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JP2010124313

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This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
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DESCRIPTION JP2010124313
An electro-acoustic transducer and an electro-acoustic transducer system capable of coping with
a large amplitude without decreasing the efficiency are provided. A magnetic circuit comprising a
magnet and a magnetic body and having a magnetic gap, a coil bobbin disposed in the magnetic
gap and connected to a diaphragm, and wound at different axial positions on the coil bobbin A
plurality of voice coils 150a to 150c, and switching circuits 201 and 210 for supplying a drive
signal to the voice coil in which the largest number of windings are included in the magnetic gap
among the plurality of voice coils. [Selected figure] Figure 1
Electro-acoustic transducer and electro-acoustic conversion system
[0001]
The present invention relates to an electroacoustic transducer and an electroacoustic transducer
system.
[0002]
As an electroacoustic transducer such as a speaker, a voice coil coupled to a diaphragm is
disposed in a direct current magnetic gap configured using a permanent magnet and a soft
magnetic material, an audio signal is applied to the voice coil, and the audio signal Thus, the
diaphragm is vibrated by the force generated in the voice coil by the current flowing through the
voice coil and the DC magnetic flux.
[0003]
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1
In recent years, it has been desired to reproduce deep bass even with a small aperture.
Here, in the speaker, since the air is vibrated by the diaphragm to generate sound, the bass
reproduction ability is proportional to the product of the area of the diaphragm and the vibration
amplitude of the diaphragm.
Therefore, in order to reproduce low-pitched sound with a small-aperture speaker, it is necessary
to increase the amplitude of the diaphragm.
[0004]
Here, in order to increase the amplitude of the speaker, the voice coil is made longer in the axial
direction than the magnetic gap portion as a long voice coil, and even if the amplitude of the
diaphragm becomes large, the voice coil It is possible to deal with it by configuring so that any
part is present.
[0005]
Further, as a countermeasure in the case where the amplitude of the diaphragm is increased as
described above, the following Patent Document 1 is made.
Unexamined-Japanese-Patent No. 11-164394
[0006]
As described above, in the case of a long voice coil, it is possible to cope with larger amplitude
than a general speaker. However, since the area of the voice coil protruding from the magnetic
gap does not contribute to the generation of vibration, there is a problem that the utilization
efficiency of the drive signal, that is, the efficiency as a speaker decreases.
[0007]
For example, when using a long voice coil having a length three times the conventional one, two
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2
thirds of the voice coil will be out of the gap, and it is expected that the efficiency will be 1/3.
[0008]
Moreover, in the above-mentioned patent documents 1, it is a proposal about a brake of a voice
coil at the time of large amplitude, and the method of realizing large amplitude efficiently is not
suggested.
The present invention has been made to solve the above problems, and it is an object of the
present invention to provide an electroacoustic transducer and an electroacoustic transducing
system capable of coping with a large amplitude without lowering the efficiency. .
[0009]
The present invention for solving the above problems is as described below. (1) The invention
according to claim 1 comprises a magnetic circuit having a magnetic gap, a magnetic circuit
having a magnetic gap, a coil bobbin disposed in the magnetic gap and connected to a
diaphragm, and an axis on the coil bobbin And a switching circuit for supplying a drive signal to
a voice coil including the largest number of windings in the magnetic gap among the plurality of
voice coils. It is an electro-acoustic transducer characterized by
[0010]
(2) The invention according to claim 2 comprises a magnetic circuit having a magnetic gap, a
magnetic circuit having a magnetic gap, a coil bobbin disposed in the magnetic gap and
connected to a diaphragm, and an axis on the coil bobbin A plurality of voice coils wound at
different positions in a direction, a sensor detecting a position of the voice coil, and a detection
result of the sensor, the largest number of the plurality of voice coils in the magnetic gap And a
switching circuit for supplying a drive signal to a voice coil including a winding.
[0011]
(3) The invention according to claim 3 comprises a magnetic circuit having a magnetic gap, a
magnetic circuit having a magnetic gap, a coil bobbin disposed in the magnetic gap and
connected to a diaphragm, and an axis on the coil bobbin A plurality of voice coils wound at
different positions in a direction, and a level of a drive signal supplied to the voice coil are
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3
detected, and among the plurality of voice coils displaced according to the drive signal, the
magnetic gap is And a switching circuit for supplying a drive signal to the voice coil in which the
largest number of windings are included.
