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JP2003274467

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DESCRIPTION JP2003274467
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the
structure of a speaker and a rotary vibrator forming a multifunctional acoustic device used in a
portable device, and in particular, the speaker and the rotary vibrator can be simultaneously
driven. The present invention relates to the overall configuration in which the acoustic
characteristics can be expected.
[0002]
2. Description of the Related Art Conventionally, portable devices such as PHSs and mobile
phones are received by the vibration of a vibration motor, not by the sound produced by the
received sound, so as not to disturb the quiet environment at the time of reception such as a
concert hall or hospital. In many cases, a vibration motor is installed to make it possible for the
user of the portable device to sense. On the other hand, not only the reception of the received
sound is required, but also a speaker having better acoustic characteristics is required. For this
reason, conventionally, two vibration motors and two speakers are often attached to a portable
device, space efficiency is deteriorated, and it is difficult to reduce the size, weight and cost of the
portable device. In order to improve this, recently, in addition to the vibration of the diaphragm
of the speaker, a permanent magnet, which is magnetically engaged with the voice coil on the
diaphragm of the speaker, is spring-fixed to the frame. The so-called multi-function device has
been announced that can be driven independently at low frequencies and vibrate in the same
direction as the speaker diaphragm. Hereinafter, representative conventional examples of socalled multifunction devices will be listed and described in detail.
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[0003]
FIG. 2 is a cross-sectional view of a conventional example corresponding to an explanatory view
of an electromagnetic induction type converter described in Japanese Patent Laid-Open No. 585192 (Reference A). FIG. 3 is a half sectional view of a conventional example of a
multifunctional device. FIG. 4 is a cross-sectional view corresponding to the explanatory view
described in the previously filed patent application and Japanese Patent Application No. 2000121852 by the applicant of the present application (Document B). FIG. 5 is a cross-sectional view
corresponding to the explanatory view described in the already filed patent application and
Japanese Patent Application No. 2000-286414 filed by the present applicant (Reference C). In
FIG. 2, the electromagnetic induction type converter is a so-called internal magnet type (a
structure in which a permanent magnet is disposed inside a voice coil), and fixes a voice coil 508
at the center of a diaphragm 506 having a central portion 507, The magnet 510 is fixed to the
center of the spring body 511, and the diaphragm 506 and the spring body 511 are vertically
opposed to a position where the magnet 510 is inserted into the voice coil 508, and the end face
of one pole of the magnet 510 is a voice coil It arrange ¦ positions so that it may be located in
508 center part, and it accommodates in the case 512, and is comprised. The spring body 511 is
vibrated in the pole direction of the magnet 510 by applying a low frequency signal or a high
frequency signal to the voice coil 508.
[0004]
In Document A, the diaphragm 506 and the spring body 511 are configured to move relative to
each other through the magnetic coupling between the voice coil 508 and the magnet 510.
Therefore, when a low frequency signal or a high frequency signal is applied to the voice coil
508, the diaphragm 506 is The coupled vibration occurs in the spring body 511. As a result,
there is a problem that distortion occurs at the time of reproduction of voice, music, etc. and the
quality thereof is deteriorated. In addition, simultaneously driving the reproduction of voice and
music and low frequency vibration causes low frequency vibration to be superimposed on the
magnetic coupling between the voice coil 508 and the magnet 510, so that large distortion is
caused at the time of voice and music reproduction. Was virtually impossible.
[0005]
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2
In FIG. 3, the multifunctional acoustic device of the conventional example is a so-called external
magnet type (a structure in which a permanent magnet is disposed outside a voice coil). A
concentric cylindrical voice coil 604 is fixed to a central portion of a speaker diaphragm 603
having an outer peripheral portion 603a with corrugation and a central portion formed of a
synthetic resin dome-shaped. The outer peripheral portion 603 a of the speaker diaphragm 603
is fixed to the frame 609 with an adhesive or the like. The outer peripheral portion 601 a of the
cylindrical top yoke 601 and the inner peripheral portion 606 a of the outer peripheral portion
yoke 606 of the hemispherical top surface form an air gap 611 magnetically engaged with the
voice coil 604. The permanent magnet 602 which is hollow disk shaped and magnetized to a
single magnetic pole in the thickness direction forms a magnetic circuit by the top yoke 601, the
lower yoke 605 and the outer peripheral yoke 606 and at the same time the lower spring 605 by
the parallel springs 607, 608. An outer peripheral portion of the part yoke 606 is fixed to and
supported by the frame 609 to constitute a permanent magnet 610 capable of vibrating in the
vibration direction of the speaker diaphragm 603.
