JP2007028523

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DESCRIPTION JP2007028523
PROBLEM TO BE SOLVED: To form a partial characteristic change portion by using heat or
pressure after forming a diaphragm, to disperse split resonance peaks and to improve frequency
characteristics. SOLUTION: A change such as heat or pressure is applied on the surface of a cone
12 to be a speaker diaphragm, and a change portion 15 having physical characteristics different
from other portions is formed on the cone 12. The changing portion 15 is formed in a pattern
that divides the circumference of the cone 12 in the radial direction. By forming the changing
portion 15 on the cone 12, the frequency characteristic of the speaker can be improved.
[Selected figure] Figure 3
Speaker diaphragm and method for manufacturing speaker diaphragm
[0001]
The present invention relates to, for example, a diaphragm for a resin speaker (hereinafter
referred to as a speaker diaphragm) used for sound output.
[0002]
The speaker diaphragm firstly aims to increase the rigidity of the speaker diaphragm material for
the purpose of improving the frequency characteristics, secondly adds structural change to the
speaker diaphragm and strengthens it, and thirdly the speaker Means such as applying a
damping material or the like in a predetermined pattern on the surface of the diaphragm is
adopted.
[0003]
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Here, in order to expand the piston movement area of the speaker diaphragm, it is required that
the specific elastic modulus E / ρ (E: elastic modulus, ρ: density) be large, and that the internal
loss be large in order to smooth the frequency characteristics. Be done.
Also, in order to improve the elastic modulus, conventionally, a material in which a high elastic
fiber (for example, glass fiber or carbon fiber) or a filler (for example, mica for coloring) is filled
in a polypropylene material having relatively large internal loss is injection molded. , It is often
used in sheet molding.
[0004]
Further, in order to improve the rigidity of the speaker diaphragm, a method of providing a rib
on the speaker diaphragm or changing the thickness is adopted (see Patent Document 1).
Furthermore, in order to improve the frequency characteristics, a method is adopted in which the
damping material is applied to the speaker diaphragm in a fixed pattern. (See Patent Document
2).
[0005]
In addition, when polyethylene, for example, is used as the polyolefin used as a speaker
diaphragm material, the elastic modulus is increased while maintaining appropriate internal loss,
and the speaker diaphragm whose characteristics are significantly improved as compared with
the conventional polypropylene molded body It is known that it can be produced (see Patent
Document 3). JP-A-10-352627 JP-A-11-215589 JP-A-5-153692
[0006]
However, when a material obtained by filling a high elastic fiber or filler in a polypropylene
material is used as a speaker diaphragm material, there arises a problem that the specific gravity
of the material increases with the increase of the amount of these additives. For this reason, the
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improvement of the specific elastic modulus is suppressed, and at the same time, the resin flow
length decreases in injection molding and the thin-wall filling becomes difficult, so it is difficult to
satisfy the requirements of both physical properties required for the speaker diaphragm there
were.
[0007]
In the technique described in Patent Document 1, when the speaker diaphragm made of a
polymer material is formed by injection molding, the presence of such a shape in the middle of
the resin flow becomes an obstacle to the flow, particularly thin-walled filling There is a limit to
reducing the weight of the speaker diaphragm because it is difficult. In addition, when
manufacturing a mold for injection molding, since processing accuracy and position accuracy are
more required than conventional products, there is a problem that the mold processing becomes
complicated naturally and the cost for this increases. .
[0008]
In the technique described in Patent Document 2, the speaker diaphragm material may be any
material having excellent adhesion such as paper, but the adhesive property is poor for resins,
particularly those based on polyolefins, so a pressure tool is used. Since it is necessary to carry
out the conventional primer treatment etc., the coating process becomes large and it is not
practical. Further, in the technique described in Patent Document 3, it is difficult to obtain
smooth characteristics depending on the shape of the speaker diaphragm, so it is necessary to
newly add a method for improving the characteristics.
[0009]
An object of the present invention is to provide a loudspeaker diaphragm having smooth
frequency characteristics by specifically cutting off highly oriented ultrahigh molecular weight
polyolefin molecular chains and changing physical properties locally.