[0012]
(4) The electroacoustic transducer according to any one of claims 1 to 3, wherein the vibrating
plate is supported in a non-contact state by a supporting means. is there.
(5) The invention according to claim 5 is a magnetic circuit comprising a magnet and a magnetic
body and having a magnetic gap, a coil bobbin disposed in the magnetic gap and connected to a
diaphragm, and an axial direction on the coil bobbin An electroacoustic transducer having a
plurality of voice coils wound at different positions, a sensor for detecting the position of the
voice coil, and a detection result of the sensor, the magnetic gap among the plurality of voice
coils being in the magnetic gap And a switching circuit for supplying a drive signal to the voice
coil including the largest number of windings.
[0013]
(6) The invention according to claim 6 is a magnetic circuit comprising a magnet and a magnetic
body and having a magnetic gap, a coil bobbin disposed in the magnetic gap and connected to a
diaphragm, and an axial direction on the coil bobbin An electro-acoustic transducer having a
plurality of voice coils wound at different positions, and a level of a drive signal supplied to the
voice coil is detected, and among the plurality of voice coils displaced according to the drive
signal, And a switching circuit for supplying a drive signal to a voice coil including the largest
number of windings in the magnetic gap.
[0014]
(7) The invention according to claim 7 is a magnetic circuit comprising a magnet and a magnetic
body and having a magnetic gap, a coil bobbin disposed in the magnetic gap and connected to a
diaphragm, and an axial direction on the coil bobbin An electro-acoustic transducer having a
plurality of voice coils wound at different positions, a sensor for detecting the position of the
voice coil, a plurality of amplification circuits whose output side is connected to each of the voice
coils, and An input signal is selectively input to each of the plurality of amplification circuits so as
to receive a detection result and supply a drive signal to a voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. And a switching circuit for
switching and connecting to each other.
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4
[0015]
(8) According to the eighth aspect of the present invention, there is provided a magnetic circuit
comprising a magnet and a magnetic body and having a magnetic gap, a coil bobbin disposed in
the magnetic gap and connected to a diaphragm, and an axial direction on the coil bobbin. An
electro-acoustic transducer having a plurality of voice coils wound at different positions, a
plurality of amplification circuits each having an output connected to each of the voice coils, and
detecting the level of an input signal to the amplification circuit; Among the plurality of voice
coils, the input signal of which is displaced according to the drive signal amplified by the
amplification circuit, the plurality of drive coils are supplied to the voice coil including the largest
number of windings in the magnetic gap. And a switching circuit for selectively switching and
connecting an input signal to each input of the amplifier circuit.
[0016]
(9) The invention according to claim 9 is characterized in that the diaphragm of the
electroacoustic transducer is supported in a non-contact state by a supporting means. Electroacoustic conversion system.
[0017]
According to the present invention, the following effects can be obtained.
(1) In the invention according to claim 1, a plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the switching circuit allows the largest
number of windings in the magnetic gap among the plurality of voice coils. Supplies a drive
signal to the voice coil included.
[0018]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
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5
[0019]
(2) In the invention according to claim 2, the plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the switching circuit receives the detection
result of the sensor for detecting the position of the voice coil. Among the voice coils, a drive
signal is supplied to the voice coil in which the largest number of windings are included in the
magnetic gap.
[0020]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
[0021]
(3) In the invention according to claim 3, a plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the plurality of switching circuits receive
the detection result of the detection unit that detects the level of the drive signal. Among the
voice coils, the drive signal is supplied to the voice coil in which the largest number of windings
are included in the magnetic gap.
[0022]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
[0023]
(4) In the invention according to claim 4, in the above-mentioned electroacoustic transducers (1)
to (3), since the diaphragm is supported in a noncontact state by the support means, the
diaphragm is vibrated with a large amplitude. It becomes possible.
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[0024]
(5) In the invention according to claim 5, the plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the switching circuit receives the detection
result of the sensor for detecting the position of the voice coil. Among the voice coils, a drive
signal is supplied to the voice coil in which the largest number of windings are included in the
magnetic gap.