[0006]
When an AC voltage is applied to the input terminals 612a and 612b of the lead wires of the
voice coil 604 drawn out so as to cover the speaker diaphragm 603, a current flows through the
voice coil 604 and the speaker diaphragm 603 vibrates in the Y direction. Sound pressure is
generated. At this time, the resonance frequency of the permanent magnet body 610 is
approximately 110 to 150 Hz, and the primary resonance frequency of the speaker diaphragm
603 is approximately 700 to 900 Hz, and the secondary resonance in a standard φ20 mm × 5
mm acoustic device. The frequency is often set around 5 kHz. Although reproduction of voice
and music is performed in a band of 700 to 5 kHz, the speaker diaphragm 603 and the
permanent magnet 610 are configured to move relative to each other through the magnetic
coupling between the voice coil 604 and the permanent magnet 610. When a low frequency
signal or a high frequency signal is applied to the voice coil 604, coupled vibration occurs in the
speaker diaphragm 603 and the permanent magnet 610. As a result, there is a problem that
distortion occurs at the time of reproduction of voice, music, etc. and the quality thereof is
deteriorated. In addition, simultaneously driving the reproduction of voice and music and low
frequency vibration causes low frequency vibration to be superimposed on the magnetic
coupling between the voice coil 604 and the permanent magnet 610. It was distorted and
virtually impossible.
[0007]
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3
The document B shown in FIG. 4 is a so-called external magnet type (a structure in which a
permanent magnet is disposed outside the voice coil). Describing in common using FIG. 3 and the
same reference numerals, a concentric cylindrical voice is formed at the center of a speaker
diaphragm 603 having a corrugation outer peripheral portion 603 a and made of a synthetic
resin whose center is formed in a dome shape. The coil 604 is fixed. The outer peripheral portion
603 a of the speaker diaphragm 603 is fixed to the frame 609 with an adhesive or the like. An
outer peripheral portion 601a of a cylindrical top yoke 601 having a hemispherical upper
surface and an inner peripheral portion 606a of a side surface yoke 606 constitute a first air gap
701 magnetically engaged with the voice coil 604. The hollow disk-shaped permanent magnet
702 forms a magnetic circuit having a second air gap 705 with the top yoke 601, the outer
peripheral portion 703a of the lower yoke 703, and the inner peripheral portion 606a of the side
surface yoke 606, and also parallel springs 707 and 708. The lower yoke 703 and the outer
peripheral portion 606 b of the outer peripheral portion yoke 606 are fixedly supported by the
frame 609 to constitute a permanent magnet 610 capable of vibrating in the vibration direction
of the speaker diaphragm 603. The second air gap 705 is provided with a concentric cylindrical
drive coil 706 fixed to the frame 609 and having input terminals 704a and 704b. The voice coil
604 and the permanent magnet 610 in the first air gap 701 are capable of relative movement,
but the relationship between the drive coil 706 and the permanent magnet 610 in the second air
gap 705 is relative. Only the permanent magnet 610 can move in the same axial direction as the
speaker diaphragm 603, not the movement.
[0008]
When an AC voltage is applied to the input terminals 612a and 612b of the lead wires of the
voice coil 604 drawn out so as to cover the speaker diaphragm 603, a current flows through the
voice coil 604 and the speaker diaphragm 603 vibrates in the Y direction. Sound pressure is
generated. At this time, the resonance frequency of the permanent magnet body 610 is
approximately 110 to 150 Hz, and the primary resonance frequency of the speaker diaphragm
603 is approximately 700 to 900 Hz, and the secondary resonance in a standard φ20 mm × 5
mm acoustic device. The frequency is often set to 5 kHz. Although reproduction of voice and
music is performed in a band of 700 to 5 kHz, the speaker diaphragm 603 and the permanent
magnet 610 are configured to move relative to each other through the magnetic coupling
between the voice coil 604 and the permanent magnet 610. When a low frequency signal or a
high frequency signal is applied to the voice coil 604, coupled vibration occurs in the speaker
diaphragm 603 and the permanent magnet 610. When a high frequency signal such as voice or
music is applied to the input terminals 612a and 612b, only the speaker diaphragm 603 is
excited, and between the speaker diaphragm 603 and the permanent magnet 610 for
reproduction of voice or music. Since no coupled vibration occurs, no distortion occurs. When a
low frequency signal of 100 to 150 Hz is applied to the input terminals 704a and 704b, only the
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permanent magnet body 610 is excited, and the speaker diaphragm 603 does not operate at all.
