JP2002223493A - Multi-channel sound collection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a compact and low-cost multi-channel sound collection device that, has a zoom function and can be mounted on a video camera. SOLUTION: The multi-channel sound collection device is provided with a 1st omnidirectional microphone 1, a 2nd omnidirectional microphone 2, a 3rd omnidirectional microphone 3, a 4th omnidirectional microphone 4, 8-sets of 1st-8th synthesis means 5-12 that receive outputs of the 4 omnidirectional microphones and synthesize 8 directional microcomputer characteristics where the directivities are set within a horizontal plane at an interval of 45-degrees, and a 9th synthesis means 13 that synthesizes multi-channel stereo signals from the outputs of the 8-sets of the synthesis means. Thus, the multi-channel sound collection device can be realized only with the 4 sets of the omnidirectional microphones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-channel sound pickup device for performing multi-channel sound pickup at one point (one location).

[0002]

2. Description of the Related Art A 3-1 system 4-channel stereo has been put to practical use in television broadcasting, and a 3-2 system 5-channel stereo represented by a DVD has recently been put to practical use.

[0003] With the spread of such multi-channel stereos in television broadcasts and DVDs, home video integrated cameras (hereinafter referred to as video cameras) have become increasingly popular.
The demand for multi-channel stereo is increasing.

[0004] Sound creation in broadcast programs and DVD software is performed by mixing materials collected by placing many microphones in close proximity to each sound source or materials previously collected individually to obtain a desired sound image localization. It is based on creating a sound field. This is a method generally used since the age of the two-channel stereo.

On the other hand, in a video camera, it is necessary to separate and collect sounds from multiple directions with a single sound pickup device attached to the video camera at the time of recording, and to record in real time.

A conventional multi-channel sound collecting apparatus is disclosed in Japanese Patent Application Laid-Open Nos. Hei 4-137997, Hei 5-191886, Hei 5-191877, and Hei 6-73.
No. 68 is known. In each of these, a plurality of directional microphones whose directional axes are directed at a predetermined angle are mounted in the same housing, and only by arranging one sound pickup device in a sound field, multi-channel pickup is achieved. It makes sound possible.

Further, Japanese Patent Application Laid-Open No. Hei 5-83784 discloses that
In addition to the above-mentioned conventional example, in order to improve the separation sound pickup performance of the front three channels, an L-channel microphone and an R-channel microphone are used.
The directivity of the microphone for the channel has been devised,
It describes a multi-channel sound pickup device that can be mounted on a video camera.

Further, in Japanese Patent Application Laid-Open Nos. 5-64289, 5-260585 and 6-54242, a plurality of omnidirectional microphones are mounted on a video camera, and the output is signal-processed. Describes a two-channel stereo sound pickup device for obtaining a stereo signal suitable for a video camera.

FIG. 12 shows the configuration of a conventional two-channel stereo sound pickup device described in Japanese Patent Application Laid-Open No. 5-260585. FIG. 13 and FIG. 14 show the detailed configuration of each combining means in FIG.

In FIG. 12, reference numeral 51 denotes a first omnidirectional microphone arranged in the front, 52 denotes a second omnidirectional microphone arranged in the rear, and 53 denotes a third omnidirectional microphone arranged in the left side. Microphone, 54 is a fourth omnidirectional microphone arranged on the right side, 55 is first synthesizing means,
56 is a second combining means, 57 is a third combining means, 58 is a fourth combining means, and 59 is a control means.

In the first combining means 55 shown in FIG.
0 is a delay unit and 61 is a subtractor. The second combining means 56 and the third combining means 57 have the same configuration as the first combining means 55. In FIG. 14, reference numeral 62 denotes a first attenuator, 63 denotes a second attenuator, 64 denotes a third attenuator, 65 denotes a first adder, and 66 denotes a second adder.

As shown in FIG. 13, in the first synthesizing means 55 of FIG. 12, first, the distance from the second omnidirectional microphone 52 to the first omnidirectional microphone 51 is determined by a delay unit 60 as an acoustic wave. The output of the second microphone 52 is delayed by the time during which the signal propagates. Next, the output of the delay unit 60 is subtracted from the output of the first omnidirectional microphone 51 by the subtractor 61. With the above configuration, the output of the primary sound pressure gradient type unidirectional microphone shown by the polar pattern in FIG.

