JP2018121321A - Sound collecting device and imaging device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound collecting device and an imaging device for reducing noise included in an audio signal even when the exterior surface has a porous shape. SOLUTION: The sound collecting device includes a housing 105 having a porous exterior surface provided with a plurality of sound holes 114, a main microphone 111R and a reference microphone 111N arranged inside the housing, and a housing. A first support member (resin case 116, sponge 131, 132, 133) provided inside and supporting the main microphone, and a second support member (116, 116,) provided inside the housing and supporting the reference microphone. The rubber member 113, sponge 134), the first shielding member (printed substrate 408, sponge 131, 132, resin case) that shields the inside of the housing from the inside of the main microphone, and the outside of the housing and the reference microphone. A second shielding member (housing) for blocking the inside and a third shielding member (resin case, rubber member) for blocking the inside of the housing and the inside of the reference microphone are provided. [Selection diagram] FIG. 5

Description

  The present disclosure relates to a sound collection device that collects sound and an imaging device using the same.

  2. Description of the Related Art Conventionally, a speech processing apparatus having an automatic level control (ALC: Auto Level Control) function for controlling the volume of input speech to an appropriate level is known (see, for example, Patent Document 1).

  The microphone device of Patent Document 1 has a mechanism unit that generates noise during operation inside the device housing. This microphone device reduces the occurrence of internal noise when capturing external sounds. The microphone device includes a main microphone, a noise reference microphone, adaptive filter means, signal subtraction means, signal level comparison means, and filter coefficient update control means. The main microphone picks up external sound coming from outside the device casing. The noise reference microphone is provided inside the device casing. The adaptive filter means inputs the detection signal of the noise reference microphone, and generates a control sound signal using the updated filter coefficient. The signal subtracting unit subtracts the control sound signal of the adaptive filter unit from the output signal of the main microphone. The signal level comparison means compares the output signal of the main microphone with the level of the detection signal of the noise reference microphone. The filter coefficient update control means inputs the comparison result of the signal level comparison means, the subtraction result of the signal subtraction means, and the detection signal of the noise reference microphone, and when the output level of the noise reference microphone is higher than the output level of the main microphone, The filter coefficient of the adaptive filter means is updated so that the subtraction result of the subtraction means is minimized.

  According to this microphone device, the signal from the noise reference microphone is supplied to the adaptive filter means to generate the control sound signal, and the noise is canceled by this control sound signal. As a result, it is possible to reduce mixing of internal noise when collecting external sound.

JP 2000-4494 A

  An object of the present disclosure is to reduce noise included in an audio signal when a sound outside the electronic device is collected to generate an audio signal even when the exterior surface has a porous shape.

  The present disclosure has a casing having a porous exterior surface provided with a plurality of holes, and is disposed inside the casing, and receives sound pressure from the outside of the casing through the plurality of holes, A main microphone that generates a first audio signal; and a reference microphone that is disposed in the vicinity of the main microphone and that generates a second audio signal inside the casing; and the interior of the casing. A first support member that supports the main microphone; a second support member that is provided inside the housing and supports the reference microphone; the interior of the housing; and the main microphone. A first shielding member that shuts off the interior; a second shielding member that shuts off the exterior of the housing and the interior of the reference microphone; and the interior of the housing and the interior of the reference microphone. Third shield to shut off And the member, with a, a sound pickup apparatus.

  The present disclosure also includes an imaging unit that images a subject to generate an image signal, the sound collection device that generates a third audio signal based on the first audio signal and the second audio signal, And a control unit that records an image signal together with the audio signal on a predetermined recording medium.

  According to the sound collection device of the present disclosure, even when the exterior surface has a porous shape, noise included in the sound signal can be reduced when sound outside the electronic device is collected to generate the sound signal.

FIG. 1 is a diagram illustrating a configuration of an imaging apparatus according to the present disclosure. FIG. 2A is a front view of the imaging apparatus according to the present disclosure and is a diagram illustrating a position of a punching metal plate. FIG. 2B is a top view of the imaging apparatus according to the present disclosure and is a diagram illustrating a position of a punching metal plate. FIG. 3 is a perspective view illustrating a configuration of the main microphone of the present disclosure. FIG. 4 is a diagram schematically showing a cross section of the main microphone taken along line 4-4 of FIG. FIG. 5 is a diagram illustrating an arrangement configuration of a main microphone and a reference microphone according to the present disclosure. FIG. 6A is a schematic diagram illustrating a cross section of a sponge C133 in the imaging device of the present disclosure. FIG. 6B is a schematic diagram illustrating a cross section of a sponge D134 in the imaging device of the present disclosure. FIG. 7 is a diagram illustrating a configuration related to a noise suppression function in the digital image / sound processing unit. FIG. 8 is a diagram showing measurement results of noise levels in various arrangements of reference microphones. FIG. 9 is a diagram illustrating the positions of the main microphone and the reference microphone in the imaging apparatus according to the modification. FIG. 10 is a diagram illustrating a list of first to third shielding members in the first embodiment and the modification.

(Background of the invention)
The present inventor is suitable for a dust-proof and drip-proof digital camera in Japanese Patent Application No. 2016-243909, and can reduce noise included in an audio signal when generating an audio signal by capturing audio outside the electronic device. A sound device is proposed.

  In general, when it is desired to improve sound quality, it is preferable to have a sufficient path for sound to reach the main microphone on the exterior surface of the electronic device (sound collecting device). Therefore, it is desirable that the exterior surface of the electronic device is made of a member having a porous shape such as a punching metal plate rather than a member in which a small hole is locally provided at a position facing the main microphone. When the exterior surface is a member having a porous shape such as a punching metal plate, and even when the punching metal plate forms a slope instead of a horizontal plane, a reference microphone that captures noise is disposed in the vicinity of the main microphone, and the reference The microphone is required to block sound pressure from the outside of the electronic device. An object of the present disclosure is to reduce noise included in an audio signal when generating an audio signal by capturing audio outside the electronic device even when the exterior surface has a porous shape.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, a detailed description of already well-known matters and a redundant description of substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The inventor provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is not intended to limit the subject matter described in the claims. Absent.

(Embodiment 1)
The first embodiment will be described below with reference to the drawings.

  In Embodiment 1, a digital camera capable of outputting an audio signal is taken as an example of an embodiment of an imaging apparatus. The sound collection device is incorporated in the digital camera and integrated. As the resolution of a digital camera increases, the captured image is more susceptible to camera shake. Therefore, it is desirable to mount a high-performance camera shake correction mechanism in the digital camera, but noise due to driving of the camera shake correction mechanism is likely to occur. That is, in a high-resolution digital camera, there is a problem that noise is more likely to occur inside the digital camera. In general, when it is desired to improve sound quality, it is desirable that there are many paths through which sound reaches the main microphone. That is, it is desirable that the exterior surface of the digital camera is a porous exterior surface such as a punching metal plate, rather than an exterior surface that locally has small holes as sound paths. However, when the exterior surface is a porous member such as a punching metal plate, it is virtually impossible to mount the main microphone and the reference microphone in the exterior member (housing). That is, since it is difficult to form a porous member by an injection molding method, it is difficult to integrally form a recess or the like (support member) for fixing the microphone with the housing. Moreover, when the punching metal plate forms a slope or a curved surface instead of a horizontal plane, it becomes more difficult to mount the microphone so as to be held in the exterior member (housing).