In this respect, although the document B is superior to the document A, when the high frequency
signal is simultaneously applied to the input terminals 612a and 612b and the low frequency
signal is simultaneously applied to the input terminals 704a and 704b, the permanent magnet
610 vibrates at a low frequency. Because the voice coil 604 in the first air gap 701 moves
relative to each other, coupled vibration occurs in the speaker diaphragm 603 and the
permanent magnet 610, and distortion occurs in reproduction of voice and music. .
[0009]
The multifunctional acoustic device of document C shown in FIG. 5 is a so-called internal magnet
type (a structure in which a permanent magnet is disposed inside a voice coil), and includes a
sound generator 800, a rotor 820 and a stator 830. Ru. A concentric cylindrical voice coil 804 is
fixed to a central portion of a speaker diaphragm 803 having an outer peripheral portion 803a
with corrugation and a central portion made of a synthetic resin formed in a dome shape. The
outer peripheral portion 803 a of the speaker diaphragm 803 is fixed to the frame 809 with an
adhesive or the like. A cylindrical top yoke 801 having a hemispheric upper surface is disposed
on the hollow cylindrical speaker magnet 805, and the outer periphery 801a of the top yoke 801
and the inner periphery 807a of the side yoke 807 have a voice coil 804 and a magnetic coil. To
form a speaker gap 701 that engages. An acoustic cover 810 having a plurality of sound output
holes is disposed on the upper surface of the speaker diaphragm 803. A hollow disk-shaped
permanent magnet 802 is fixed to a side yoke 807 disposed on the outer peripheral portion of
the lower yoke 808, and a stator 830 having a stator side 830a housed on the bottom of the
frame 809 and a motor gap 835 It is disposed through. A rotor shaft 806 having a diameter
enlarged portion 806a fixed to the center of the bottom of the frame 809 supports the rotor 820
on which the weight 822 is mounted in the axial direction by the washer 807 and also in the
rotational direction. In the embodiment of the present invention, the stator 830 wound with the
stator winding 836 having the stator input terminals 805a and 805b is the upper stator yoke
831, the upper shielding plate 832, the lower stator yoke 833, and the lower shielding. It is
formed of the plate 834, the magnetic pole of the upper stator yoke 831, and the magnetic pole
of the lower stator yoke 833, but the detailed configuration will be omitted because it is a normal
configuration.
[0010]
When an AC voltage is applied to the input terminals 812a and 812b of the lead wires of the
voice coil 804 drawn out so as to cover the speaker diaphragm 803, a current flows through the
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voice coil 804 and the speaker diaphragm 803 vibrates in the Y direction. Sound pressure is
generated. At this time, in a standard acoustic apparatus having a size of about φ20 mm × 5
mm, the primary resonance frequency of the speaker diaphragm 803 is often set to about 700 to
900 Hz, and the secondary resonance frequency is often set to 5 kHz. Although the reproduction
of voice and music is performed in the band of 700 to 5 kHz, the vibration of the speaker
diaphragm 803 and the rotation direction of the rotor 820 are different by 90 degrees, so there
is no coupled vibration and the sounding body 800 and the rotor 820 simultaneously. It can be
driven. Although the document C is superior to the document A, the motor drive requires a
switching circuit, and there are problems in the arrangement and the cost.
[0011]
Further, Japanese Patent Application Laid-Open No. 5-305270 (document D) is known as a
known technique for sensing vibration by half-rotational vibration (reciprocal vibration of a
rotational angle) of a rotary vibrator. However, Document D does not propose a configuration
relating to a multi-functional acoustic device with a speaker.
