JP5014100B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging device, and more particularly to an imaging device capable of processing an audio signal.

  Conventionally, a video camera or the like is known as an imaging device that processes an audio signal. In a video camera, sound of a subject is collected by a sound collecting element (microphone) and recorded together with an image.

Some of these video cameras generate a 2-channel stereo audio signal using audio signals collected by three omnidirectional sound collecting elements (for example, Patent Document 1).
JP 2000-224688 A

  In recent years, with the development of audio technology and audio reproduction equipment, it has become possible to view multi-channel audio such as 5.1 channel, not stereo audio, even on a DVD or the like.

  The present invention provides an imaging device that is easy to perform calculations for generating a surround sound signal when, for example, a multi-channel surround sound signal is generated using sound signals collected by four omnidirectional sound collecting elements. The purpose is to provide. Furthermore, it aims at providing the imaging device which can prevent the enlargement of the whole apparatus by making small the area where the above-mentioned four omnidirectional sound-collecting elements are arrange | positioned.

  In order to solve such a problem, an imaging apparatus according to the present invention is an imaging apparatus having an imaging unit that captures an optical image of a subject in front, a sound collection unit that collects surrounding sounds, and the collection unit. Generating means for generating audio signals of a plurality of channels based on the audio signal obtained by the sound means, the sound collecting means passing through the first sound collecting element and the first sound collecting element A second sound collecting element arranged on a straight line substantially parallel to the optical axis of the image pickup means and rearward of the first sound collecting element, the first sound collecting element, and the second sound collecting element. A third sound collecting element disposed at an apex angle of a substantially isosceles triangle having a sound element as a vertex and a line segment connecting the first sound collecting element and the second sound collecting element as a base; A line segment connecting the first sound collecting element and the second sound collecting element with the first sound collecting element and the second sound collecting element as vertices A fourth is disposed at an inner side of a triangle having an apex angle of a substantially isosceles triangle having a base and having the first sound collecting element, the second sound collecting element, and the third sound collecting element as vertices; And the generating means generates a first channel sound signal from the sound signal obtained by the first sound collecting element and the sound signal obtained by the second sound collecting element. Generating a second channel sound signal from the sound signal obtained by the first sound collecting element and the sound signal obtained by the fourth sound collecting element, and generating the fourth sound collecting element. A third channel sound signal is generated from the sound signal obtained by the second sound collecting element and the sound signal obtained by the second sound collecting element, and the sound signal obtained by the second sound collecting element and the third sound signal are obtained. Audio signal of the fourth channel from the audio signal obtained by the sound collecting element of Generated, and generates said third fifth channel audio signal from an audio signal obtained audio signal obtained as the sound collection devices by said first sound collection devices.

  According to the present invention, for example, when a multi-channel surround sound signal is generated using sound signals collected by four omnidirectional sound collection elements, calculation for generating a surround sound signal is facilitated. . Moreover, the enlargement of the whole apparatus can be prevented by reducing the area where the above-mentioned four omnidirectional sound collecting elements are arranged.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A video camera capable of generating a multi-channel audio signal based on audio signals input from four sound collecting elements will be described.

  FIG. 1 is a perspective view of the video camera of this embodiment.

  In FIG. 1, reference numeral 100 denotes a video camera of this embodiment. Reference numeral 101 denotes a photographing lens that captures an optical image of a subject. Reference numeral 102 denotes a microphone unit having four built-in sound collecting elements for collecting surrounding sounds. The arrangement of the sound collecting elements will be described later. 103 displays an image obtained by processing an optical image of a subject captured by the photographing lens 101 by a video processing unit 206 (described later) during shooting, and displays a video processed by a video playback processing unit 211 (described later) during playback. In addition, the display unit displays a menu screen and the like.

  In this embodiment, as shown in FIG. 1, the front side of the video camera 100 is the direction in which the photographing lens 101 is arranged.

  FIG. 2 is a block diagram of the video camera of FIG.

