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JP2016039550

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This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
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DESCRIPTION JP2016039550
To suppress the occurrence of side lobes. When an acoustic signal is supplied, a coil (100)
provided on a diaphragm vibrates in the front-rear direction according to the acoustic signal. In
the air gap 70 in which the coil 100 is located, the upper magnetic flux density is smaller than
the lower magnetic flux density because the upper width is larger than the lower width. At the
upper part of the air gap 70, the force acting on the coil 100 is smaller compared to the lower
side where the magnetic flux density is large, so the displacement of the upper side of the
diaphragm becomes smaller than the lower side, and the sound of the sound generated on the
upper side of the diaphragm The pressure is smaller than the sound pressure of the sound
generated on the lower side. If there is a difference in the sound pressure of the sound generated
between the upper side and the lower side of the diaphragm, the directivity characteristics will be
different compared to the case where there is no difference. [Selected figure] Figure 6
Electro-acoustic transducer
[0001]
The present invention relates to an electroacoustic transducer.
[0002]
As an electroacoustic transducer which arranges a conductor pattern on the surface of a
diaphragm and this conductor pattern is located in a magnetic gap, there is an electroacoustic
transducer indicated by patent documents 1, for example.
12-05-2019
1
In this electro-acoustic transducer, when an audio signal is passed through the conductor pattern
in the magnetic gap, a driving force is generated by the magnetic field of the magnetic gap and
the magnetic flux change generated by the current flowing through the conductor pattern, and
the diaphragm is displaced. Do. The diaphragm is displaced in accordance with the audio signal,
and the displacement direction is changed sequentially to become vibration, and a sound wave
corresponding to the vibration state (frequency, amplitude, phase) is generated from the
diaphragm.
[0003]
Japanese Patent Laid-Open No. 2002-78079
[0004]
In the electro-acoustic transducer of Patent Document 1, the width of the magnetic gap in which
the conductor pattern is located is constant along the longitudinal direction of the conductor
pattern.
Therefore, the strength of the magnetic field acting on the conductor pattern becomes uniform,
and in the longitudinal direction of the conductor pattern, there is no difference in the driving
force acting between the central portion and the end portion, and the amplitude of the
diaphragm is different. Will not occur. Therefore, in the speaker having such a structure, the
occurrence of unnecessary side lobes in the directivity characteristic can not be suppressed. For
this reason, even if the direction of the main lobe of the speaker is determined and it is intended
to emit a sound to a predetermined area, the sound generated by the side lobe is also emitted to
other than the direction, and the sound is generated outside the predetermined area. However, it
may cause an unwanted sound to be heard, howling may occur, and the intelligibility may be
reduced.
[0005]
The present invention has been made under the above-described background, and an object of
the present invention is to provide a technique for suppressing the occurrence of side lobes in
directional characteristics.
[0006]
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2
In order to solve the problems described above, according to the present invention, a pair of
vertical split cylindrical surfaces are formed in parallel, and a vibrating body in which valleys are
formed between adjacent vertical split cylindrical surfaces, and the valley A conversion unit for
converting a vibration along a depth direction of the unit and an electrical signal corresponding
to the vibration, and a support unit for vibratably supporting the vibrator in the depth direction
of the valley, An electro-acoustic transducer is provided that reduces vibration at least at one end
side in the extension direction of the valley portion of the vibrating body.
[0007]
In the present invention, the conversion unit includes a magnetic circuit having an air gap along
the extension direction of the valley, and a coil provided in the vibrator and flowing in the air gap
and through which the electric signal flows. The magnetic flux density may be different between
one end side and the other end side of the air gap.
[0008]
Further, in the present invention, the conversion portion may be disposed at a position deviated
from the center of the extension direction of the valley portion of the vibrator.
[0009]
Further, in the present invention, the vibration suppression member may be provided to suppress
the vibration of one end of the valley portion in the extending direction of the vibrator from the
vibration of the other end.
[0010]
Further, in the present invention, the conversion unit has a magnetic circuit having an air gap,
and a coil provided in the vibrator, and located in the air gap and through which the electric
signal flows, and the coil is The density of the conductor per unit area may be different between
the end side and the center side in the extending direction of the valley.
[0011]
Further, in the present invention, the conversion unit has a magnetic circuit having an air gap,
and a coil provided in the vibrator, and located in the air gap and through which the electric
signal flows, and the coil is One end side of the valley in the extending direction may be located
in the air gap, and the other end side may be located outside the air gap.
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3
[0012]
Further, in the present invention, the conversion unit is a plurality of voice coil motors disposed
along the extension direction of the valley, and the plurality of the conversion units are directed
from one end side to the other end side in the extension direction of the valley. The amplitudes of
the electrical signals flowing through the voice coil motor may be different.
[0013]
According to the present invention, the occurrence of side lobes can be suppressed.
[0014]
BRIEF DESCRIPTION OF THE DRAWINGS The external view of the speaker 1 which concerns on
one Embodiment of this invention.
The front view of the speaker 1.
AA sectional view taken on the line of FIG.
BB sectional drawing of FIG.
The external view of diaphragm 20A.
The coil 100 and the schematic diagram of a magnetic circuit.
The figure which showed the example of arrangement | positioning of the speaker 1. FIG.
The figure which showed the modification of the speaker 1. FIG.
The figure which showed the speaker 1F which concerns on a modification.
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4
The external view of diaphragm 20C. Sectional drawing of the speaker 1A which concerns on
2nd Embodiment. CC sectional view taken on the line of FIG. The coil 100 and the schematic
diagram of the magnetic circuit of 2nd Embodiment. Sectional drawing of the speaker 1B which
concerns on 3rd Embodiment. The coil 101 and the schematic diagram of the magnetic circuit of
3rd Embodiment. Sectional drawing of the modification of 3rd Embodiment. Sectional drawing of
the modification of 3rd Embodiment. Sectional drawing of the speaker 1C which concerns on 4th
Embodiment. Sectional drawing of speaker 1D which concerns on 5th Embodiment. Sectional
drawing of the speaker 1E which concerns on 6th Embodiment. The figure which showed the
diaphragm 20A which concerns on the modification of 6th Embodiment. The figure which
showed the diaphragm 20E which concerns on 7th Embodiment. The figure which showed the
diaphragm 20G which concerns on the modification of 7th Embodiment. The figure which
showed the diaphragm 20J which concerns on the modification of 7th Embodiment. The figure
which showed the diaphragm 20K which concerns on the modification of 7th Embodiment. The
figure which showed the diaphragm 20L which concerns on the modification of 7th Embodiment.
The disassembled perspective view of the speaker 1H which concerns on 8th Embodiment. The
perspective view showing the assembling state of speaker 1H. The top view of speaker 1H.
[0015]
First Embodiment [Structure] FIG. 1 is an external view of a speaker 1 (electro-acoustic
transducer) according to an embodiment of the present invention, FIG. 2 is a front view of the
speaker 1, and FIG. It is an AA line sectional view. 4 is a cross-sectional view taken along the line
B-B of FIG. In the figure, the directions are indicated by the X, Y, and Z axes orthogonal to each
other. The left and right direction when the speaker 1 is viewed from the front is the direction of
the X axis, and the front and back direction is the direction of the Y axis, height ) Direction is the
direction of the Z axis. In the following description, for convenience of explanation, the positive
direction side of the X axis is the right side, the negative direction side of the X axis is the left
side, the positive direction side of the Y axis is the front side, the negative direction side of the Y
axis is the rear side, The positive direction side may be referred to as the upper side, and the
negative direction side of the Z axis may be referred to as the lower side. The dimensions of the
respective members in the drawing are different from the actual dimensions so that the shapes
and positional relationships of the respective members can be easily understood.