Hereinafter, the same processing is also performed in the second synthesizing means 56 and the third synthesizing means 57 in FIG. 12 to obtain outputs of three directional microphones indicated by polar patterns in FIG.

Next, these three outputs correspond to the fourth output shown in FIG.
Is input to the combining means 58. The output of the first combining means 55 is gain-adjusted by the attenuator 62, and the output of the second combining means 56 is gain-adjusted by the attenuator 63. The two are added by the adder 65 and the L channel output is synthesized. Similarly,
After the output of the third combining means 57 is adjusted in gain by the attenuator 64, the output of the third combining means 57 is added to the output of the attenuator 62 by the adder 66 to obtain an R channel output.

The gain of the first attenuator 62 and the gains of the second attenuator 63 and the third attenuator 64 are equal to the first attenuator 6.
When the gain of the second attenuator 63 is high, the gains of the second attenuator 63 and the third attenuator 64 are low, and when the gain of the first attenuator 62 is low, the second attenuator 63 and the third attenuator 64 are provided. Is controlled by the control means 59 in conjunction with the zoom lens of the video camera so that the gain of the video camera becomes high.

That is, as shown in FIG. 16, on the wide-angle side, the gain of the first attenuator 62 is set to the minimum, the output of the second synthesizing means 56 is changed to the output of the L channel, The output of 57 becomes the output of the R channel. On the telephoto side, the gains of the second attenuator 63 and the third attenuator 64 are set to the minimum, and the output of the first combining means 55 is the output of the L channel and the R channel.

With the above configuration, a zoom microphone whose directivity changes in conjunction with the zoom lens can be obtained.

[0018]

The conventional sound pickup device shown in FIG. 12 is a small and low-cost device using four omnidirectional microphones, but is a sound pickup device for two-channel stereo, and is a multi-channel sound pickup device. It was not compatible with channel stereo.

In a video camera, there is a demand for a small-sized, low-cost, multi-channel sound collecting device that supports a multi-channel stereo having a zoom function.

An object of the present invention is to realize a small-sized, low-cost multi-channel sound pickup device for multi-channel stereo that can be mounted on a video camera.

[0021]

According to a first aspect of the present invention, there is provided a multi-channel sound pickup apparatus comprising four omnidirectional microphones arranged in front, rear, left and right sides. Eighth first to eighth synthesizing the outputs of the eight directional microphones whose directivities are directed in eight directions all around the horizontal plane every 45 ° C. from the outputs of the four omnidirectional microphones A configuration comprising a synthesizing means and a ninth synthesizing means for synthesizing a multi-channel stereo signal from the outputs of the eight synthesizing means, and using only four omnidirectional microphones, various sound fields and various systems A small, low-cost multi-channel sound pickup device that can handle multi-channel stereos has been realized.

According to a second aspect of the present invention, four omnidirectional microphones are disposed at the front left, the front right, the rear left, and the rear right, and the same operation as the invention according to the first aspect is provided. It has gained.

[0023] Further, the invention according to claim 3 is the following.
Method Assuming a 5-channel stereo system, the sound field that emphasizes the consistency between the first output state in which the sound from the side and the rear is actively collected and the sense of sound spread is emphasized, and the speaker direction during playback is emphasized The ninth synthesizing means compares a second output state for high-fidelity reproduction of the first output state and a third output state for emphasizing sound from the front to obtain an effect of approaching the sound source by a ninth synthesizing unit. It is configured to switch and output, enabling flexible sound collection according to the sound field and purpose.

Further, according to the present invention, the ninth synthesizing means is interlocked with the zoom lens of the video camera, and is in the first output state at the wide angle, in the second output state at the standard time, and at the second output state at the telephoto. By switching the sound pickup state, for example, to the output state of No. 3, a 3-2 system 5-channel stereo compatible zoom microphone capable of sound pickup with a sense of reality synchronized with the video is realized.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a configuration of a multi-channel sound collecting apparatus according to Embodiment 1 of the present invention.