  In FIG. 2, reference numeral 201 denotes a control unit that controls each block according to various functions of the video camera. Reference numeral 202 denotes an operation unit for inputting an external instruction to the video camera. Reference numeral 203 denotes a control signal bus through which a control signal from the control unit 201, an instruction signal from the operation unit 202, and the like come and go. Reference numeral 204 denotes an image / audio data bus through which image data and audio data are transferred between the blocks.

  An imaging unit 205 includes an aperture for controlling the amount of light from the photographing lens 101, an imaging element that converts an optical image into an electrical signal, and the like. Reference numeral 206 denotes a video processing unit that performs processing necessary for a video recording method, such as converting the video signal obtained from the imaging unit 205 to an appropriate signal level, converting the digital signal into digital data, and recording one frame at a time.

  Reference numeral 207 denotes an audio processing unit that performs a process of amplifying the obtained audio signal to an appropriate level by the microphone unit 102 and converting the audio signal into digital data. The sound processing unit performs processing such as converting sound signals obtained from the four sound collecting elements of the microphone unit 102 into, for example, 5.1 channel sound data. The audio processing unit 207 will be described later.

  Reference numeral 208 denotes a display control unit for controlling display on the display unit 103. The display control unit 208 causes the display unit 103 to display information corresponding to various modes in response to an instruction from the control unit 201.

  Reference numeral 209 denotes a hard disk (hereinafter referred to as an HDD) as a recording medium for recording video data obtained from the video processing unit 206, audio data obtained from the audio processing unit 207, and other data in association with each other as necessary. is there. An access unit 210 accesses the HDD 209 to read / write the video data, audio data, and other data.

  A video reproduction processing unit 211 processes the video data of the HDD 209 read by the access unit 210 according to a video recording method, and converts the processed data into a predetermined format. Reference numeral 212 denotes a video output terminal for outputting the video signal reproduced by the video reproduction processing unit 211 to the outside.

  Reference numeral 213 denotes an audio reproduction processing unit that reproduces audio data of the HDD 209 read by the access unit 210 in accordance with a video recording method. Reference numeral 214 denotes an audio output terminal for outputting the audio signal reproduced by the audio reproduction processing unit 213 to the outside.

  A USB terminal 215 communicates with an external device such as a PC, and exchanges video data, audio data, and the like recorded on the HDD 209 with the external device. A USB controller 216 controls data exchange with an external device connected to the USB terminal 215.

  Reference numeral 217 denotes a transmission terminal for transmitting a control signal to an external device.

  First, the basic shooting operation of the video camera of this embodiment will be described.

  In response to the operation of the power switch of the operation unit 202, the video camera enters a shooting standby state. In this state, when the user operates the shooting button on the operation unit 202, the video camera is instructed to start moving image shooting. In response to the moving image shooting start instruction, the control unit 201 transmits a shooting start instruction signal to the imaging unit 205, the video processing unit 206, and the like.

  When shooting starts, the image pickup unit 205 controls the light amount of the optical image of the subject captured by the shooting lens 101 with a diaphragm and converts it into an electrical signal with the image pickup device. The converted electrical signal is adjusted to an appropriate level by the video processing unit 206 and converted into digital data. The video signal converted into digital data is adjusted to an appropriate number of pixels by a pixel number adjustment circuit of the video processing unit 106, and is compressed and encoded by a predetermined video recording method to become video data.

  The sound processing unit 207 amplifies the four sound signals collected by the four sound collecting elements of the microphone unit 102 to an appropriate level. Then, these four audio signals are converted into digital data, and are subjected to processing necessary for an audio recording method, for example, converted into 5.1 channel audio data, to become audio data.

  Then, the control unit 201 synthesizes the video data and the audio data to form a data stream, and outputs the data stream to the access unit 210. Based on an instruction from the control unit 201, the access unit 210 starts to write a data stream of video data and audio data into the HDD 209 as one moving image file under management of a file system such as UDF or FAT. The file system means a structure system composed of management information and file data for managing files. By sharing this file system, recording and reproduction can be performed on different storage media or recording / reproduction devices.