[0012]
As is apparent from the above description, in the case of simultaneously exciting a low frequency
signal and a high frequency signal in any of the prior art, coupling occurs and the quality of
speech and music is degraded. It was virtually impossible to prevent. This is because both the low
frequency vibration and the high frequency vibration are configured to vibrate in the same
direction as the speaker diaphragm. Furthermore, there is a need for a multifunctional acoustic
device that can further reduce costs, and the present invention addresses this.
[0013]
SUMMARY OF THE INVENTION An object of the present invention is to realize a multifunctional
acoustic device with a simple structure by removing defects on the heel, and in particular, low
frequency vibration is constituted by a rotary vibrator. It is characterized by Claim 1 of the
multifunctional acoustic device according to the present invention made to solve the problem
comprises a concentric cylindrical voice coil fixed to a speaker diaphragm and a magnetic circuit
magnetically engaged with the voice coil. In an acoustic device, there is provided a spring capable
of rotational vibration of a rotary vibrator provided with a multipolar permanent magnet on the
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outer peripheral portion of a magnetic circuit formed by a yoke and a permanent magnet
provided so as to magnetically engage the voice coil. And a weight is mounted on the rotary
vibrator so as to generate a large vibrational excitation force by a centrifugal force generated by
half-rotational vibration. It is
[0014]
According to a second aspect of the present invention, there is provided a multi-function sound
device according to the present invention, which comprises a concentric cylindrical voice coil
fixed to a speaker diaphragm and a magnetic circuit magnetically engaged with the voice coil. In
an acoustic device, a cylindrical speaker magnet magnetized to a single magnetic pole in a
thickness direction magnetically engaged with the voice coil at a central portion of a frame, and
an outer peripheral portion on the speaker magnet is an inner peripheral portion of the voice
coil. And a cylindrical top yoke made of a magnetic material to form a gap to be engaged is fixed
to a central portion of a cup-shaped speaker yoke made of a magnetic material, and the outer
periphery of the cup-shaped yoke supported by a bearing is A rotary vibrator provided with a
pole permanent magnet is disposed opposite to the stator provided on the inner peripheral
portion of the frame via a spring capable of rotary vibration, and a semi-rotational vibration is
provided on the rotary vibrator. Centrifugal force caused by Thus it is characterized in that the
vibration pressure Shinryoku is disposed so as to Katatsumu by decentering a weight to generate
large.
[0015]
The rotary vibrator according to claim 3 of the multifunctional acoustic device of the present
invention made to solve the problem is constructed by mounting a cylindrical rotor yoke with a
cylindrical permanent magnet magnetized with multiple poles on the outer periphery. It is
characterized in that it is formed so that the speaker yoke can be used as a rotation axis so as to
be capable of half-rotational vibration with respect to the stator.
[0016]
A rotary vibrator according to claim 4 of the multifunctional acoustic device of the present
invention made to solve the problem is that a member having a large specific gravity is produced
by rotational vibration on any of the upper and lower surfaces of the rotor permanent magnet. 4.
The multiple vibrator according to any one of claims 1 to 3, characterized in that it is disposed
eccentrically with respect to the rotary vibrator axis so as to become a single weight where a
large vibrational vibration force is generated by a centrifugal force. Functional acoustic device.
[0017]
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The number of pole pairs of the rotary vibrator shown in claim 5 of the multifunctional acoustic
device of the present invention made to solve the problem is characterized by at least one or
more.
[0018]
The rotary vibrator according to claim 6 of the multifunctional acoustic device of the present
invention made to solve the problem is characterized in that one end is fixed to the frame and the
other end has a spring connected to the rotary vibrator. It is said that.