In FIG. 1, with the upper part of the figure facing the front, 1 is a first omnidirectional microphone arranged in the front, 2 is a second omnidirectional microphone arranged in the rear, and 3 is a left side. A third omnidirectional microphone 4 is arranged, a fourth omnidirectional microphone 4 is arranged on the right side, and 5 is an output of the first omnidirectional microphone 1 and an output of the second omnidirectional microphone 2. First synthesizing means for synthesizing a directional microphone having directivity in front of the camera, 6
Is a second combining means for combining a directional microphone having directivity backward from the output of the first omnidirectional microphone 1 and the output of the second omnidirectional microphone 2;
Third synthesizing means for synthesizing a directional microphone having directivity in the left direction from the output of the omnidirectional microphone 3 and the output of the fourth omnidirectional microphone 4, and 8 indicates the third omnidirectional microphone 3 Fourth synthesizing means for synthesizing a directional microphone having directivity in the right direction from the output of the first omnidirectional microphone 1 and the output of the fourth omnidirectional microphone 4. Fifth synthesizing means for synthesizing a directional microphone having directivity to the left front from the output of the omnidirectional microphone 4 is the output of the first omnidirectional microphone 1 and the third omnidirectional microphone 3.
A sixth synthesizing means for synthesizing a directional microphone having directivity in the front right direction from the output of the second omnidirectional microphone 2 and the output of the fourth omnidirectional microphone 4 on the left rear side. A seventh synthesizing means for synthesizing a directional microphone having directivity in the right direction from the output of the second omnidirectional microphone 2 and the output of the third omnidirectional microphone 3, Synthesizing means for synthesizing sexual microphones, 13 is ninth synthesizing means for synthesizing a multi-channel stereo signal from the outputs of the eight first to eighth synthesizing means 5 to 12, and 14 is ninth synthesizing means. 1
3 is a control means for controlling the combining method.

In FIG. 1, L is the L channel output in the 3-2 system 5-channel stereo, R is the R channel output, SR is the SR channel output, SL is the SL channel output, and C is the C channel output. This signal
Playback is performed by the playback system corresponding to the 3-2 system 5-channel stereo shown in FIG.

The operation of the multi-channel sound collection device configured as described above will be described below.

FIG. 3 shows the directivity combined by the first to eighth combining means 5 to 12 in FIG. FIG. 4 shows the directivity of FIG. 3 more clearly.

FIG. 5 shows the principle of directivity synthesis in the first to eighth synthesis means 5 to 12.

First, the first to the eighth shown in FIGS.
, The eight primary sound pressure gradient type directivities shown in FIG. 4 in eight directions of front, rear, left, right, left front, right front, left rear, and right rear. Synthesize a sexual microphone. In the present embodiment in which the four omnidirectional microphones 1 to 4 are arranged at the vertices of a regular square, the outputs of eight directional microphones whose directivity is directed every 45 ° are obtained. The detailed configurations of the first synthesizing unit 5 and the second synthesizing unit 6 shown in FIG. 5 are equivalent to the first synthesizing unit of the conventional example shown in FIG.

In FIG. 5, reference numeral 15 denotes a first delay unit;
Is a first subtractor, 17 is a second delay unit, and 18 is a second subtractor.

In the first synthesizing means 5, first, the first delay unit 15 sets the distance between the second omnidirectional microphone 2 and the first omnidirectional microphone 1 to the second omnidirectional microphone by the time for which the sound wave propagates. Of the microphone 2 is delayed. next,
The first subtractor 16 subtracts the output of the first delay unit 15 from the output of the first omnidirectional microphone 1. With the above configuration, the output of the primary sound pressure gradient type unidirectional microphone having directivity directed forward as shown by the polar pattern is combined by the first combining means 5.

The second synthesizing means 6 includes a second delay unit 17
Then, the output of the first microphone 1 is delayed by the time that the sound wave propagates in the distance from the first omnidirectional microphone 1 to the second omnidirectional microphone 2. Next, the output of the second delay unit 17 is subtracted from the output of the second omnidirectional microphone 2 by the second subtractor 18. With the above configuration, the output of the primary sound pressure gradient type unidirectional microphone whose directivity is directed rearward as indicated by the polar pattern is combined by the second combining means 6. Hereinafter, the same processing is performed for third to
This is also performed by the eighth synthesizing means 7 to 12 to obtain outputs of a total of eight primary sound pressure gradient type directional microphones shown in FIGS.

Next, the ninth combining means 13 shown in FIG.
A signal for multi-channel stereo is synthesized from the outputs of the eight primary sound pressure gradient type directional microphones.

In order to obtain a 3-2 system 5-channel stereo signal, the directivity shown in FIG. 6 should be assigned to each channel in consideration of the speaker arrangement shown in FIG. 2 and the directivity of the primary sound pressure gradient type. preferable. Therefore, in this embodiment, as can be understood from FIG. 3, the output of the first synthesizing unit 5 is set to the C channel, the output of the fifth synthesizing unit 9 is set to the L channel, and the output of the sixth synthesizing unit 10 is set to the output. R channel,
The output of the seventh combining means 11 is output to the SL channel, and the output of the eighth combining means 12 is output to the SR channel.
The ninth combining means 13 is controlled by the control means 14 of FIG.

According to the present embodiment described above, it is possible to obtain a 5-channel signal corresponding to the 3-2 system 5-channel stereo simply by arranging four omnidirectional microphones. A cost-effective multi-channel sound collecting device can be realized.

In particular, considering the mounting on a video camera,
Small size is a huge advantage. In the market, there is a great demand for a small and lightweight video camera. Considering the mounting mechanism and wiring when mounting the microphones, the mounting area per microphone is extremely large, and the utility of forming eight directional microphones using only four microphones is extremely large. Another great advantage is that only four AD converters for microphones, which are essential elements for digital signal processing, are required.

The allocation example of the output of each synthesizing means to the 5-channel stereo signal shown in FIG. 6 is based on a standard sound collection purpose and sound field, and according to this embodiment, the position of the sound source is The directivity of each channel can be freely changed according to the state of the sound field such as noise, reverberation, and the like, and a multi-channel sound pickup apparatus that can flexibly adapt to the purpose of sound pickup and the state of the sound field can be realized. As described in the conventional example, the weighted average of the outputs of the two directional microphones makes it possible to synthesize a microphone having a directivity between the two.

It is preferable that the levels of the outputs C, L, R, SL, and SR are optimally distributed depending on the purpose of sound collection and the conditions of the sound field. For example, when there is a lot of ambient noise or when it is desired to obtain an effect of approaching a sound source, it is preferable to set the level distribution such that (output C, output L, output R)> (output SL, output SR).

(Embodiment 2) FIGS. 7 and 8 show a configuration of a multi-channel sound collecting apparatus according to Embodiment 2 of the present invention.

In FIG. 7, reference numeral 21 denotes a first omnidirectional microphone disposed on the front left side of the drawing with the upper side of the drawing as the front direction, and reference numeral 22 denotes a second non-directional microphone also disposed on the front right side. A directional microphone, 23 is a third omnidirectional microphone arranged on the left rear, and 24 is a fourth omnidirectional microphone arranged on the right rear.

In FIG. 8, reference numeral 25 denotes the output of the first omnidirectional microphone 21 and the third omnidirectional microphone 23.
First combining means for combining a directional microphone having directivity forward from the output of the second omnidirectional microphone 22 and the fourth omnidirectional microphone 24;
A second combining means for combining a directional microphone having directivity backward from the output of the second omnidirectional microphone 22 and the output of the first omnidirectional microphone 21;
A third combining means for combining a directional microphone having directivity in the left direction from the output of the third omnidirectional microphone 23 and the fourth omnidirectional microphone 2;
Fourth combining means for combining a directional microphone having directivity in the right direction from the output of the fourth omnidirectional microphone and the output of the fourth omnidirectional microphone. Fifth synthesizing means 30 for synthesizing a directional microphone having directivity in the front has directivity to the right front from the output of the second omnidirectional microphone 22 and the output of the third omnidirectional microphone 23. Sixth synthesizing means for synthesizing the directional microphone, 31 synthesizes a directional microphone having directivity to the left rear from the output of the second omnidirectional microphone 22 and the output of the third omnidirectional microphone. A seventh combining unit 32 combines a directional microphone having directivity rightward and rearward from the output of the first omnidirectional microphone 21 and the output of the fourth omnidirectional microphone 24. A eighth combining means for. This 8
The processing after each of the synthesizing units 25 to 32 is the same as that of the first embodiment in FIG.
And illustration and explanation are omitted.

The principle of the second embodiment is the same as that of the first embodiment shown in FIGS. 1 and 3. The difference between the first embodiment of FIG. 3 and this embodiment of FIG. That is, the arrangement of the four omnidirectional microphones is rotated by 45 °, and the omnidirectional microphones that are input to the first to eighth combining means 25 to 32 are changed based on this difference.

The principle and performance of the present embodiment are exactly the same as those of the first embodiment, and when mounting on a video camera or the like, one of them may be selected in consideration of the design.

(Embodiment 3) FIG. 9 shows a directional characteristic of each channel output of a multi-channel sound collecting apparatus according to Embodiment 3 of the present invention. This embodiment relates to the combining means 13 and the control means 14 in FIG.
An object of the present invention is to provide an optimal sound collecting method according to a sound collecting purpose in a 3-2 system 5-channel stereo. Hereinafter, FIG.
This embodiment will be described with reference to FIG.

In FIG. 9, the first output state is such that the output of the first synthesizing means 5 in FIG.
In this output state, the output of the combining means 7 is an L channel signal, the output of the fourth combining means 8 is an R channel signal, and the output of the second combining means 6 is an SL and SR channel signal.

In the second output state, the output of the first synthesizing means 5 in FIG. 1 is a C channel signal, the output of the fifth synthesizing means 9 is an L channel signal, and the output of the sixth synthesizing means 10 is The output state is an R channel signal, the output of the seventh combining means 11 is an SL channel signal, and the output of the eighth combining means 12 is an SR channel signal.

The third output state is such that the output of the first synthesizing means 5 in FIG. 1 is a C channel signal, the output of the fifth synthesizing means 9 is an L channel signal, and the output of the sixth synthesizing means 10 is An R channel signal, an output of the third synthesizing means 7 as an SL channel signal, and an output of the fourth synthesizing means 8 as S
This is the output state for the R channel signal.

This embodiment is different from the ninth combining means 13 shown in FIG.
And the control means 14 have a function of switching and outputting the three first to third output states.

The first output state shown in FIG. 9 is for actively collecting sound from the side or from the rear, and in a sound field in the presence of a sound source for sound collection in the surroundings. This is a sound collection method suitable for entering and collecting sound. The second output state is
This sound pickup method is suitable when the sound source you want to pick up is in front and the back sound is also picked up to convey the atmosphere of the sound field.
This sound collection method seems to be the most common method. Also, the third
The output state is a sound collection method suitable for a case where a sound source to be picked up is located in front of the sound source and a sound source close to the sound source is to be produced.

In addition to the above-described selection based on the purpose of collecting sound, it is also possible to select a third output state in a sound field having a lot of noise and reverberation.

As described above, according to the present embodiment, it is possible to realize a multi-channel sound collecting apparatus which can flexibly cope with a sound collecting method suitable for a sound collecting purpose and a sound field state.

(Embodiment 4) FIG. 10 shows the configuration of a multi-channel sound collecting apparatus according to Embodiment 4 of the present invention, and FIG. 11 shows the directivity of each channel output of this embodiment. . This embodiment is different from the third embodiment in that the output switching function provided in the ninth combining means 13 and the control means 14 shown in FIG. 1 in the first embodiment, that is, the multi-channel sound pickup apparatus shown in FIG. The switching of the three first to third output states, which are the directivities of the respective channel outputs, is linked with zoom control which is lens drive control such as telephoto or wide angle in a video camera.

In FIG. 10, reference numerals 1 to 12 have the same structure and operation and effect as those of the reference numerals 1 to 12 shown in FIG. 1 in the first embodiment. Reference numeral 41 denotes second to eighth combining means 6 to 12. Ninth synthesizing means for inputting the output of, a zoom control means 42, and a lens driving mechanism 43.

In this embodiment, the zoom control means 42 of the video camera controls the lens driving mechanism 43 and the ninth synthesizing means 41 at the same time, and as shown in FIG. By continuously switching the sound pickup state, for example, to the second output state at the time of standard and to the third output state at the time of telephoto, a 3-2 system 5 capable of sound pickup with a sense of reality synchronized with the video. A zoom microphone compatible with channel stereo can be realized. Further, as shown in the conventional example, if the weighted average of the two directional microphones is calculated, the direction of the directivity can be continuously changed in the middle.

[0058]

As described above, according to the first aspect of the present invention, the four elements arranged on the front, rear, left and right sides.
Eight omnidirectional microphones and eight directional microphones that combine the outputs of the four omnidirectional microphones with the outputs of eight directional microphones whose directivity is directed in eight directions all around the horizontal plane at 45 ° C. And a ninth combining means for combining multi-channel stereo signals from the outputs of the eight combining means.
With only four omnidirectional microphones, it is possible to obtain an effect of realizing a small and low-cost multi-channel sound pickup device that can support various sound fields and various types of multi-channel stereo.

Further, according to the second aspect of the present invention, 4
With the configuration in which the omnidirectional microphones are arranged at the front left, front right, rear left, and rear right, the same effect as the first aspect of the invention can be obtained.

Further, according to the third aspect of the present invention,
The first output state in which the sound from the side or the rear is actively collected and the sound spread is emphasized, and the high fidelity reproduction of the sound field is emphasized by emphasizing the consistency with the speaker direction at the time of reproduction. The ninth synthesizing means switches and outputs the three output states of the second output state and the third output state for obtaining an effect of approaching the sound source while placing importance on the sound from the front. Thus, an effect is obtained in which it is possible to perform optimal 3--2 system 5-channel stereo sound collection according to the sound field and purpose.

Further, according to the fourth aspect of the present invention,
The ninth synthesizing means is linked to the zoom lens of the video camera, and is in the first output state at the time of wide angle, the second output state at the time of standard, the third output state at the telephoto, and so on.
By continuously switching the sound pickup state, it is possible to achieve a 3-2 system 5-channel stereo compatible zoom microphone capable of realizing sound pickup synchronized with video.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a multi-channel sound collection device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a speaker arrangement at the time of reproduction of a 3-2 system 5-channel stereo.

FIG. 3 is a diagram showing directivity characteristics of outputs of first to eighth combining units in the multi-channel sound collection device according to the first embodiment of the present invention;

FIG. 4 is a directional characteristic diagram of eight directional microphones synthesized in the multi-channel sound collection device according to the first embodiment;

FIG. 5 is a block diagram showing a detailed configuration of a first synthesizing unit and a second synthesizing unit in the multi-channel sound collection device according to the first embodiment;

FIG. 6 is a directional characteristic diagram of an output of a ninth synthesizing unit with respect to a layout diagram of four omnidirectional microphones in the multi-channel sound collection device according to the first embodiment;

FIG. 7 is a layout diagram of four omnidirectional microphones and a directional characteristic diagram of eight synthesized directional microphones in the multi-channel sound collection device according to the second embodiment of the present invention;

FIG. 8 is a block diagram showing a configuration of first to eighth combining means in the multi-channel sound collecting apparatus according to the second embodiment and a directional characteristic diagram of an output;

FIG. 9 is a directional characteristic diagram in three output states of the multi-channel sound collection device according to the third embodiment of the present invention.

FIG. 10 is a block diagram illustrating a configuration of a multi-channel sound collection device according to a fourth embodiment of the present invention.

FIG. 11 is a directional characteristic diagram of an output of the multi-channel sound collection device according to the fourth embodiment;

FIG. 12 is a block diagram showing a configuration of a conventional two-channel sound collecting device.

FIG. 13 is a block diagram showing a detailed configuration of a first synthesizing unit of the two-channel sound collection device.

FIG. 14 is a block diagram showing a detailed configuration of a fourth synthesizing unit of the two-channel sound collection device.

FIG. 15 is a diagram showing directivity characteristics of outputs of first to third synthesizing means of the two-channel sound collecting apparatus.

FIG. 16 is a directional characteristic diagram of an output of the two-channel sound pickup device.

[Description of Signs] 1,21 First omnidirectional microphone 2,22 Second omnidirectional microphone 3,23 Third omnidirectional microphone 4,24 Fourth omnidirectional microphone 5,25 First 6,26 Second combining means 7,27 Third combining means 8,28 Fourth combining means 9,29 Fifth combining means 10,30 Sixth combining means 11,31 Seventh combining Means 12, 32 Eighth synthesis means 13, 41 Ninth synthesis means 14, 41 Control means 42 Zoom control means 43 Lens drive mechanism

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoru Ibaraki 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 5D011 AB17 5D018 BB23 5D020 BB04

Claims (4)

[Claims] 1. Four omnidirectional microphones arranged on the front, rear, left and right sides, and first synthesizing means for extracting a sound signal from the front from the outputs of the four omnidirectional microphones. Second synthesizing means for extracting an audio signal from the rear, third synthesizing means for extracting an audio signal from the left direction, fourth synthesizing means for extracting an audio signal from the right direction, and front left. A fifth synthesizing means for extracting an audio signal from the right front, a seventh synthesizing means for extracting an audio signal from the left rear, and a A multi-channel sound collecting apparatus comprising: an eighth synthesizing unit for extracting an audio signal; and a ninth synthesizing unit for synthesizing a multi-channel stereo signal from the outputs of the first to eighth synthesizing units. . 2. A first omnidirectional microphone arranged at the left front, right front, left rear and right rear, and a first audio signal extracted from the output of the four omnidirectional microphones. A second synthesizing means for extracting an acoustic signal from the rear, and a third synthesizing means for extracting an acoustic signal from the left.
, A fourth synthesizing unit that extracts an audio signal from the right front, a fifth synthesizing unit that extracts an audio signal from the front left, and a sixth synthesis that extracts an audio signal from the front right Means, a seventh synthesizing means for extracting an audio signal from the left rear, an eighth synthesizing means for extracting an audio signal from the right rear, and multi-channel stereo from the output of the first to eighth synthesizing means. And a ninth synthesizing means for synthesizing a signal. 3. The ninth synthesizing means uses the output of the first synthesizing means as a sound signal for reproduction from the front of the listener, and uses the output of the third synthesizing means as the sound for reproduction from the front left of the listener. A first signal as a reproduction sound signal from the front right of the listener, and an output of the second synthesis means as a reproduction sound signal from the rear left and right rear of the listener. And the output of the first synthesizing means as a reproduction sound signal from the front of the listener, the output of the fifth synthesis means as a reproduction sound signal from the front left of the listener, and the sixth synthesis The output of the means is a sound signal for reproduction from the front right of the listener, the output of the seventh synthesis means is a sound signal for reproduction from the rear left of the listener, and the output of the eighth synthesis means is the sound from the rear right. A second output state as a sound signal for reproduction and an output of the first synthesizing means are reproduced from the front of the listener. An output of the fifth synthesizing means as a reproduction audio signal from the front left of the listener, an output of the sixth synthesis means as a reproduction audio signal from the front right of the listener, Switching between three output states: a third output state in which the output of the combining means is a sound signal for reproduction from the rear left of the listener and an output of the fourth combining means is a sound signal for reproduction from the right rear. 3. The multi-channel sound collecting device according to claim 1, wherein the multi-channel sound collecting device outputs the data. 4. The ninth combining means switches to a first output state at the time of wide angle, to a second output state at the time of standard, and to a third output state at the time of telephoto, in conjunction with a zoom operation of the video camera. The multi-channel sound collection device according to claim 3, wherein: