sound is output is wide and thin. As a system capable of realizing
space saving required for these earbud headphones and portable information terminals and
capable of reproducing the low tone range, one system of an electrodynamic speaker disclosed in
Patent Document 1 has been proposed.
[0049]
FIG. 23 is a structural cross-sectional view of the speaker 1100 disclosed in Patent Document 1.
As shown in FIG. FIG. 23A is a top view of the speaker 1100 in FIG. FIG. 23B is a structural crosssectional view of the speaker 1100 when the speaker 1100 is cut along the line A-O-B shown in
FIG. 23A and viewed from the arrow direction. As shown in FIG. 23, the speaker 1100 of Patent
Document 1 includes a yoke 1101, a magnet 1102, a plate 1103, a diaphragm 1106, edge pieces
1108a to 1108d, a spacer 1109, a voice coil 1107, and a magnetic fluid. And 1110. The
magnetic fluid 1110 is filled on the inner peripheral side of the voice coil 1107 in the magnetic
gap G2. According to the disclosure of Patent Document 1, since the support that vibratably
supports the diaphragm 1106 is configured of a plurality of edge pieces 1108a to 1108d, the
stiffness of the support is reduced even when the speaker 1100 is miniaturized. It is possible to
operate with a large amplitude. Further, since the magnetic fluid 1110 is filled on the inner
peripheral side of the voice coil 1107 in the magnetic gap G2, the sound wave emitted from the
back surface of the diaphragm 1106 leaks to the front surface of the diaphragm 1106 via the
magnetic gap G2. It is possible to prevent the sound wave emitted from the front surface of the
diaphragm 1106 from being canceled and to improve the sound pressure.
[0050]
As described above, according to the disclosure of Patent Document 1, it is possible to expand
the bass range while miniaturizing the speaker. On the other hand, in the space-saving
electrodynamic speaker, the wiring space of the lead wire connecting the voice coil to the
external terminal is narrow, and the risk of abnormal noise and disconnection due to contact with
11-05-2019
19
other members during operation is high. In addition, since a copper wire with a relatively small
wire diameter is used for the purpose of weight reduction, the risk of disconnection due to
bending at the time of assembly is also high for the voice coil of the space-saving electrodynamic
speaker.
[0051]
In order to prevent these problems, a structure has been proposed in which a slit-like notch is
provided on the side surface of the yoke and a lead wire is passed, and the lead wire can be
vibrated without contacting other members. FIG. 24 is a cross-sectional view of the speaker
device 1 disclosed in Patent Document 2. As shown in FIG. The speaker device 1 includes a yoke
21, a magnet 22, a plate 23, a vibrating body 3, a voice coil 33, a lead wire 4, a frame 5, and a
terminal portion 6. The vibrator 3 is omitted in the plan view. Further, a pair of lead wires 4 are
drawn from the voice coil 33. Further, as shown in FIG. 24, the yoke 21 has a notch 71 formed in
the side portion 21C of the yoke. The lead wire 4 is drawn from the lower end of the voice coil
33 in the vicinity of the notch 71, and the end is electrically connected to the terminal 6 formed
on the frame 5 through the notch 71. As a result, even when the voice coil 33 is displaced in the
vertical direction, contact of the lead wire 4 with other members such as the yoke 21 and the
edge 32 can be reduced. As described above, according to the disclosure of Patent Document 2, it
is possible to provide a thin speaker or a small speaker which can vibrate without the lead wire
contacting another member.
[0052]
Hereinafter, the present disclosure will be described with reference to the drawings.
[0053]
The structure of the speaker 100 according to the present disclosure will be described with
reference to FIGS. 9 to 11.
FIG. 9 is a top view of the speaker 100. FIG. Fig.10 (a) is structure sectional drawing when it cut |
disconnects in the 1A-1A 'line cross section of FIG. 10B is a cross-sectional view of speaker 100
taken along line 2A-2A ′ in FIG. 10A. In FIG. 10A, the speaker 100 includes the yoke 101, the
magnet 103, the plate 104, the diaphragm 105, the voice coil 106, the suspensions 107a and
107b, the frame portions 108a and 108b, and the magnetic fluid 109. Equipped with The yoke
11-05-2019
20
101 is in the form of a box whose upper surface is open, and includes notches 102a and 102b.