  Therefore, in the first embodiment, even when the main microphone and the reference microphone cannot be mounted so as to be held in the exterior member, the reference microphone can be disposed in the vicinity of the main microphone and the sound pressure from the outside is applied to the reference microphone. Easily realize the configuration to shut off.

[1-1. Constitution]
[1-1-1. overall structure]
FIG. 1 is a diagram illustrating a configuration of a digital camera 100 that is an embodiment of an imaging apparatus including a sound collection device according to the present disclosure. The digital camera 100 images a subject, generates image data (still image, moving image), and records it on a recording medium. The digital camera 100 includes a camera body 102 and an interchangeable lens 301 attached to the camera body 102. The digital camera 100 can also input sound during moving image shooting, and record the sound data together with the image data on a recording medium.

[1-1-2. Interchangeable lens configuration]
The interchangeable lens 301 has an optical system that includes a focus lens 310, a correction lens 318, and a zoom lens 312. The interchangeable lens 301 further includes a lens controller 320, a lens mount 330, a focus lens driving unit 311, a zoom lens driving unit 313, an aperture 316, an aperture driving unit 317, an operation ring 315, an OIS (Optical Image Stabilizer) driving unit 319, a DRAM ( Dynamic Random Access Memory) 321, flash memory 322, and the like.

  The lens controller 320 controls the entire operation of the interchangeable lens 301. The lens controller 320 can control the zoom lens driving unit 313 to accept the operation by the user of the operation ring 315 and drive the zoom lens 312. The lens controller 320 can control the focus lens driving unit 311, the OIS driving unit 319, and the diaphragm driving unit 317 so as to drive the focus lens 310, the correction lens 318, and the diaphragm 316, respectively.

  The OIS drive unit 319 includes a drive mechanism configured with, for example, a magnet and a flat plate coil. The OIS drive unit 319 controls the drive mechanism based on the detection signal of the gyro sensor that detects the shake of the interchangeable lens 301, and corrects the correction lens 318 in a plane perpendicular to the optical axis of the optical system according to the shake of the interchangeable lens 301. Shift. This reduces the influence of camera shake due to camera shake in the captured image.

  The lens controller 320 is connected to the DRAM 321 and the flash memory 322, and information can be written to and read from these memories as necessary. The lens controller 320 can communicate with the controller 130 via the lens mount 330. The lens controller 320 may be configured with a hard-wired electronic circuit or a microcomputer using a program.

  The lens mount 330 is connected to the body mount 340 of the camera body 102 and mechanically and electrically connects the interchangeable lens 301 and the camera body 102. When the interchangeable lens 301 and the camera body 102 are connected, the lens controller 320 and the controller 130 can communicate with each other. The body mount 340 can transmit a signal received from the lens controller 320 via the lens mount 330 to the controller 130 of the camera body 102.

[1-1-3. Configuration of camera body]
The camera body 102 includes a CCD (Charge Coupled Device) image sensor 143 and an AFE (Analog Front End) 144. The exterior member (housing) of the camera body 102 includes a case 105 shown in FIG. 2A and punching metal plates 119a, 119b, and 119c shown in FIG. 2B.

  The CCD image sensor 143 captures a subject image formed through the interchangeable lens 301 and generates image information. Note that another type of image sensor (for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor) may be used as the image sensor.

  The AFE 144 suppresses noise by correlated double sampling with respect to image information read from the CCD image sensor 143, amplifies the analog / digital (A / D) converter to the input range width, and performs A / D conversion. A / D conversion is performed by the instrument.

  The camera body 102 further includes an audio input unit 111 and an analog audio processing unit 115. The audio input unit 111 includes two main microphones (main microphone 111R and main microphone 111L) for separately collecting main sounds (recording target sounds) from the left and right directions. In the first embodiment, an example of the first direction is the left direction, and an example of the second direction is the right direction. The first main microphone is the main microphone 111R, and the second main microphone is the main microphone 111L.

  Furthermore, the audio input unit 111 includes a reference microphone 111N that acquires noise information inside the camera body 102. That is, the reference microphone 111N inputs at least one of noise caused by vibration of the camera body 102 and various noises generated inside the camera body 102. Information acquired by the reference microphone 111N is used to generate a signal (noise component) for suppressing noise included in the main voice.

  Each microphone (main microphone 111R, main microphone 111L, and reference microphone 111N) converts an audio signal into an electrical signal (analog audio signal). Analog audio signals from the microphones (main microphone 111R, main microphone 111L, and reference microphone 111N) are input to the analog audio processing unit 115.

  The analog audio processing unit 115 performs predetermined signal processing on the analog audio signal. The analog audio processing unit 115 converts the processed analog audio signal into a digital audio signal by an A / D converter, and outputs the digital audio signal to the digital image / audio processing unit 120. The analog audio processing unit 115 is an example of an audio signal processing device. The analog sound processing unit 115 is composed of an electronic circuit including an analog circuit, and is composed of one or a plurality of semiconductor integrated circuits. The analog voice processing unit 115 has an automatic level control (ALC) function. The automatic level control function is a function that automatically adjusts the gain so that the level of the output digital audio signal does not exceed a predetermined upper limit threshold regardless of the level of the input analog audio signal.

  The digital image / sound processor 120 performs various processes on the image information output from the AFE 144 and the sound signal output from the analog sound processor 115. For example, the digital image / audio processing unit 120 performs gamma correction, white balance correction, flaw correction, encoding processing, and the like on the image information in accordance with an instruction from the controller 130. In addition, the digital image / audio processing unit 120 performs various processes on the audio signal in accordance with instructions from the controller 130. The digital image / audio processing unit 120 may be realized by a hard-wired electronic circuit, or may be realized by a microcomputer that executes a program. The digital image / audio processing unit 120 may be realized as one semiconductor chip integrally with the controller 130 or the like. For example, the digital image / sound processing unit 120 may be a CPU (Central Processing Unit), an FPGA (Field-Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a DSP (Digital Procedural Signal).

  The digital image / audio processing unit 120 performs an arithmetic process on the audio signal that is the output of the audio input unit 111 to perform directivity synthesis processing and noise suppression processing. A circuit for realizing the digital image / audio processing unit 120 may be integrated in one or a plurality of semiconductor integrated circuits.

  The display unit 190 is disposed on the back surface of the digital camera 100. The display unit 190 can be configured by a liquid crystal display or an organic EL (Electro Luminescence) display. The display unit 190 displays an image based on the image information processed by the digital image / sound processing unit 120.

