close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JP5143306

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 JP5143306
Abstract: PROBLEM TO BE SOLVED: To provide a microphone which can be easily manufactured,
can obtain stable acoustic impedance, and can use a wider frequency range. SOLUTION: A slit 12
is formed in an air pressure adjustment spacer 6 without providing a cut in the inner edge 6a
and the outer edge 6b of an annular flat air pressure adjustment spacer 6, and one end 12a of
the slit 12 is on the back air chamber 10 side. The back air chamber 10 is closed by closing the
slit 12 with the contact surface 1b of the housing 1 and the upper surface 2a of the insulating
support member 2 from the both surfaces 6d and 6c of the air pressure adjustment spacer 6 so
that the other end 12c opens to the outside. And an air passage 15 communicating the outside
with the outside. [Selected figure] Figure 3
マイクロホン
[0001]
The present invention relates to a microphone that improves the variation in acoustic impedance
due to the variation in the shape of an air passage that communicates the back air chamber with
the outside.
[0002]
The cutoff frequency on the low frequency side of the microphone depends on the acoustic
impedance of the air passage formed between the back air chamber and the outside.
16-04-2019
1
The acoustic impedance increases as the air passage narrows and lengthens, and the cutoff
frequency extends toward the low frequency region if the acoustic impedance is large.
[0003]
Patent Document 1 discloses a communication member in which a lower member in which a
groove is formed and an upper member in which a through hole is provided are coaxially
stacked, and the groove and the through hole are combined sufficiently long to connect the back
air chamber with the outside. There is described a condenser microphone which forms an arcshaped communication hole (vent) to improve the variation in acoustic impedance, reduce the
variation in cutoff frequency in a low frequency region, and obtain a low cutoff frequency.
[0004]
In addition, Patent Document 2 describes a condenser microphone that adjusts a cutoff
frequency by forming a vent groove in a curved shape so as to be long in a vent ring.
[0005]
Patent No. 3613786 JP, 2004-320144, A (Drawing 6)
[0006]
However, in the condenser microphone described in Patent Document 1, since it is necessary to
form a groove by cutting in the insulating member constituting the communicating member, cost
is required, and even when molding is performed using a mold, there is a problem of accuracy.
Come.
Further, since the insulating member constituting the lower member usually has a large
coefficient of thermal expansion, variations in the dimensions of the groove may occur due to
temperature changes.
Further, in the condenser microphone described in Patent Document 2, it is not easy to process
the depth of the vent groove which is formed long in a curved shape with the required accuracy.
[0007]
16-04-2019
2
The present invention has been made in view of such problems in the prior art, and the object of
the present invention is to provide a stable acoustic impedance which is easy to manufacture and
to use a wider frequency range. It is intended to provide a microphone that can
[0008]
In order to solve the above problems, the invention according to claim 1 forms a slit in the air
pressure adjusting spacer without providing a cut in the inner edge portion and the outer edge
portion of an annular flat plate shaped air pressure adjusting spacer, and one end of the slit By
closing the slit from both sides of the air pressure adjustment spacer so that the other end is
open to the outside, an air passage connecting the back air chamber and the outside is formed on
the air chamber side.
[0009]
Further, the slits of the pressure adjustment spacer can be formed by etching.
[0010]
According to the first aspect of the present invention, the slit is formed instead of the groove
requiring the dimension of the depth, so that the manufacture becomes easy and the cost can be
reduced.
In addition, since the air pressure adjustment spacer has a shape in which the slit outer periphery
is closed without providing a cut, the deformation of the air passage becomes small, and a stable
acoustic impedance can be obtained.
In addition, by increasing the acoustic impedance, the cutoff frequency is lowered and the flat
frequency range is expanded, so that a wider frequency range can be used.
[0011]
If the slits of the air pressure adjustment spacer are formed by etching, the shape of the slits can
be processed with high accuracy, so that the variation itself of the falling direction can be
suppressed and further cost reduction can be achieved.
16-04-2019
3
[0012]
FIG. 2A is a plan view of a partial front view of a partial cross section of a microphone according
to the present invention, and FIG. 3A is an explanatory view of a pressure adjustment spacer in a
state of being held by an insulation support member; (B) is an enlarged cross-sectional view
taken along the line A-A in (a), (c) is an enlarged cross-sectional view taken along the line B-B in
(a), and (d) is an enlarged cross-section taken along the line C-C in (a) Figure
[0013]
Embodiments of the present invention will be described below based on the attached drawings.
As shown in FIG. 1, the microphone according to the present invention is, as shown in FIG. 1, a
housing 1, an insulating support member 2, a pole 3, a vibrating membrane 4, a vibrating
membrane holder 5, an air pressure adjusting spacer 6, a pressing member 7, a buckling 8, a grid
9. And so on.
10 is a back room.
The grid 9 has radial slits and is fixed to the housing 1.
[0014]
The housing 1 is formed in a cylindrical shape using a conductive member such as metal.
In the housing 1, an edge portion 1a at the opening end, an annular contact surface 1b against
which the air pressure adjustment spacer 6 abuts, a groove 1c around the contact surface 1b, a
gap 1d with the grid 9, a gap 1d and a groove 1c There is provided a vent 1e in communication.
[0015]
The insulating support member 2 is formed in a disk shape with a through hole at the center by
16-04-2019
4
using a ceramic material or a polymer material. The insulating support member 2 is in contact
with the contact surface 1b of the housing 1 via an annular flat pressure adjusting spacer 6, and
a cylindrical back ring 8 in which a male screw is formed on the outer peripheral surface via the
annular pressing member 7 It is fixed to the housing 1 by screwing and tightening an internal
screw formed on the inner peripheral surface of the housing 1.
[0016]
The pole 3 is formed in a disc shape by using the conductive member such as metal, and the
electret film 11 provided on the plate portion 3a, and the electrode lead portion 3b fitted in the
through hole of the insulating support member 2 at the center of the lower portion. And is
supported by the insulating support member 2.
[0017]
The vibrating film 4 is formed of a conductive foil such as titanium or stainless steel.
Then, after the vibrating membrane 4 is attached to the vibrating membrane holder 5, the
vibrating membrane 4 is pressed against the edge portion 1 a of the housing 1 and a
predetermined tension is applied. The vibrating film 4 is disposed between the electret film 11
and the grid 9.
[0018]
As shown in FIG. 2, the pressure adjusting spacer 6 is formed in a ring shape of a thin plate made
of metal. For example, a plate material (for example, 20 μm in thickness) of titanium easy to etch
is used as the pressure adjustment spacer 6, and a substantially annular slit 12 (for example,
width 0.07 mm) is formed by etching. The pressure adjustment spacer 6 is sandwiched between
the housing 1 and the insulating support member 2.
[0019]
A rectangular opening 12b is formed on one end 12a of the slit 12 on the inner edge 6a side of
the air pressure adjustment spacer 6, and a rectangular opening on the outer edge 6b of the air
16-04-2019
5
pressure adjustment spacer 6 also on the other end 12c of the slit 12 12 d are formed. And since
there is no cut by the slit 12 in the inner edge 6a and the outer edge 6b of the air pressure
adjustment spacer 6, the dimension of the width of the slit 12 is stabilized.
[0020]
When the insulating support member 2 is fixed to the housing 1 via the air pressure adjustment
spacer 6, the entire surface 6 c of the air pressure adjustment spacer 6 on the insulation support
member 2 side abuts on the upper surface 2 a of the insulation support member 2. As shown in
FIG. 3A, the surface 6d of the air pressure adjustment spacer 6 on the housing 1 side is covered
with the contact surface 1b of the housing 1 with a portion (hatched portion) covering a part of
the slit 12 and the openings 12b and 12d. It is broken. The opening 12b on the inner edge 6a
side communicates with the back air chamber 10 as shown in FIG. 3 (c), and the opening 12d on
the outer edge 6b side communicates with the vent hole 1e as shown in FIG. 3 (d). It
communicates with the outside through.
[0021]
Then, as shown in FIGS. 3A to 3D, the housing 1 is a contact surface 1b of the housing 1, the slit
12 and openings 12b and 12d of the pressure adjustment spacer 6, and the top surface 2a of the
insulating support member 2. A ventilation passage 15 is formed, which communicates the back
air chamber 10 formed by the insulating support member 2 and the vibrating membrane 4 with
the ventilation hole 1e of the housing 1.
[0022]
The operation of the microphone according to the present invention configured as described
above will be described.
In the microphone according to the present invention, as shown in FIG. 3A to FIG. 3D, the air
passage 15 leading to the air hole 1e of the housing 1 facing the outside from the back air
chamber 10 is formed. Since air flows in and out as shown, the pressure in the back air chamber
10 can be maintained at atmospheric pressure.
[0023]
16-04-2019
6
Then, as shown in FIG. 2, since the air pressure adjustment spacer 6 has a continuous shape
without a break in the inner edge portion 6a and the outer edge portion 6b, the width W of the
slit 12 shown in FIG. It is hard to be affected by the handling method in the above, the magnitude
of the tightening force of the back ring 8 with respect to the housing 1, heat, deterioration over
time, and the like, and hardly changes.
[0024]
In addition, since the slits can be formed with high precision by etching, the internal shape of the
air passage 15 functioning as an acoustic impedance affecting the frequency characteristics of
the low frequency region of the microphone does not vary depending on the product, and the
cutoff frequency The variation in phase characteristics of the low frequency region is also
reduced.
When the surface roughness of the insulating support member 2 affects the acoustic impedance
by the slits 12, a metal washer with a smooth surface may be interposed between the insulating
support member 2 and the air pressure adjustment spacer 6.
[0025]
Further, since the length and width W of the slit 12 forming the air passage 15 can be
manufactured to a desired value by etching, it is possible to easily set the frequency
characteristic of the low frequency region of the microphone, for example, the value of the cutoff
frequency. become.
[0026]
According to the present invention, by increasing the acoustic impedance, the cutoff frequency is
lowered and the flat frequency range is expanded, so it is possible to provide a microphone
which can use a wider frequency range.
[0027]
DESCRIPTION OF SYMBOLS 1 ... Housing, 1a ... Edge part, 1b ... Contact surface, 1c ... Groove, 1d
... Gap, 1e ... Ventilation hole, 2 ... Insulating support member, 2a ... Upper surface, 3 ... Pole, 3a ...
Plate part, 4 ... Vibration Membrane, 5: Vibrating membrane holder, 6: Pressure adjustment
spacer, 6a: inner edge, 6b: outer edge, 6c, 6d, face, 7: pressing member, 8: buckling, 9: grid, 10:
back air chamber 11: electret film, 12: slit, 12a: one end, 12b, 12d: opening, 12c: other end, 15:
16-04-2019
7
air passage, W: width.
16-04-2019
8
Документ
Категория
Без категории
Просмотров
0
Размер файла
16 Кб
Теги
jp5143306, description
1/--страниц
Пожаловаться на содержимое документа