  The data stream may be displayed on the display unit 103 through the display control unit 208 as necessary.

  Then, when the user operates the shooting button of the operation unit 202 again, the control unit 201 completes shooting to the imaging unit 205, the video processing unit 206, and the like in response to the video camera being instructed to end moving image shooting. The instruction signal is transmitted.

  In response to receiving the instruction signal for ending moving image shooting, the imaging unit 205 and the video processing unit 206 end the shooting operation. Under the instruction of the control unit 201, the access unit 210 writes a series of video data and audio data recorded from the start of shooting to the end of shooting as one file in the HDD 209, and ends the recording operation. The control unit 201 causes the video camera to transition to the shooting standby state.

  Next, normal playback operation of the video camera of this embodiment will be described.

  The control unit 201 controls the access unit 210 to read video data and still image data from the HDD 209 in response to the reproduction mode being designated by the selection switch of the operation unit 202. Then, the display control unit 208 is controlled so that the thumbnail screen on which the thumbnails of the read video data and still image data are arranged and the file names of the video data and still image data are displayed on the display unit 103. In addition, the display control unit 208 may be controlled so that the last captured video data, still image data, or the like is displayed on the display unit 103.

  When the user operates the operation unit 202 with the thumbnail screen displayed and gives an instruction to reproduce video data or still image data, the control unit 201 controls each block to reproduce each image data. To do.

  When reproducing video data, the control unit 201 separates content data read from the HDD 209 into audio data and video data by the control unit 201 in accordance with an instruction from the operation unit 202. The video data is decompressed by the video reproduction processing unit 211 and displayed as video on the display unit 103 by the display control unit 208. At this time, since the video signal is also output from the video terminal 212, a video display device connected through the video terminal 212 can display the video. The audio data is transmitted to the audio reproduction processing unit 213, the decoded information amount is expanded, converted to 5.1 channel surround audio data or surround audio signal, and output from the audio terminal 214. As a result, audio is output from the audio output device connected to the audio terminal 214.

  Here, the configuration of the microphone unit 102 and the sound processing unit 207 of this embodiment will be described in detail with reference to FIG.

  3 shows the microphone unit 102 when viewed from the top surface of the video camera 100 of FIG. The sound processing unit 207 generates 5.1 channel surround sound. Here, the description of the generation of the sub-channel audio signal corresponding to the low-frequency component audio is omitted.

  First, the microphone unit 102 will be described. Reference numerals 301 to 304 denote sound collecting elements. Each sound collecting element has a substantially non-directional sound collecting characteristic.

  The sound collection element 301 is disposed in the microphone unit 102 in front of the imaging direction of the video camera 100. The sound collection element 302 is disposed behind the imaging direction of the video camera 100 in the microphone unit. The sound collection element 302 is arranged on a straight line substantially parallel to the optical axis of the imaging lens 101 passing through the sound collection element 301 and behind the sound collection element 301. The distance between the sound collection element 301 and the sound collection element 302 is L. The distance L is, for example, about 14 mm.

  The sound collection element 303 is arranged at the apex angle of a substantially isosceles triangle having the sound collection element 301 and the sound collection element 302 as apexes and a line segment connecting the sound collection elements 301 and 302 as a base. In the present embodiment, the sound collecting element 303 is arranged on the right side of the line connecting the sound collecting element 301 and the sound collecting element 302. The sound collecting element 304 is arranged at the apex angle of a substantially isosceles triangle having the sound collecting element 301 and the sound collecting element 302 as apexes and a line segment connecting the sound collecting elements 301 and 302 as a base. And it arrange | positions inside the triangle which makes the sound collection element 301, the sound collection element 302, and the sound collection element 303 a vertex.

  In this embodiment, the angle of the vertices of the sound collecting element 301 and the sound collecting element 302 in the isosceles triangle having the sound collecting element 303 as a vertex is θ1, and is arranged to form, for example, approximately 60 degrees to 80 degrees. ing. Further, the angle between the sound collecting element in the isosceles triangle having the sound collecting element 304 as a vertex and the vertex of the sound collecting element 302 is θ2, and is arranged to form, for example, approximately 30 degrees.

  In the present embodiment, the surface including the sound collection element 301, the sound collection element 302, and the sound collection element 303 is disposed so as to be substantially parallel to the bottom surface of the video camera 100. In addition, the surface including the sound collection element 301, the sound collection element 302, and the sound collection element 304 is disposed so as to be substantially parallel to the bottom surface of the video camera 100.

  Next, the audio processing unit 207 will be described. Reference numeral 305 denotes an auto gain controller (hereinafter referred to as AGC) that adjusts the sound signal collected by each sound collecting element to an appropriate level. Reference numeral 306 denotes an AD conversion unit (hereinafter referred to as A / D) that converts an audio signal adjusted to an appropriate level by the AGC 305 from analog data to digital data. Reference numeral 307 denotes a delay unit that delays input audio data. A subtracter 308 subtracts the audio data delayed by the delay unit 307 from the undelayed audio data. Reference numeral 309 denotes an equalizer (hereinafter referred to as EQ) for attenuating high frequency components.

  Here, a procedure for generating 5-channel surround sound data from sound signals obtained by the four substantially non-directional sound collecting elements in the sound processing unit 207 will be described.

  The front center channel (FC) is generated from the sound signal obtained by the sound collection element 301 and the sound signal obtained by the sound collection element 302. The front left channel (FL) is generated from the audio signal obtained by the sound collection element 301 and the audio signal obtained by the sound collection element 304. The front light channel (FR) is generated from the audio signal obtained by the sound collection element 302 and the audio signal obtained by the sound collection element 304. The surround left channel (SL) is generated from the sound signal obtained by the sound collection element 302 and the sound signal obtained by the sound collection element 303. The surround light channel (SR) is generated from the sound signal obtained by the sound collection element 301 and the sound signal obtained by the sound collection element 303.

  Taking a front center channel (FC) as an example, a method of generating audio data of individual channels of 5-channel surround audio data will be described.

  As described above, the front center channel (FC) is generated from the audio signal obtained by the sound collection element 301 and the audio signal obtained by the sound collection element 302. Specifically, it is generated from the sound data obtained by delaying the sound signal obtained by the sound collection element 302 by a certain phase φ1 and the sound data obtained from the sound collection element 301. A specific calculation method will be described below.

  The sound signal obtained by the sound collection element 301 is adjusted to a sound of an appropriate level by the AGC 305 and converted into first sound data by the A / D 306. The audio signal obtained by the sound collection element 302 is adjusted to an appropriate level of audio by the AGC 305, converted to second audio data by the A / D 306, and delayed by the delay unit 307. Then, the second audio data is subtracted from the first audio data by the subtractor 309 to generate the audio of the front center channel (FC).