[0016]
The speaker 1 is roughly divided into a housing, a magnetic circuit, a support member for
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5
supporting the magnetic circuit, and a vibrator. The housing is composed of a top plate 10A, a
bottom plate 10B, a side plate 10C, a side plate 10D, and a side plate 10E. The top plate 10A, the
bottom plate 10B, the side plate 10C, the side plate 10D, and the side plate 10E are, for example,
plates obtained by processing wood into a rectangular shape. In addition, the material of each
board is not limited to a wood, A synthetic resin etc. may be sufficient. The magnetic circuit is
composed of a magnet 30, yokes 40A to 40C, and spacers 50A and 50B. The magnet 30 is a rodshaped magnet having a rectangular cross section. As shown in FIG. 4, the magnet 30 is disposed
by the support member 60 so that the longitudinal direction is along the Z-axis direction, and the
N pole is the front side and the S pole is the rear side when viewed from the upper side. The
support member 60 is, for example, a square bar of synthetic resin. One end of the support
member 60 in the longitudinal direction is fixed to the side plate 10E, and the magnet 30 is fixed
to the other end. In the present embodiment, one end of the support member 60 is fixed to the
central portion of the side plate 10E. The support member 60 is a member that supports the
magnet 30.
[0017]
The yoke 40A, the yoke 40B and the yoke 40C are rectangular iron plates in the present
embodiment. The yoke 40 </ b> A, the yoke 40 </ b> B and the yoke 40 </ b> C are members for
controlling the path of magnetic lines of force of the magnet 30. The yokes 40A and 40B are
arranged such that the longitudinal direction is along the Z-axis direction. The yoke 40A is
disposed in contact with the N pole of the magnet 30, and the yoke 40B is disposed in contact
with the S pole of the magnet 30. The yoke 40C is disposed on the right side of the yokes 40A
and 40B at an interval, and the spacer 50A is sandwiched on the upper side between the yoke
40C and the yokes 40A and 40B, and the spacer 50C is sandwiched on the lower side. It is done.
Thus, the yoke 40C is connected to the yoke 40A on the front side via the spacers 50A and 50B,
and connected to the yoke 40B on the rear side via the spacers 50A and 50B.
[0018]
The spacer 50A and the spacer 50B are rectangular synthetic resin plates in the present
embodiment. The spacer 50A and the spacer 50B are members for setting the width of the air
gap 70 between the yoke 40C and the yokes 40A and 40B. Each spacer is formed of a material
that allows magnetic lines of force to pass, and as shown in FIG. 4, the length of the spacer 50A
in the left-right direction is longer than the length of the spacer 50B in the left-right direction.
And the air gap 70 along the extension direction of the valley of the vibrating body 20 is wider as
it goes from the lower side to the upper side. That is, the air gap 70 is configured to have
12-05-2019
6
different widths at one end and the other end in the longitudinal direction of the air gap 70.
[0019]
By arranging the magnet 30, the yokes 40A to 40C, and the spacers 50A and 50B as described
above, a magnetic circuit is formed in the housing of the speaker 1. The direction of magnetic
lines of force in the magnetic circuit is a direction from the yoke 40A to the yoke 40C between
the yoke 40A and the yoke 40C, and a direction from the yoke 40C to the yoke 40B between the
yoke 40B and the yoke 40C. ing.
[0020]
The vibrating body 20 is composed of a diaphragm 20A and a diaphragm 20B. The diaphragm
20A and the diaphragm 20B are rectangular and flexible synthetic resin films. The diaphragm
20A is fixed to the side plate 10E at both ends in the front-rear direction, and as shown in FIG. 3,
the diaphragm 20A is bent so that the central portion is positioned in the air gap 70 when
viewed from the upper side. That is, when viewed from the upper side, the diaphragm 20A is
curved so as to be gradually separated from the side plate 10E as it goes from the fixed part to
the central part. As a result, the diaphragm 20A has a vertically split cylindrical shape obtained
by dividing the cylindrical member in the direction of the central axis. Hereinafter, the surface of
the vertically split cylindrical shape is referred to as a vertically split cylindrical surface. Further,
both ends in the front and rear direction of the diaphragm 20B are fixed to the side plate 10C,
and as shown in FIG. 3, the diaphragm 20B is bent so that the central portion is positioned in the
air gap 70 when viewed from the upper side. It has a vertically split cylindrical shape. Further,
portions of the diaphragm 20A and the diaphragm 20B located in the air gap 70 are joined to
each other, and are not in contact with the respective yokes. By joining the diaphragm 20A and
the diaphragm 20B, the vibrating body 20 has a shape in which longitudinally divided cylindrical
surfaces are arranged in parallel. And between the diaphragm 20A and the diaphragm 20B, a
valley part is linearly formed along the up-and-down direction of a vertical split cylindrical
surface. The shapes of the cross sections taken along the line A-A of the diaphragm 20A and the
diaphragm 20B are formed in line symmetry in the left-right direction with respect to the
common tangent line of the diaphragm 20A and the diaphragm 20B as viewed from above.
Although it is preferable, in the present invention, it does not necessarily have to be line
symmetrical.
[0021]
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7
The diaphragm 20A and the diaphragm 20B are not limited to a configuration in which a
rectangular film is bent. For example, a longitudinally split cylindrical shape is obtained by
vacuum forming a film made of a synthetic resin such as polypropylene or polyester. It may be
molded in the shape of Moreover, the material of the vibrating body 20 is not limited to a
synthetic resin, In addition, materials, such as paper and a metal, can be used. The vertically split
cylindrical surface does not necessarily have to be a single circular arc surface, but a plurality of
continuous curvatures, the cross section viewed from the upper side has a constant or
continuous change in curvature such as a parabolic shape or a spline curve A thing, what was
made into a square tube-like surface, and what was made into the shape which has a several step
part in step shape etc. is employable.
[0022]
FIG. 5 is an external view of the diaphragm 20A. As shown in the drawing, the coil 100 is
disposed in a portion of the diaphragm 20A to be joined to the diaphragm 20B (a central portion
in the front-rear direction when disposed in the housing). In addition, the conducting wire which
forms the coil 100 is not limited to a conducting wire whose cross section is circular, and may be
a strip-like conducting wire. The coil 100 is disposed so that the longitudinal direction is along
the vertical direction of the diaphragm 20A, one end of the lead wire of the coil is connected to
the lead wire 101A, and the other end is connected to the lead wire 101B. The coil 100 may be
provided not on the diaphragm 20A but on the diaphragm 20B. The coil 100 and the abovedescribed magnetic circuit function as a conversion unit that converts the vibration of the
vibrating body 20 and an acoustic signal that is an electrical signal corresponding to the
vibration.
[0023]
[Operation] Next, the operation of the speaker 1 (electroacoustic transducer) will be described
below. When an acoustic signal is supplied to the lead wires 101A and 101B, the acoustic signal
flows through the coil 100, and the diaphragms 20A and 20B vibrate. Here, a mechanism in
which the diaphragms 20A and 20B vibrate will be described with reference to FIG. The figure is
a view schematically showing the coil 100, the magnet 30 constituting the magnetic circuit, and
the yokes 40A to 40C. In addition, in order to prevent that a drawing becomes complicated,
illustration of spacer 50A, 50B is abbreviate | omitted in FIG.
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8
[0024]
In the coil 100 and the magnetic circuit, the lengths in the vertical direction are substantially the
same as the lengths of the diaphragms 20A and 20B. When current flows in the direction of the
arrow shown in FIG. 6, coil 100 is displaced to the positive side (front side) of the Y axis, and
when current flows in the direction opposite to the direction shown in FIG. , The negative
direction side (rear side) of the Y axis. When the coil 100 is displaced, the diaphragms 20A and
20B are displaced together with the coil 100. The diaphragms 20A and 20B are displaced in the
positive direction or the negative direction of the Y axis, ie, in the depth direction of the valleys
according to the acoustic signal, and the displacement direction changes to become vibration as
the displacement direction changes successively. Sound waves corresponding to the amplitude
and phase) are generated from the diaphragms 20A and 20B.
[0025]
In the present embodiment, the width of the air gap 70 between the yokes 40A and 40B and the
yoke 40C is wider from the lower side to the upper side, as shown in FIGS. The wider portion has
a smaller magnetic flux density than the narrower portion. And since the upper part of the coil
100 is located in the region where the magnetic flux density is smaller in the air gap 70 than in
the lower side, the force acting on the upper part of the coil 100 is smaller than the force acting
on the lower side. That is, in the conversion unit constituted by the magnetic circuit and the coil
100, the conversion efficiency between the force acting on the vibrating body 20 and the
acoustic signal flowing through the coil 100 is one end side of the valley in the vibrating body 20
and the other. Unlike the end side, the conversion efficiency at one end side is smaller than that
at the other end side. In the diaphragms 20A and 20B, when the magnitude of the force acting
between the upper side and the lower side is different, the upper side vibration amplitude is
different from the lower side vibration amplitude, and the upper side vibration amplitude
becomes smaller than the lower side vibration amplitude. . That is, the vibration of the vibrating
body 20 has a portion with large amplitude and a portion with small amplitude in the extending
direction of the valley portion of the vibrating body 20. Then, on the upper side where the
vibration amplitude decreases, the sound pressure of the generated sound decreases as
compared to the lower side.
[0026]
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9
As described above, when the sound pressure of the sound generated by the diaphragms 20A
and 20B differs depending on the location in the vertical direction, the directional characteristics
differ from the case where the sound pressure of the generated sound is uniform in the vertical
direction. Become. For example, as shown in FIG. 7, when the speakers 1 with the top 10A side
up and the speakers 1 with the top 10A side down are arranged vertically, the sound generated
on the side close to the top 10A The sound pressure of the sound is small, and the sound
pressure of the sound generated on the bottom plate 10B side is large. That is, since the sound
pressure at the end in the vertical direction is smaller than the sound pressure at the central
portion in the vertical direction of the two stacked speakers 1, the side lobes can be reduced in
the sound generated from the two speakers 1 it can. Also in FIG. 7, the magnetic circuit is
omitted to prevent the drawing from being complicated.
[0027]
In FIG. 7, in order to arrange two sets of diaphragms 20A and 20B up and down, the
configuration is such that the speakers 1 are vertically stacked, but the configuration in which
two sets of diaphragms 20A and 20B are arrayed up and down is It is not limited to this
configuration. For example, as shown in FIG. 8, two sets of the diaphragms 20A and 20B, the coil
100, and the magnetic circuit may be arranged in one case. In FIG. 8 as well, illustration of the
magnetic circuit is omitted in order to prevent the drawing from being complicated. In the
configuration shown in FIG. 8, a magnetic circuit configured of the magnet 30, the yokes 40A to
40C, and the spacers 50A and 50B is also provided for the lower pair of diaphragms 20A and
20B. In the magnetic circuit provided for the lower pair of diaphragms 20A and 20B, the width of
the air gap 70 is wide on the bottom plate 10B side and narrow on the top plate 10A side. Also in
this configuration, the sound pressure of the sound generated at both end portions in the vertical
direction becomes lower than the sound pressure of the sound generated at the central portion,
and the side lobe can be reduced.
[0028]
In the present invention, the shape of the vibrator is not limited to the above-described shape.
FIG. 9 is a cross-sectional view when the speaker 1F according to the modification is cut at the
same portion as the line AA in FIG. The speaker 1F has a vibrating body 22 in place of the
vibrating body 20. The vibrating body 22 is composed of a diaphragm 20C and a diaphragm
20D. FIG. 10 is a view showing a diaphragm 20C provided in the speaker 1F. As shown in FIGS. 9
and 10, in the speaker 1F, the shape of the diaphragm is different from that of the abovedescribed embodiment. The diaphragm 20C is bent and vibratably supported so that its front end
12-05-2019
10
is fixed to the front end of the side plate 10E and its rear end is located in the air gap 70. The coil
100 is disposed on the diaphragm 20C, but may be provided not on the diaphragm 20C but on
the diaphragm 20D.
[0029]
The front end of the diaphragm 20D is fixed to the front of the side plate 10C. The diaphragms
20C and 20D are joined to each other at their rear portions, and the coil 100 is positioned in the
air gap 70. In this configuration, since the positional relationship between the magnetic circuit
and the coil 100 is as shown in FIG. 6 as in the above embodiment, when an acoustic signal is
supplied to the coil 100, the magnetic circuit and the coil 100 are used. In the conversion unit,
the conversion efficiency between the force acting on the vibrator and the acoustic signal flowing
through the coil 100 differs between the one end and the other end in the extension direction of
the valley of the vibrator 20, and the conversion efficiency at one end is Since the vibration
plates 20C and 20D are smaller than the other end side, the upper amplitude is smaller than the
lower amplitude. Then, on the upper side where the amplitude decreases, the sound pressure of
the generated sound decreases as compared to the lower side.
[0030]
Second Embodiment Next, a loudspeaker 1A according to a second embodiment of the present
invention will be described. The speaker 1A differs from the first embodiment in the
configuration of the magnetic circuit as compared with the first embodiment. The housing and
the diaphragms 20A and 20B have the same configuration as the first embodiment. For this
reason, about the same structure as 1st Embodiment, description is abbreviate | omitted and the
difference with 1st Embodiment is demonstrated hereafter.
[0031]
11 is a cross-sectional view when the speaker 1A is cut at the same part as the line AA in FIG. 2,
and FIG. 12 is a cross-sectional view along the line CC in FIG. The supporting member 60A is, for
example, a square bar of synthetic resin, and one end in the longitudinal direction is fixed to the
side plate 10C, and the magnet 30A is fixed to the other end. The support member 60A is a
member that supports the magnet 30A. In the present embodiment, the support member 60A is
fixed to the central portion of the side plate 10C.
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11
[0032]
The magnet 30A is a rod-shaped magnet having a rectangular cross section. As shown in FIG. 12,
the magnet 30A is supported by the support member 60A, with the south pole on the front side
and the north pole on the rear side. The yoke 40D and the yoke 40E are rectangular iron plates.
The yoke 40D is disposed in contact with the S pole of the magnet 30A, and the yoke 40E is
disposed in contact with the N pole of the magnet 30A. Here, the magnet 30A, the yoke 40D and
the yoke 40E are disposed inclined when viewed from the front side, and the air gap 70 between
the set of the yokes 40A and 40B and the set of the yokes 40D and 40E is the upper side. The
width of the is wider than the width of the lower side.
[0033]
FIG. 13 is a view schematically showing the coil 100 and members constituting the magnetic
circuit according to the present embodiment. In the coil 100 and the magnetic circuit, the lengths
in the vertical direction are substantially the same as the lengths of the diaphragms 20A and
20B. When an acoustic signal is supplied to the coil 100, the coil 100 is displaced in response to
a change in the current of the acoustic signal. Then, the diaphragms 20A and 20B vibrate
together with the coil 100, and sound waves are generated from the diaphragms 20A and 20B.
Also in the present embodiment, the width of the air gap 70 is wider from the lower side to the
upper side as shown in FIGS. That is, also in the present embodiment, the air gap 70 along the
extension direction of the valley portion of the vibrating body 20 has a configuration in which
the width is different between one end and the other end of the air gap 70 in the longitudinal
direction. The wider portion has a smaller magnetic flux density than the narrower portion. As a
result, in the conversion unit configured by the magnetic circuit and the coil 100, the conversion
efficiency between the force acting on the vibrating body 20 and the acoustic signal flowing
through the coil 100 is one end side in the extending direction of the valley portion of the
vibrating body 20. Different from the other end side, the conversion efficiency at one end side is
smaller than that at the other end side, and the amplitude on the upper side and the lower side of
the diaphragms 20A and 20B are different. There will be a big part and a small part. Then, on the
upper side where the amplitude decreases in the vibrating body 20, the sound pressure of the
generated sound becomes smaller than in the lower side.
[0034]
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12
If the speaker 1A according to the present embodiment is arranged in the same manner as in FIG.
7, the side lobe can be reduced as in the first embodiment. Also in the present embodiment, if
two sets of diaphragms 20A, 20B, coil 100 and magnetic circuit are arranged in the case as in the
configuration shown in FIG. The sound pressure can be lower than the sound pressure of the
sound generated in the central portion, and the side lobe can be reduced.
[0035]
Third Embodiment Next, a loudspeaker 1B according to a third embodiment of the present
invention will be described. The speaker 1B is different from the second embodiment in the
configuration of the magnetic circuit. The housing and the diaphragms 20A and 20B have the
same configuration as the second embodiment. For this reason, about the same structure as 2nd
Embodiment, description is abbreviate | omitted and the difference with 2nd Embodiment is
demonstrated hereafter.