[0010]
In order to solve the above problems and to achieve the object of the present invention, the
present invention is to increase the thermoplasticity so as to disperse the local vibration based on
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the characteristics of the local vibration measured in advance on the diaphragm molded of resin.
It forms the change part which changed the physical property of the molecular material partially.
As a structure of a speaker diaphragm, resin uses the polyolefin composition mentioned above. In
addition, as a method of causing a local change in characteristics, after forming the diaphragm,
heating or the surface layer is selectively melted. Thereby, the non-heated part can change the
elastic modulus of a heating part, maintaining a high elastic modulus. That is, it is possible to
intentionally change the vibration propagation speed in the diaphragm to control the vibration
mode generated at a specific frequency. This makes it possible to create a diaphragm that
achieves smoother frequency characteristics.
[0011]
As described above, according to the present invention, after the diaphragm is formed, a thermal
change is applied to the resin surface to form a physical change portion, and the rigidity of the
diaphragm is specifically changed by partially changing the characteristics. The physical
properties were partially controlled, the eigenmodes of the diaphragm were dispersed, the
frequency characteristics were improved, and the frequency characteristics were smoothed.
[0012]
As described above, in the speaker using the diaphragm of the present invention, since the
divided vibration of the diaphragm is dispersed and the peak and dip on the frequency
characteristic at the corresponding portion are alleviated, the effect of the smooth frequency
characteristic is obtained. can get.
[0013]
Hereinafter, embodiments of the present invention will be described in detail using the drawings.
FIG. 1 is an explanatory view of a speaker vibration portion.
As shown in FIG. 1, the speaker vibration part is provided to constitute a speaker unit. In FIG. 1,
the cone 1 serving as the speaker diaphragm needs to be thin, light, and strong in order to
facilitate movement, and is called internal loss to reduce peak-to-peak and transient
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characteristics of frequency characteristics. It should be such as to give a modest loss.
[0014]
The center cap 2 is provided to prevent radial deformation of the cone 1 and to prevent iron
powder and dust from entering the air gap. The center cap 2 has a hole 3 in the vicinity of the
center, and a rough cloth 4 is attached to the hole 3. The holes 3 function to release the air
compressed and stretched by the vibration of the cone 1.
[0015]
The rough cloth 4 plays the role of dustproof without disturbing the flow of air. The voice coil 5
is vertically driven along the periphery of the pole 6 to vibrate the cone 1. The damper 7 holds
the voice coil 5 properly around the pole 6. Arrows 8 secure the edge 9 of the cone 1 to the
frame 10.
[0016]
FIG. 2 is a block diagram of the speaker diaphragm, FIG. 2A is a side view, and FIG. 2B is a front
view. In FIG. 2A, by injecting the resin 13 from the gate 11 into the mold, a cone 12 to be a
speaker diaphragm is formed. At this time, in FIG. 2B, since the resin 13 flows from the gate 11
at the center to the outer peripheral direction in the cone 12, as shown by 14, the resin flow
direction and orientation direction are from the center to the outer periphery. This diaphragm is
an injection molded polyolefin composition. As indicated by 14, a changing portion 15 (see FIG.
3) is formed on the speaker diaphragm so as to cancel local vibration of the speaker diaphragm
caused by the resin flow direction and the orientation direction.
[0017]
FIG. 3 is a view showing a change portion formed on the speaker diaphragm. In FIG. 3, the
changing portion 15 is formed in a pattern of a shape that radially divides the circumference of
the cone 12 to be the speaker diaphragm in accordance with the shape of the cone 12 to be the
speaker diaphragm. When the cone 12 serving as the speaker diaphragm is a regular circle, the
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changing portions 15 are formed uniformly arranged so as to radially divide the circumference of
the cone 12 serving as the speaker diaphragm.
[0018]
For example, the changing portion 15 is formed to have a maximum width on the outer
peripheral side of the circumference of the cone 12 as a speaker diaphragm and a minimum
width on the inner peripheral side, and has a vertex in the inner peripheral direction It is formed
in a triangular shape having a base in the outer peripheral direction. The triangular shape formed
as the change portion 15 has a pattern which is continuous in the tangential direction of the
circumference.
