close

Вход

Забыли?

вход по аккаунту

?

JP2005184320

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2005184320
PROBLEM TO BE SOLVED: To provide a diaphragm for a dynamic microphone having a center
dome and a sub dome, and to form a thin film for braking with stable quality on the sub dome.
SOLUTION: A diaphragm 1 having a center dome 10 and a sub dome 20 is temporarily fixed on a
rotating table 40, and a UV curable resin 50 containing no volatile component over the entire
circumference of the inner peripheral end 20a of the sub dome 20. Are applied in a streak form
continuously, and the ultraviolet-curing resin 50 is allowed to flow down naturally along the
curved surface of the sub dome 20 without causing a centrifugal force to conform to the dome
surface, and the rotating table 40 is rotated. The ultraviolet curing resin 50 is spread to the side
of the outer peripheral end 20b of the sub dome 20 by the centrifugal force to form a thin film,
and the ultraviolet ray is irradiated and cured to form the braking thin film 50a. [Selected figure]
Figure 1
Diaphragm for dynamic microphone and method of manufacturing the same
[0001]
The present invention relates to a diaphragm for a dynamic microphone and a method of
manufacturing the same, and more particularly to a technique for applying mechanical damping
means to a sub dome.
[0002]
In the dynamic microphone, as shown in FIG. 3, a diaphragm made of a synthetic resin such as
polyethylene or polyester having a center dome 10 and a sub dome 20 continuously provided
around the center dome 10 so as to elastically support the center dome 10 1 is commonly used.
13-05-2019
1
[0003]
A voice coil 30 for power generation is attached to the center dome 10 by, for example, an
adhesive.
The voice coil 30 is disposed in a magnetic gap (not shown), and vibrates in the magnetic gap
with the center dome 10 by the incoming sound wave, thereby converting the sound wave into
an electrical signal.
[0004]
In the case of a unidirectional dynamic microphone, the control scheme is mass control.
From this, it is possible to pick up sound at a low frequency by lowering the low resonance
frequency of the diaphragm. As described in Patent Document 1, (1) a method of making the
voice coil 30 heavier and (2) a method of weakening the spring of the sub dome 20 (a method of
reducing the stiffness) as a method of lowering the resonance frequency of the diaphragm. There
is a way.
[0005]
However, if the voice coil 30 is made heavy according to the above (1), the handling noise
increases, which is inconvenient as a hand-held hand microphone. On the other hand, in the case
of reducing the stiffness of the sub dome 20 according to the above (2), the thickness of the sub
dome 20 may be reduced or the radius of curvature of the sub dome 20 may be increased as a
general method. Since the mechanical strength of the sub dome 20 is reduced, as shown in the
graph of FIG. 4, an abnormal resonance is generated in the middle to high frequency region of 2
kHz to 8 kHz of the frequency response, which is not preferable.
[0006]
Therefore, as a method to solve the problems by the method (2), a peripheral treatment agent is
applied over almost the entire surface of the back surface (lower concave surface in FIG. 3) of the
13-05-2019
2
sub dome 20 to make a thin film for mechanical braking. It has been conventionally performed to
suppress abnormal resonance to the above-mentioned middle and high frequencies by forming.
[0007]
JP-A-4-115696
[0008]
A coating type resin is used as the peripheral processing agent, but in order to facilitate the
coating operation, it is diluted with an organic solvent such as toluene.
However, as a practical matter, it is difficult to uniformly dilute the coating resin for each lot.
Therefore, the quality of the thin film for braking varies from lot to lot, and the effect of
preventing abnormal resonance is not uniform.
[0009]
In addition, although the thin film for braking is cured by volatilizing the organic solvent, the
curing time may be different due to environmental factors such as temperature and humidity,
and the quality of the thin film for braking may not be stabilized. It has become.
[0010]
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a
diaphragm for a dynamic microphone having a center dome and a sub dome, and a diaphragm
having a thin film for stable braking in the sub dome and a manufacturing method thereof.
[0011]
In order to solve the above problems, according to a first aspect of the present invention, there is
provided a diaphragm for a dynamic microphone including a center dome on which a voice coil
for power generation is mounted and a sub dome continuously provided around the center dome.
A damping thin film made of an ultraviolet-curable resin is integrally formed on substantially the
entire surface of the back surface of the sub dome.
13-05-2019
3
[0012]
In the first invention, the film thickness of the thin film is 10 μm to 0.5 mm and the hardness is
15 on the Shore D scale in order to effectively suppress abnormal resonance in the middle to
high frequency range of 2 kHz to 8 kHz in the frequency response. It is preferable that it is ± 10
(especially 15 ± 5).
[0013]
Further, in order to solve the above-mentioned problems, according to a second invention of the
present application, there is provided a diaphragm for a dynamic microphone comprising a
center dome on which a voice coil for power generation is mounted and a sub dome continuously
provided around the center dome. In the manufacturing method, the first step of temporarily
fixing the diaphragm having the center dome and the sub dome on the rotary table with the back
surface side up by a predetermined fixing means, and the inner peripheral end side of the sub
dome A second step of continuously applying a UV curable resin containing no volatile
component in a streak form all over the entire circumference of the surface, and the UV curable
resin naturally along the curved surface of the sub-dome without applying a centrifugal force The
third step of flowing down and conforming to the dome surface, and rotating the diaphragm
together with the rotary table, the centrifugal force of the diaphragm causes the UV curable resin
to A fourth step of thinning by spread to the outer peripheral end side of the dome, is
characterized by carrying out a fifth step of curing by irradiating ultraviolet rays to the thinned
ultraviolet curable resin.
[0014]
In the second invention, in order to form a uniform thin film for braking, the rotational speed of
the diaphragm in the third step is set to 10 to 500 rpm, and the ultraviolet irradiation in the
fourth step is performed to rotate the diaphragm. It is preferable to carry out.
[0015]
According to the present invention, the UV curable resin containing no volatile component is
used as the peripheral treatment agent for forming the braking thin film on the sub dome,
whereby the braking thin film having stable quality is subjected to the surroundings such as
temperature and humidity. It can be formed in a short time without being influenced by
environmental factors, and it is possible to collect sound at a low frequency by this, but a
dynamic response that does not generate abnormal resonance over the middle to high frequency
of 2kHz to 8kHz of frequency response. A diaphragm for a microphone is provided.
13-05-2019
4
[0016]
Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2,
but the present invention is not limited thereto.
1 (a) to 1 (d) are explanatory views showing the manufacturing process of the diaphragm
according to the present invention, but FIGS. 1 (b) to 1 (d) are enlarged cross-sectional views of
the left half of FIG. 1 (a). It is.
FIG. 2 is a graph showing frequency response characteristics of a dynamic microphone provided
with a diaphragm obtained by the present invention.
[0017]
In the manufacturing method of the present invention, first, as a first step, the diaphragm 1 is set
on the rotary table 40 as shown in FIG. 1 (a).
The diaphragm 1 includes the center dome 10 and the sub domes 20 connected to the center
dome 10 as described above with reference to FIG. 3, and the whole is integrally molded from a
synthetic resin such as polyethylene or polyester.
Although the voice coil 30 is not yet attached to the diaphragm 1 at the stage of the
manufacturing process in this example, the voice coil 30 may be attached in advance in the
previous step.
[0018]
The rotary table 40 is formed with a support surface 41 including a concave surface that
matches the convex surfaces of the center dome 10 and the sub dome 20. The diaphragm 1 is
reversed with respect to the support surface 41, ie, the concave surfaces of the center dome 10
and the sub dome 20. The side is placed as the upper side in FIG. 1 (a).
[0019]
13-05-2019
5
In this example, an adsorption hole 42 communicating with a negative pressure source (not
shown) is provided at the center of the rotary table 40, and the diaphragm 1 is temporarily fixed
to the rotary table 40 by the negative pressure adsorption action of the adsorption holes 42. Be
done.
Note that as another fixing means, for example, a claw that holds the edge of the diaphragm 1
can be used.
[0020]
Next, as a second step, as shown in FIG. 1B, a UV curable resin 50 containing no volatile
component (organic solvent), which is a peripheral treatment agent for forming a damping thin
film, is applied to the sub dome 20 .
The application means may be a commonly used dispenser nozzle or the like, but it is preferable
that the application position is on the inner peripheral end 20a side of the sub dome 20, for
example, in a streak shape over the entire circumference while rotating the rotary table 40 .
[0021]
Product name 5X634A (composition: urethane acrylate prepolymer 40 to 50 wt%, acrylate
monomer 40 to 50 wt%, balance is adhesion auxiliaries, light, manufactured by Chemitec as UVcurable resin 50 containing no volatile component used in the present invention The initiator can
be exemplified (containing 3.6 to 5 wt%).
The application amount may be optionally determined by the film thickness of the damping thin
film to be finally obtained, the area of the sub dome 20 and the like.
[0022]
In the third step after the second step, the ultraviolet curable resin 50 is allowed to flow down
naturally along the curved surface of the sub dome 20 by gravity as shown in FIG. Carry out the
13-05-2019
6
process of getting familiar with the surface.
[0023]
In this case, the rotary table 40 may be slowly rotated as long as the centrifugal force hardly acts
on the ultraviolet curable resin 50.
Moreover, it is preferable to allow the ultraviolet curable resin 50 to flow down to the lowest
point of the sub dome 20 as a degree of causing the resin to flow naturally by gravity.
[0024]
After the UV curable resin 50 is made to conform to the sub dome 20 in the third step, the rotary
table 40 is rotated in the fourth step, and the UV curable resin 50 is sub dome by its centrifugal
force as shown in FIG. The film is pushed to the outer peripheral end 20b side of 20 and spread.
[0025]
In this case, although the rotation speed of the rotating table 40 depends on the viscosity of the
ultraviolet curable resin 50, it is preferably approximately 10 to 500 rpm.
If it is less than 10 rpm, the UV curable resin 50 may not be able to be spread uniformly to the
outer peripheral end 20 b side, and if it exceeds 500 rpm, the UV curable resin 50 may scatter
out of the sub dome 20. Absent.
[0026]
After confirming that the ultraviolet curable resin 50 has been made thin, ultraviolet light is
irradiated by an ultraviolet lamp (not shown) in the fifth step to cure the thin film resin to form a
braking thin film 50a.
In order to uniformly cure the entire thin film 50a for braking, it is preferable to perform the
13-05-2019
7
ultraviolet irradiation while rotating the rotating table 40. After that, the negative pressure
suction action of the suction holes 42 is released, and the diaphragm 1 is taken out from the
rotary table 40.
[0027]
Thus, according to the present invention, it is possible to form a stable thin film 50a for braking
with stable quality in a short time without being influenced by peripheral environmental factors
such as temperature and humidity. The film thickness of the damping thin film 50a is 10 μm to
0.5 mm, and the hardness is 15 ± 10 (Shore D scale) in order to effectively suppress abnormal
resonance in the middle to high frequency range of 2 kHz to 8 kHz of the frequency response. In
particular, 15 ± 5) is preferable.
[0028]
FIG. 2 is a graph showing the frequency response characteristic of the dynamic microphone
provided with the diaphragm according to the present invention, but abnormal resonance over
the middle to high frequency range of 2 kHz to 8 kHz is reduced compared to the frequency
response characteristic according to the conventional example of FIG. I understand that
[0029]
(A)-(d) Explanatory drawing which shows the manufacturing process of the diaphragm by this
invention.
5 is a graph showing frequency response characteristics of a dynamic microphone provided with
a diaphragm according to the present invention. The side view which shows the diaphragm used
for the conventional dynamic microphone. The graph which shows the frequency response
characteristic of the conventional dynamic microphone.
Explanation of sign
[0030]
Reference Signs List 1 diaphragm 10 center dome 20 sub dome 30 voice coil 40 rotary table 50
13-05-2019
8
UV curable resin 50 a thin film for braking
13-05-2019
9
Документ
Категория
Без категории
Просмотров
0
Размер файла
17 Кб
Теги
jp2005184320
1/--страниц
Пожаловаться на содержимое документа