  The controller 130 controls the overall operation of the digital camera 100. The controller 130 may be realized by a hard-wired electronic circuit, or a microcomputer that executes a program. The controller 130 may be realized as a single semiconductor chip integrally with the digital image / audio processing unit 120 and the like. A ROM (Read Only Memory) 170 does not need to exist outside the controller 130 (separate from the controller 130), and may be incorporated in the controller 130. For example, the controller 130 can be configured by a CPU, FPGA, ASIC, DSP, or the like.

  The ROM 170 performs operations of the entire digital camera 100 in addition to programs related to auto focus control (Automatic Focus: AF control), automatic exposure control (Automatic Exposure: AE control), strobe light emission control, and the like, which are executed by the controller 130. A program for overall control is stored. The ROM 170 stores various conditions and settings regarding the digital camera 100. In the first embodiment, the ROM 170 is a flash ROM.

  A RAM (Random Access Memory) 150 functions as a work memory for the digital image / sound processor 120 and the controller 130. The RAM 150 can be realized by an SDRAM (Synchronous Dynamic Random Access Memory) or a flash memory. The RAM 150 also functions as an internal memory for recording image information and audio signals.

  The external storage medium 160 is a memory device that includes a nonvolatile storage element such as a flash memory. The external storage medium 160 is detachable from the camera body 102. The external storage medium 160 records image and sound data processed by the digital image / sound processing unit 120 under the control of the controller 130.

  The operation unit 180 is a general term for operation interfaces such as operation buttons and operation dials arranged on the exterior of the digital camera 100. The operation unit 180 receives an operation by a user. For example, the operation unit 180 includes a release button, a power switch, a mode dial, a center button, a cross button, and a touch panel provided on the back surface of the digital camera 100. When receiving an operation by the user, the operation unit 180 notifies the controller 130 of signals for instructing various operations.

  In addition, the camera body 102 shifts the CCD 143 in accordance with the camera body 102 shake, thereby reducing the influence of camera shake due to camera shake in the captured image. As a configuration for realizing this function, the camera body 102 includes a BIS (Body Image Stabilizer) drive unit 181 that moves the CCD 143 based on the camera body 102 shake. The BIS drive unit 181 includes, for example, a drive mechanism composed of a magnet and a flat plate coil. The BIS drive unit 181 controls the drive mechanism based on the signals from the gyro sensor and the position sensor, and shifts the CCD 143 in a plane perpendicular to the optical axis so as to cancel the camera body 102 shake.

[1-1-4. Microphone configuration]
The main microphone 111R, the main microphone 111L, and the reference microphone 111N are arranged inside the camera body 102 shown in FIG. 2A. The positions and detailed arrangement of the main microphone 111R, the main microphone 111L, and the reference microphone 111N in the camera body 102 will be described later.

  Hereinafter, the configuration of the main microphone 111R will be described. Since the configuration of the main microphone 111L and the reference microphone 111N is the same as that of the main microphone 111R, description thereof is omitted.

  The main microphone 111R has a cylindrical shape as shown in FIG. As shown in FIG. 4, the main microphone 111R includes a case 401, a vibrating membrane 402, a vibrating membrane ring 403, a spacer 404, a back electrode plate 405, an electrode 406, an insulator 407, and a printed circuit board 408. , FET (Field Effect Transistor) 409.

  Case 401 constitutes a part of the exterior portion of main microphone 111R. A sound hole 410 is formed on the surface of the case 401 opposite to the printed circuit board 408. The material of the case 401 is a metal. The material of the case 401 is SUS (Steel Use Stainless) or aluminum.

  The shape of the vibration film 402 is a disk shape. The vibration film 402 is obtained by coating a surface of a thin film made of a polymer material such as polyethylene terephthalate (PET) with a thickness of several microns to several tens of microns with a metal such as gold or nickel by sputtering or vapor deposition. . The vibration film 402 is disposed inside the case 401. The vibration film 402 is bonded to a ring-shaped vibration film ring 403 and is tensioned like a drum film. The material of the diaphragm ring 403 is a metal, for example, SUS or brass. The vibrating membrane 402 and the vibrating membrane ring 403 are at the same potential as the case 401 due to contact with the case 401.

  The spacer 404 has a ring shape. The thickness of the spacer 404 is about several microns to several tens of microns. The material of the spacer 404 is an insulating material such as polyimide.

  The shape of the back electrode plate 405 is a disc shape. The back electrode plate 405 is a plate in which an electret material such as FEP (tetrafluoroethylene / hexafluoropropylene copolymer) is coated on a metal base material such as SUS or brass. An electret material is a polymer material that holds a charge semipermanently. Thereby, the back electrode plate 405 retains electric charges. The back electrode plate 405 has several holes for allowing air to pass therethrough. The back electrode plate 405 faces the vibration film 402 with the spacer 404 interposed therebetween. That is, the distance between the back electrode plate 405 and the diaphragm 402 is substantially the same as the thickness of the spacer 404.

  The shape of the electrode 406 is, for example, a pipe shape, that is, a cylindrical shape. The electrode 406 is disposed between the back electrode plate 405 and the printed circuit board 408. The electrode 406 electrically connects the back electrode plate 405 and the printed circuit board 408.

  The shape of the insulator 407 is, for example, a pipe shape. The insulator 407 is disposed between the back electrode plate 405 and the electrode 406 and the case 401. The insulator 407 prevents the back electrode plate 405 and the electrode 406 from conducting with the case 401.

  The printed circuit board 408 constitutes a part of the exterior portion of the main microphone 111R. The printed circuit board 408 is electrically connected to the back electrode plate 405 through the electrode 406. The printed circuit board 408 is surface-mounted with chip components such as an FET 409. Terminals (138 in FIG. 5) are provided on the outside of the printed circuit board 408, that is, on the lower surface on the paper surface of FIG. The electrical output of the main microphone 111R can be taken out from this terminal.

  Note that one end of the case 401 is crimped around the lower side of the printed circuit board 408. That is, one end of the case 401 is sealed so that there is no gap between the printed circuit board 408 and the case 401. Further, the case 401 and the printed circuit board 408 are electrically connected by one end of the case 401.

  Hereinafter, operations of the main microphone 111R, the main microphone 111L, and the reference microphone 111N will be described.

  Here, the sound is a dense wave of air and is a pressure fluctuation of the air. When sound passes through the sound hole 410 and arrives at the vibration film 402, the vibration film 402 receives pressure. The vibrating membrane 402 is displaced according to the pressure. That is, the distance d between the vibrating membrane 402 and the back electrode plate 405 changes. Let the amount of change be Δd. The area of the vibration film 402 is S. Further, let Q be the amount of charge held by the back electrode plate 405. Opposing diaphragm 402 and back electrode plate 405 form a capacitor. When the capacitance of the capacitor is C and the dielectric constant is ε, the following formula 1 is established.

  Further, assuming that the potential formed by the vibrating membrane 402 and the back electrode plate 405 is V, the following formula 2 is established from Coulomb's law.

  From the above formulas 1 and 2, the following formula 3 is established.

  The change ΔV in potential when the vibration film 402 is displaced by sound and the distance between the vibration film 402 and the back electrode plate 405 changes by Δd is expressed by the following Equation 4.

  Formula 4 shows that the displacement of the vibrating membrane 402 due to sound can be taken out as a change in potential.

  Note that the capacitance C of the capacitor formed by the vibrating membrane 402 and the back electrode plate 405 is several pF to several tens pF, and the impedance is high. Therefore, the FET 409 mounted on the printed circuit board 408 is used to convert this impedance.

[1-1-5. Microphone placement]
2A and 2B are views showing the positions of the punching metal plates 119a, 119b, and 119c in the digital camera 100. FIG. The punching metal plates 119a, 119b, and 119c are metal plates formed by pressing a plate-like metal material that has been punched (perforated). The punching metal plates 119a, 119b, and 119c are each provided with a large number of sound holes 114 of 20 or more. In the first embodiment, the number of sound holes is about 100 each. The diameters of the sound holes 114 are 0.3 mm or more and 1.0 mm or less, respectively. Therefore, the digital camera 100 of the first embodiment is more suitable for a digital camera that is not dustproof and dripproof. Note that the punching metal plates 119a, 119b, and 119c are replaced with a metal sheet formed by pressing a sheet-like metal material that has been punched (perforated), or a molded wire mesh. The punching metal plates 119a, 119b, and 119c are fitted so as to cover the resin case 105. In the first embodiment, the punching metal plates 119a, 119b, 119c and the case 105 constitute a casing having a porous exterior surface. The punching metal plates 119a, 119b, and 119c are curved and are disposed obliquely with respect to the horizontal direction during normal photographing (the left-right direction on the paper surface of FIG. 2A).

  As shown in FIG. 2B, a main microphone 111R is disposed below the punching metal plate 119a. A main microphone 111L is disposed below the punching metal plate 119b. The area of the punching metal plate 119a is larger than the area of the vibration film 402 of the main microphone 111R. Therefore, the punching metal plate 119a is disposed not only in the region facing the main microphone 111R but also on the outer periphery thereof. Here, in the case of a digital camera with dustproof and splashproof specifications, the number of sound holes in the housing is a small number of 1 or more and less than 10 for one main microphone, and the sound holes are localized only on the upper part of the main microphone. It is common to be arranged in. On the other hand, the punching metal plate 119a of the first embodiment has a large number of sound holes 114 uniformly in a region facing the main microphone 111R and a region on the outer periphery thereof. Similarly, the punching metal plate 119b has sound holes 114 uniformly in a region facing the main microphone 111L and a region on the outer periphery thereof. 2A and 2B, the punching metal plate 119c is also disposed above the reference microphone 111N. However, the punching metal plate 119c may not be disposed above the reference microphone 111N. That is, the upper portion of the reference microphone 111N may be sealed with the case 105.

  The main microphone 111 </ b> R, the main microphone 111 </ b> L, and the reference microphone 111 </ b> N are arranged in an upper region of the camera body 102 inside the camera body 102, that is, inside the case 105. The region where the main microphone 111R is disposed is in the region facing the punching metal plate 119a and in the region 112R represented by the dotted line. The region where the main microphone 111L is disposed is in the region facing the punching metal plate 119b and in the region 112L. The region where the reference microphone 111N is disposed is in the region facing the punching metal plate 119c and in the region 112N.

  The main microphone 111L and the main microphone 111R are arranged side by side in the longitudinal direction of the camera body 102 by a predetermined distance (for example, about 15 mm). The longitudinal direction of the camera body 102 is the left-right direction on the paper surface of FIG. 2A.

  The reference microphone 111N is disposed in the vicinity of the main microphone 111R and the main microphone 111L. The reference microphone 111N is arranged at a position where the distances from the main microphone 111R and the main microphone 111L are equal. As a result, it is possible to perform noise suppression processing on the main audio signals of the left and right channels using one reference microphone 111N. Specifically, the reference microphone 111N is disposed at a position where the distance from each of the main microphone 111R and the main microphone 111L is 5 mm or more and 50 mm or less (for example, 10 mm).

  FIG. 5 is a view for explaining the arrangement of the main microphone 111R and the reference microphone 111N inside the camera body 102. As shown in FIG. FIG. 5 schematically shows a cross section taken along line 5-5 of FIG. 2B. Although only the main microphone 111R is shown in FIG. 5, the main microphone 111L is also arranged in the same manner as the main microphone 111R. In the first embodiment, the main microphone 111R and the main microphone 111L are such that the surface having the sound hole 410 of the case 401 shown in FIG. 3 faces outward (upward on the paper surface of FIG. 5), and the printed circuit board 408 is the camera body 102. Are arranged so as to face the inside (the lower side on the paper surface of FIG. 5). In the reference microphone 111N, the surface of the case 401 having the sound hole 410 faces inward (lower side on the paper surface of FIG. 5), and the printed circuit board 408 faces outward of the camera body 102 (upper side on the paper surface in FIG. 5). Are arranged as follows. The direction of the reference microphone 111N is opposite to the direction of the main microphone 111R and the main microphone 111L. The direction of sound collection between the reference microphone 111N, the main microphone 111R and the main microphone 111L, that is, the respective vibrating membranes 402 is different. Indicates that the direction to receive sound pressure is opposite.

  As shown in FIG. 5, a resin case 116 is arranged inside the case 105. Further, in the case 105, a sponge A131, a sponge B132, a sponge C133, and a sponge D134 are disposed so as to fill the gaps between the case 105, the resin case 116, the main microphones 111R and 111L, and the reference microphone 111N. .

  The main microphone 111 </ b> R is disposed on a resin case 116 and a sponge A 131 provided on the resin case 116. A space between the upper surface of the main microphone 111R and the back surface of the case 105 (the surface facing the inside of the digital camera) is filled with a sponge C133. The sponge C133 can pass sound pressure from the outside of the case 105. In addition, the outer peripheral surface of the main microphone 111R (the side surface of the case 401 that is perpendicular to the vibration film 402) is surrounded by a sponge B132. The sponge B132 is provided with a cylindrical hole so that the cylindrical main microphone 111R can be fitted therein.

  The reference microphone 111 </ b> N is disposed in a recess formed of a resin case 116 with a rubber member 113 interposed therebetween.