[0025]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
[0026]
(6) In the invention according to claim 6, a plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the plurality of switching circuits receive
the detection result of the detection unit that detects the level of the drive signal. Among the
voice coils, the drive signal is supplied to the voice coil in which the largest number of windings
are included in the magnetic gap.
[0027]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
[0028]
(7) In the invention according to claim 7, a plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the switching circuit receives the detection
result of the sensor that detects the position of the voice coil. The amplification circuit is
selectively used to supply a drive signal to a voice coil in which the largest number of windings
are included in the magnetic gap among the voice coils, and the amplified drive signal is supplied
to the corresponding voice coil. .
12-05-2019
7
[0029]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
[0030]
(8) In the invention according to claim 8, a plurality of voice coils are provided at different
positions in the axial direction on the coil bobbin, and the plurality of switching circuits receive
the detection results of the detection unit that detects the level of the drive signal. The amplifier
drive circuit is selectively used to supply a drive signal to the voice coil in which the largest
number of windings are included in the magnetic gap among the voice coils, and the amplified
drive signal is transmitted to the corresponding voice coil. The amplifier circuit is selectively used
to supply an amplified drive signal to the corresponding voice coil.
[0031]
By doing this, it is possible to cope with the large amplitude vibration of the diaphragm by the
plurality of voice coils on the coil bobbin, and further, the voice coil including the largest number
of windings in the magnetic gap among the plurality of voice coils. By selectively supplying the
drive signal to the above, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, and it becomes possible to cope with large amplitude without lowering
the efficiency.
[0032]
(9) In the invention as set forth in claim 9, in the electroacoustic conversion system of the above
(5) to (8), the diaphragm of the electroacoustic transducer is supported in a noncontact state by
the support means. It becomes possible to vibrate with large amplitude.
[0033]
Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an
embodiment) will be described in detail with reference to the drawings.
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8
In each of the following embodiments, in the case where the electroacoustic transducer 100 has
a symmetrical cross-sectional configuration, the description will be made while illustrating the
cross section of one (for example, the right half).
[0034]
First Embodiment FIG. 1 is a cross-sectional view showing a configuration of an electroacoustic
transducer 100 according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of the electroacoustic transducer 100
according to the first embodiment of the present invention and an electroacoustic transducer
system using the electroacoustic transducer.
[0035]
In FIG. 1A, a ring 110 is formed in the back direction of the diaphragm 170 (in the direction
opposite to the sound output direction, here, the lower direction in the drawing) with respect to
the diaphragm 170 and the frame 110 as a housing supporting the components. A top plate
120b, a ring-shaped (cylindrical) permanent magnet 130 magnetized in the axial direction, and a
yoke 120a serving as a bottom portion are attached.
A cylindrical center pole 120ac is provided at the center of the yoke 120a in the direction of the
top plate 120b.
[0036]
The outer peripheral surface of the center pole near the tip of the center pole of the yoke 120a
faces the inner peripheral surface of the top plate 120b to form a magnetic gap in the magnetic
path.
[0037]
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9
Further, a coil bobbin 140 having one end attached to the diaphragm 170 is disposed in a ringshaped space between the outer peripheral surface of the center pole and the inner peripheral
surface of the top plate 120 b. 150 are wound.
A damper 180 whose outer peripheral portion is attached to the frame 110 is attached near the
portion where the diaphragm 170 and the coil bobbin 140 are in contact, and the diaphragm
170 and the coil bobbin 140 vibrate in the axial direction of the center pole It supports to
become possible.
[0038]
In the first embodiment of the present invention, a plurality of voice coils are provided at
different axial positions on the coil bobbin 140.
Further, the coil bobbin 140 is also made longer than a conventional general coil bobbin so as to
be able to cope with such multiple voice coils.
[0039]
In the specific example shown in FIG. 1B, as the voice coil 150, a voice coil 150a substantially
equivalent to a conventional voice coil, a voice coil 150b disposed closer to the diaphragm 170
than the voice coil 150a, and a voice coil 150a. Three sets of voice coils of the voice coil 150c
disposed at a position farther from the diaphragm 170 (closer to the bottom side of the center
pole) than the diaphragm 170 are provided.
The plurality of voice coils are not limited to three, and may be two or four or more.
[0040]
Further, the voice coil 150 having the plurality of voice coils 150a, 150b, 150c is different from
the conventional long voice coil, and is configured to be able to supply a drive signal to each of
the plurality of voice coils (see FIG. 2). ).