Here, attention is focused on the input of a sine wave sinωt sound from a certain sound source A to the video camera. It is assumed that the sound is input from an angle X when the right side is 0 degree, and the position of the sound source A is sufficiently large with respect to the distance L between the sound collection element 301 and the sound collection element 302. Assume that the input is from a distance. If the position of the sound source is in front of the video camera, the sound is input to the sound collection element 301 and then input to the sound collection element 302. When the difference in distance from the sound source A to each microphone is represented by a general formula, the following formula (1) is obtained.
(Distance difference) = L × sinX = L · sinX (1)
If the speed of sound is c, the wavelength of the sound of sin ωt can be obtained by the following equation (2).
(Sound wavelength) = c ÷ (ω / 2π) = 2π · c / ω (2)
The time until the sound input to the sound collection element 301 is input to the sound collection element 302 is expressed by the following expression (3) when expressed by the phase difference φx of the sound of sin ωt.
φx = L · sinX ÷ (2π · c / ω) × 2π
= (L · ω · sinX) / c (3)
The sound of the sine wave sin ωt output from this sound source is converted into a sound signal a by the sound collecting element 301. The audio signal a is expressed by the following equation (4).
a = sin ωt (4)
The sound of the sine wave sin ωt output by this sound source is converted into the sound signal b by the sound collecting element 302 after the sound collecting element 301. The audio signal b is expressed by the following equation (5).
b = sin (ωt + φx) (5)
The delay unit 307 delays the audio signal obtained by the sound collection element 302 by a certain phase φ1. Therefore, the audio data b ′ delayed by the delay unit 307 is expressed by the following equation (6).
b ′ = sin (ωt + φx + φ1) (6)
From the expressions (4) and (6), the audio data output from the subtracter 308 is expressed by the following expression (7).
a−b ′ = sin ωt−sin (ωt + φx + φ1) (7)
Here, attention is paid to the case where X is 270 degrees. At this time, the time until the sound input to the sound collection element 301 is input to the sound collection element 302 is expressed by the following equation (8) when expressed by the phase difference φb of the sound of sin ωt.
φb = − (L · ω) / c (8)
When X is 270 degrees, Expression (7) is expressed as the following Expression (9).
a−b ′ = sin ωt−sin (ωt + φb + φ1) (9)
Here, in this description, since it is desired to generate the sound of the front center channel (FC), it is necessary to lower the sensitivity for the sound from the rear. That is, when the sound source is behind (X is 270 degrees), the output of Expression (9) is set to zero. Therefore, the equation (9) can be rewritten as the following equation (10).
0 = sinωt−sin (ωt + φb + φ1) (10)
In order to establish the above equation (10), it may be set so that φ1 = −φb. Therefore, φ1 is represented by the following equation (11): φ1 = (L · ω) / c (11)
From Expression (7) and Expression (11), a general expression indicating the sound of the front center channel (FC) is expressed by the following Expression (12).
(FC) = a−b ′ = sin ωt−sin (ωt + φx + φ1)
= Sinωt
-Sin (ωt + L · ω · (sinX + 1) / c) (12)
Further, in EQ 309, high frequency components are attenuated as necessary, and sound data with good directivity is output. As described above, the sound of the front center channel (FC) can be obtained.

  In the above description, the method of generating audio data of five channels has been described by taking the front center channel (FC) as an example, but other channels can be obtained in the same manner. FIG. 4 shows the polar pattern of the 5-channel audio calculated by this method.

  FIG. 4A shows a polar pattern of the sound of the front center channel (FC) calculated from the sound collection element 301 and the sound collection element 302. FIG. 4B shows a polar pattern of the sound of the front left channel (FL) calculated from the sound collection element 301 and the sound collection element 304. FIG. 4C shows a polar pattern of the sound of the front light channel (FR) calculated from the sound collection element 304 and the sound collection element 302. FIG. 4D shows a polar pattern of the sound of the surround left channel (SL) calculated from the sound collection element 302 and the sound collection element 303. FIG. 4E shows a sound polar pattern of the surround light channel (SR) calculated from the sound collection element 303 and the sound collection element 301.

  As described above, 5-channel audio data can be generated with the microphone arrangement shown in FIG.

  By arranging the four substantially omnidirectional sound collecting elements in this way, when generating a surround sound signal, it is easy to perform calculations for generating the surround sound signal. The arranged area can be reduced. Therefore, it is possible to prevent the entire apparatus from becoming large.

  Also, the angle θ2 shown in FIGS. 4B and 4C corresponds to the angle θ2 of FIG. 3, and the angle θ1 shown in FIGS. 4D and 3E corresponds to the angle θ1 of FIG. ing. That is, by changing the arrangement of the sound collecting elements, the directivity of the sound obtained as a calculation result can be changed.

  In this embodiment, the front left channel (FL) is generated from the audio signal obtained by the sound collection element 301 and the audio signal obtained by the sound collection element 304. However, it may be generated from the sound signal obtained by the sound collection element 301 and the sound signal obtained by the sound collection element 303. The front light channel (FR) is generated from the audio signal obtained by the sound collection element 302 and the audio signal obtained by the sound collection element 304. However, the sound signal obtained by the sound collecting element 302 and the sound signal obtained by the sound collecting element 303 may be generated. The surround left channel (SL) is generated from the audio signal obtained by the sound collection element 302 and the audio signal obtained by the sound collection element 303. However, the sound signal may be generated from the sound signal obtained by the sound collection element 302 and the sound signal obtained by the sound collection element 304. The surround light channel (SR) is generated from the audio signal obtained by the sound collection element 301 and the audio signal obtained by the sound collection element 303. However, it may be generated from the sound signal obtained by the sound collection element 301 and the sound signal obtained by the sound collection element 304.

  In the present embodiment, in the microphone unit 102, the sound collection element 303 and the sound collection element 304 are arranged on the right side of the line connecting the sound collection element 301 and the sound collection element 302, but may be arranged on the left side. good.

  In this embodiment, generation of multi-channel audio data of 5 channels has been described. However, sub-channel audio data corresponding to low-frequency component audio may be generated simultaneously. At that time, audio data of at least one subchannel may be generated, or audio signals of a plurality of subchannels may be generated. Furthermore, the audio data of the channels corresponding to the audio of the high frequency component of the audio data of 5 channels may be generated simultaneously.

  In this embodiment, the audio data for the five channels is generated. However, the audio data for the rear center channel, the left channel, and the right channel may be further generated. Furthermore, audio data of a channel between the front left channel and the left channel and a channel between the front right channel and the right channel may be generated. Further, audio data of a channel between the rear channel and the surround left channel and a channel between the rear channel and the surround right channel may be generated. This can be calculated by the calculation method described above. By utilizing this, 12-channel audio data can be generated.

  In this embodiment, the phase delay in the delay unit 307 is φ1 = (L · ω) / c. Therefore, the delay angle changes according to the frequency of the sound. That is, instead of the delay unit 307, for example, a low-pass filter with a cutoff frequency set to 3 kHz may be used. When the low-pass filter is applied, it may be a low-pass filter in which the phase delay near the center frequency of the human audible region, for example, around 1 kHz is φ1 (ω = 1000 · 2π) described above. Further, it may be a low-pass filter having a frequency-phase characteristic in which the phase delay increases with increasing frequency.

(Other examples)
In the embodiment, the video camera has been described as an apparatus having a function of collecting sound in the embodiment, but other apparatuses may be used.

  Needless to say, the object of the present invention can also be achieved by supplying a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus. At this time, the computer (or CPU or MPU) of the supplied system or apparatus reads and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, the OS (basic system or operating system) running on the computer performs part or all of the processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Needless to say, cases are also included.

  Further, the program code read from the storage medium may be written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, and the functions of the above-described embodiments may be realized. Needless to say, it is included. At this time, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

It is a perspective view of a video camera to which the present invention is applied. It is a block diagram of a video camera to which the present invention is applied. It is a figure for demonstrating the detail of the microphone unit and audio | voice processing part of the video camera of a present Example. It is a figure which shows the polar pattern of the 5-channel audio | voice produced | generated with the video camera of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Video camera 101 Shooting lens 102 Microphone unit 103 Display unit 201 Control unit 202 Operation unit 203 Control signal bus 204 Image / audio data bus 205 Imaging unit 206 Video processing unit 207 Audio processing unit 208 Display control unit 209 HDD
210 Access Unit 211 Video Playback Processing Unit 212 Video Output Terminal 213 Audio Playback Processing Unit 214 Audio Output Terminal 215 USB Terminal 216 USB Controller 217 Transmission Terminal 301 Sound Collection Element 302 Sound Collection Element 303 Sound Collection Element 304 Sound Collection Element 305 AGC
306 A / D
307 Delay unit 308 Subtractor 309 EQ

Claims (8)