  Here, the shape of the rubber member 113 is a cylindrical shape having an end face. The end surface of the rubber member 113 has an opening 113H. However, the opening 113H may not be provided. One end of the rubber member 113 is opened on the side opposite to the end face, and the reference microphone 111N is inserted from the opened end. In Embodiment 1, it arrange | positions so that the end surface of the rubber member 113 may be located below the paper surface of FIG. Therefore, the lower surface of the reference microphone 111N is covered with the end surface of the rubber member 113. The side surface of the reference microphone 111N is covered with the side surface of the rubber member 113. The reference microphone 111N is press-fitted into the recess of the resin case 116 by elastically deforming the rubber member 113 (particularly the rib of the rubber member 113), and is fixed inside the camera body 102. This makes it difficult for the sound pressure that enters between the resin case 116 and the reference microphone 111N to reach the diaphragm 402 of the reference microphone 111N. Here, as a method of fixing the reference microphone 111N to the resin case 116, the sound pressure entering from between the resin case 116 and the reference microphone 111N is blocked by being buried with adhesive or clay instead of the rubber member 113. May be.

  Further, the space between the upper surface of the reference microphone 111N and the back surface of the case 105 is filled with a sponge D134. The sponge D134 can block sound pressure from the outside of the case 105.

  Here, in Embodiment 1, the sponge A131, sponge B132, sponge C133, and sponge D134 are used as the filling members that fill the gaps in the case 105. However, instead of the sponge, a foam material such as foamed plastic is used. Also good. Sponge A131, sponge B132, sponge C133, and sponge D134 are roughly classified into two types according to the structure of bubbles. One is a sponge having an open cell structure typified by urethane foam as shown in FIG. 6A, and allows sound to pass through a plurality of bubbles 118. That is, the sponge of an open cell structure (an example of a filling member) has many sound pressure transmission paths that penetrate from one end to the other end. In Embodiment 1, a sponge having an open cell structure is used as the sponge C133. The other is a general-purpose PE (polyethylene) foam as shown in FIG. 6B or a sponge having a closed cell structure typified by a rubber sponge. Since each bubble 118 of the sponge of the closed cell structure is an independent cell 118, the sound pressure transmission path is extremely small compared to the sponge of the open cell structure, and substantially no sound passes. A closed cell structure is used for the sponge A131, the sponge B132, and the sponge D134. However, the sponge A131 and the sponge B132 may use an open cell structure. The sponge D134 preferably uses a closed cell structure as much as possible, but can also use an open cell structure.

  As described above, the sponge A 131 to the sponge D 134, the resin case 116, and the rubber member 113 are arranged with respect to the main microphones 111R and 111L and the reference microphone 111N. A131, sponge B132, and sponge C133 correspond to the first support member of the present disclosure. The resin case 116, the rubber member 113, and the sponge D134 correspond to the second support member of the present disclosure. Furthermore, the sponge C133 corresponds to the first filling member of the present disclosure. Further, the sponge A131 and the sponge B132 correspond to a second filling member of the present disclosure.

  Further, the sound pressure transmission path from the outside and inside of the digital camera 100 to the diaphragms 402 of the main microphones 111R and 111L will be described below. Sound pressure due to sound (air vibration) from the outside of the digital camera 100 is transmitted through the plurality of sound holes 114 of the punching metal plate 119a, the plurality of bubbles 118 of the sponge C133, and the sound hole 410 of the main microphone 111R. Are transmitted to the vibrating membrane 402 of the main microphone 111R. Similarly, the sound pressure due to the sound from the outside of the digital camera 100 is mainly transmitted through the plurality of sound holes 114 of the punching metal plate 119b, the plurality of bubbles 118 of the sponge C133, and the sound hole 410 of the main microphone 111L. It is transmitted to the vibrating membrane 402 of the microphone 111L.

  In the first embodiment, as shown in FIG. 5, the diaphragm 402 of the main microphone 111R and the internal space located on the center side of the case 105 include the printed circuit board 408, the sponge A131, and the sponge B132 of the main microphone 111R. It is blocked by the resin case 116. Similarly, the inside of the main microphone 111L and the inside located on the center side of the case 105 are blocked by the resin case 116, the sponge A131, the sponge B132, and the printed circuit board 408 of the main microphone 111L. That is, the sound pressure due to the sound inside the case 105 is hardly transmitted to the diaphragms 402 of the main microphones 111R and 111L by the resin case 116, the sponge A131, the sponge B132, and the printed circuit board 408.

  Next, a transmission path of sound pressure from the outside and inside of the digital camera 100 to the vibrating membrane 402 of the reference microphone 111N will be described. In the first embodiment, the sound pressure from the outside of the digital camera 100 passes through the sound hole 114 of the punching metal plate 119c, but is transmitted by the sponge D134, the rubber member 113, the resin case 116, and the printed circuit board 408 of the reference microphone 111N. It is hard to be done. In the region 112N where the reference microphone 111N is disposed, the sound hole 114 of the punching metal plate 119c is not necessarily provided in the case 105, and part of the transmission of the sound pressure from the outside of the camera body 102 to the inside of the reference microphone 111N. May be shielded by the case 105.

  The inside of the reference microphone 111N and the inside located on the center side of the case 105 are blocked by the resin case 116 and the rubber member 113.

  As described above, in the first embodiment, as summarized in the list of FIG. 10, the printed circuit board 408, sponge A131, sponge B132, and resin case 116 of the main microphones 111R and 111L block the sound pressure transmission path. This corresponds to the first shielding member. Further, the sponge D134, the rubber member 113, the resin case 116, and the printed circuit board 408 of the reference microphone 111N correspond to the second shielding member of the present disclosure. Further, the resin case 116 and the rubber member 113 correspond to the third shielding member of the present disclosure.

  Each terminal 138 of the printed circuit board 408 of the main microphone 111R and the main microphone 111L and the printed circuit board 408 of the reference microphone 111N is connected to a PCB (Printed Circuit Board) 135 via an FPC (Flexible Printed Circuits) 136 passing through the hole 116H. It is connected.

[1-2. Operation of sound collection device]
The noise suppression process for the audio signal in the digital image / audio processing unit 120 of the digital camera 100 will be described. The digital image / sound processor 120 performs noise suppression processing based on the signal input from the reference microphone 111N.

  The main microphone 111R and the main microphone 111L receive the main sound outside the digital camera 100 and convert it into an electric signal (hereinafter referred to as “main sound signal”) as a first sound signal. The reference microphone 111N inputs noise inside the digital camera 100 and converts it into an electrical signal (hereinafter referred to as “noise signal”) as a second audio signal.

  The analog sound processing unit 115 receives a main sound signal from the main microphone 111R and the main microphone 111L, receives a noise signal from the reference microphone 111N, performs a predetermined process, and outputs it to the digital image / sound processing unit 120. The digital image / sound processing unit 120 filters the noise signal to generate a noise component, and subtracts the noise component from the main audio signal. Thereby, the digital image / audio processing unit 120 generates an audio signal in which noise is suppressed.

  FIG. 7 is a diagram illustrating a main configuration for realizing noise suppression processing for an audio signal in the digital image / audio processing unit 120. In FIG. 7, for convenience of explanation, a configuration for an audio signal from one of the two main microphones 111R and 111L on the left and right (the main microphone 111L) is shown. That is, the digital image / audio processing unit 120 has the configuration shown in FIG. 7 for each channel. In the following, the configuration and operation related to noise suppression for an audio signal from the microphone of one channel (main microphone 111L) will be described, but the same applies to the microphone of the other channel (main microphone 111R).