[0036]
FIG. 14 is a cross-sectional view when the speaker 1B is cut at the same part as the line C-C in
FIG. 11, and FIG. 15 is a schematic view of a magnetic circuit according to the present
embodiment. The speaker 1B includes magnets 31, 31A, yokes 41A, 41B, 41D, 41E, support
members 60, 60A, and a coil 101, and the shape and arrangement of the magnet and the yoke
are different from those of the second embodiment. Specifically, as shown in FIG. 14, in the
relationship between the vertical length of the diaphragms 20A and 20B and the vertical length
of the magnets 31 and 31A, the magnet length is shorter than the diaphragm length. It is a
structure. Further, the lengths in the vertical direction of the yokes 41A, 41B, 41D, 41E are
shorter than the lengths in the vertical direction of the diaphragms 20A, 20B, unlike the aspect of
the first and second embodiments. In short, in the first and second embodiments, the length in
the vertical direction of the coil 100 and the magnetic circuit is substantially the same as the
length of the diaphragm, whereas in the present embodiment, the length in the vertical direction
of the coil 101 and the magnetic circuit is The length is shorter than the diaphragm, and a part of
the diaphragms 20A and 20B in the vertical direction is driven. That is, the vibration of the
vibrating body 20 and the electrical signal corresponding to the vibration are converted at a
position shifted from the center of the extension direction of the valley portion of the vibrating
body 20.
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13
[0037]
The positions of the support members 60 and 60A in the vertical direction are positions deviated
from the center as shown in FIG. 14, and in the present embodiment, are positions above the
center. The position of the support members 60 and 60A in the vertical direction may be below
the center. Since the magnet 31 is fixed to the support member 60 and the magnet 31A is fixed
to the support member 60A, the position of the magnets 31 and 31A is a position above the
center in the present embodiment.
[0038]
The yokes 41A and 41B are in contact with the magnet 31, and the yokes 41D and 41E are in
contact with the magnet 31A. In the present embodiment, the yokes 41D and 41E are disposed
without being inclined as shown in FIG. For this reason, the width of the air gap 70 between the
yoke 41A and the yoke 41D and between the yoke 41B and the yoke 41E is the same at the
upper side and the lower side.
[0039]
As shown in FIG. 15, the length of the coil 101 in the vertical direction is shorter than that in the
second embodiment. In this configuration, since a part above the center of diaphragms 20A and
20B is driven, in diaphragms 20A and 20B, the amplitude on the upper side with coil 101 is
larger than the amplitude on the lower side without coil 101. . That is, in the extension direction
of the valley portion of the vibrating body 20, there are a portion with large amplitude and a
portion with small amplitude.
[0040]
When a difference occurs in the amplitude between the upper side and the lower side of the
diaphragms 20A and 20B by driving a part of the diaphragms 20A and 20B out of the center, the
amplitude decreases at the lower side. Sound pressure becomes smaller than the upper side. And
if two speakers 1B are arranged vertically, the sound pressure of the sound generated on the
upper side and the lower side becomes lower than the sound pressure of the sound generated on
the central portion, and the side lobe can be made smaller. Also in the present embodiment, two
12-05-2019
14
sets of the diaphragms 20A and 20B, the coil and the magnetic circuit are disposed in the
housing, and the magnetic circuit related to the set of the diaphragms located on the upper side
is from the center in the vertical direction The sound pressure of the sound generated at both
end portions in the vertical direction is generated in the central portion by arranging the
magnetic circuit related to the lower pair and the pair of diaphragms positioned lower than the
center in the vertical direction of the diaphragm. Lower than the sound pressure of the sound,
and the side lobe can be made smaller.
[0041]
When the magnets 31 and 31A constituting the magnetic circuit and the coil 101 are disposed
on the upper side or the lower side out of the vertical center of the diaphragm as in the present
embodiment, the yokes 41B and 41E are used instead. The yokes 40B and 40E of the first
embodiment may be employed, and the yokes 40B and 40E may be arranged without being
inclined as shown in FIG. Further, the yokes 40A and 40D of the first embodiment may be
adopted instead of the yokes 41A and 41D, and the yokes 40A and 40D may be disposed without
being inclined as in the yokes 40B and 40E shown in FIG. In this configuration, the positions at
which magnets 31 and 31A are located in the vertical direction are offset from the vertical
position of diaphragms 20A and 20B in the vertical direction, and are offset from the center of
the valley of vibrator 20 in the extending direction. The conversion of the vibration of the
vibrating body 20 and the electric signal corresponding to the vibration is performed. In the
configuration in which the magnet 31 and the coil 101 are disposed on the upper side or the
lower side out of the center in the vertical direction of the diaphragm as in the third embodiment,
the yokes 41D and 41E and the magnet 31A are replaced by Even if the yoke 41C shorter than
the yoke 40C of one embodiment is adopted and the yoke 41C is supported by the support
member 60A and the yoke 41C is opposed to the yokes 41A and 41B and the magnet 31 as
shown in FIG. Good. In this configuration, the positions at which magnets 31, yokes 41A and
41B, and yokes 41C are present in the vertical direction are offset from the central position of
diaphragms 20A and 20B in the vertical direction, and the valleys of vibrators 20 extend in the
extending direction At a position shifted from the center, the vibration of the vibrating body 20
and the electric signal corresponding to the vibration are converted. Further, the yoke 40A of the
first embodiment is arranged by arranging the yoke 40A of the first embodiment on the front
side of the magnet 31 and arranging the yoke 40B of the first embodiment on the rear side of the
magnet 31 by modifying the embodiment of FIG. The length in the vertical direction of 40B may
be equal to the length in the vertical direction of the diaphragms 20A and 20B. In this
configuration, the position where magnet 31 and coil 101 are located in the vertical direction is
offset from the central position of diaphragms 20A and 20B in the vertical direction, and vibrator
20 is in the extension direction of the valley of vibrator 20. At a position shifted from the center,
the vibration of the vibrating body 20 and the electric signal corresponding to the vibration are
12-05-2019
15
converted.
[0042]
Fourth Embodiment A loudspeaker 1C according to a fourth embodiment of the present
invention will now be described. The speaker 1C is different from the second embodiment in the
configuration of the magnetic circuit. The housing and the diaphragms 20A and 20B have the
same configuration as the second embodiment. For this reason, about the same structure as 2nd
Embodiment, description is abbreviate | omitted and the difference with 2nd Embodiment is
demonstrated hereafter.
[0043]
FIG. 18 is a cross-sectional view of the speaker 1 </ b> C cut along the same line as the line CC in
FIG. 11. The speaker 1C includes magnets 30, 30A and support members 60, 60A as in the
second embodiment. Further, the speaker 1C has a yoke 42A, a yoke 42B, a yoke 42D, and a
yoke 42E.
[0044]
The yokes 42B and 42E of the present embodiment are plate-like, but as shown in FIG. 18, the
width in the upper left-right direction is smaller than the width in the lower left-right direction.
Although not shown in FIG. 18, the yokes 42A and 42D also have the same shape as the yokes
42B and 42E, respectively. The yoke 42A is disposed in contact with the N pole of the magnet
30, and the yoke 42B is disposed in contact with the S pole of the magnet 30. The yoke 42D is
disposed in contact with the S pole of the magnet 30A, and the yoke 42E is disposed in contact
with the N pole of the magnet 30A. The magnet 30A is disposed without being inclined when
viewed from the front side as shown in FIG.
[0045]
In the present embodiment, the width of the air gap 70 between the right end face of the yoke
42A and the left end face of the yoke 42D and the width of the air gap 70 between the right end
12-05-2019
16
face of the yoke 42B and the left end face of the yoke 42E are It has the same width from the top
to the bottom. On the other hand, the width of the lower side in the left-right direction is wider
than the upper side. In this configuration, on the upper side where the width of the yoke is
narrow in the magnetic circuit, the magnetic flux density in the air gap 70 is larger than that on
the lower side where the width of the yoke is wide. Since the lower side of the coil 100 is located
in the region of the air gap 70 where the magnetic flux density is smaller than the upper side, the
force acting on the lower side of the coil 100 is smaller than the force acting on the upper side.
That is, in the conversion unit constituted by the magnetic circuit and the coil 100, the
conversion efficiency between the force acting on the vibrating body 20 and the acoustic signal
flowing through the coil 100 is one end side of the valley in the vibrating body 20 and the other.
Unlike the end side, the conversion efficiency at one end side is smaller than that at the other end
side. For this reason, the amplitude on the upper side of the coil 100 is larger than the amplitude
on the lower side, and there are a portion with large amplitude and a portion with small
amplitude in the extending direction of the valley portion of the vibrating body 20. On the lower
side where the amplitudes of the diaphragms 20A and 20B decrease, the sound pressure of the
generated sound decreases as compared to the upper side. By arranging the two speakers 1C
vertically, the sound pressure of the sound generated on the upper side and the lower side of the
speakers 1C arranged vertically can be lower than the sound pressure of the sound generated in
the central portion, and the side lobes It can be made smaller. Also in this embodiment, if two
sets of diaphragms 20A, 20B, coil 100 and magnetic circuit are arranged in the housing, the
sound pressure of the sound generated at both end portions in the vertical direction is generated
at the central portion The sound pressure can be lower than the sound pressure, and the side
lobe can be made smaller.
[0046]
Fifth Embodiment A loudspeaker 1D according to a fifth embodiment of the present invention
will now be described. The speaker 1D differs in the configuration of the magnetic circuit
compared to the second embodiment. The housing and the diaphragms 20A and 20B have the
same configuration as the second embodiment. For this reason, about the same structure as 2nd
Embodiment, description is abbreviate | omitted and the difference with 2nd Embodiment is
demonstrated hereafter.
[0047]
FIG. 19 is a cross-sectional view of the speaker 1D taken along the same line as the line CC in
FIG. The speaker 1D includes the yokes 40A, 40B, 40D, and 40E, and the support members 60
12-05-2019
17
and 60B, as in the second embodiment. Further, the speaker 1D has magnets 32, 32A. As shown
in FIG. 19, the magnets 32 and 32A of the present embodiment have a trapezoidal shape in
which the upper width is wider than the lower width when viewed from the front. Further, as
compared with the second embodiment, the yokes 40A, 40B, 40D, and 40E are disposed without
being inclined with respect to the vertical direction. Therefore, the width of the air gap 70
between the right end face of the yoke 40A and the left end face of the yoke 40D is constant
from the upper side to the lower side, and the air gap between the right end face of the yoke 40B
and the left end face of the yoke 40E. The width of 70 is also constant from top to bottom, and
both widths are the same.
[0048]
On the other hand, in the present embodiment, the width of the upper side in the left-right
direction is wider than the lower side of the magnets 32 and 32A. In this configuration, in the
magnetic circuit, the magnetic flux density in the air gap 70 is larger in the upper part where the
width in the left-right direction of the magnet is wide than in the lower part where the width is
narrow. Since the lower side of the coil 100 is located in the region of the air gap 70 where the
magnetic flux density is smaller than the upper side, the force acting on the lower side of the coil
100 is smaller than the force acting on the upper side. That is, in the conversion unit constituted
by the magnetic circuit and the coil 100, the conversion efficiency between the force acting on
the vibrating body 20 and the acoustic signal flowing through the coil 100 is one end side of the
valley in the vibrating body 20 and the other. Unlike the end side, the conversion efficiency at
one end side is smaller than that at the other end side. For this reason, the amplitude on the
upper side of the coil 100 is larger than the amplitude on the lower side, and there are a portion
with large amplitude and a portion with small amplitude in the extending direction of the valley
portion of the vibrating body 20. Then, on the lower side of the diaphragms 20A and 20B where
the amplitude is smaller, the sound pressure of the generated sound is smaller than that on the
upper side. By arranging two speakers 1D vertically, the sound pressure of the sound generated
at the upper side and the lower side of the vertically arranged speakers 1D can be made lower
than the sound pressure of the sound generated at the central portion, and the side lobe is small
can do. Also in the present embodiment, if two sets of the diaphragms 20A and 20B, the coil 100
and the magnetic circuit are arranged in the housing, the sound pressure of the sound generated
at both end portions in the vertical direction is generated at the central portion The sound
pressure can be lower than the sound pressure, and the side lobe can be made smaller.
[0049]
In the second to fifth embodiments described above, the diaphragms 20C and 20D may be
employed instead of the diaphragms 20A and 20B.
12-05-2019
18
[0050]
Sixth Embodiment A loudspeaker 1E according to a sixth embodiment of the present invention
will now be described.
The speaker 1E is characterized in that the amplitude on one end side in the vertical direction of
the diaphragms 20A and 20B is smaller than that on the other end side as compared with the
second embodiment described above. In the present embodiment, the housing and the
diaphragms 20A and 20B have the same configuration as the second embodiment. For this
reason, about the same structure as 2nd Embodiment, description is abbreviate | omitted and the
difference with 2nd Embodiment is demonstrated hereafter.
[0051]
FIG. 20 is a cross-sectional view of the speaker 1E taken along the same line as the line CC in FIG.
The speaker 1E differs from the second embodiment in that the magnet 30A and the yokes 40B
and 40E are disposed without being inclined as viewed from the front side. Although not shown
in FIG. 20, the yokes 40A and 40D are also arranged without being inclined as viewed from the
front side. Therefore, in the present embodiment, the width of the air gap 70 between the right
end face of the yoke 40A and the left end face of the yoke 40D is constant from the upper side to
the lower side, and the right end face of the yoke 40B and the left end face of the yoke 40E. The
width of the air gap 70 between them is also constant from the upper side to the lower side, and
both widths are the same.
[0052]
In the speaker 1E, the vibration suppression member 80 is disposed above the air gap 70. The
vibration suppressing member 80 is a member that suppresses the vibration of one end of the
valley portion of the vibrating body 20 in the extending direction from the vibration of the other
end. The vibration suppression member 80 is a plate-like member having the same shape as the
spacer 50A, and is fixed to the right end face of the yokes 40A and 40B and the left end face of
the yokes 40D and 40E. Furthermore, on the lower surface side of the vibration suppression
member 80, the upper ends of the diaphragms 20A and 20B are fixed. With such a configuration,
12-05-2019
19
the upper ends of the diaphragms 20A and 20B located in the air gap 70 do not displace as
compared with the lower ends of the diaphragms 20A and 20B.
[0053]
In the present embodiment, since the width of the air gap 70 is the same from the upper side to
the lower side, the force acting on the coil 100 is the same on the upper side and the lower side
of the diaphragms 20A and 20B. However, since the upper ends of the diaphragms 20A and 20B
are fixed to the vibration suppression member 80, the upper ends of the diaphragms 20A and
20B do not vibrate even if an acoustic signal is supplied to the coil 100. In the extension
direction of the valley portion, there are a large portion and a small portion of the amplitude. For
this reason, the amplitude on the upper side and the amplitude on the lower side of the coil 100
are different, and the amplitude increases from the upper side to the lower side. Then, on the
lower side where the amplitude increases, the sound pressure of the generated sound is larger
than that on the upper side. If two speakers 1E are arranged vertically and the vibration
suppressing member 80 is positioned on the upper side and the lower side, the sound pressure of
the sound generated at the upper side and the lower side of the speakers 1E arranged vertically
is the center It becomes lower than the sound pressure of the sound generated in the part, and
the side lobe can be made smaller. Also in this embodiment, if two sets of the diaphragms 20A
and 20B, the coil 100, the vibration suppressing member 80 and the magnetic circuit are
disposed in the housing, the sound pressure of the sound generated at both end portions in the
vertical direction is It can be lower than the sound pressure of the sound generated in the part,
and the side lobe can be reduced.
[0054]
In the present embodiment, the diaphragms 20C and 20D may be employed instead of the
diaphragms 20A and 20B. Further, in the above embodiment, the diaphragms 20A and 20B are
fixed to the vibration suppressing member 80, but instead of the vibration suppressing member
80, the vibration suppressing member 81 may be adopted. A member that is in contact with the
diaphragms 20A and 20B so that friction occurs with the diaphragms 20A and 20B, and a
member that makes the vibration of one end of the valley of the vibrator 20 in the extending
direction smaller than the vibration of the other end It is. Also in this configuration, the vibration
at the upper end of the diaphragms 20A and 20B is suppressed, and the upper and lower ends of
the diaphragms 20A and 20B have different amplitudes. FIG. 21 is a view showing a diaphragm
20A according to a modification of the present embodiment. As shown in FIG. 21, the vibration
suppression member 82 may be added to the diaphragm 20A. In the present embodiment, the
12-05-2019
20
vibration suppression member 82 is a plate-like member, and is fixed to the upper side of the coil
100 in the diaphragm 20A. The vibration suppressing member 82 is also a member that makes
the vibration at one end of the valley portion of the vibrating body 20 in the extending direction
smaller than the vibration at the other end. The vibration suppression member 82 is a member
that adds a mass to the diaphragm 20A. In the diaphragm 20A, the vibration suppression
member 82 is added to make the upper side heavier, and when an acoustic signal is supplied to
the coil 100, the upper side vibration is suppressed and the upper side has smaller amplitude
than the lower side. The configuration in which the weights differ between the upper side and
the lower side of the diaphragm 20A is not limited to the configuration in which the vibration
suppressing member 82 is added, and for example, the plate thickness of the diaphragm 20A is
from the lower side to the upper side It may be made thicker as
[0055]
Seventh Embodiment Next, a loudspeaker 1G according to a seventh embodiment of the present
invention will be described. The speaker 1G is different from the configuration of FIGS. 9 and 10,
which is a modification of the first embodiment, in the configuration of the magnetic circuit and
the diaphragm. The other configuration is the same as the modification of the first embodiment.
For this reason, description is abbreviate | omitted about the same structure as the modification
of 1st Embodiment, and below, difference with the modification of 1st Embodiment is
demonstrated.
[0056]
FIG. 22 is a view showing a diaphragm 20E according to the present embodiment. As compared
with the diaphragm 20C of the modification of the first embodiment, the diaphragm 20E has a
plurality of coils and slits 21 and the plurality of coils are vertically arranged at the rear end of
the diaphragm 20E. It differs in that it is not placed throughout. In the present embodiment, the
diaphragm 20E has two coils 100A and 100B as an example of the plurality of coils. The length
in the vertical direction of coil 100A is shorter than the length from slit 21 to the upper end of
diaphragm 20E, and the length in the vertical direction of coil 100B is the length from slit 21 to
the lower end of diaphragm 20E Shorter than. The coils 100A and 100B are vertically disposed
at the rear end of the diaphragm 20E with the slit 21 interposed therebetween when disposed in
the housing. However, in the diaphragm 20E, both ends in the vertical direction are disposed.
There is a region where the coils 100A and 100B are not disposed on the part side. That is, in the
vertical direction, the coils 100A and 100B are arranged closer to the center side, that is, the slit
21 side, not in the end portion side of the diaphragm. The slits 21 are provided with a
12-05-2019
21
predetermined length from the side where the coils 100A and 100B are located toward the front
side. Further, in the present embodiment, the diaphragm 20F is disposed in the housing in place
of the diaphragm 20D of the modification of the first embodiment. The configuration of the
diaphragm 20F is different from the diaphragm 20E in that the coils 100A and 100B are not
provided, and is similar to the diaphragm 20E in having a slit 21. The diaphragms 20E and 20F
are joined to each other on the side where the slits 21 are provided, and the position of the slit
21 of the diaphragm 20E and the position of the slit 21 of the diaphragm 20F are the same in
the vertical direction. The length of the coils 100A and 100B in the vertical direction is shorter
than that of the coil 100 of the first embodiment. The coil 100A is positioned above the slit 21 in
the diaphragm 20E, and the coil 100B is positioned below the slit 21 in the diaphragm 20E.
[0057]
Next, the magnetic circuit according to the present embodiment will be described. In the present
embodiment, a spacer 51B is provided instead of the spacer 50B. Since the spacer 51B has the
same length in the left-right direction as the spacer 50A, the air gap 70 has the same width from
the upper side to the lower side.
[0058]
When an acoustic signal is supplied to coils 100A and 100B, if the direction of current flowing
through coil 100A in FIG. 22 is clockwise, current is also supplied to coil 100B in the clockwise
direction, and the current flowing through coil 100A When the direction is counterclockwise,
current is also applied to the coil 100B in the counterclockwise direction. In this embodiment,
since the coils 100A and 100B are at positions offset from the vertical center of the diaphragm
20E, the conversion between the vibration of the vibrating body and the acoustic signal which is
an electrical signal corresponding to the vibration is a vibrating body It will be carried out at a
position deviated from the center of the extension direction of the valley of the. In the present
embodiment, since the width of the air gap 70 is the same from the upper side to the lower side,
the forces acting on the coils 100A and 100B in the air gap 70 have the same magnitude.
However, in the diaphragms 20E and 20F, since the slits 21 are provided at the central portion in
the vertical direction and the coils 100A and 100B are disposed close to the slit 21 side, a
moment is applied to the coils 100A and 100B. The central side is driven relatively strongly
compared to the end, and the amplitude of the central portion is larger than the amplitude of the
end. That is, the vibrator has a portion with large amplitude and a portion with small amplitude
in the extension direction of the valley. Then, on the upper end side and the lower end side where
the amplitude decreases, the sound pressure of the generated sound becomes smaller compared
12-05-2019
22
to the central portion, so the side lobe becomes smaller.
[0059]
In the present embodiment, the diaphragms 20E and 20F are configured to have one slit 21 at
the central portion, but the number of slits 21 is not limited to one, and three diaphragms are
used. When arranging the above coils, two or more slits may be formed. That is, the slits may be
formed at positions between the upper and lower directions of the plurality of coils. FIG. 23 is a
view showing a diaphragm 20G according to a modification of the seventh embodiment. The
diaphragm 20G is a diaphragm which is disposed in the housing in place of the diaphragm 20E,
and as shown in FIG. 23, three coils 100C, 100D, 100E arranged in a line in the vertical direction,
and these three And two slits 21 provided between each of the coils 100C, 100D, and 100E. In
addition, in FIG. 23, in order to prevent that a drawing becomes complicated, illustration of the
lead wire which each coil has is abbreviate | omitted. Of the coils 100C, 100D, and 100E
arranged in the vertical direction, the coil 100D at the center has a larger number of turns than
the coil 100C on the upper side and the coil 100E on the lower side. The coils 100C and 100E
have the same number of turns. That is, in the vibrating body, the density of the conductor per
unit area is different depending on the position in the vertical direction, and in the conversion
unit constituted by the magnetic circuit and the coil, the force acting on the vibrating body and
the coil The conversion efficiency with the flowing acoustic signal is different between one end
side and the other end side in the extending direction of the valley portion of the vibrator, and
the conversion efficiency at one end side is smaller than that at the other end side. Therefore,
when the same acoustic signal is supplied to the coils 100C to 100E, the force acting on the
portion of the coil 100D becomes larger than the force acting on the portions of the coils 100C
and 100E.
[0060]
Further, in the present modification, the diaphragm 20H is disposed in the housing in place of
the diaphragm 20F. The configuration of the diaphragm 20H is different from the diaphragm
20G in that the coils 100C to 100E are not provided, and is the same as the diaphragm 20G in
that it has two slits 21. The diaphragms 20G and 20H are joined to each other on the side where
the slits 21 are provided, and the position of the slit 21 of the diaphragm 20G and the position of
the slit 21 of the diaphragm 20H are the same in the vertical direction.
[0061]
12-05-2019
23
Since the slits 21 are respectively provided between the coil 100D and the coils 100C and 100E,
the portion with the coil 100C, the portion with the coil 100D, and the portion with the coil 100E
are easily moved individually. When the acoustic signal is supplied to the coils 100C to 100E so
that the current flows in the same direction, the force acting on the coil 100D becomes larger
than the force acting on the coils 100C and 100E. In the extension direction of the part, there are
a large amplitude part and a small amplitude part, and the part of the coil 100D has a large
sound pressure of the generated sound as compared with the parts of the coils 100C and 100D.
Therefore, in the diaphragms 20G and 20H, the sound pressure of the generated sound is small
on the side close to the top plate 10A and the bottom plate 10B, and the sound pressure of the
generated sound is large in the central portion. That is, since the sound pressure at the end in the
vertical direction is smaller than the sound pressure at the central portion in the vertical
direction, the side lobe can be made smaller.
[0062]
Further, in the configuration in which the width of the air gap 70 is equal in the vertical
direction, the configuration of the diaphragm may be as follows. FIG. 24 is a view showing a
diaphragm 20J according to a modification of the seventh embodiment. In this modification, the
diaphragms 20E and 20F are replaced by diaphragms 20J and 20D, and the portions on the rear
sides of the diaphragms 20J and 20D are joined to each other. As shown in FIG. 24, the
diaphragm 20J has a coil 100F whose length in the vertical direction is shorter than that of the
diaphragm 20J. The coil 100F is disposed at a position deviated from the center of the
diaphragm 20J when viewed in the vertical direction, and is disposed above the center. As a
result, the conversion between the vibration of the vibrating body and the acoustic signal that is
an electrical signal corresponding to the vibration is performed at a position deviated from the
center in the extension direction of the valley portion of the vibrating body.
[0063]
When an acoustic signal is supplied to the coil 100F, the diaphragm 20J is displaced together
with the coil 100F. In this configuration, since a part above the center of the diaphragm 20J is
driven, the vibrator has portions with large amplitude and small amplitude in the extension
direction of the valley, and the diaphragms 20J, 20D The upper amplitude with coil 100F
becomes larger than the lower amplitude. Therefore, in the diaphragm 20J, the sound pressure of
the generated sound becomes smaller on the lower side, and the sound pressure of the generated
12-05-2019
24
sound becomes larger on the upper side. If two speakers using diaphragm 20J are arranged
vertically, the sound pressure at the end in the vertical direction can be made smaller than the
sound pressure in the central portion in the vertical direction, and in the sound generated from
the two speakers Can reduce the side lobes.
[0064]
FIG. 25 is a view showing a diaphragm 20K according to another modification of the seventh
embodiment. In this modification, the diaphragms 20E and 20F are replaced by diaphragms 20K
and 20D, and the portions on the rear sides of the diaphragms 20K and 20D are joined to each
other. As shown in FIG. 25, the diaphragm 20K has a coil 100G. The coil 100G is configured such
that the density of the conductor per unit area is different depending on the position in the
vertical direction, and the density is sparse as going from the upper side to the lower side.
[0065]
When an acoustic signal is supplied to the coil 100G, the diaphragm 20K is displaced together
with the coil 100G. Here, as shown in FIG. 25, in the coil 100G, when viewed in the vertical
direction, the density per unit area of the conducting wire differs depending on the position, and
the number of turns is larger in the upper side than the lower side. In the conversion unit
constituted by the circuit and the coil, the conversion efficiency between the force acting on the
vibrating body and the acoustic signal flowing through the coil differs between the one end side
and the other end side in the extending direction of the valley of the vibrating body The
conversion efficiency on the side is smaller than on the other side. The force acting on the coil
100G is larger on the upper side than on the lower side, and the vibrator has a large amplitude
part and a small amplitude part in the extension direction of the valley. Thereby, in the
diaphragms 20K and 20D, the sound pressure of the generated sound is small on the lower side,
and the sound pressure of the generated sound is large on the upper side. If two speakers using
the diaphragm 20K are vertically arranged, it is possible to reduce the side lobe in the sound
generated from the two speakers.
[0066]
FIG. 26 is a view showing a diaphragm 20L according to another modification of the seventh
embodiment. In this modification, the diaphragms 20L and 20D are used, and when the
12-05-2019
25
diaphragms 20L and 20D are disposed in the housing, the portions that become the rear side are
joined to each other. As shown in FIG. 26, the diaphragm 20L has a coil 100H. The coil 100H is
configured such that the width of the coil in the front-rear direction becomes wider as it goes
from the upper side to the lower side. The coil 100H faces the yoke 40C, but the A portion in the
coil 100H whose width in the front-rear direction is narrower than the width in the front-rear
direction of the yoke 40C, that is, the portion on one end side of the valley of the vibrator in the
extending direction Located inside the 70s. On the other hand, in the coil 100H, the B portion
whose width in the front-rear direction is wider than the width in the front-rear direction of the
yoke 40C, that is, the portion on the other end side of the valley portion of the vibrator in the
stretching direction The coil 100H is positioned outside the air gap 70 as it is positioned
rearward of the side end surface.
[0067]
Then, when an acoustic signal is supplied to the coil 100H, the diaphragm 20L is displaced
together with the coil 100H. Here, since the portion A is located in the air gap 70 and the portion
B is located outside the air gap 70, in the conversion unit configured by the magnetic circuit and
the coil, the force acting on the vibrating body and the coil are The conversion efficiency with the
flowing acoustic signal is different between one end side and the other end side in the extending
direction of the valley portion of the vibrator, and the conversion efficiency at one end side is
smaller than that at the other end side. In the coil 100H, the force acting on the portion A is
larger than the force acting on the portion B, and the vibrator has a portion with large amplitude
and a portion with small amplitude in the extension direction of the valley. As a result, the sound
pressure of the sound generated from the diaphragms 20L and 20D is larger in the upper side
where the acting force is larger than in the lower side. Therefore, if two speakers using the
diaphragm 20L are arranged vertically, the side lobe can be reduced in the sound generated from
the two speakers.
[0068]
Eighth Embodiment Next, a loudspeaker 1H according to an eighth embodiment of the present
invention will be described with reference to FIGS. The speaker (electro-acoustic apparatus) of
this embodiment includes a vibrating body 1001, an actuator (converter) 1002 for
reciprocatingly driving the vibrating body 1001, and a support frame 1003 for supporting the
vibrating body 1001 and the actuator 1002. An edge portion 1004 for supporting the vibrating
body 1001 in a reciprocating manner on the support frame 1003 is provided. In the following
description, for convenience of description, in FIG. 27, the vertical direction is set so that the side
12-05-2019
26
on which the edge portion 1004 is provided is on the top and the side on which the actuator
1002 is provided is on the bottom. Thus, the long side direction of the support frame 1003
formed in a rectangular shape is taken as the vertical direction, and the short side direction is
taken as the horizontal direction. Further, a surface facing upward is referred to as a front
surface, a surface facing downward is referred to as a back surface, and as shown in the
drawings, the vertical direction may be referred to as x direction, the horizontal direction may be
referred to as y direction, and the vertical direction may be referred to as z direction.
[0069]
The vibrating body 1001 has a surface shape in which a pair of vertical split cylindrical surfaces
1005 are formed in parallel, and a valley portion 1006 is formed between one side portions of
adjacent vertical split cylindrical surfaces 1005. . The vibrating body 1001 in the illustrated
example is constituted by a pair of curved plates 1011 curved along the longitudinally split
cylindrical surface 1005 and a connecting plate 1012 for connecting the curved plates 1011.
The side portions forming the valley portion 1006 are in a state of being joined to each other.
The connecting plates 1012 are provided at both ends of the pair of curved plates 1011 so as to
close the whole of the valleys 1006.
[0070]
The pair of curved plates 1011 are disposed in parallel with their convex directions directed to
the same surface side, and the adjacent side portions share the tangential direction when viewed
in the cross section of the yz plane. It is joined. The joint portion 1013 of the both curved plates
1011 is formed in, for example, a band plate shape in the longitudinal direction by bonding one
side portion of the both curved plates 1011 or the like. Then, along the joint portion 1013, a
valley portion 1006 is formed between the both curved plates 1011 in a straight line along the
longitudinal direction of the vertically split cylindrical surface 1005.
[0071]
The actuator 1002 uses, for example, a voice coil motor, and includes a voice coil 1020 and a
magnet mechanism 1021 fixed to a support frame 1003. The voice coil 1020 is formed by
winding a coil 1020 b around a cylindrical bobbin 1020 a, and the upper end of the voice coil
1020 and the lower edge of the bonding portion 1013 are fixed via an adhesive or the like. In the
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27
example shown in FIGS. 27 and 28, since the actuator 1002 is provided at a position deviated
from the longitudinal center of the joint portion 1013 of the curved plate 1011, the voice coil
1020 is provided from the longitudinal center of the vibrating body 1001. It is connected to the
vibrating body 1001 at the shifted position. As a result, conversion of the vibration of the
vibrating body and the acoustic signal, which is an electrical signal, is performed at a position
shifted from the center of the valley of the vibrating body in the extending direction. The outer
peripheral portion of the voice coil 1020 is supported by the support frame 1003 via the damper
1022, and the voice coil 1020 can be reciprocated along the axial direction of the voice coil
1020. The damper 1022 can apply the thing of the material used for a general dynamic speaker.
The magnet mechanism 1021 includes an annular magnet 1023, a ring-shaped outer yoke 1024
fixed to one pole of the magnet 1023, and an inner yoke 1025 fixed to the other pole. A
magnetic gap 1026 is annularly formed between the outer yoke 1024 and the inner yoke 1025
by arranging the tip of the pole portion 1025 a at the center in the outer yoke 1024, and a voice
coil is formed in the magnetic gap 1026. The end of 1020 is placed in the inserted state.
[0072]
The support frame 1003 includes a rectangular frame-shaped flange portion 1030 and a
plurality of arm portions 1031 extending downward from the flange portion 1030. The lower
end of the arm portion 1031 includes an annular frame portion 1032. The vibrating body 1001
is disposed in the space in the flange portion 1030 so that the valley portion 1006 is parallel to
the long side direction of the flange portion 1030, and the peripheral portion of the vibrating
body 1001 and the upper end portion of the connecting plate 1012 are edge portions It is
supported on the upper surface of the flange portion 1030 via 1004. Therefore, the edge portion
1004 is formed in a rectangular frame shape corresponding to the outer peripheral portion of
the vibrating body 1001. In the present invention, the support portion 1035 for supporting the
vibrating body 1001 so as to be able to vibrate in the depth direction (z direction) of the valley
portion 1006 is configured of the support frame 1003 and the edge portion 1004 in this
embodiment.
[0073]
When an acoustic signal is supplied to the voice coil 1020 of the actuator 1002, the voice coil
1020 vibrates in the axial direction of the voice coil 1020). Then, the vibrating body 1001
connected to the voice coil 1020 vibrates along the depth direction of the valley portion 1006,
and the reproduced sound due to the vibration is emitted from the vertical split cylindrical
surface 1005.
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28
[0074]
The portion where the voice coil 1020 is connected to the vibrating body 1001 is located at a
position shifted from the center in the extension direction of the valley portion of the vibrating
body 1001, so the voice coil 1020 is connected in the vibrating body 1001. The amplitude of the
part away from the part is smaller than the amplitude of the part to which the voice coil 1020 is
connected, and the vibrator has large and small parts of the amplitude in the extension direction
of the valley. Then, in the portion where the amplitude decreases, the sound pressure of the
generated sound decreases as compared with the portion where the amplitude increases. When
two speakers 1H shown in FIG. 27 are arranged in the vertical direction and arranged so that the
conversion unit of the speaker 1H is located on the center side where the two are arranged, the
sound pressure of the generated sound is two on the center side Since the sound pressure of the
sound generated at both ends is small, the side lobe can be reduced in the sound generated from
the two speakers 1H.
[0075]
By the way, although one actuator 1002 is provided in the above-described speaker 1H, the
number of actuators may be two or more. For example, when there are two actuators 1002, the
voice coils 1020 of the two actuators 1002 are connected to one end side and the other end side
of the vibrating body 1001 in the longitudinal direction. Then, the acoustic signal supplied to one
actuator 1002 is made larger than the acoustic signal supplied to the other actuator 1002 by the
amplification circuit. With this configuration, in the vibrating body 1001, the portion connected
to the voice coil 1020 of one actuator 1002 has a larger amplitude than the portion connected to
the voice coil 1020 of the other actuator 1002. Then, in the portion where the amplitude
increases, the sound pressure of the generated sound becomes larger than the portion connected
to the voice coil 1020 of the other actuator 1002. When the sound pressure of the sound
generated by the vibrating body 1001 is different in the vertical direction, the directivity
characteristic is different from the case where the sound pressure of the generated sound is
uniform in the vertical direction.
[0076]
Note that the configuration in which the amplitude of one actuator 1002 is larger than the
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29
amplitude of the other actuator 1002 is not limited to the above-described configuration using
an amplification circuit. For example, the winding amount of the coil 1020 b of one actuator
1002 is larger than the winding amount of the coil 1020 b of the other actuator 1002. In this
case, in the two actuators which are conversion units, the conversion efficiency between the
force acting on the vibrator and the acoustic signal flowing through the actuator 1002 differs
between the one end side and the other end side in the extending direction of the valley of the
vibrator, The conversion efficiency at one end is smaller than that at the other end. With this
configuration, even if acoustic signals of the same magnitude are supplied to one of the actuators
1002 and the other of the actuators 1002, in the vibrating body 1001, the portion connected to
the voice coil 1020 of one of the actuators 1002 is the other. The amplitude is larger than that of
the portion connected to the voice coil 1020 of the actuator 1002, and the sound pressure of the
sound generated by the vibrating body 1001 differs in the vertical direction, and the sound
pressure of the generated sound as in the configuration using the amplification circuit. Is
different from that in the case of being uniform in the vertical direction.
[0077]
Further, in the configuration in which three or more actuators 1002 are provided, the plurality of
actuators 1002 are arranged in the longitudinal direction of the vibrating body 1001, and the
voice coil 1020 of each actuator 1002 is connected to the vibrating body 1001. Then, the
acoustic signal supplied to the actuator 1002 may be enlarged by the amplification circuit, and
the acoustic signal supplied to the actuator 1002 may be increased from the one end side of the
vibrating body 1001 toward the other end. Further, in a configuration in which three or more
actuators 1002 are provided, an acoustic signal of the same size is supplied to each actuator
1002, and the amount of winding of the coil 1020b is increased from one end to the other end of
the vibrating body 1001. The density of the conductor per unit area in the voice coil 1020 may
be different for each actuator. Also in this configuration, in the three or more actuators which are
conversion units, the conversion efficiency between the force acting on the vibrating body and
the acoustic signal flowing to the actuator 1002 is one end side and the other end side in the
extending direction of the valley portion of the vibrating body And the conversion efficiency at
one end is smaller than that at the other end.
[0078]
[Modifications] Note that one or more of the embodiments and the modifications described above
may be implemented in combination as appropriate.
[0079]
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The embodiments described above are all speakers that emit sound, but the configurations of the
embodiments and the modifications described above can also be applied to a microphone that is
an electro-acoustic transducer.
When the present invention is applied to a speaker, a conversion unit such as a coil or a voice
coil motor converts an electrical signal based on an audio signal into vibration of a vibrating
body, but also when the present invention is applied to a microphone A coil or a voice coil motor
can be used. The converter in that case converts the vibration of the vibrating body that vibrates
upon receiving the sound wave into an electrical signal. Then, in the microphone to which the
present invention is applied, the vertically split cylindrical surface is a vibrating surface, and the
entire vibrating body vibrates to collect sound.
[0080]
DESCRIPTION OF SYMBOLS 1, 1A-1H ... Speaker, 20 ... Vibrator, 20A-20H, 20L ... Diaphragm, 21
... Slit, 30, 30A, 31, 31A, 32, 32A ... Magnet, 40A-40E ... Yoke, 41A, 41B, 41C, 41D, 41E, 42A,
42B, 42E, ... yoke, 50A, 50B, ... spacer, 60, 60A ... support member, 70 ... air gap, 80-82 ...
vibration suppression member, 100, 100A-100H ... coil, 1001 ... vibration body, 1002 ... actuator
(conversion unit), 1003 ... support frame, 1004 ... edge portion, 1005 ... longitudinally split
cylindrical surface, 1006 ... valley portion, 1011 ... curved plate, 1012 ... connection plate, 1013
... junction portion 1015 Reinforcement plate 1016 Joints 1020 Voice coil 1020a Bobbin 1020b
Coil 1021 Magnet mechanism, 1022 ... Damper, 1023 ... Magnet, 1024 ... Outer yoke, 1025 ...
Inner yoke, 1025 a ... Pole part, 1026 ... Magnetic gap, 1030 ... Flange part, 1031 ... Arm part,
1032 ... Annular frame part, 1035 ... Support Department.
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