[0019]
FIG. 4 is a diagram illustrating an example of a cross-sectional view of the change portion. In FIG.
4, as indicated by 21 in FIG. 4, the concave portion 24 and the convex portions 22 and 23 are
continuously formed by the formation of melting and bulging by laser irradiation of the cone 12
as indicated by 21. The concave portions 24 and the convex portions 22 and 23 are formed, for
example, at a pitch of 0.5 mm on the surface of the cone 12 having a thickness of 0.35 mm as
indicated at 25 as indicated at 25.
[0020]
FIG. 5 is a view showing a vibration mode by the speaker unit using the speaker diaphragm
without the change portion. In FIG. 5, four relatively large peaks 32, 32, 33, 34 appear upward in
the circumferential direction of the cone 12, and two relatively large bottoms 35, 36 appear
downward in the circumferential direction of the cone 12. Appear in The appearance of relatively
large peaks and bottoms in this way is that the resin flow direction and orientation direction
indicated by 14 in FIG. 2 are strongly generated in a fixed direction, so that the vibration
characteristics are not smooth and local vibrations appear. Responsible.
[0021]
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FIG. 6 is a diagram showing a vibration mode by the speaker unit using the speaker diaphragm
with the change portion. In FIG. 6, six peaks 41, 42, 43, 44, 45, 46 distributed relatively small in
the circumferential direction of the cone 12 appear upward. The reason why the peaks appear
relatively small and dispersed in this way is that the changing portion 15 in FIG. 3 and the
circumference of the cone 12 to be the speaker diaphragm in the radial direction according to
the shape of the cone 12 to be the speaker diaphragm This is because local vibration is divided to
make the vibration characteristic smooth by forming the pattern of the shape to be divided.
[0022]
Here, for example, a carbon dioxide gas laser is used to form the change portion 15. What
pattern should the selective change be made is to form a shape and pattern so as to divide the
local vibration that causes the peak and the bottom according to the occurrence of the peak and
the bottom shown in FIG. 5 measured in advance. It can be determined by controlling the
physical properties of the relevant part.
[0023]
Here, as can be seen from the peak and the bottom shown in FIG. 5, since concentric divided
vibrations are generated, they mutually cancel each other to cause a drop in frequency
characteristics. In order to solve this, as a method of dispersing the divided vibration, for
example, the physical property of the corresponding portion is changed by performing
irradiation with a laser in a fixed shape that divides the circumference of the cone 12 in the
radial direction. Thereby, the changing portion 15 is formed, but this method has a very large
effect of improving the frequency characteristic without changing the weight of the speaker
diaphragm.
[0024]
In the present embodiment, first, the speaker diaphragm is formed of a thermoplastic polymer
material, and then the characteristic of local vibration of the speaker diaphragm after molding is
measured. Then, based on the characteristics of the local vibration, data of the change portion is
generated so as to disperse the local vibration, and furthermore, the physical properties of the
thermoplastic polymer material on the speaker diaphragm are partially based on the data of the
change portion. A change part is formed by irradiating a laser beam so that it may be changed.
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[0025]
As described above, in the speaker diaphragm manufacturing method for manufacturing a resin
speaker diaphragm made of a thermoplastic polymer material, it is possible to manufacture a
speaker diaphragm having smooth frequency characteristics by dispersing divided vibrations.
[0026]
Hereinafter, embodiments of the present invention will be described based on specific
experimental results.
FIG. 7 is a view showing an example of the configuration of a change portion forming device. FIG.
7 shows an apparatus used to form the selective change portion 15 on the cone 12 which is a
speaker diaphragm. This apparatus comprises a marker 53 which is a carbon dioxide gas laser
processing machine, a controller 52, and a control personal computer (personal computer) 51,
and has a structure in which an arbitrary figure is formed by laser light irradiation under
appropriate irradiation conditions.
[0027]
In FIG. 7, when a specific figure and laser processing conditions are input to the control personal
computer 51, a drawing command is output to the controller 52. The controller 52 converts the
input drawing command into a command for irradiating the laser light to an arbitrary position of
the cone 12 and supplies the command to the marker 53 which is a laser processing machine. As
a result, the laser beam is controlled to be able to be irradiated in a shape that matches the figure
on the personal computer 51.
[0028]
Here, some types of the marker 53 which is a laser processing machine are mentioned, but it is
known that there is compatibility between the cone 12 which is a processing object and the
wavelength of the laser light. In the case of the resin used to form an orientation layer at the time
of injection, for example, a special polyolefin resin obtained by multistage polymerization of an
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ultrahigh molecular weight polyolefin and a high molecular weight olefin, Lubber L3000
(manufactured by Mitsui Chemicals), a carbon dioxide gas laser is suitable.
[0029]
The reason is that although it is desired to melt the cone 12 to a certain extent deep, control of
output and operation speed can be performed, and a machine that requires a short processing
time is required at the time of mass production. Although it takes time to be satisfied with a YAG
(yttrium aluminum garnet) laser, a carbon dioxide gas laser has been able to set realistic
conditions. The specifications of the carbon dioxide gas laser of this example are as follows. The
laser is a carbon dioxide gas laser, the wavelength is 10.6 μm, the average output is 30 W, the
drawing area is 110 mm × 110 mm, and the printing speed is a maximum of 600 characters /
second.
[0030]
[Experimental Example 1] The speaker diaphragm used in the examination of Experimental
Example 1 is a cone-shaped diaphragm having an outer diameter of 115 mm and a thickness of
0.35 mm as shown in FIG. As shown in FIG. 2, the injection molding has a shape that spreads
uniformly from the gate 11 at the central portion to the thin diaphragm portion through the
inside of the cone 12.
[0031]
The specifications of the injection molding machine are as follows. It is a super high-speed
molding machine with a maximum injection pressure of 2800 kg / cm <2>, a maximum injection
speed of 1500 mm / sec, a rise speed of 10 msec, a clamping force of 160 tons and a screw
diameter of 32 mm. As the resin used, a special polyolefin resin obtained by multistage
polymerization of an ultra-high molecular weight polyolefin and a high molecular weight olefin,
which easily forms an alignment layer upon injection, used is Lubmer L3000 (manufactured by
Mitsui Chemicals, Inc.).
[0032]
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The injection conditions for introducing the resin from the hopper of the injection molding
machine are as follows. The temperature of the plasticizing screw portion is 220 ° C., the
injection speed is 1500 mm / sec, and the mold temperature is 45 ° C. Injection molding was
performed under the above conditions, and the speaker diaphragm was taken out.
[0033]
When the vibration mode was measured using the speaker diaphragm injection molded in this
way, generation of divided vibration as seen from the peak and the bottom shown in FIG. 5 was
confirmed, so a shape for canceling this is provided. I made it. That is, for example, the change
portion 15 having the shape shown in FIG. 3 is provided on the cone 12 which is a speaker
diaphragm.
[0034]
In the present embodiment, a pattern is formed by a carbon dioxide gas laser. The processing
conditions were an output of 80% and a scanning speed of 750 mm / sec. Physical property
values at this time are shown in Table 1.
[0035]
[0036]
In Table 1, in the comparative example (polypropylene), the decrease in Young's modulus is
relatively small and the internal loss hardly changes even when laser irradiation is performed,
whereas in the present example (lubmer), laser irradiation causes Young The decrease in rate is
relatively large, and the internal loss is also relatively large.
From this Table 1, it can be seen that, in this example, the rate of change in physical properties
due to laser irradiation is larger than in other resins, and the effect of disconnecting the
alignment layer is obtained.
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[0037]
FIG. 6 shows a vibration mode in the speaker unit using the diaphragm of the present
embodiment. The peak of the divided vibration is smaller than that in FIG. 5, and the effect of the
present embodiment appears.