  The digital image / sound processing unit 120 includes an adaptive filter 117a, a coefficient setting unit 117b, and a subtractor 117c.

  The coefficient setting unit 117b sets the filter coefficient of the adaptive filter 117a according to a noise signal or the like. The adaptive filter 117a filters the output signal (noise signal) from the reference microphone 111N according to the filter coefficient set by the coefficient setting unit 117b, and is included in the audio signal (main audio signal) collected by the main microphone 111L. A noise component estimated to be generated is generated. The subtractor 117c subtracts the noise component output from the adaptive filter 117a from the audio signal (main audio signal) collected by the main microphone 111L. As a result, an audio signal in which noise is suppressed is generated.

  In FIG. 7, the transfer function regarding the noise suppression function in the digital image / sound processor 120 is defined as follows. Assume that the main audio signal input from the main microphone 111R and the main microphone 111L is S (ω, t), and the noise signal input from the reference microphone 111N is N (ω, t). The noise signal includes signals due to various noises generated in the camera body 102. For example, the noise indicated by the noise signal includes driving sound of the driving mechanism when the BIS driving unit 181 drives the CCD 143.

The transfer function for the main audio signal S (ω, t) in the main microphone 111R and the main microphone 111L is H _SM (ω, t). A transfer function for the noise signal N (ω, t) in the main microphone 111R and the main microphone 111L is H _NM (ω, t). A transfer function for the noise signal N (ω, t) in the reference microphone 111N is assumed to be H _NR (ω, t). When defined in this way, the output signal M (ω, t) of the main microphone 111R and the main microphone 111L and the output signal R (ω, t) of the reference microphone 111N are expressed by the following equations (5) and (6), respectively. can get.

M (ω, t) = H _SM (ω, t) · S (ω, t) + H _NM (ω, t) · N (ω, t) (Formula 5)
R (ω, t) = H _NR (ω, t) · N (ω, t) (Expression 6)
Here, the signal component for the main audio signal included in the output signal R (ω, t) of the reference microphone 111N is assumed to be negligibly small.

In the output signal M (ω, t) of the main microphone 111R and the main microphone 111L, the noise component is H _NM (ω, t) · N (ω, t). Therefore, by estimating H _NM (ω, t) · N (ω, t) as this noise component and subtracting it from the output signal M (ω, t), it is possible to obtain a speech signal with suppressed noise.

Therefore, in the digital image / sound processing unit 120, the coefficient setting unit 117b outputs the output signal M (ω, t) of the main microphone 111R and the main microphone 111L and the output signal R (ω, t) of the reference microphone 111N. Then, the noise components are estimated by comparing them, and the filter coefficient of the adaptive filter 117a is set according to the estimated noise components (H _ENM (ω, t) · N (ω, t)). The adaptive filter 117a generates and outputs a noise component (H _ENM (ω, t) · N (ω, t)) from the output signal R (ω, t). The subtractor 117c subtracts the output signal (H _ENM (ω, t) · N (ω, t)) of the adaptive filter 117a from the output signal M (ω, t). As a result, an audio signal in which noise is suppressed is output from the analog audio processing unit 115.

[1-3. Experimental result]
FIG. 8 is a diagram showing measurement results of noise levels in various arrangements of reference microphones 111N. The horizontal axis in FIG. 8 indicates the frequency (Hz) of the audio signal collected by the sound collection device, and the vertical axis indicates the level (dB) of the audio signal.

  In FIG. 8, a curved line S indicated by a thick line indicates the waveform of the audio signal collected by the main microphone 111 </ b> R and the main microphone 111 </ b> L when the above-described noise suppression processing is not performed by the digital image / audio processing unit 120.

  In FIG. 8, the curve shown in the solid line (Embodiment 1) is output from the sound collection device in which the main microphone 111R (main microphone 111L) and the reference microphone 111N are arranged as shown in FIG. The waveform of an audio signal is shown.

  In FIG. 8, a curved line (modified example) indicated by a broken line indicates a waveform of an audio signal output from the sound collecting device in which the main microphone 111R (main microphone 111L) and the reference microphone 111N are arranged as shown in FIG.

  In the modification, the following changes are made to the arrangement of the first embodiment of the main microphone 111R (main microphone 111L) and reference microphone 111N shown in FIG. Specifically, first, as shown in FIG. 9, the main microphone 111R (main microphone 111L) and the reference microphone 111N are arranged in the same direction. That is, the main microphone 111R (main microphone 111L) and the reference microphone 111N are arranged so that each printed circuit board 408 faces the inside of the digital camera 100 (lower side on the paper surface of FIG. 9) with respect to each vibration film 402. ing. In the modification, the reference microphone 111N is fixed between the resin case 116 and the sponge D134 using a sponge E131A and a sponge F132A instead of the rubber member 113 of FIG. That is, in the modification, the reference microphone 111N is disposed on the resin case 116 via the sponge E131A, and the bottom surface of the reference microphone 111N is covered with the sponge E131A. The sponge F132A is provided with a cylindrical hole so that a cylindrical reference microphone 111N can be fitted therein. Accordingly, the sponge F132A is disposed so as to cover the outer peripheral surface of the reference microphone 111N (the side surface perpendicular to the vibration film 402 of the surface of the case 401). The sponge E131A is the same material as the sponge A131. The sponge F132A is the same material as the sponge B132. In addition, in the modification, a tape 137 is attached so as to close the sound hole 410 at the top of the reference microphone 111N. In summary, as shown in the list of FIG. 10, in the modified example, as in the first embodiment, the resin case 116, the sponge A131, the sponge B132, and the printed circuit board 408 of the main microphone 111R (main microphone 111L) Corresponds to the first shielding member of the present disclosure. Further, in the modified example, unlike the first embodiment, the sponge D134 and the tape 137 correspond to the second shielding member of the present disclosure. Further, in the modification, unlike in the first embodiment, the resin case 116, the sponge E131A, the sponge F132A, and the printed board 408 of the reference microphone 111N correspond to the third shielding member of the present disclosure.

  In the modified example, as in the first embodiment, the sponge A131, the sponge B132, the sponge C133, and the resin case 116 correspond to the first support member of the present disclosure. Further, in the modification, unlike the first embodiment, the sponge D134, the sponge E131A, the sponge F132A, and the resin case 116 correspond to the second support member of the present disclosure. Further, in the modification, as in the first embodiment, the sponge C133 corresponds to the first filling member of the present disclosure. In the modified example, as in the first embodiment, the sponge A131 and the sponge B132 correspond to the second filling member of the present disclosure.