The external shape of the speaker 100 as viewed from above is long as shown in FIG. The entire
shape of the diaphragm 105 is elongated, and a rib is provided inside the portion fixed to the
voice coil 106. In addition, a rib is not an essential structure. Moreover, the external shape which
looked at the magnetic circuit part of the speaker 100 from the upper surface is a substantially
oval shape which consists of a semicircle part and a linear part, as shown to FIG. 10B. The voice
coil 106 is disposed so as to be vertically vibrated in the gap between the inner periphery of the
side portions 101 a and 101 b of the yoke 101 and the outer periphery of the plate 104, and the
shape viewed from the top is substantially oval. Furthermore, as shown in FIG. 11, the voice coil
106 is provided with lead portions 110a and 110b.
[0054]
The lower surface of the magnet 103 is fixed to the inner bottom surface of the yoke 101 as
shown in FIG. The plate 104 is fixed to the upper surface of the magnet 103. The upper surface
of the magnet 103 forms one of the magnetic poles of the magnet 103, and the lower surface of
the magnet 103 forms the other of the magnetic poles of the magnet 103. Between the side
portions 101a and 101b of the yoke 101 and the plate 104, a cylindrical magnetic gap having a
substantially oval cross section is formed. The voice coil 106 is disposed so as to be able to
vibrate in the magnetic gap in the direction of the central axis O which is the vertical direction.
The magnetic fluid 109 is filled between the plate 104 and the voice coil 106, and distributed in
a substantially oval annular shape in top view. Generally, the magnetic fluid 109 may be filled in
at least one of the gap between the voice coil 106 and the plate 104 and the gap between the
voice coil 106 and the yoke 101. Further, through holes formed in each of the yoke 101, the
magnet 103, and the plate 104, a through hole 111 along the central axis O is provided. The
diaphragm 105 has a peripheral edge portion joined to the top surface of the voice coil 106. The
suspension 107a connects the left end side of the diaphragm 105 to the frame 108a, and the
suspension 107b is installed to connect the right end side of the diaphragm 105 to the frame
108b. The cross-sectional shapes of the suspensions 107a and 107b are curved downward
convex as shown in FIG. 10 (a).
[0055]
Like the shapes of the yoke 101 and the plate 104 described above, the shape of the inner edge
of the outer magnetic pole of the magnetic circuit with respect to the voice coil 106 and the
shape of the outer edge of the inner magnetic pole of the magnetic circuit with respect to the
voice coil 106 face each other in top view And two curved portions facing each other, the curved
11-05-2019
21
portions having an outwardly convex shape. The yoke 101 has at least two slits in the bending
portion for passing the lead wire of the voice coil 106 out of the magnetic circuit.
[0056]
The operation of the speaker 100 configured as described above will be described. When an
electrical signal is input to the voice coil 106, the voice coil 106 vibrates according to Fleming's
left-hand rule. Since the diaphragm 105 is joined to the voice coil 106, it vibrates with the
vibration of the voice coil 106, causing pressure change in the air on the upper surface and the
lower surface, and emitting a sound wave. By using either the upper surface or the lower surface
of the speaker as a radiation surface, it becomes possible to listen to voice.
[0057]
The magnetic fluid 109 is filled between the plate 104 and the voice coil 106, and is held by the
magnetic field generated by the yoke 101, the magnet 103, and the plate 104, thereby
generating the upper and lower surfaces of the speaker 100 with each other. Block the sound
waves of opposite phase and prevent the decrease of the reproduced sound pressure due to the
wraparound of the sound waves. As shown in FIG. 11, the lead-out portion 110a of the voice coil
106 passes through the notch portion 102a of the yoke 101, and the lead-out portion 110b
passes through the notch portion 102b to prevent contact with the frames 108a and 108b and
the yoke 101. It is bent into a shape and finally electrically connected to an external terminal not
shown.
[0058]
Here, the relationship between the shapes of the yoke 101 and the plate 104 and the magnetic
fluid 109 will be described with reference to FIG. 12A to 12C are diagrams showing the speaker
100 with the elements other than the yoke 101, the plate 104, and the magnetic fluid 109
omitted. In FIGS. 12 (a) to 12 (c), FIG. 12 (c) shows the speaker 100. FIG. The distance between
the inner periphery of the yoke 101 and the outer periphery of the plate 104 in FIGS. 12A and
12B is d1, and the inner periphery of the yoke 101 and the plate 104 in the vicinity of the
notches 102a and 102b in FIG. The distance to the outer circumference is d2.
