close

Вход

Забыли?

вход по аккаунту

?

JP2013247399

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 JP2013247399
Abstract: In a loudspeaker array including a plurality of loudspeaker units, degradation of
frequency characteristics is reduced. An acoustic signal reproduction apparatus according to the
present invention includes a speaker array having a plurality of speaker units, and at least a part
of the speaker units are spatially unevenly arranged. [Selected figure] Figure 2
Acoustic signal reproduction device
[0001]
The present invention relates to an acoustic signal reproduction apparatus, and more particularly
to an acoustic signal reproduction apparatus including a speaker array having a plurality of
speaker units.
[0002]
A speaker array based on the theory of Wave Field Synthesis (WFS) is used as a technique for
reproducing the physical characteristics of the original sound field using a large number of
speaker units and providing desired sound image localization (for example, Non-Patent
Document 1).
As a speaker array based on the theory of WFS, one in which speaker units are arranged linearly
at equal intervals is used. In this case, sufficient sound image localization can be provided only
for the sound image on the plane formed by the linear speaker array and the listening point.
03-05-2019
1
Moreover, it is also known that the frequency characteristic of the reproduced sound field is
degraded due to the interference generated between the speaker units.
[0003]
A. J. Berkhout, D de Vries, and P. Pogal, Journal of Acoustical Society of America, 93 (1993), p.
2764.
[0004]
FIG. 5 is a diagram showing an example of a sound wave path in the speaker array.
Naturally, the WFS theory applies to the fact that the speaker units are very closely spaced on the
plane, and the distance between the virtual sound source and the speaker array is sufficiently
larger than the wavelength of the sound wave, and the wavefront of the sound image to be
reproduced Is a plane wave. However, in an actual design, the speaker unit configures the
speaker array with a certain distance, and in order to make the sound image localization clear, it
is effective to bring the virtual sound image closer to the speaker array. In this case, the wave
front of the sound image to be reproduced is a spherical wave, and the interference of the sound
waves of each path from the virtual sound source to the listening position via each speaker unit
occurs. FIG. 6 is a diagram showing an example of the frequency characteristics of the input
acoustic signal and the sound outputted from the speaker array. When interference of sound
waves in each path of the speaker array occurs with respect to the input acoustic signal shown in
FIG. 6A, dip occurs in the high frequency band as in the frequency characteristic shown in FIG.
The frequency characteristics to be given may be impaired.
[0005]
The cause of dips in the frequency characteristics by the speaker array will be described in detail
with reference to FIGS. FIG. 7 is a diagram showing an example of a path difference of sound
waves with respect to two speaker units in the speaker array. For example, let L1 and L2 be the
path lengths of sound passing through the two speaker units S1 and S2 of the speaker array from
the virtual sound source to the listening position, respectively. Here, ΔL, which is the path
difference between L1 and L2, is expressed by equation (1).
03-05-2019
2
[0006]
[0007]
Here, when the path difference ΔL is a half wavelength of a certain frequency and an odd
multiple of a half wavelength, the sound waves of the frequency are in opposite phase at the
listening position and cancel each other.
Therefore, assuming that the sound velocity in the air is c, the frequency fn (n is an integer of 0
or more) that cancels out due to the path difference ΔL can be expressed by equation (2).
[0008]
[0009]
FIG. 8 is a diagram showing an example of dips in frequency characteristics generated due to a
path difference.
As illustrated, a dip occurs at the frequency shown in equation (2). Here, since the speaker array
includes a large number of speaker units, a path difference is generated for each combination of
speaker units, and the above-described dip is also generated, so that the correction by signal
processing involves complexity. In particular, in the speaker array in which the speaker units are
arranged at equal intervals as in the prior art, regularity easily occurs in the path difference
between the speaker units, and the frequency characteristics deteriorate due to the individual
dips strengthening each other due to mutual interference. There is a problem that the sound
quality is deteriorated.
[0010]
Therefore, an object of the present invention made in view of such a point is to provide a sound
reproducing apparatus capable of reducing deterioration of frequency characteristics due to
mutual interference in a speaker array including a plurality of speaker units.
03-05-2019
3
[0011]
In order to solve the various problems described above, an acoustic signal reproduction
apparatus according to the present invention includes a speaker array having a plurality of
speaker units, and at least a part of the speaker units are spatially unevenly arranged. It is
characterized by
[0012]
Further, it is desirable that all of the speaker units be spatially unevenly arranged.
[0013]
Further, it is desirable that the speaker units arranged spatially unevenly be arranged spatially
unevenly based on any random number.
[0014]
Further, the speaker units arranged spatially unevenly are arranged spatially unevenly by adding
correction values based on arbitrary random numbers to positions when the speaker units are
arranged at equal intervals. Is desirable.
[0015]
According to the sound reproducing apparatus according to the present invention, it is possible
to reduce deterioration of frequency characteristics due to mutual interference in a speaker array
including a plurality of speaker units.
[0016]
It is a figure which shows the functional block of the acoustic signal reproduction apparatus
which concerns on one Embodiment of this invention.
It is a figure which shows an example of arrangement | positioning of the speaker unit in a
speaker array.
It is a figure which shows an example of the correction value regarding speaker unit
arrangement | positioning.
03-05-2019
4
It is a figure which shows an example of a change of the frequency characteristic by speaker unit
arrangement | positioning.
It is a figure which shows an example of the path | route of the sound wave in a speaker array.
It is a figure which shows an example of the frequency characteristic of an input acoustic signal
and a speaker array output.
It is a figure which shows an example of the path difference of the sound wave in a speaker
array. It is a figure which shows an example of the dip of a frequency characteristic.
[0017]
Hereinafter, embodiments of the present invention will be described in detail with reference to
the drawings.
[0018]
FIG. 1 is a diagram showing functional blocks of an acoustic signal reproduction device 1
according to an embodiment of the present invention.
The acoustic signal reproduction device 1 includes a decoder 10, an amplifier 20, and a speaker
array 30.
[0019]
The decoder 10 decodes the input acoustic signal, and outputs the decoded acoustic signal to the
amplifier 20 as a drive signal. Here, as the sound signal, various multi-sound type sound signals
such as 5.1 channel sound used in home theater and digital broadcasting, 22.2 channel sound
which is super hi-vision sound, etc. can be used.
03-05-2019
5
[0020]
The amplifier 20 amplifies the drive signal from the decoder 10 and outputs it to each speaker
unit of the speaker array 30.
[0021]
The speaker array 30 has a plurality of speaker units, and each speaker unit converts a drive
signal input from the amplifier 20 into a sound and emits the sound.
The speaker array 30 is not limited to a linear shape, but may have an arbitrary shape such as an
arc shape, a planar shape in which an array of a plurality of stages is arranged, or a window
frame shape along the outer periphery of a display unit such as a liquid crystal display. Is
possible.
[0022]
The speaker units of the speaker array 30 are spatially unevenly arranged. Here, spatially
nonuniformly arranged means that the speaker units are irregularly arranged, as compared to
the conventional equally spaced speaker units. In addition, spatially nonuniformly arranged is not
limited to making the spacing between the linearly arranged speaker units nonuniformly, but
makes the vertical and horizontal arrangements uneven in plan view, and further, It includes a
configuration in which the arrangement in the three-dimensional directions of the speaker unit is
uneven, such as making the arrangement in the depth direction uneven. Moreover, it is also
possible to shift to a different direction for every speaker unit. By arranging the speaker units
spatially unevenly, regularity is less likely to occur in the path difference of the sound passing
through each speaker unit, and deterioration of sound reproduction quality due to strengthening
of dips of predetermined frequency characteristics It can be prevented.
[0023]
Among the speaker units of the speaker array 30, at least a part of the speaker units can be
unevenly arranged, or all the speaker units can be unevenly arranged. For example, by arranging
at least a part of the speaker units nonuniformly, the stability of sound image localization is
03-05-2019
6
ensured by the speaker units arranged regularly, and the speaker units arranged nonuniformly
have predetermined frequency characteristics. It is possible to prevent dips from strengthening
each other. Further, by arranging all the speaker units unevenly, the dip of the frequency
characteristic is dispersed, so that it is possible to improve the frequency characteristic especially
in the high frequency region.
[0024]
Each speaker unit can be spatially unevenly arranged based on arbitrary random numbers. By
using the random arrangement based on the random numbers in this manner, it is possible to
arrange the speaker units unevenly without performing complicated calculations. In addition, the
spatially non-uniform arrangement of the speaker units can be realized by adding correction
values based on arbitrary random numbers to positions when the speaker units are arranged at
equal intervals. As a result, it is possible to disperse the path length of the route passing through
each speaker unit while dispersing the arrangement of each speaker unit, so that the stability of
sound image localization is ensured and dips of predetermined frequency characteristics are
intensified. You can prevent that.
[0025]
FIG. 2 is a view showing an example of the arrangement of speaker units in the speaker array 30.
As shown in FIG. The speaker array 30 in the present embodiment has 41 speaker units, and is
arranged such that the intervals between the speaker units are not uniform.
[0026]
Here, the speaker array 30 has a nonuniform arrangement by adding correction values based on
arbitrary random numbers to the positions of the speaker units arranged at equal intervals. For
example, when 41 speaker units are uniformly arranged at equal intervals in the range of 2 m,
the speaker units are arranged at intervals of 0.05 m. FIG. 3 is a diagram showing an example of
correction values regarding the speaker unit arrangement. As shown in FIG. 3, by adding a
random correction value distributed in the range of -0.025 m to 0.025 m to each speaker unit
and shifting it in the lateral direction, the speaker arrays arranged at equal intervals are random
The speaker array 30 can be arranged unevenly.
03-05-2019
7
[0027]
FIG. 4 is a diagram showing an example of a change in frequency characteristics due to the
speaker unit arrangement. FIG. 4 (a) shows the frequency characteristics of the sound
reproduced by the speaker array arranged at equal intervals, and FIG. 4 (b) shows the sound
reproduced by the speaker array 30 of the nonuniform arrangement according to the present
embodiment. Frequency characteristics. 4 (a) and 4 (b), it can be seen that the speaker array 30
with nonuniform arrangement according to the present embodiment reduces deep dips
particularly in the high frequency band and improves the frequency characteristics. .
[0028]
As described above, according to the present embodiment, the acoustic signal reproduction
device 1 includes the speaker array 30 having a plurality of speaker units, and at least a part of
the speaker units are spatially unevenly arranged. As a result, the stability of sound image
localization can be ensured by the speaker units arranged regularly, and the dips of
predetermined frequency characteristics can be prevented from strengthening each other by the
speaker units arranged nonuniformly. The acoustic signal reproducing apparatus 1 according to
the present embodiment can improve the frequency characteristics of the sound image
reproduced by the speaker array 30 while maintaining the localization of the sound image, and
can achieve higher quality sound field reproduction. Further, the acoustic signal reproduction
device 1 according to the present embodiment is also applicable to the case of reproducing a
22.2 channel acoustic signal for Super Hi-Vision with a window frame type speaker array, and
facilitates three-dimensional acoustic reproduction in a home environment. It can be done.
[0029]
Also, all of the speaker units may be spatially unevenly arranged. This makes it possible to
improve the frequency characteristics particularly in the high frequency region by dispersing the
dip of the frequency characteristics.
[0030]
03-05-2019
8
Also, the speaker units that are spatially nonuniformly distributed may be spatially nonuniformly
distributed based on any random number. As a result, it is not necessary to perform exact
calculation processing after grasping each path difference for nonuniform arrangement, and the
arrangement of each speaker can be determined by calculation with less load.
[0031]
Also, even if the speaker units arranged spatially nonuniformly are spatially arranged
nonuniformly by adding correction values based on arbitrary random numbers to the positions
when the speaker units are equally spaced. Good. As a result, it is possible to disperse the path
length of the route passing through each speaker unit while dispersing the arrangement of each
speaker unit, so that the stability of sound image localization is ensured and dips of
predetermined frequency characteristics are intensified. You can prevent that.
[0032]
Although the present invention has been described based on the drawings and examples, it
should be noted that those skilled in the art can easily make various changes and modifications
based on the present disclosure. Therefore, it should be noted that these variations and
modifications are included in the scope of the present invention. For example, functions included
in each functional unit can be rearranged so as not to be logically contradictory, and it is possible
to combine or divide a plurality of functional units or steps into one.
[0033]
For example, in the above embodiment, the correction value is set in the range of -0.025 m to
0.025 m for the speaker unit interval of 0.05 m, but for example, the size (for example, diameter)
of the speaker unit itself Then, the range of -0.020 m to 0.020 m can be set as the range of the
correction value random numbers. The number (41) of the speaker units and the width (2 m) for
installation in the above embodiment are merely an example, and it goes without saying that the
present invention is not limited to the numerical values.
[0034]
Further, in the present embodiment, the case where the arrangement of the speaker units is
03-05-2019
9
adjusted from uniform spacing using uniform distribution random numbers is shown, but it is of
course possible to use random numbers according to other statistical quantities such as normal
distribution.
[0035]
ADVANTAGE OF THE INVENTION According to the sound reproduction apparatus which
concerns on this invention, in the speaker array containing several speaker units, there exists a
usefulness that deterioration of the frequency characteristic by mutual interference can be
reduced.
[0036]
1 sound signal reproduction apparatus 10 decoder 20 amplifier 30 speaker array
03-05-2019
10
Документ
Категория
Без категории
Просмотров
0
Размер файла
18 Кб
Теги
jp2013247399
1/--страниц
Пожаловаться на содержимое документа