[0038]
FIG. 8 is a diagram showing frequency characteristics of a speaker unit using a speaker
diaphragm with a change portion. In FIG. 8, in the frequency characteristic of the speaker unit
using the speaker diaphragm with the change portion, the band 2 k to 10 KHz as shown by the
dotted line in the no change portion 61 before the pattern of the change portion 15 is drawn by
the laser. Inside, dip 65, peak 62, dip 66, peak 63, dip 67 and peak 64 appeared. On the other
hand, in the change portion 71 after drawing the pattern of the change portion 15 with a laser,
as shown by the solid line, the number of dips 73 and peaks 72 decreased.
[0039]
Further, compared with the case where the difference 68 between the peak and the dip is 50 (dB)
or more in the case without the change portion 61, the difference 74 between the peak and the
dip is 20 It is remarkable that it becomes smaller within dB), which shows the effect in the
present embodiment.
[0040]
[Experimental Example 2] FIG. 9 is a configuration view of an elliptical speaker diaphragm, FIG.
9A is a side view, and FIG. 9B is a front view.
FIG. 9 shows an elliptical cone-shaped diaphragm used in the second experimental example. A
diaphragm was formed by injection molding under the same conditions as in Experimental
Example 1. In FIG. 9A, by injecting a resin from the same gate as in FIG. 2 into the mold, a cone
81 to be a speaker diaphragm is formed. At this time, in FIG. 9B, in the cone 81, the resin flows in
from the gate in the center toward the outer periphery, so as shown by 82, the resin flow
direction and the orientation direction are from the center to the outer periphery. This
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diaphragm is an injection molded polyolefin composition. The speaker diaphragm was taken out
by injection molding as described above, and the vibration mode was measured.
[0041]
FIG. 10 is a diagram showing a vibration mode by the speaker unit using the speaker diaphragm
without the change portion. In FIG. 10, six relatively large peaks 82, 83, 84, 85, 86, 87 appear
upward in the circumferential direction of the cone 81, and one relatively large bottom 88 in the
circumferential direction of the cone 81. Appears downward. The appearance of relatively large
peaks and bottoms in this way is that the resin flow direction and orientation direction shown by
82 in FIG. 9 are strongly generated in a fixed direction, so that the vibration characteristics are
not smooth and local vibrations appear. Responsible.
[0042]
When the vibration mode is measured using the speaker diaphragm injection molded in this way,
generation of divided vibration as can be seen from the peak and the bottom shown in FIG. 10
can be confirmed, so that a shape for canceling this is provided. I made it.
[0043]
FIG. 11 is a view showing a change portion formed on the speaker diaphragm.
In FIG. 11, when the cone 81 serving as the speaker diaphragm is elliptical, the changing portion
91 is disposed in the focal direction so as to divide the circumference of the cone 81 serving as
the speaker diaphragm in the radial direction. It is formed. For example, the changing portion 91
is formed to have a maximum width on the outer peripheral side of the circumference of the cone
81 serving as a speaker diaphragm and a minimum width on the inner peripheral side, and has a
vertex in the inner peripheral direction It is formed in a triangular shape having a base in the
outer peripheral direction. The triangular shape formed in the change portion 91 has a pattern
which is continuous in the tangential direction of the circumference.
[0044]
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In the speaker diaphragm used in Experimental Example 2, since generation of divided vibration
as shown in FIG. 10 was confirmed, it was decided to provide, for example, a change portion 91
having a shape as shown in FIG. . Then, in the present embodiment, a pattern is formed by a
carbon dioxide gas laser. The processing conditions were an output of 80% and a scanning speed
of 750 mm / sec. The vibration mode was measured after the formation of such a change in
shape.
[0045]
FIG. 12 is a diagram showing a vibration mode by the speaker unit using the speaker diaphragm
with the change portion. In FIG. 12, six peaks 102, 103, 104, 105, 106, 107 distributed relatively
small in the circumferential direction of the cone 81 appear upward. The reason why the peaks
appear relatively small and dispersed in this way is that the change portion 91 in FIG. 11 is made
radial in the circumferential direction of the cone 81 to be the speaker diaphragm in accordance
with the shape of the cone 81 to be the speaker diaphragm. This is because local vibration is
divided and the vibration characteristics are smoothed by forming the pattern of the shape
arranged in the focal direction so as to divide.
