close

Вход

Забыли?

вход по аккаунту

?

JP3020625

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 JP3020625
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
acoustic filter used for a directional microphone.
[0002]
2. Description of the Related Art FIG. 3 is an explanatory view showing a configuration of a
directional microphone. As shown in FIG. 3, the directional microphone 1 includes a terminal
plate 7 on which the IC 6 mounted in the case 4 is mounted, and a resistance plate 2 disposed at
a position facing the IC 6 and to which the acoustic filter 13 is attached. An electrode 8 mounted
on the resistance plate 2 and facing the acoustic filter 13, and a diaphragm 9 held by the
electrode 8 and the diaphragm ring 10 are configured. FIG. 4 is a side view showing a
conventional acoustic filter. As shown in FIG. 4, the acoustic filter 13 is made by weaving
synthetic fibers, and is attached to the resistance plate 2 by a double-sided tape 11. However,
since the conventional acoustic filter is produced by interlacing synthetic fibers, there is
unevenness in weaving, and the unevenness in the volume tends to occur due to the unevenness
in the weaving, so the acoustic resistance value when receiving the acoustic filter It is necessary
to measure the The result of the measurement results that the non-standard ones become
defective and can not be used, so the yield of the acoustic filter is poor, and since the woven
fabric is fibrous and changes with temperature and humidity, it is necessary to measure the
acoustic resistance each time it is used It was. Furthermore, since the sound comes from the
three directions of the back, front and side of the microphone, the sound is completed again at
the completion to keep the sound performance in three directions within the allowable range (-
03-05-2019
1
64.5 dB to -66.0 dB). If the resistance value is 100% measured and the value exceeds the
allowable range, there is a problem that the sound volume must be adjusted.
[0003]
SUMMARY OF THE INVENTION The present invention has been made to solve the abovementioned problems, and there is no variation in the acoustic performance for buffering the
volume, and the change in the acoustic resistance value due to temperature and humidity is also
possible. It is an object of the present invention to provide a highly reliable acoustic filter that
satisfies the tolerance without requiring measurement of the acoustic resistance value as little as
possible.
[0004]
SUMMARY OF THE INVENTION The acoustic filter according to the present invention is an
acoustic filter attached to a resistance plate mounted inside a directional microphone to buffer
the volume, wherein the acoustic filter is a thin metal plate. More specifically, six or more
minimal holes (5) are formed by pressing on a flat surface.
[0005]
According to the above-described acoustic filter of the present invention, the use of a thin metal
plate formed by pressing six or more small holes on a flat surface stabilizes sound transmission
and dampens the volume. Performance is reduced, and changes in temperature and humidity do
not occur, and the acoustic resistance value is stabilized, so it is not necessary to adjust the sound
volume, and an acoustic filter with high functional reliability satisfying the allowable range of
acoustic performance can be provided. .
[0006]
FIG. 1 is a view showing an embodiment of the present invention, wherein (a) is a side view and
(b) is a plan view.
The acoustic filter 3 of the present invention is made of a thin metal plate having a thickness of
0.06 mm. As shown in FIG. 1A, the acoustic filter 3 is attached to the resistance plate 2 by a
double-sided tape 11.
03-05-2019
2
Further, as shown in FIG. 1 (b), ten small holes 5 of 0.06 mm? are formed on the surface of the
acoustic filter 3 by a press.
The resistance plate 2 to which the acoustic filter 3 is attached is incorporated into the
directional microphone 1 and used. The acoustic filter 3 attached to the resistance plate 2 is
made of a metal plate so that there is no unevenness of mesh unlike the woven fabric, and the
volume is effectively dispersed by the ten minimal holes 5 formed in a plane. The sound
transmission is also averaged and the acoustic resistance value becomes stable. In this case, it
was found that the hole area had a greater influence on the acoustic resistance value than the
thickness of the metal plate. In addition, since there is no influence of temperature and humidity
due to the metal plate, the volume change is small and the sound volume is stabilized and the
acoustic performance is improved. Furthermore, since a minute hole can be formed in a metal
plate by press processing, manufacture is easy, and measurement of the acoustic resistance value
performed at the time of receiving or completion is also unnecessary, and the number of steps
can be significantly reduced. FIG. 2 is a distribution diagram of acoustic resistance values by the
acoustic filter of the present invention. As shown in FIG. 2, in the result of measuring the sound
permeability of 72 samples by the acoustic resistance value, the average value of the acoustic
resistance value is -64.1 dB, and all the measured values are within the allowable range of the
acoustic resistance value. Since a stable acoustic resistance value with less variation is obtained,
which is sufficiently satisfied from -64.5 dB to -66.0 dB, the acoustic resistance value is stabilized
and the acoustic performance is improved. From this result, it is possible to provide a low-cost
and highly reliable acoustic filter, with less variation in sound permeability, less change in
volume, and no need to measure the acoustic resistance each time, as compared with the woven
fabric. Become. In the embodiment of the present invention, the example in which the thickness
of the metal plate is 0.06 mm has been described. However, even if one having a thickness of
0.04 mm to 0.08 mm is used, the minimum hole diameter is 0. 0. The same effect can be
obtained even if the number of minimum holes is 6 to 10 even if the one adjusted to 05 mm? to
0.08 mm ? is used. In the embodiments of the present invention, although an example in which
a metal plate is used as the material of the acoustic filter has been described, iron, a copper alloy,
an aluminum alloy, a film material or the like can be used as the material of the acoustic filter.
[0007]
According to the above-described acoustic filter of the present invention, since six or more
minimal holes are formed in the thin metal plate, the sound volume is effectively dispersed and
the sound transmission is also stable. There is also little variation in performance to buffer the
volume, no change due to temperature and humidity, and the acoustic resistance value is stable,
so there is no need to adjust the sound volume, and a highly reliable acoustic filter that satisfies
03-05-2019
3
the acceptable range of acoustic performance. Can be provided. Further, compared to the case of
using a woven fabric for a metal plate, the influence of temperature and humidity and the change
in volume are reduced, the acoustic resistance value is made uniform, the sound volume is
stabilized and the acoustic performance is improved. Furthermore, since the minimum hole of a
metal plate can be formed by press processing and it becomes unnecessary to measure an
acoustic resistance value each time, manufacture becomes easy and a man-hour can be reduced
significantly.
[0008]
Brief description of the drawings
[0009]
1 is a view showing an embodiment of the present invention, (a) is a side view, (b) is a plan view.
[0010]
2 distribution diagram of the acoustic resistance value by the acoustic filter of the present
invention.
[0011]
3 is an explanatory view showing the configuration of the directional microphone.
[0012]
4 is a side view showing a conventional acoustic filter.
[0013]
Explanation of sign
[0014]
1 и и и Directional microphone 2 и и и Resistance plate 3, 13 и и и Acoustic filter 4 и и и Case 5 и и и Hole
6 и и и IC 7 и и и Terminal plate 8 и и и Electrode 9 и и и Diaphragm 10 иии Diaphragm ring 11 иии Doublesided tape
03-05-2019
4
Документ
Категория
Без категории
Просмотров
0
Размер файла
12 Кб
Теги
jp3020625
1/--страниц
Пожаловаться на содержимое документа