[0019]
The stator according to claim 7 of the multifunctional acoustic device of the present invention
made to solve the problem is a hollow disk-shaped magnetic material, and the inner peripheral
portion is bent in a sawtooth shape to form a stator pole of a plurality of poles. A magnet wire
wound in a plurality of windings by a stator upper yoke formed with the above and a stator lower
yoke made of a hollow disk-like magnetic material and having an inner peripheral portion bent in
a sawtooth shape to form a plurality of stator poles. Are arranged so that the magnetic pole
formed of the stator upper yoke and the magnetic pole formed of the stator lower yoke are
arranged adjacent to each other so as to form a multi-pole stator. It is characterized by
[0020]
A stator according to claim 8 of the multifunctional acoustic device of the present invention
made to solve the problem is characterized in that the number of upper and lower pole teeth of a
pair of stators is twice the number of rotor poles. It is
[0021]
The stator according to claim 9 of the multifunctional acoustic device of the present invention
made for the purpose of solving the problem is that a plurality of stator poles are inserted into a
pair of disc-shaped electrically conductive scraping plates. It is characterized in that it is a pole
stator.
[0022]
A drive circuit of a rotary vibrator according to claim 10 of the multifunctional acoustic device of
the present invention made to solve the problem is characterized in that it is driven by a bipolar
drive circuit in response to an excitation signal of 100 Hz or more. It is.
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[0023]
The drive circuit of the rotary vibrator according to claim 11 of the multifunctional acoustic
device of the present invention made to solve the problem is characterized in that it receives an
excitation signal of 100 Hz or more and performs unipolar drive.
[0024]
The drive circuit according to claim 12 of the multifunctional acoustic device of the present
invention made to solve the problem is a bipolar drive circuit or unipolar drive in response to
excitation by the broadband signal of the speaker diaphragm and an excitation signal of 100 Hz
or more. A circuit simultaneously drives the rotor.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be
described below with reference to the drawings.
FIG. 1 is a sectional view of an essential part showing an embodiment of a multifunctional
acoustic device according to the present invention.
[0026]
In FIG. 1, the multifunctional acoustic device of the present invention is composed of a sound
generator 100, a rotary vibrator 200 and a stator 300.
A cup-shaped speaker yoke made of a magnetic material and composed of a lower yoke 108 and
a side yoke 109 at the center of a cup-shaped frame 111 made of resin or the like and a diskshaped top yoke at the center of the speaker yoke The sound producing body 100 for fixing the
speaker magnet 105 mounted thereon to form the cylindrical speaker gap 103 is formed in the
speaker gap 103 described later in the speaker diaphragm 101 having the dome 101a at the
central portion formed of synthetic resin. A concentric cylindrical voice coil 102 having voice coil
input terminals 112a and 112b that can operate is fixed, and the speaker diaphragm outer
peripheral portion 101b is fixed to the frame 111 with an adhesive or the like.
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The outer periphery of an acoustic cover 110 having a plurality of sound output holes is fixed to
the outer end of the frame 111 on the upper surface of the speaker diaphragm 101.
The speaker gap 103 magnetically engaged with the voice coil 102 is formed by the top yoke
outer peripheral portion 104 a of the top yoke 104 and the upper rotor yoke inner peripheral
portion 112 formed in the side surface yoke 109.
[0027]
The rotary vibrator 200 is configured by mounting a cylindrical rotary vibrator permanent
magnet 201 which is multipolar-magnetized on the outer peripheral portion of a cylindrical side
yoke 109 made of a magnetic material.
The rotor shaft 106 having the enlarged diameter portion 106a fixed to the central portion of the
bottom surface of the frame 111 supports the rotary vibrator 200 on which the weight 202 is
mounted in the axial direction by the washer 107 and at the same time supports the rotational
direction. There is.
The rotary vibrator 200 has a spiral vibration spring 114 whose one end is fixed to the fixed pinshaped spring retainer 113 at the bottom of the frame 111 and the other end is fixed to the
spring ring 115 fixed to the rotary vibrator 200 ( A multi-rolled spiral cross-section is shown in
the figure).
Therefore, the multifunctional acoustic device of the present invention has a natural frequency
determined by the stiffness of the vibrating spring 114 and the moment of inertia of the rotary
vibrator 200.
In the embodiment of the present invention, the stator 300 having the stator side portion 303a
housed in the bottom portion of the frame 111 is fixed to the upper stator yoke 301, the upper
shielding plate 302, the lower stator yoke 303, the lower shielding plate 304, and the like. The
magnetic pole is formed by the magnetic pole of the upper yoke 301 and the magnetic pole of
the lower stator yoke 303, but the detailed configuration will be omitted because it is a normal
configuration.