[0046]
In the vibration mode of the speaker unit using the speaker diaphragm of the present
embodiment shown in FIG. 12, the peak of divided vibration is smaller than that of FIG. 10, and
the effect of the present embodiment appears I understand that.
[0047]
FIG. 13 is a diagram showing frequency characteristics of a speaker unit using a speaker
diaphragm with a change portion.
In the frequency characteristic of the speaker unit using the speaker diaphragm according to the
present embodiment of FIG. 13, the laser shown by a dotted line 112 before drawing the pattern
of the shape of the changing portion 91 shown in FIG. As such, the dip 113 appeared in the band
near 600 Hz. On the other hand, it can be seen that with the change portion 111 after drawing
the pattern of the shape of the change portion 91 with a laser, as shown by the solid line, the
occurrence of dip is suppressed in the band near 600 Hz.
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[0048]
[Experimental Example 3] The loudspeaker diaphragm used in the examination of Experimental
Example 3 is a cone of the same circular shape as the loudspeaker diaphragm used in
Experimental Example 1 (that is, used in the examination shown in FIG. 2). An outer diameter of
156 mm, a thickness of 0.45 mm, and a cone-shaped diaphragm having a large outer diameter
and a large thickness.
[0049]
In injection molding, by injecting resin into the mold from the same gate as in FIG. 2, a cone to be
a speaker diaphragm is formed.
At this time, in FIG. 2B, since the resin flows uniformly in the outer peripheral direction since the
thickness is large from the gate at the central portion in the cone, the resin flow direction and the
orientation direction become a direction spreading uniformly from the central portion to the
outer periphery. This diaphragm is an injection molded polyolefin composition.
[0050]
The specifications of the injection molding machine are as follows. The maximum injection
pressure is 2800 kg / cm <2>, the maximum injection speed is 1500 mm / sec, the rising speed
is 10 msec, the clamping force is 160 tons, and the screw diameter is Φ32 mm. The resin used
was a special polyolefin resin obtained by multistage polymerization of an ultra-high molecular
weight polyolefin and a high molecular weight olefin, which easily forms an alignment layer
when injected, and a fiber composite of Ljubmer L3000 (manufactured by Mitsui Chemicals) .
The injection conditions for introducing the resin from the hopper are the temperature of the
plasticizing screw portion of 260 ° C., the injection speed of 1500 mm / sec, and the mold
temperature of 45 ° C. It injection-molded on the above conditions, took out the speaker
diaphragm, and measured vibration mode.
[0051]
FIG. 14 is a view showing a vibration mode by the speaker unit using the speaker diaphragm
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without the change part. In FIG. 14, relatively large uniform peaks 122 appear upward in the
circumferential direction of the cone 121. Such relatively large uniform peaks appear because
the resin flow direction and the orientation direction are strongly generated in the direction that
uniformly spreads from the central portion to the outer periphery, so that the vibration
characteristics are not smooth and local vibration appears. Responsible.
[0052]
When the vibration mode was measured using the speaker diaphragm injection molded in this
way, generation of divided vibration can be confirmed in the radial direction as can be seen from
the peak shown in FIG. 14, so a shape is provided to cancel this. To
[0053]
The shape of the change portion is the same as the shape shown in FIG.
For example, the shape of the change part in FIG. 3 is provided on the speaker diaphragm. In the
embodiment, a pattern is formed on the marker 53 which is a laser processing machine by
partial heating and pressing. The processing conditions were a temperature of 100 ° C. and a
pressure of 5 kg / cm <2>. As a result, a recess shape of 0.2 to 0.5 mm was formed. The vibration
mode was measured after the formation of such a change in shape.
[0054]
FIG. 15 is a diagram showing a vibration mode by the speaker unit using the speaker diaphragm
with the change portion. In FIG. 15, two peaks 132 and 133 dispersed relatively small in the
circumferential direction of the cone 131 appear upward. The peaks appear relatively small and
dispersed like this in the same way as in FIG. 3 by dividing the circumference of the cone which
will be the speaker diaphragm in the radial direction according to the shape of the cone which is
the speaker diaphragm This is because local vibration is divided to make the vibration
characteristic smooth by forming the pattern of the following shape.
[0055]
In the vibration mode of the speaker unit using the speaker diaphragm according to the present
embodiment shown in FIG. 15, the peak of the divided vibration in the radial direction is smaller
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than that in FIG. 14, and the effect in the present embodiment is You can see that it has
appeared.
[0056]
FIG. 16 is a diagram showing frequency characteristics of a speaker unit using a speaker
diaphragm having a change portion.
In the frequency characteristic of the speaker unit using the speaker diaphragm of this
embodiment of FIG. 16, as shown by the dotted line in the no change portion 142 before drawing
the pattern of the shape of the change portion similar to FIG. In the band of 2 k to 5 kHz, dip 145
and peak 146 appeared. On the other hand, in the change portion 141 after drawing the pattern
of the shape of the change portion by laser, as shown by the solid line, the difference between
dip 143 and peak 144 appears small within the band of 2k to 5 kHz. There is.
[0057]
Thus, in the frequency characteristic of the speaker unit using the speaker diaphragm of the
embodiment of FIG. 16, the difference between the peak 144 and the dip 143 is suppressed as
compared with that before drawing a pattern by partial heating and pressing. It is remarkable
that it is approaching a flat and it shows the effect in the present embodiment.
[0058]
Needless to say, the present invention is not limited to the above-described embodiment, and
may be modified as appropriate without departing from the scope of the present invention
described in the claims.
[0059]
It is explanatory drawing of a speaker vibration part.
It is a block diagram of a speaker diaphragm, FIG. 2A is a side view, FIG. 2B is a front view.
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It is a figure which shows the change part formed on the speaker diaphragm. It is a figure which
shows the example of sectional drawing of a change part. It is a figure which shows the vibration
mode by the speaker unit using the speaker diaphragm without a change part. It is a figure which
shows the vibration mode by the speaker unit using the speaker diaphragm with a change part. It
is a figure which shows the structural example of a change part formation apparatus. It is a
figure which shows the frequency characteristic of the speaker unit using the speaker diaphragm
with a change part. FIG. 9A is a side view, and FIG. 9B is a front view of an elliptical speaker
diaphragm. It is a figure which shows the vibration mode by the speaker unit using the speaker
diaphragm without a change part. It is a figure which shows the change part formed on the
speaker diaphragm. It is a figure which shows the vibration mode by the speaker unit using the
speaker diaphragm with a change part. It is a figure which shows the frequency characteristic of
the speaker unit using the speaker diaphragm with a change part. It is a figure which shows the
vibration mode by the speaker unit using the speaker diaphragm without a change part. It is a
figure which shows the vibration mode by the speaker unit using the speaker diaphragm with a
change part. It is a figure which shows the frequency characteristic of the speaker unit using the
speaker diaphragm with a change part.
Explanation of sign
[0060]
11: Gate, 12: Cone, 13: resin, 14: resin flow direction and orientation direction, 15: change
portion, 22, 23: recess, 24: protrusion, 31, 32, 33, 34, 35: peak, 36: Bottom, 41, 42, 43, 44, 45,
46: Peak, 51: PC for control, 52: Controller, 53: Marker, 61: No change portion, 62, 63, 64: Peak,
65, 66, 67: dip, 68: difference, 71: change portion, 72: peak, 73: dip, 74: difference, 81: cone, 82:
flow direction and alignment direction of resin 82, 83, 84, 85, 86, 87: peak, 88: bottom, 91:
change portion, 102, 103, 104, 105, 106, 107: peak, 108, 109: bottom, 111: change portion,
112: no change portion, 113 ... Ippu, 121 ... corn, 122 ... peak, 131 ... corn, 132, 133 ... peak, 141
... In changing unit, 142 ... change section without, 143, 145 ... dip, 144, 146 ... peak
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