12-05-2019
10
[0041]
That is, for each of the voice coils 150a, 150b, 150c of the speaker 100, the switching circuit
(the control unit 201 and the switch unit 210) of the drive circuit 200 makes the largest number
of turns in the magnetic gap among the plurality of voice coils. The drive signal is supplied to a
voice coil including a wire.
[0042]
Note that, in the case of FIG. 2, the control unit 201 obtains the level of the drive signal supplied
to any one of the voice coils 150 from the input signal of the amplifier 220.
In this case, the level of the drive signal can be calculated by the control unit 201 multiplying the
level of the input signal by the amplification factor of the amplifier 220.
Then, the control unit 201 obtains the displacement of the voice coil 150 from the level of the
drive signal.
In this case, the level of the drive signal and the displacement of the voice coil 150 can be
obtained from a previously obtained table (not shown) or the like.
Then, in accordance with the displacement of the voice coil 150, of the plurality of voice coils
150a to 150c, a drive signal is supplied to the voice coil including the largest number of
windings in the magnetic gap. The connection state of the switch unit 210 on the input side is
switched.
[0043]
For example, the input signal at the small and medium levels is input to the amplifier 221 and
amplified, and the drive signal is supplied to the voice coil 150a, and the + high level signal is
input to the amplifier 223 and amplified, and the drive signal is supplied to the voice coil 150c. A high level signal is input to the amplifier 222 and amplified, and a drive signal is supplied to
the voice coil 150b.
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11
[0044]
Thus, among the plurality of voice coils 150a to 150c, a drive signal is supplied from one of the
amplifiers 221 to 223 to the voice coil in which the largest number of windings are included in
the magnetic gap.
[0045]
The switch unit 210 can also be switched on the output side of the amplifier 220 (221 to 223),
but by switching in a state where the signal level is small, the switch unit 210 can be configured
simply.
Also, since any one of the amplifiers 221 to 223 is always used, no waste of power occurs.
[0046]
Also, although the switch unit 210 may be a changeover switch as shown in FIG. 2, it becomes
possible to prevent the occurrence of blanking of the switching time by using a plurality of
independent switches as shown in FIG. 3. .
[0047]
The characteristic of the speaker 100 according to the first embodiment shown in FIGS. 1 and 2
is shown in FIG. 4 (a).
Here, in FIG. 4, a conventional normal speaker having a conventional voice coil having a length
corresponding to a conventional magnetic gap portion, and a conventional long voice coil
speaker having a long voice coil having a length three times the length of a normal voice coil
State of comparing how the efficiency changes between the present embodiment of the samelong three-divided speaker of this embodiment (see FIG. 1) and a long voice coil three times the
length of a normal voice coil It shows by.
[0048]
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12
Here, the horizontal axis in FIG. 4 (a) is the displacement of the voice coil, and the state of each
displacement is shown in FIGS. 4 (b) to 4 (c).
FIG. 4B is a neutral state in which no displacement occurs in the voice coil, and in the case of this
embodiment, the voice coil 150a (see FIG. 1B) is present in the magnetic gap.
In this case, the conventional normal speaker having a normal voice coil and the speaker
according to the present embodiment are in a good state, and this state is defined as a relative
efficiency of 1.0.
In the conventional long voice coil speaker having a long voice coil, only 1/3 of the entire voice
coil exists in the magnetic gap, so the relative efficiency is about 0.33.
[0049]
FIG. 4C shows a state in which the voice coil is raised, and in the case of this embodiment, the
voice coil 150c (see FIG. 1B) is present in the magnetic gap.
Therefore, the relative efficiency is 1.
0のままである。
Further, in the conventional long voice coil speaker having the long voice coil, only 1/3 of the
entire voice coil exists in the magnetic gap, so the relative efficiency remains at about 0.33.
On the other hand, in the conventional speaker, the relative efficiency is almost zero since no
voice coil exists in the magnetic gap.
[0050]
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13
FIG. 4D shows a state in which the voice coil is further raised, and in the case of this embodiment,
a state in which the voice coil 150c (see FIG. 1B) has come out of the magnetic gap.
Therefore, in this state, neither the present embodiment nor the conventional long voice coil
speaker has a voice coil at all in the magnetic gap, so the relative efficiency is almost zero.
[0051]
As described above, in the speaker 100 according to the present embodiment, the plurality of
voice coils 150a to 150c on the coil bobbin 140 can cope with the large amplitude vibration of
the diaphragm 170, and further, among the plurality of voice coils 150a to 150c. By selectively
supplying the drive signal to the voice coil in which the largest number of windings are included
in the magnetic gap, it is not necessary to supply the drive signal to the voice coil protruding
from the magnetic gap, without reducing the efficiency. It becomes possible to cope with large
amplitude.
[0052]
In the above description, the level of the drive signal is obtained from the input signal of the
amplifier 220 (221 to 223), and the control unit 201 predicts the position of the voice coil 150
to be displaced by this drive signal. It is not something to be done.
For example, as shown in FIG. 5, the sensor 190 is provided in the vicinity of the coil bobbin 140,
the actual displacement of the voice coil 150 is detected, and the control unit 201 controls the
switching state of the switch unit 210 according to the detection result. It is also good.
[0053]
Further, in the above description, the switching of the drive signal to each of the voice coils 150a
to 150c is controlled by the drive circuit 200 having the amplifier 220 for driving the speaker
100, but the present invention is not limited to this.
For example, as shown in FIG. 6, the control unit 101 equivalent to the above-described control
unit 201 can be disposed in the speaker 100, and the switch unit 102 equivalent to the above-
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14
described switch unit 210 can be disposed. .
By doing this, even when connected to a general amplifier, the switching circuit (the control unit
101 and the switch unit 102) alone on the speaker 100 side is the most in the magnetic gap
among the plurality of voice coils. The drive signal can be supplied to a voice coil including a
winding of.
Then, by doing this, it becomes possible to cope with the large amplitude of the diaphragm by
the plurality of voice coils on the coil bobbin, and furthermore, the voice including the largest
number of windings in the magnetic gap among the plurality of voice coils. By selectively
supplying the drive signal to the coil, it is not necessary to supply the drive signal to the voice
coil protruding from the magnetic gap, and it becomes possible to cope with large amplitude
without lowering the efficiency.
[0054]
In the above description, the level of the drive signal is obtained, and the control unit 101
predicts the position of the voice coil 150 displaced by the drive signal. However, the present
invention is not limited to this.
For example, as shown in FIG. 7 as in FIG. 5, the sensor 190 is provided in the vicinity of the coil
bobbin 140 to detect the actual displacement of the voice coil 150, and the control unit 101
switches the switch unit 102 according to the detection result. May be controlled.
[0055]
Further, in the case of FIG. 2 and FIG. 3, the control unit 201 controls the switching of the switch
unit 210 according to the level of the input signal. However, the invention is not limited thereto.
It is also possible to use
For example, as this distribution circuit 210 ′, a circuit such as a bias circuit of the amplifier
220 is used so that only a signal of a predetermined level passes and is input to one of the
amplifiers 221 to 223. deep.
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[0056]
For example, the medium level signal reaches the amplifier 221 and the drive signal is supplied
to the voice coil 150a, the high level signal reaches the amplifier 223 and the drive signal is
supplied to the voice coil 150c, and the high level signal is the amplifier At 222, a drive signal is
supplied to the voice coil 150b.
[0057]
Second Embodiment FIG. 9 is a cross-sectional view showing a configuration of an
electroacoustic transducer 100 according to a second embodiment of the present invention.
FIG. 10 is a block diagram showing the configuration of the second embodiment of the present
invention. In the first embodiment described above, the voice coil 150 is configured of the voice
coils 150a to 150c divided into three, but in the second embodiment, the voice coil 150 is
divided into two voice coils 150a to 150b. It is configured.
[0058]
That is, for each of the voice coils 150a and 150b of the speaker 100, the switching circuit (the
control unit 201 and the switch unit 210) of the drive circuit 200 makes the largest number of
windings in the magnetic gap among the plurality of voice coils. The drive signal is supplied to
the included voice coil.
[0059]
As shown in FIGS. 9A and 9B, when the drive signal is not supplied, both the voice coil 150a and
the voice coil 150b are uniformly present in the magnetic gap.
Then, by displacing the voice coil in any direction, one of the voice coils has many windings in
the magnetic gap.