An imaging apparatus having an imaging means for imaging an optical image of a front subject,
A sound collecting means for collecting surrounding sounds;
Generating means for generating audio signals of a plurality of channels based on the audio signal obtained by the sound collecting means;
The sound collecting means is disposed on the first sound collecting element and a straight line substantially parallel to the optical axis of the image pickup means that passes through the first sound collecting element and behind the first sound collecting element. A line segment connecting the first sound collecting element and the second sound collecting element with the second sound collecting element, the first sound collecting element, and the second sound collecting element at the top is a bottom side. And the first sound collecting element and the second sound collecting element with the third sound collecting element arranged at the apex angle of the substantially isosceles triangle, the first sound collecting element and the second sound collecting element as vertices. The first sound collecting element, the second sound collecting element, and the third sound collecting element, each having an apex angle of a substantially isosceles triangle having a line segment connecting the two sound collecting elements as a base. Consisting of a fourth sound collecting element arranged inside the triangle as the apex,
The generating means generates a first channel sound signal from the sound signal obtained by the first sound collecting element and the sound signal obtained by the second sound collecting element, and the first sound collecting element. Generating an audio signal of the second channel from the audio signal obtained by the sound element and the audio signal obtained by the fourth sound collecting element; and the audio signal obtained by the fourth sound collecting element and the A sound signal of the third channel is generated from the sound signal obtained by the second sound collecting element, and the sound signal obtained by the second sound collecting element and the third sound collecting element are obtained. A fourth channel sound signal is generated from the sound signal, and a fifth channel sound is generated from the sound signal obtained by the third sound collecting element and the sound signal obtained by the first sound collecting element. An imaging device characterized by generating a signal.   The first sound collecting element, the second sound collecting element, the third sound collecting element, and the fourth sound collecting element each have substantially non-directional sound collecting characteristics. Item 2. The imaging device according to Item 1.   The imaging apparatus according to claim 1, wherein the sound collecting means is disposed on an upper surface of the imaging apparatus.   The angle of the apex of the triangular first sound collecting element having the first sound collecting element, the second sound collecting element, and the third sound collecting element as apexes is approximately 30 degrees. An angle of a vertex at which the first sound collecting element having a triangular shape with the first sound collecting element, the second sound collecting element, and the fourth sound collecting element as vertices is arranged is substantially equal. The imaging apparatus according to claim 1, wherein the imaging apparatus is between 60 degrees and 80 degrees.   The generating means generates an audio signal of a front center channel from an audio signal obtained by the first sound collection element and an audio signal obtained by the second sound collection element, and the first sound collection A front left channel audio signal is generated from an audio signal obtained by the element and an audio signal obtained by the fourth sound collecting element, and the audio signal obtained by the fourth sound collecting element and the second sound signal are obtained. A sound signal of the front light channel is generated from the sound signal obtained by the sound collecting element, and the sound signal obtained by the second sound collecting element and the sound signal obtained by the third sound collecting element; A surround left channel audio signal is generated, and a surround right audio signal is generated from the audio signal obtained by the third sound collection element and the audio signal obtained by the first sound collection element. Imaging device according to any one of the preceding claims, characterized 4 of that.   The generating means generates an audio signal of a front center channel from an audio signal obtained by the first sound collection element and an audio signal obtained by the second sound collection element, and the first sound collection The sound signal of the surround light channel is generated from the sound signal obtained by the element and the sound signal obtained by the fourth sound collecting element, and the sound signal obtained by the fourth sound collecting element and the second sound signal are obtained. A sound signal obtained by the second sound collecting element and a sound signal obtained by the third sound collecting element; and a sound signal obtained by the second sound collecting element; Front right channel sound signal is generated from the sound signal obtained by the third sound collecting element and the sound signal obtained by the first sound collecting element. Imaging device according to any one of claims 1, wherein generating a signal 4.   7. The surface formed by the first sound collecting element, the second sound collecting element, and the third sound collecting element is parallel to the bottom surface of the imaging device. The imaging apparatus of any one of Claims.   8. The surface formed by the first sound collecting element, the second sound collecting element, and the fourth sound collecting element is parallel to the bottom surface of the imaging device. The imaging apparatus of any one of Claims.

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