11-05-2019
22
[0059]
Assuming that the magnetic fluid 109 is uniformly distributed around the plate 104 in the shape
of the yoke 101 and the plate 104 in FIG. 12A when the yoke 101 is not provided with the
notches 102a and 102b. . When notches 102a and 102b are provided in the arc portion of yoke
101 without changing the shapes of yoke 101 and plate 104, the distance between the magnetic
poles of yoke 101 and plate 104 in the vicinity of notches 102a and 102b is Because the
magnetic flux density is lowered, the magnetic fluid 109 is retained in the vicinity of the notches
102a and 102b shown in FIG. 12B in a smaller amount than the other portions. As a result, the
magnetic fluid 109 is not filled between the voice coil 106 and the plate 104 and air leakage may
occur, and the sound pressure of the speaker 100 may be reduced. In addition, even when air
leakage does not occur, the distribution of the magnetic fluid 109 is uneven, so the surface
tension of the magnetic fluid weakens the function of holding the voice coil 106 at a
predetermined position, which may cause rolling or the like. . Furthermore, since the
electromagnetic force acting on the voice coil 106 itself is also reduced at the notches 102a and
102b, there is also the possibility of rolling, etc., and the efficiency itself of the speaker 100 is
also reduced.
[0060]
On the other hand, in FIG. 12C, the semicircular portion of the outer periphery of the plate 104 is
closer to the inner periphery of the yoke 101 than in the case of FIGS. 12A and 12B. That is, the
distance d2 between the inner periphery of the yoke 101 and the outer periphery of the plate
104 in the vicinity of the notch portions 102a and 102b is smaller than the distance d1 as shown
in FIG. 12 (c). As a result, the magnetic flux density does not decrease even near the notches
102a and 102b, and the magnetic fluid 109 is uniformly held over the entire circumference.
Therefore, it is possible to prevent the sound pressure drop, the rolling, and the efficiency drop
of the speaker 100 due to the air leak that occur in the configuration of FIG. 12 (b).
[0061]
Therefore, according to the speaker 100, the distance between the inner periphery of the yoke
and the outer periphery of the plate in the vicinity of the notches 102a and 102b is smaller than
that of the other portion, thereby preventing contact with other members of the lead wire and
magnetism. Thus, it is possible to provide a small and thin speaker which achieves both of the
uniform holding of the fluid and the improvement of the reliability and the bass reproduction
11-05-2019
23
ability. Thus, the gap between the inner edge of the outer magnetic pole and the outer edge of
the inner magnetic pole is smaller between the curved portions of each other than between the
substantially straight portions of each other. This has the effect of making the distribution of the
magnetic fluid uniform. That is, this is not effective only for a speaker having a notch. It is
employable also as the speaker which does not have a notch part. That is, not only the abovedescribed problem described in the present embodiment is solved, but adopting the speaker
having no cutout portion also solves the problem described in the first embodiment.
[0062]
Further, according to the speaker 100, the suspensions 107a and 107b are divided in the long
axis direction. That is, the suspension does not cover the entire periphery of the diaphragm.
Therefore, the length in the short axis direction of the speaker 100 can be reduced to the length
in the short axis direction of the yoke 101, and a narrow-width, wide-band reproduction speaker
can be configured.
[0063]
Further, since the lead-out portions 110a and 110b of the voice coil 106 are disposed between
the yoke 101 and the frame portions 108a and 108b and in the space under the suspensions
108a and 108b, the placement places of the lead-out portions 110a and 110b There is no need
to provide Therefore, it is possible to configure a space-saving speaker while making the voice
coil 106 free to vibrate.
[0064]
In order to effectively achieve the purpose of the present disclosure, the detailed shapes of the
notches 102a and 102b of the yoke 101 and the plate 104 may be determined in the following
manner. FIG. 13 shows the distribution (b) of the magnetic flux that causes the magnetic circuit
in the vicinity of the notch 102a in comparison with the case (a) in which the yoke 101 does not
have the notches 102a and 102b. In order to simplify the description, it is assumed that the
polarity of the magnetic circuit is N pole on the plate 104 side and S pole on the yoke 101 side.
The width of the notched portion 102a is set to a height H between the range Y and Y '. The
density per unit area of the magnetic flux passing through the voice coil is the average length of
the magnetic flux lines starting from the plate 104 and ending from the yoke 101 in the range Y-
11-05-2019
24
Y 'in FIGS. 13 (a) and 13 (b). It is inversely proportional to the square of. That is, by setting d2
such that the average length of the magnetic flux lines in the range Y-Y 'is equal to the average
length of the magnetic flux lines when the yoke does not have the notched portion, the magnetic
flux density near the notched portion 102a Can be equal to the magnetic flux density when the
yoke does not have a notch.
[0065]
When the yoke 101 does not have a notch, the average length of the magnetic flux lines may be
regarded as the distance d1 between the inner wall of the yoke 101 and the outer periphery of
the plate 104 as shown in FIG. When the yoke 101 has the notches 102a and 102b, as shown in
FIG. 13B, the average length of the magnetic flux lines becomes a value d2 'longer than the
distance d2 between the inner wall of the yoke 101 and the outer periphery of the plate 104, and
the value d2' It changes with the width H of notch 102a. In practice, the distribution of magnetic
flux lines may be approximated by a quadratic curve such as an arc of an ellipse, and the YY 'may
be divided into a plurality of minute regions, and the average length of magnetic field lines
passing through each minute region may be determined. . In the speaker 100, the entire shape of
the diaphragm 105 is elongated, but the shape of the diaphragm 105 is substantially oval with
substantially the same shape as the magnetic circuit portion, and the long corner portion is cut
out. It may be a form. According to the above-described diaphragm shape, the lead portions 110a
and 110b can be extended to the corner portions, and the range in which the diaphragm 105 can
vertically vibrate without coming into contact with the lead portions 110a and 110b can be
expanded.
[0066]
Further, although the rib of the diaphragm 105 is provided on the inner side of the portion fixed
to the voice coil 106, it may be provided on a long corner. Further, although the shape of the
diaphragm 105 is a flat surface provided with a rib, it may be a dome shape in which the central
portion is convex. According to these diaphragm shapes, by increasing the rigidity of the
diaphragm 105, it is possible to prevent the sound pressure drop due to the divided vibration
and to provide a speaker excellent in the output frequency characteristic in the high frequency
band.
[0067]
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25
The outer shape of the magnetic circuit section as viewed from the top is substantially an oval
shape consisting of a semicircular part and a straight part, but the shape of the magnetic circuit
part is a substantially elongated shape with the corner part as an arc. It may be. According to this
configuration, the volume of the magnet 103 can be further expanded within the shape of the
speaker 100, and a highly efficient speaker can be provided.
[0068]
Further, the lead-out portions 110a and 110b of the voice coil 106 are not limited to the lead-out
arrangement on the long side as shown in FIG. 11. For example, they are extended to the lower
space of the frame portions 108a and 108b. You may pull it out to the side. According to the
present disclosure, various lead wire arrangements can be realized without changing the shape of
the magnetic circuit. Furthermore, since the direction of the voice coil 106 can be stably
maintained by the holding force of the magnetic fluid 109, even if the lead portions 110a and
110b are disposed asymmetrically with respect to the voice coil 106, the tension of the lead wire
is biased. It is possible to reduce the risk of rolling and inefficiency. Therefore, according to the
present disclosure, it is possible to increase the choice of the direction of the terminal portion
without changing the shape of the member, and to provide a low cost and highly customizable
speaker.
[0069]
Further, the positions of the notched portions 102 a and 102 b are not limited to on the long axis
of the speaker 100, and may be formed at an arbitrary position of the semicircular portion of the
yoke 101. For example, the notch portions 102a and 102b are formed between one end of the
semicircular portion of the yoke 101 and the middle point, so that the arrangement of the lead
portions 110a and 110b of the voice coil 106 approaches the long side of the speaker 100. The
possibility of the lead wires 110a and 110b coming into contact with the suspensions 107a and
107b, the frame portions 108a and 108b, and the yoke 101 can be reduced.
[0070]
Moreover, in the speaker 100, although the shape of notch part 102a, 102b is a slit shape
extended from the upper surface of yoke 101 to an inner bottom, it is not restricted to this shape.
11-05-2019
26
As one example, the lower ends of the notches 102 a and 102 b may extend to the outer bottom
of the yoke 101. According to this configuration, the cutaway portions 102a and 102b can be
easily formed by cutting in the side surface direction of the yoke 101 by the cutting means, so
that the processing cost can be reduced. Also, as an example, a filler may be filled in the upper
portions of the notches 102a and 102b. According to this configuration, it is possible to prevent
the drawers 110a and 110b from jumping out above the yoke due to an impact such as falling.
[0071]
In the speaker 100, the distance between the outer periphery of the plate 104 and the outer
periphery of the yoke 101 in the vicinity of the notches 102a and 102b is reduced by changing
only the shape of the plate 104. The circumference may be close to the plate 104, or the shapes
of both the yoke 101 and the plate 104 may be changed.
[0072]
Further, instead of providing the slit portion as the notch portion, the slit portion may be
provided as a through hole provided on the side wall of the yoke 101 so as to have a
predetermined clearance above and below the vibration range of the lead wire.
[0073]
The structure of the speaker 700 according to the present disclosure will be described with
reference to FIGS. 14 and 15.
FIG. 15 is a top view of the speaker 700. FIG.
14A is a cross-sectional view taken along line 4A-4A 'in FIG. 15 of the speaker 700, and FIG. 14B
is a cross-sectional view taken along line 3A-3A' in FIG. The speaker 700 includes a yoke 701, a
magnet 703, a plate 704, a diaphragm 705, a voice coil 706, suspensions 707a and 707b,
suspension attaching parts 708a and 708b, and a magnetic fluid 709. Although not shown, the
voice coil 706 includes the same lead-out portion as described above. The external shape of the
speaker 700 in top view is substantially rectangular as shown in FIG. The outer shape of the
magnet 703, the plate 704 and the voice coil 706 is substantially rectangular such as a rectangle
with rounded corners, and the outer shape of the yoke 701 and the diaphragm 705 is
substantially rectangular such as a rectangle with rounded corners. .
11-05-2019
27
[0074]
The positional relationship and contact relationship between the yoke 701, the magnet 703, the
plate 704, the diaphragm 705, the voice coil 706 and the magnetic fluid 709 are substantially
rectangular in shape of the yoke 701, the magnet 703, the plate 704, the diaphragm 705 and the
voice coil 706. Except that the yoke 701 does not have a notch, and is the same as that described
in FIGS. In addition, you may form a notch similarly.
[0075]
The operation of the speaker 700 having the above configuration is the same as the operation of
the speaker 100.
[0076]
The structure of the speaker 200 according to the present disclosure will be described with
reference to FIGS. 16 and 17.
The figure is a top view of the speaker 200. 17A is a cross-sectional view taken along line 5A-5A
'in FIG. 16 of the speaker 200, FIG. 17B is a cross-sectional view taken along line 5B-5B' in FIG.
16 for the speaker 200, and FIG. FIG. 6 is a cross-sectional view of the speaker 200 taken along
line 6A-6A 'in FIG. The speaker 200 includes a yoke 201, a magnet 203, a plate 204, a
diaphragm 205, a voice coil 206, suspensions 207a to 207d, suspension attaching sections 208a
to 208d, and a magnetic fluid 209. The voice coil 206 is provided with drawers 210a and 210b
as shown in FIG. 17 (c). The yoke 201 includes notches 202a and 202b. The external shape of
the speaker 200 in top view is substantially square as shown in FIG. The outer shape of the
magnet 203, the plate 204, and the voice coil 206 is a substantially perfect circular shape, and
the outer shape of the yoke 201 and the diaphragm 205 is a substantially elliptical shape having
the major axis in the vertical direction in the figure.
[0077]
The positional relationship and contact relationship between the yoke 201, the magnet 203, the
plate 204, the diaphragm 205, the voice coil 206, the magnetic fluid 209, and the notches 202a
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and 202b are the yoke 201, the magnet 203, the plate 204, the diaphragm 205, and the voice
coil. Except that the shape of 206 is substantially circular shape, it is the same as that of what
was demonstrated in FIGS. The notched portions 202a and 202b are provided on side walls in
the short diameter direction of the yoke 201 as linear notches that are point symmetrical with
respect to the center of the speaker 200 and are inclined with respect to the short axis. The
suspensions 207a to 207d are arranged in four bands as shown in FIG. 16 unlike the ones
described in FIGS. 9 to 13 and are connected to the diaphragm 205 at the center side and fixed
to the suspension sticking portions 208a to 208d. It is done.
[0078]
The operation of the speaker 200 having the above configuration is the same as the operation of
the speaker 100.
[0079]
In the speaker 200, the outer periphery of the plate 204 has a substantially perfect circular
shape, while the inner periphery of the side wall portion of the yoke 201 has a substantially
elliptical shape.
Thus, the distance between the inner periphery of the yoke 201 and the outer periphery of the
plate 204 near the notch portions 202 a and 202 b is smaller than the distance between the
inner periphery of the yoke 201 and the outer periphery of the plate 204 in the major axis
direction of the yoke 201. Therefore, similar to the speaker 100, it is possible to provide a smallsized and thin-typed speaker with improved reliability and low-pitched sound reproducing ability,
while simultaneously preventing contact with other members of the lead wire and equally
holding the magnetic fluid. .
[0080]
Further, in the speaker 200, since the notched portions 202a and 202b are provided in a straight
line inclined to the side wall of the yoke 201, it is possible to easily provide a space for bending
the lead wires 210a and 210b inside the speaker 200. The risk of breakage of the lead wires
210a, 210b due to the pulling force can be avoided.
[0081]
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In the speaker 200, the outer periphery of the plate 204 has a substantially perfect circular
shape, and the inner periphery of the side wall portion of the yoke 201 has a substantially
elliptical shape, but the shapes of the plate 204 and the yoke 201 are not limited thereto.
For example, the outer shape of the magnet 203, the plate 204, and the voice coil 206 may be
substantially elliptical with the major axis in the left-right direction of FIG. 16A, and the outer
shape of the yoke 201 and the diaphragm 205 may be substantially circular.
[0082]
Further, in the speaker 200, the notches 202a and 202b are straight cuts that are pointsymmetrical to each other and are inclined with respect to the short axis, but the notches 202a
and 202b are mutually in the short axis direction of the yoke 201. It may be a linear symmetrical
cut. According to this configuration, both of the lead wires 210a and 210b can be drawn outside
without bending at the root, and the risk of breakage of the lead wires 210a and 210b due to
repeated bending can be avoided.
[0083]
The structure of the speaker array 311 according to the present disclosure will be described with
reference to FIG. 18A is a top view of the speaker array 311, and FIG. 18B is a cross-sectional
view of the speaker array 311 taken along line 7A-7A 'in FIG. The speaker array 311 consists of
four speakers 300 arranged in a straight line. The speaker 300 has a shape and a configuration
similar to the speaker 200, and includes the yoke 301, the magnet 303, the plate 304, the
diaphragm 305, the voice coil 306, the suspensions 307a to 307d, and the suspension sticking
portions 308a to 308d. , And magnetic fluid 309. The voice coil 306, as shown in FIG. 17A,
includes the lead portions 310a and 310b. The yoke 301 includes notches 302a and 302b.
Among the suspension attaching parts 308a to 308d, the suspension attaching parts 308a 'and
308d of the adjacent speakers 300 are integrated with the suspension attaching parts 308c' of
the adjacent speakers 300, respectively.
[0084]
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30
The operation of the speaker 300 having the above configuration is the same as the operation of
the speaker 200. Therefore, similar to the speaker 200, the prevention of the contact with the
other member of the lead wire and the uniform holding of the magnetic fluid can be compatible.
As a result, according to the speaker array 311 of the present disclosure, it is possible to provide
a narrow and thin speaker array with improved reliability and bass reproduction capability.
[0085]
Further, in the speaker 300, the notch portion 302b and the notch portion 302a 'of the adjacent
speaker 300 are connected to the outside on the same side with respect to the 7A-7A' cross
section of the lead portion 310b and the lead portion 310a '. It is designed to As a result, it is
possible to prevent the contact between the lead portions of the adjacent speakers 300 and to
prevent the generation of abnormal noise.
[0086]
In the speaker array 311, the speaker 300 has a substantially square shape according to the
speaker 200. However, the shape of the speaker 300 is not limited to this, and the speaker 300
according to the speaker 100 as described in FIG. 14 and FIG. Alternatively, the loudspeakers
300 may be arranged in the long side direction. According to this configuration, a narrower
speaker array 311 can be realized.
[0087]
Also, although the yoke 301 has been described in the figure formed by the cylindrical side wall
and the bottom portion, the yoke 301 is formed as a plurality of cylindrical depressions, and the
rectangular outer periphery of the speaker array 311 is the outer wall of the yoke 301 It may be
integrated. In this case, it is desirable that the notched portion be provided as a groove of an
integrally configured pedestal. According to this configuration, it is not necessary to form the
yokes 301 separately, and the manufacturing cost can be reduced.
[0088]
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31
Also, although the four speakers 300 constituting the speaker array 311 are described as being
provided with the lead-out portions 310a and 310b independent of one another, the lead-out
portions of the voice coils 306 of the adjacent speakers 300 are made common and the speaker
300 is used. You may connect in series. In this case, it is desirable that the shape of the notch be
a straight line passing through the 7A-7A 'line cross section. According to this configuration, the
end of the lead-out portion of the speaker array 311 can be made only at two places on both
ends of the speaker array 311, and the risk of contact between the lead-out portion and another
member can be further reduced.
[0089]
An example in which the speaker 100 is mounted on the inner ear headphone 410 will be
described with reference to FIG. FIG. 19 is a partial cross-sectional view of the inner ear
headphone 410. As shown in FIG. In FIG. 19, among the components of the inner ear headphone
410, the speaker 400, the case 402, the cross section of the ear tip 403, the housing 407, and
the cord 408 are shown. Case 402 has a front volume 404, a port 405, and a back sound hole
406. The speaker 400 has a shape and a configuration similar to the speaker 100, and the
surface of the diaphragm opposed to the magnetic circuit is a sound wave emitting surface, and
the listener's speaker receives the sound through the front volume 404, the port 405 and the ear
tip 403. Output sound in the ear canal.
[0090]
Here, the speaker 400 achieves both the prevention of contact with the other member of the lead
wire and the uniform holding of the magnetic fluid by adopting the configuration of the present
disclosure. As a result, even if the inner ear headphone 410 moves due to movement or shaking
of the wearer and the magnetic fluid receives an external force that moves the magnetic fluid
relative to the magnetic circuit, the efficiency decline due to the uneven distribution of the
magnetic fluid and the air due to the drop of the magnetic fluid It is possible to prevent the
occurrence of a leak and to prevent the reduction in volume.
[0091]
Also, by attaching the speaker 400 to the back of the earpiece at an angle, the port portion can
be made smaller so that it can be inserted into the entrance of the ear canal, and at the same time
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the opposite phase sound radiated from the back sound hole 406 is heard Can be prevented from
interfering with the volume reduction. Therefore, according to the inner-ear headphone 410
according to the present disclosure, by configuring the plate according to the present disclosure,
it is possible to reproduce a wide band from the low tone range to the high tone range while
being small, and improving the feeling of wearing It is possible to provide an inner ear
headphone having high sound quality.
[0092]
An example in which the speaker 100 is mounted as an audio receiver of a portable information
terminal will be described with reference to FIG. FIG. 20A is an external view of the portable
information terminal 510. FIG. FIG. 20B is a cross-sectional view of portable information terminal
510 taken along line 10A-10A ′. In FIG. 20, of the components of the portable information
terminal 510, a speaker 500, a housing 502, a display 503, a substrate 504, and a sound hole
505 are shown.
[0093]
The speaker 500 is housed in the housing 502 in a state of being attached to a perforated
portion provided on the substrate 504. In addition, the speaker 500 has a shape and
configuration according to the speaker 100, and outputs a call voice to the user's ear via the
sound hole 505, with the surface opposed to the magnetic circuit as the sound wave emitting
surface. Similar to the inner-ear headphones 410, the above-described speaker 500 prevents the
occurrence of the efficiency drop due to the uneven distribution of magnetic fluid and the drop
of magnetic fluid due to the movement or shaking of the portable information terminal 510 by
adopting the configuration of the present disclosure. It is possible to prevent a drop in volume.
[0094]
An example in which the speaker 200 is mounted as a speaker of a tablet type video and audio
information terminal will be described with reference to FIG. FIG. 21A is an external view of the
video and audio information terminal 610. FIG. 21B is a sectional view taken along line 9A-9A ′
or a sectional view taken along line 9B-9B ′ of the audiovisual information terminal 610. In FIG.
21, among the components of the video and audio information terminal 610, a speaker module
600, a case 602, a display 603, a case reinforcing frame 604, and a sound hole 605 are shown.
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The speaker module 600 is housed in the housing 602 in a state of being attached to the housing
reinforcing frame 604. In addition, the speaker module 600 has a shape and configuration
according to the speaker array 311, and outputs a call voice to the user's ear via the sound hole
605, with the surface opposed to the magnetic circuit as the sound wave emitting surface. .
Similar to the inner ear headphones 410, the above-described speaker module 600 prevents the
occurrence of efficiency drop due to uneven distribution of magnetic fluid or drop of magnetic
fluid due to movement or shaking of the video and audio information terminal 610 by adopting
the configuration of the present disclosure. , Can prevent the volume drop.
[0095]
Although the speaker array 311 in which the speakers 200 are arranged is described in FIG. 18,
the configuration and shape of the speakers to be arranged are not limited to this, and the
configuration and shape of the speakers 100 may be arranged.
[0096]
In addition, although an example in which the speaker 100 is mounted is illustrated in FIGS. 19
and 20, the configuration and the shape of the speaker are not limited to this, and the
configuration and the shape of the speaker 200 may be employed.
[0097]
Although FIG. 21 illustrates an example in which the speaker array 311 according to FIG. 18 is
mounted, the configuration and shape of the speakers are not limited to this, and the
configuration and shapes of the speakers 100 and 200 are also illustrated. good.
[0098]
Moreover, although the example which mounted the speaker and speaker array which concern
on this indication in inner-ear headphones, a portable information terminal, and a tablet type
video audio information terminal was shown in FIG. 19, 20 and 21, the apparatus to mount is
limited to this. Instead, for example, a hearing aid, a headset, a display device, etc. may be
provided with the loudspeaker according to the present disclosure.
[0099]
As described above, according to the present disclosure, even in the case of a loudspeaker having
an elongated shape, the distribution of the magnetic fluid in the magnetic gap can be made
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uniform. Even with an elongated shape, it realizes a speaker excellent in bass reproduction.
In addition, in the case of earphones and hearing aids, since a long and narrow shape that fits in
the ear canal can be realized, a speaker can be installed near the tympanic membrane.
As a result, the same sound pressure level can be realized with the conventional input voltage as
well.
[0100]
In addition, the speaker according to the present disclosure can provide a small and thin speaker
with improved reliability and low-pitched sound reproduction capability, such as inner-ear
headphones, portable information terminals, video and audio information terminals, hearing aids,
headsets, It can be used for display devices and other AV devices.
[0101]
1 to 8 and FIG. 22 for 100, 203, 300, 400, 500, 600, 700 Speakers 101, 301, 401, 501, 601
Yokes 102, 302, 402, 502, 602 Magnets 103, 303, 403, 503 , 603 plates 104, 304, 404, 504,
604, diaphragms 105a, 105b, 305a, 305b, 405a, 405b, 505a, 505b, 605a, 605b suspensions
106, 306, 406, 506, 606 voice coils 107, 307, 507 607 Magnetic air gaps 108, 308, 408, 508,
608, 708 Sound holes 109, 609 Ribs 110, 310, 410, 510, 610 Magnetic fluid 201 Housing 202
Display part 411 Auxiliary magnets P, Q, R, S Point LP , Q Distance w1, w2 Width FIGS. 9 to 21,
FIG. 23, FIG. 24 for 100, 200, 300, 400, 500, 700, 1100, 1200 Speakers 101, 201, 301, 701,
1101, 21, 1201 Yoke 102a, 102b, 202a, 202b, 302a, 302b, 1202a, 1202b Notches 103, 203,
303, 703, 1102 Magnets 104, 204, 304, 704, 1103, 23, 1204 Plates 105, 205, 305, 705, 1106
Vibrations Plates 106, 206, 306, 706, 1107, 33, 1206 Voice coils 107a, 107b, 207a-207d,
307a-307d, 707a, 707b Suspensions 108a, 108b Frames 208a-208d, 308a -308 d, 308 a ', 308
c', 708 a, 708 b Suspension attaching portions 109, 209, 309, 709, 1110, 1209 Magnetic fluids
110a, 110b, 210a, 210b, 310a, 310b Drawers 311 Speaker array 410 Inner ear headphones
402 Case 404 Front volume 405 port 406 back sound hole 407 housing 408 code 510 portable
information terminal 502, 602 housing 503, 603 display 504 substrate 505, 605a to 605d
sound hole 610 video and audio information terminal 600a to 600d speaker module 604
housing reinforcement frame 1108a to 1108d Edge piece 1109 Spacer G2 Magnetic gap 1
Speaker device 21C Side portion 22 Magnet 3 Vibrator 4 Lead wire 5 Frame 6 Terminal portion
71 Notched portion
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