close

Вход

Забыли?

вход по аккаунту

?

JPS63169697

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 JPS63169697
[0001]
[Industrial field of application] The present invention is a swash plate type acoustic in which fins
of a plurality of plates disposed in parallel are disposed at an angle to the direction of arrival of
sound waves to obtain desired directivity characteristics. It is about the lens. [Prior Art] FIGS. 3A
and 3B are a side view and a plan view showing a conventional swash plate type acoustic lens. In
the figure, (1) is a reference plane perpendicular to the direction of arrival of radio waves. (2) is a
plurality of fins arranged in parallel with each other at an angle θ with respect to the reference
plane (1), (3) is an imaginary line showing the sound wave in the traveling direction, (4) is the
sound wave An imaginary line indicating a wave front surface formed by 3), and (5) is a sound
path formed by adjacent fins (2). FIG. 4 is a directional characteristic diagram of acoustic wave
expressed in polar coordinates, the solid line shows the case without an acoustic lens, and the
broken line shows the characteristics when a conventional swash plate acoustic lens is attached.
Now, as shown in FIG. 3 (a), a plurality of fins (2) arranged in parallel are inclined by an angle θ
with respect to the direction of arrival of the sound wave (3), and an appropriate number of fins
(2 The sound speed C 'of the sound wave (3) when passing through the sound path (5) formed by
the fins (2) is C' = CXCo5.theta. Here, C is the speed of sound of the sound wave (3) in free space.
If the center of the inclined fin (2) is cut in shape as shown in FIG. 3 (b), the center of the sound
wave (3) passing through the vicinity of the central part (0-0) The sound wave (3) that has
passed through the side of the part (A or B) will come out later. As a result, the wave front
surface (4) of the sound wave (3) is not parallel to the reference surface (1), but becomes circular
as shown in FIG. 3 (b), and the sound wave (3) It will spread and propagate. As a result, as shown
by the broken line in FIG. 4, the directivity characteristic becomes broad and is improved. The
diagram of FIG. 4 shows the difference in directivity characteristics depending on the presence or
absence of the above-mentioned conventional acoustic lens, and shows that the directions of 60
degrees and 300 degrees, that is, both the left and right directions are improved. [Problems to be
03-05-2019
1
Solved by the Invention] However, the conventional swash plate type acoustic lens can
simultaneously improve the directivity characteristics in the horizontal direction in the horizontal
plane with respect to the direction of arrival of the sound wave (3). There is a problem that it is
not possible to improve the directivity characteristic of either the left or right direction. It is to be
noted that improving the directivity characteristic only in the desired left or right direction is a
very important element in the technology of expanding the optimum listening range when
reproducing the sound in stereo.
The present invention has been made to solve the above-mentioned problems, and it is an object
of the present invention to improve an directivity characteristic in only one desired direction,
that is, to obtain an acoustic lens capable of forming a polar directivity. Do. [Means for Solving
the Problems] In the acoustic lens according to the present invention, the central portions of the
plurality of fins are not parallel to each other but are inclined at an angle with respect to the
reference plane and not adjacent to each other. The length of the sound path formed by the fins
is formed so as to sequentially decrease from one end of the lens toward the center, and the
length of the sound conduction is constant from near the center to the other end The abovementioned fins are arranged to be In the acoustic lens according to the present invention, the
lengths of the respective sound paths formed by the fins arranged as described above gradually
change from one end of the lens toward the central portion and from the vicinity of the central
portion As the sound wave passes through these sound paths, the sound velocity from the one
end of the lens to the vicinity of the central portion changes in order from the other, and the
sound velocity changes from the other portion to the other. By being constant to the end, the
wave front of the sound wave is inclined within the range that is relative to the reference surface.
As a result, the directional characteristic of only one direction is improved. An embodiment of the
present invention will be described below with reference to the drawings. 1 (a) and 1 (b) are a
plan view and a front view showing an embodiment of the present invention, in which (1) is a
reference plane perpendicular to the direction of arrival of sound waves, and (2) is a vertical
direction. A plurality of fins disposed in parallel to each other and inclined with respect to the
reference surface (1), (3) an imaginary line indicating a sound wave, (4) a wave front surface
formed by the sound wave (3), (5) is a sound path formed by adjacent fins (2). FIG. 2 is a
directional characteristic diagram of sound waves expressed in polar coordinates, the solid line
shows the case without an acoustic lens, and the broken line shows the case with an acoustic lens
according to the present invention attached. Now, in FIG. 1 (a), the plurality of fins (2) arranged
in parallel in the vertical direction are in the direction to obtain the polarization (in the case of
FIG. 1 (a), to the left direction A of 5). Of the sound path (5) formed by adjacent fins (2) inclined
at an angle O1 in the opposite direction to the direction of The length of each sound path (5) is
assumed to be constant from the vicinity of the central portion (0-0) to the other end B such that
the length gradually decreases from A toward the central portion (0-0). The fin (2) is provided to
be
03-05-2019
2
As a result, the tip of the fin (2) is a line inclined at an angle 0 □ with respect to the reference
plane (1) from the end A to the center (0-0), and the center (0-0) From near to the other end B, it
comes to a line parallel to the reference plane (1). A locus reached after a certain period of time
of each sound wave (3) which has passed through each sound path (5) formed in this way can be
represented as a wave front surface (4) in the figure. The wave front surface (4) is inclined to the
longer side of the sound path (5) through which the sound wave (3) passes with respect to the
reference surface (1). That is, the directivity characteristic in the direction opposite to the
direction of the fins (2) is improved, and it is possible to obtain the non-polarity. FIG. 2 is a
characteristic diagram showing the difference in directivity of sound waves depending on the
presence or absence of the acoustic lens according to the present invention. Although there is no
difference in the direction of 300 degrees due to the presence or absence of the acoustic lens, the
difference appears in the effect in the direction of 60 degrees. This directional characteristic
indicates that the acoustic lens according to the present invention has polarizability. The smaller
the range in which the length of the sound path (5) becomes constant relative to the reference
surface (1), the larger the effect of the polarization will be. It is desirable to appropriately
determine this in balance with the entire design Also, in the above embodiment, either the angle
01 or the angle θ2 may be larger or the same. [Effects of the Invention] As described above,
according to the present invention, the sound formed by the adjacent fins of the plurality of fins
disposed in parallel with each other at an angle to the direction of arrival of the sound wave is
formed. Change the length of the fin so that the length of the road gradually decreases from one
end of the lens toward the center, and fix the length of the fin so that the length of the sound
path becomes constant from the middle As a result, it is possible to obtain a swash plate-shaped
acoustic lens having a desired polarization and a desired design.
[0002]
Brief description of the drawings
[0003]
1 (a) and 1 (b) are a plan view and a front view showing an embodiment of the present invention,
and FIG. 2 is a characteristic diagram showing the difference in directivity characteristics in polar
coordinates with and without the acoustic lens of this embodiment. FIGS. 3 (a) and 3 (b) are side
and plan views showing a conventional acoustic lens, and FIG. 4 is a characteristic diagram
showing differences in directivity characteristics in polar coordinates depending on the presence
or absence of the conventional acoustic lens.
03-05-2019
3
In the figure, (1) is a reference plane, (2) is a fin, (3) is a virtual line showing a sound wave, (4) is
a virtual line showing a wave front, and (5) is a sound path. In the drawings, the same reference
numerals denote the same or corresponding parts.
03-05-2019
4
Документ
Категория
Без категории
Просмотров
0
Размер файла
12 Кб
Теги
jps63169697
1/--страниц
Пожаловаться на содержимое документа