[0060]
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16
In the case of FIG. 10, the control unit 201 obtains the level of the drive signal supplied to one of
the voice coils 150 from the input signal of the amplifier 220. In this case, the level of the drive
signal can be calculated by the control unit 201 multiplying the level of the input signal by the
amplification factor of the amplifier 220. Then, the control unit 201 obtains the displacement of
the voice coil 150 from the level of the drive signal. In this case, the level of the drive signal and
the displacement of the voice coil 150 can be obtained from a previously obtained table (not
shown) or the like. Then, in accordance with the displacement of the voice coil 150, of the
plurality of voice coils 150a to 150b, a drive signal is supplied to the voice coil including the
largest number of windings in the magnetic gap. The connection state of the switch unit 210 on
the input side is switched.
[0061]
For example, a signal at the + level is input to the amplifier 221 to be amplified and a drive signal
is supplied to the voice coil 150a, and a signal at the-level is input to the amplifier 222 to be
amplified and the drive signal is supplied to the voice coil 150b.
[0062]
As a result, among the plurality of voice coils 150a to 150b, a drive signal is supplied from one of
the amplifiers 221 to 222 to the voice coil in which the largest number of windings are included
in the magnetic gap.
[0063]
The switch unit 210 can be switched on the output side of the amplifier 220 (221 to 222), but by
switching in a state where the signal level is small, the switch unit 210 can be configured simply.
Also, since any one of the amplifiers 221 to 222 is always used, no waste of power occurs.
[0064]
Also, although the switch unit 210 may be a changeover switch as shown in FIG. 10, a plurality of
independent switches as shown in FIG. 3 of the first embodiment prevents the occurrence of
blanking of the switching time. It becomes possible.
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17
[0065]
In the above description, the level of the drive signal is obtained from the input signal of the
amplifier 220 (221 to 222), and the control unit 201 predicts the position of the voice coil 150
to be displaced by this drive signal. It is not something to be done.
For example, as shown in FIG. 11, a sensor 190 is provided in the vicinity of the coil bobbin 140,
the actual displacement of the voice coil 150 is detected, and the control unit 201 controls the
switching state of the switch unit 210 according to the detection result. It is also good.
[0066]
Further, in the above description, the switching of the drive signal to each of the voice coils 150a
to 150b is controlled by the drive circuit 200 having the amplifier 220 for driving the speaker
100, but the present invention is not limited to this.
For example, as shown in FIG. 12, the control unit 101 equivalent to the above-described control
unit 201 can be disposed in the speaker 100, and the switch unit 102 equivalent to the abovedescribed switch unit 210 can be disposed. . By doing this, even when connected to a general
amplifier, the switching circuit (the control unit 101 and the switch unit 102) alone on the
speaker 100 side is the most in the magnetic gap among the plurality of voice coils. The drive
signal can be supplied to a voice coil including a winding of. Then, by doing this, it becomes
possible to cope with the large amplitude of the diaphragm by the plurality of voice coils on the
coil bobbin, and furthermore, the voice including the largest number of windings in the magnetic
gap among the plurality of voice coils. By selectively supplying the drive signal to the coil, it is
not necessary to supply the drive signal to the voice coil protruding from the magnetic gap, and
it becomes possible to cope with large amplitude without lowering the efficiency.
[0067]
In the above description, the level of the drive signal is obtained, and the control unit 101
predicts the position of the voice coil 150 displaced by the drive signal. However, the present
invention is not limited to this. For example, as shown in FIG. 13 as in FIG. 11, the sensor 190 is
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provided in the vicinity of the coil bobbin 140 to detect the actual displacement of the voice coil
150, and the control unit 101 switches the switch unit 102 according to the detection result.
May be controlled.
[0068]
Further, in the case of FIG. 10, the control unit 201 controls the switching of the switch unit 210
according to the level of the input signal. However, the present invention is not limited thereto.
Each waveform of +/− as shown in FIG. The amplifiers 221 and 222 can be used to amplify the
[0069]
For example, the signal at the + level reaches the amplifier 221 and the drive signal is supplied to
the voice coil 150a, and the signal at the-level reaches the amplifier 222 and the drive signal is
supplied to the voice coil 150b.
The amplifiers 221 to 222 in this case can use amplifier circuits equivalent to general push-pull
circuits.