  From the results shown in FIG. 8, it can be seen that the noise suppression effect is enhanced in the first embodiment and the modification as compared with the case where noise processing is not performed. Further, comparing the first embodiment and the modification, it can be seen that the noise suppression effect is higher in the first embodiment. With the configuration as in the modified example, it is considered that a part of the sound pressure input from the outside is transmitted to the vibrating membrane 402 via the sponge D134 and the tape 137 as the second shielding member. That is, the second shielding member for blocking the transmission of the sound pressure has a relatively thick thickness, such as at least one of the resin case 116 and the printed circuit board 408, as compared with a thin member such as an adhesive tape, and transmits the sound. It is considered more effective that the member is a combination of a member having no path (hole) and the sponge D134.

[1-4. Effect]
The digital camera 100 (an example of an imaging device) according to Embodiment 1 includes a sound collection device. The sound collecting device includes a case 105 (housing) having a porous (a plurality of sound holes 114) -shaped exterior surface of a punching metal plate 119, and a case 105 disposed inside the case 105 via the plurality of sound holes 114. The main microphone 111R and the main microphone 111L that receive the sound pressure from the outside of the computer 105 and generate a first audio signal, and the inside of the case 105, are arranged in the vicinity of the main microphone 111R and the main microphone 111L, and the second A reference microphone 111N that generates a sound signal of the first and a first support member (resin case 116, sponge A131, sponge B132, and sponge C133) provided inside case 105 and supporting main microphone 111R and main microphone 111L; Provided inside the case 105 and supports the reference microphone 111N. The first supporting member (resin case 116, sponge A131, sponge B132) that shuts off the second support member (resin case 116 and rubber member 113) and the inside of case 105 and the inside of main microphone 111R and main microphone 111L. , And the printed circuit board 408), a second shielding member (sponge D134, printed circuit board 408, rubber member 113, and resin case 116) that shields the outside of the case 105 and the inside of the reference microphone 111N, and the inside of the case 105 And a third shielding member (resin case 116 and rubber member 113) that shields the inside of the reference microphone 111N.

  In the first embodiment, the first shielding member, the second shielding member, and the third shielding member are arranged to generate inside the digital camera 100 from the external main sound collected by the digital camera 100. Noise can be reduced efficiently.

  Further, in the first embodiment, even when the main microphones 111R and 111L and the reference microphone 111N cannot be mounted so as to be held in the case 105, the reference microphone 111N can be disposed in the vicinity of the main microphones 111R and 111L and the reference microphone 111N. On the other hand, it is possible to easily realize a configuration that blocks sound pressure from the outside. Therefore, it is possible to suppress the noise generated inside the digital camera 100 from being mixed into the audio signal output from the sound collection device. For example, in the first embodiment, the resin case 116 and the sponge C133, which are filling members, are combined as the first support member, and the resin case 116 and the rubber member 113 are combined as the second support member. By using, the main microphones 111R and 111L and the reference microphone 111N can be easily arranged in the vicinity even when a casing having a porous exterior surface is used. Further, by changing the material of the sponge C133 and the materials of the sponges A131, B132, and D134, the sponges A131, B132, and D134 can be used as a part of the shielding member.

  In the first embodiment, since the punching metal plates 119a to 119c are used as a casing (a part of the casing) having a porous exterior surface, it is easy to form a porous shape. Further, since the material of the punching metal plates 119a to 119c is a metal, it is sturdy and an electric shielding effect can be obtained.

  Further, in the first embodiment, by using sponges A131, B132, and C133 as the first filling member or the second filling member, even if the back surface of the housing is an inclined surface or a curved surface, it conforms to the shape of the back surface. Can be easily molded with a punching die. Further, by combining a plurality of sponges (for example, sponge A131, sponge B132, and sponge C133), the filling member can be easily configured even with a complicated shape. Further, as a part of the first shielding member or the second shielding member, the rigidity is lower than that of the resin case 116 and the printed circuit board 408, and by using the porous sponge A131, sponge B132, sponge D134, the wind pressure can be absorbed, Noise can be further suppressed.

  In Embodiment 1, the exterior surface (for example, punching metal 119a, punching metal 119b, or punching metal 119c) is a slope or a curved surface. In the first embodiment, since the first support member and the second support member are provided, the main microphone and the reference microphone can be easily arranged in the vicinity even if the exterior surface is a slope or a curved surface.

  Further, in the first embodiment, the first support member and the second support member are configured by separate members that are separable from the portion (punching metal 119a to 119c) having the exterior surface of the housing (case 105). The Therefore, even if the exterior surface is a slope or a curved surface, the main microphones 111R and 111L and the reference microphone 111N can be easily arranged in the vicinity.

  In the first embodiment, the first support member includes a member (resin case 116) having a fixed shape, a member that is deformable in the compression direction (for example, sponge C133 as the first filling member, and second member A sponge A131 and a sponge B132) as filling members are combined. Accordingly, the main microphones 111R and 111L and the reference microphone 111N can be easily arranged in a desired layout even inside the casing having a porous exterior surface. Furthermore, even if the exterior surface of the case 105 of the digital camera 100 is a slope or a curved surface, the main microphones 111R and 111L and the reference microphone 111N can be easily arranged in a desired layout.

  Main microphones 111R and 111L according to Embodiment 1 input a first main microphone (for example, main microphone 111R) that inputs sound from a first direction and a sound from a second direction that is different from the first direction. Second main microphone (for example, main microphone 111L). Thereby, in Embodiment 1, it is possible to pick up sound from more directions.

  The distance between reference microphone 111N and the first main microphone (for example, main microphone 111R) in Embodiment 1 is equal to the distance between reference microphone 111N and the second main microphone (for example, main microphone 111L). Thereby, in Embodiment 1, a noise component can be suppressed for the audio signal from any of the main microphones 111R and 111L.

  In the first embodiment, as shown in FIG. 5, at least a part of the second shielding member is an exterior part (printed circuit board 408) of the reference microphone 111N, and at least a part of the third shielding member is a resin case. 116. This arrangement is effective when it is desired to reverse the directions of the main microphones 111R and 111L and the reference microphone 111N, or when it is desired to use the rubber member 113 having the opening 113H.

  In the first embodiment, the first filling member (sponge C133) that fills the space between the front surfaces of the main microphones 111R and 111L and the back surface of the case 105 and passes the sound pressure from the outside of the case 105 is used. Have. Thereby, the sound pressure from the outside can be transmitted to the vibrating membrane 402 of the main microphones 111R and 111L.

  In the first embodiment, at least a part of the first shielding member is a part of the first support member, and the second filling member (sponge A131 and sponge A131) disposed on the outer periphery of the main microphones 111R and 111L. Sponge B132). As a result, noise generated inside the digital camera 100 can be blocked, and the main microphones 111R and 111L can be easily arranged inside the digital camera 100.

  The sound collection device according to Embodiment 1 further includes an audio processing unit that obtains a noise component based on the audio signal from the reference microphone 111N and subtracts the noise component from the main audio signal from the main microphone 111R and the main microphone 111L. . As a result, the noise component can be suppressed by the sound collecting device itself.