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The number of poles of the rotary vibrator 200 and the number of spiders (number of poles) of
the stator 300 on which the stator winding 306 having the stator input terminals 305a and 305b
is wound are determined by the vibration angle and vibration frequency of the rotary vibrator
200. It may be set appropriately.
[0028]
In the embodiment of the present invention, the magnetomotive force of the speaker magnet 105
is supplied to the speaker gap 103, and the necessary magnetic flux density is supplied by
designing appropriately.
In particular, in a sintered NdFeB-based magnet having an energy product of 360 to 400 [J / m
3] (45 to 50 [MGOe]) as in recent years, 0.4 to 0.6 [T] (4 to 6 [kG ] Can be supplied.
[0029]
Further, in the embodiment of the present invention, the magnetomotive force of the rotor
permanent magnet 201 is supplied to the motor gap 203, and the necessary magnetic flux
density is supplied by designing appropriately.
For example, a bonded ferrite magnet or a bonded NdFeB magnet is selected according to the
required specifications.
[0030]
Next, the operation of the multifunctional acoustic device of the present invention will be
described. First, when a wide band so-called high frequency signal alone is applied to the voice
coil input terminals 112a and 112b, a force acts on the voice coil 102 in the speaker gap 103 in
the Y direction, and the speaker diaphragm 101 of the sounding body 100 Vibrates in the Y
direction to generate sound pressure, and emits a sound wave through the sound emission hole
of the sound cover 110.
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[0031]
When a low frequency signal of about 100 to 300 Hz is input to the input terminals 305a and
305b of the stator winding 306, an alternating current flows in the stator winding 306. As a
result, the rotary vibrator 200 is pulled into this to generate rotational vibration determined by
the drive frequency. At this time, assuming that the weight 202 of the rotary vibrator 200 is M,
the angular amplitude is A, the angular frequency of the rotary vibrator 200 is ω [rad / sec], and
the rotational radius is R, the centrifugal force F is expressed by the following equation Naturally,
the centrifugal force F is set to be as large as possible.
[0032]
F = RA ω 2 M [N] ...... (1)
[0033]
A so-called high frequency signal of a wide band is applied to the input terminals 112a and 112b
of the voice coil 102 of the multifunctional acoustic device of the present invention, and a low
frequency signal of about 100 Hz or more is applied to the input terminals 305a and 305b of the
stator winding 306, When simultaneously applied to the rotary vibrator drive circuit, the
magnetic flux density of the speaker gap 103 hardly changes even if the rotary vibrator 200
vibrates at the natural frequency, so the sound pressure generated by the sounding body 100 is
the rotary vibrator The sound quality does not deteriorate almost the same as when 200 does not
vibrate.
[0034]
Also, in the embodiment of the multifunctional acoustic device of the present invention, it is
apparent that the low frequency drive circuit can be driven by a bipolar drive circuit, or the
stator winding 306 can be driven by a unipolar drive circuit as a double winding with a center
tap. It is.
[0035]
Further, in the embodiment of the multifunctional acoustic device according to the present
invention, it is apparent that the permanent magnet on the rotary vibrator may be arranged
slightly eccentrically in addition to the eccentric weight to enhance the vibrational vibration
force. .
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[0036]
Further, according to the multifunctional acoustic device of the present invention, it is possible to
faithfully reproduce the broadband signal of the sounding body with a simple configuration.
[0037]
Furthermore, according to the multifunctional acoustic device of the present invention, it is
possible to reliably obtain a low frequency vibration with a high sensitivity to a low-frequency
signal with a simple configuration.
[0038]
Furthermore, according to the multifunctional acoustic device of the present invention, it is
possible to realize a cost / performance sounding body which can simultaneously drive a high
frequency signal and a low frequency signal and has no deterioration in sound quality.
[0039]
In the conventional example, the low frequency vibration with large amplitude is in the same
direction as the vibration of the speaker diaphragm, so the thickness of the device is required to
some extent, but according to the multifunctional acoustic device of the present invention, the
low frequency vibration is rotated Since the magnetic circuit of the speaker magnet and the rotor
can be arranged almost on the same plane for the purpose of reducing the thickness of the
multifunctional acoustic device, it contributes to the miniaturization and thinning of portable
equipment.
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