[0070]
Third Embodiment Here, FIG. 15 shows an example of the configuration of the third embodiment.
In this third embodiment, the yoke 120a portion in contact with the permanent magnet 130 is
added to the magnetic gap (first magnetic gap G1) between the conventional top plate 120b and
the outer peripheral portion of the tip of the center pole. The second magnetic gap G2 is
configured to protrude to the voice coil side and form a second magnetic gap G2 with the center
pole.
[0071]
Therefore, while the magnetic gap (corresponding to the first magnetic gap G1) and the bottom
of the yoke 120a have conventionally been magnetic paths, in the third embodiment, the first
magnetic gap G1 to the second magnetic gap G2 are It is a magnetic path.
[0072]
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And in this third embodiment, a plurality of (6 in this case) voice coils can cope with the large
amplitude of the diaphragm 170 across the first magnetic gap G1 to the second magnetic gap G2
and the front and rear thereof. It is arranged.
[0073]
Furthermore, in the first magnetic gap G1 and the second magnetic gap G2, the states of the
windings of the voice coil present in the magnetic gap are made different.
That is, here, one voice coil is present in the first magnetic gap G1.
And, in the second magnetic gap G2, two voice coils are evenly present.
[0074]
In this way, the switching timing of the voice coil is shifted between the magnetic gap G1 and the
magnetic gap G2, so that not only the driving force increases, but also the smooth switching
without instantaneous disturbance due to the switching. It is possible to expect high sound
quality by
[0075]
Here, two sets of magnetic gaps are provided to set the switching phase to 180 degrees, but it is
also possible to provide three sets of magnetic gaps and set the switching phase to 120 degrees
to realize smoother switching.
Moreover, it is also possible to provide more magnetic gaps and voice coils to realize smoother
switching.
[0076]
[Other Embodiments (1)] In the configuration shown in FIG. 1 described above, the vibration of
the diaphragm 170 is supported using an edge and a damper, but the vibration of the diaphragm
170 is supported using a technique such as magnetic levitation. It is desirable that the large
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amplitude of the diaphragm 170 according to each of the above embodiments can be performed
more smoothly by supporting the above.
[0077]
[Other Embodiments (2)] In the cross-sectional views shown in the above-described
embodiments, the plurality of voice coils are shown as being open, but close-contact winding may
be performed without opening such a gap. .
[0078]
[Other Embodiments (3)] The structure shown in each of the above embodiments is an example
shown as a specific example, and for example, the arrangement of the top plate, permanent
magnet, yoke, etc. may be different. .
[0079]
It is a sectional view showing the composition of the electroacoustic transducer of a first
embodiment of the present invention.
It is a circuit diagram showing composition of an electroacoustic transducer system of a first
embodiment of the present invention.
It is a circuit diagram showing composition of an electroacoustic transducer system of a first
embodiment of the present invention.
It is a characteristic view showing the characteristic of the electroacoustic transducer system of a
first embodiment of the present invention. It is a circuit diagram showing composition of an
electroacoustic transducer system of a first embodiment of the present invention. It is a circuit
diagram showing composition of an electroacoustic transducer of a first embodiment of the
present invention. It is a circuit diagram showing composition of an electroacoustic transducer of
a first embodiment of the present invention. It is a circuit diagram showing composition of an
electroacoustic transducer system of a first embodiment of the present invention. It is sectional
drawing which shows the structure of the electroacoustic transducer of 2nd embodiment of this
invention. It is a circuit diagram which shows the structure of the electroacoustic transducer
system of 2nd embodiment of this invention. It is a circuit diagram which shows the structure of
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the electroacoustic transducer system of 2nd embodiment of this invention. It is a circuit diagram
showing composition of an electroacoustic transducer of a second embodiment of the present
invention. It is a circuit diagram showing composition of an electroacoustic transducer of a
second embodiment of the present invention. It is a circuit diagram which shows the structure of
the electroacoustic transducer system of 2nd embodiment of this invention. It is sectional
drawing which shows the structure of the electroacoustic transducer of 3rd embodiment of this
invention.
Explanation of sign
[0080]
100 electro-acoustic transducer 110 frame 120 yoke 120 a yoke 120 ac center pole 130
permanent magnet 140 coil bobbin 150 voice coil (multiple voice coils) 170 diaphragm
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