(Other embodiments)
As described above, the first embodiment is described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component currently demonstrated in the said Embodiment 1, and it can also be set as a new embodiment.

  In the first embodiment, as shown in FIGS. 2A and 2B, the reference microphone 111N is arranged on the front side (subject side) of the camera with respect to the main microphone 111R and the main microphone 111L. May be arranged on the rear side of the camera with respect to the main microphone 111R and the main microphone 111L. Further, although the main microphone 111R, the main microphone 111L, and the reference microphone 111N are arranged on the upper part of the digital camera 100 (an example of an electronic device), the positions of these microphones are not limited thereto. For example, the main microphone 111R, the main microphone 111L, and the reference microphone 111N may be arranged on at least one of the side surface and the front surface of the digital camera 100.

  In the above embodiment, the reference microphone 111N is fixed to the concave portion of the resin case 116 via the rubber member 113, but may be fixed to the resin case 116 by other means. For example, the reference microphone 111N may be directly fixed to the resin case 116 using an adhesive.

  In the above embodiment, the noise suppression processing for suppressing the noise in the main audio signal generated by the main microphones 111R and 111L using the noise signal generated by the reference microphone 111N has been described with reference to FIG. However, the noise suppression processing is not limited to this, and various known methods can be applied.

  In the first embodiment, a punching metal plate, a wire mesh, or the like is given as an example of a casing having a porous exterior surface (a part of the casing). However, if it can be molded into a porous shape, a resin or carbon plate is processed. It may be a member.

  In the first embodiment, the first support member includes the resin case 116, the sponge A131, the sponge B132, and the sponge C133, but this configuration is merely an example. For example, the resin case 116 may be changed to a metallic case. Further, for example, the sponge A131 and the sponge B132 may be an integral sponge or an integral rubber. Or sponge A131 or sponge B132 may be further divided into a plurality of parts. In any case, by combining a member whose shape is fixed like the resin case 116 and a member that is deformable in the compression direction such as the sponge A131 to sponge C133, even if the internal space of the housing is complicated, The main microphones 111R and 111L can be easily fixed. However, even when the first support member is composed of only a member having a fixed shape such as the resin case 116, it is possible to obtain a noise suppression effect by arranging the first shielding member separately.

  In the first embodiment, the second support member includes the resin case 116 and the rubber member 113, but this configuration is merely an example. For example, as in the modification of FIG. 9, the resin case 116, the sponge D134, the sponge E131A, and the sponge F132A may be used as the second support member. Furthermore, the sponge E131A and the sponge F132A, or the sponge F132A and the sponge D134 may be an integral sponge or an integral rubber, respectively. Alternatively, the sponge D134 to the sponge F132A may be further divided into a plurality of parts. In any case, by combining a member whose shape is fixed like the resin case 116 and a member that is deformable in the compression direction such as the sponge D134 to the sponge F132A, even if the internal space of the casing is complicated, The reference microphone 111N can be easily fixed.

  In the above embodiment, an example in which the sound collection device of the present disclosure is applied to an interchangeable lens type digital camera has been described. However, the sound collection device of the present disclosure is applied to a digital camera having an integrated lens and body. You can also.

  The above embodiment assumes that the digital camera is not a dustproof / splashproof digital camera, but if a very fine porous shape can be formed on the exterior surface of the housing, it is a dustproof / splashproof digital camera. May be.

  In the above-described embodiment, an example in which the sound collection device of the present disclosure is applied to a digital camera has been described, but the configuration of the sound collection device of the present disclosure can also be applied to other electronic devices. For example, the configuration of the sound collection device of the present disclosure can also be applied to other electronic devices (such as a video camera and an integrated circuit (IC) recorder) that input sound. The configuration of the sound collection device of the present disclosure is particularly useful for an electronic device having a noise source inside the electronic device.

  As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings or detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The sound collection device according to the present disclosure can generate an audio signal in which noise is suppressed by removing a noise component from an input audio signal, and converts the sound into an electric signal and inputs the electronic device (video camera, IC recorder, etc.) And is particularly useful for electronic devices having a noise source inside.

100 Digital camera (imaging device)
102 Camera body 105 Case (housing)
111 voice input unit 111R, 111L main microphone 111N reference microphone 112R, 112L, 112N region 113 rubber member (fixing member)
113H opening 114 sound hole 115 analog sound processing unit 116 resin case 117a adaptive filter 117b coefficient setting unit 117c subtractor 118 bubble 119a, 119b, 119c punching metal plate 120 digital image / sound processing unit 130 controller 131 sponge A
132 Sponge B
131A Sponge E
132A Sponge F
133 Sponge C
134 Sponge D
137 Tape 138 Terminal 143 CCD image sensor 160 External storage medium 180 Operation unit 181 BIS drive unit 301 Interchangeable lens 319 OIS drive unit 401 Case (exterior part)
402 Vibration Film 403 Vibration Film Ring 404 Spacer 405 Back Electrode Plate 406 Electrode 407 Insulator 408 Printed Circuit Board (Exterior)
409 FET
410 sound hole

Claims (8)

A housing having a porous exterior surface provided with a plurality of holes;
A main microphone that is disposed inside the casing, receives a sound pressure from the outside of the casing through the plurality of holes, and generates a first audio signal;
A reference microphone disposed within the housing and in the vicinity of the main microphone for generating a second audio signal;
A first support member provided inside the housing and supporting the main microphone;
A second support member provided inside the housing and supporting the reference microphone;
A first shielding member that shields the interior of the housing from the interior of the main microphone;
A second shielding member that shields the outside of the housing from the inside of the reference microphone;
A third shielding member that shields the interior of the housing from the interior of the reference microphone;
A sound collecting device.   The sound collecting device according to claim 1, wherein the exterior surface is a slope or a curved surface.   The sound collecting device according to claim 1, wherein at least a part of the second shielding member is an exterior portion of the reference microphone, and at least a part of the third shielding member is the second support member. A first filling member that fills a space between the surface of the main microphone and the back surface of the housing opposite to the exterior surface, and allows the sound pressure from the outside of the housing to pass therethrough; Prepared,
The sound collecting apparatus according to claim 1, wherein the first filling member also serves as a part of the first support member. A second filling member disposed on an outer periphery of the main microphone;
The second filling member also serves as at least a part of the first shielding member,
The sound collecting device according to claim 1, wherein the second filling member also serves as a part of the first support member.   The sound collecting device according to claim 1, wherein the first support member and the second support member are configured by separate members that are separable from a portion of the housing having the exterior surface.   The sound collecting device according to claim 1, wherein at least one of the first support member and the second support member is configured by combining a member whose shape is fixed and a member that is deformable in a compression direction. An imaging unit that images a subject and generates an image signal;
The sound collection device according to any one of claims 1 to 7, wherein a third sound signal is generated based on the first sound signal and the second sound signal.
A controller that records the image signal together with the third audio signal on a predetermined recording medium;
An imaging apparatus comprising: