Imaging device

Abstract

Provided is an imaging device having a structure for reducing wind noise.　This imaging device has: a housing in which is formed an opening in communication with the inside and outside; and a microphone disposed inside an internal space communicating with the opening, wherein the value obtained by dividing the volume of the internal space from the opening to the microphone by the area of the opening is at least 3.

Description

Imaging device

[0001] The present disclosure relates to an imaging device.

[0002] Many recent imaging devices are capable of capturing not only still images but also videos. When capturing videos, ambient sounds are picked up by the imaging device's built-in microphone, and the picked-up sounds are stored as appropriate. When capturing sounds, wind noise may be picked up by the built-in microphone. When wind noise is mixed in, the quality of the captured video deteriorates. Such wind noise cancellation technology is widely used in headphones (see, for example, Patent Documents 1 and 2 listed below).

[0003] JP 2011-125065 A JP 2020-178244 A

[0004] Although noise cancellation processing is widely used in headphones, conventional technology has been insufficient in terms of suppressing wind noise in imaging devices. Furthermore, suppressing wind noise through signal processing increases the load on the signal processing during video capture, which is undesirable because it leads to delays in each process and increases power consumption. Furthermore, suppressing wind noise through signal processing can cause users to feel uncomfortable with the audio during playback due to a loss of low-frequency sounds.

[0005] An object of the present disclosure is to provide an imaging device having a structure capable of suppressing wind noise.

[0006] The present disclosure relates to an imaging device having, for example, a housing with an opening communicating with the inside and outside, and a microphone disposed in an internal space communicating with the opening, wherein the value obtained by dividing the volume of the internal space from the opening to the microphone by the area of ​​the opening is 3 or more.

[0007] 12A to 12C are graphs showing measurement results. FIGS. 12A to 12C are graphs showing measurement results. FIGS. 12B ... FIG. 1 is a diagram for explaining another example of the arrangement of each component that constitutes the voice input unit. FIG. 2 is a diagram for explaining an example of the configuration of the flow path dividing unit. FIG. 3 is a diagram for explaining the operation of the flow path dividing unit. A to D are diagrams for explaining another example of the arrangement of each component that constitutes the voice input unit. FIG. 4 is a diagram for explaining another example of the arrangement of each component that constitutes the voice input unit. A is a diagram for explaining another example of the configuration of the flow path dividing unit, and B is a diagram for explaining the operation of the flow path dividing unit. A diagram for explaining a modified example. A diagram for explaining a modified example. A to D are diagrams for explaining the modified example. A and B are diagrams for explaining the modified example.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The description will be made in the following order: <First embodiment> <Second embodiment> <Third embodiment> <Fourth embodiment> <Fifth embodiment> <Modification> The embodiments described below are preferred specific examples of the present disclosure, and the contents of the present disclosure are not limited to these embodiments.

[0009] First Embodiment [Shape Example of Imaging Device] Fig. 1 is a diagram for explaining a shape example of an imaging device (imaging device 100) according to the first embodiment. The imaging device 100 has a housing 10. The housing 10 has, for example, a rectangular parallelepiped shape. Specifically, the housing 10 has a front surface 10A, a back surface 10B opposite the front surface 10A, a top surface 10C, a bottom surface 10D, a left side surface 10E, and a right side surface 10F.

[0010] An annular mount 11 is provided on the front surface 10A of the housing 10. A lens barrel 12 housing a lens is detachably attached to the mount 11. Figure 1 shows the lens barrel 12 attached to the mount 11.

[0011] An eyepiece viewfinder 13 and a monitor are provided on the rear surface 10B of the housing 10. The viewfinder 13 and the monitor are used, for example, to check the subject being photographed. The monitor displays the photographed image and a menu screen. The monitor is movable so that it can be adjusted to an angle that is easy to view, for example. The monitor may be configured as a touch panel and be capable of receiving operational inputs.

[0012] A convex portion 14 protruding upward (in the +Z direction in FIG. 1 ) is formed near the center of the top surface 10C of the housing 10. The convex portion 14 has an internal space that is connected to the interior space of the housing 10. The convex portion 14 houses a pentatonics, an optical component that guides light captured through the lens in the lens barrel 12 to the viewfinder 13. An interface mechanism 15 is provided on the top surface 14A of the convex portion 14 for connecting auxiliary shooting components such as a flash. An audio input unit 31 is also formed on the left side surface 14B of the convex portion 14. The audio input unit 31 includes, for example, a microphone (microphone 46, described below) and is configured to pick up ambient sounds during video shooting. Although not shown in FIG. 1 , an audio input unit with a similar configuration to the audio input unit 31 is also formed on the right side surface of the convex portion 14. Sound input to the audio input unit 31 provided on the left side surface 14B is picked up as sound on the L (left) channel, and sound input to the audio input unit provided on the right side surface 14C is picked up as sound on the R (right) channel. Details of these audio input units will be described later.

[0013] A plurality of input sections are provided on the right side of the top surface 10C, with the protrusion 14 as the boundary. For example, the right side of the top surface 10C has a shape that protrudes slightly forward (in the -Y direction), and is provided with an input button 16 that serves as a power switch and shutter button, and a front dial 17 for changing settings for each shooting mode. Also provided on the right side of the top surface 10C are, for example, a mode dial 18 for switching modes, a rear dial 19 for changing settings for each shooting mode, an exposure compensation dial 20 for performing exposure compensation, and a first custom button 21 and a second custom button 22 to which any function can be set.

[0014] Note that these types and locations of buttons are merely examples, and the types, locations, shapes, etc. of the buttons can be changed as appropriate.

[0015] 2 is a block diagram showing an example of the configuration of the imaging device 100 according to this embodiment. The imaging device 100 includes, for example, a control unit 41, an imaging device 42, an output signal generation unit 43, a signal output unit 44, an operation unit 45, and a microphone 46. The control unit 41, the imaging device 42, the output signal generation unit 43, the signal output unit 44, and the microphone 46 are connected to one another via a bus B, enabling transmission and reception of various data, commands, and the like.

[0016] Each unit of the imaging device 100 will be described. The control unit 41 is composed of a microcomputer or the like, and controls each block that constitutes the imaging device 100. The control unit 41 has a read-only memory (ROM) and a random access memory (RAM), not shown. The ROM stores programs executed by the control unit 41. The RAM is used as a work memory when the control unit 41 executes the programs. Note that other functional blocks may also have memories that store the programs that they themselves execute.

[0017] The control unit 41 is connected to the operation unit 45, and an operation signal corresponding to an operation on the operation unit 45 is supplied to the control unit 41. The control unit 41 executes control corresponding to the operation signal. Examples of the operation unit 45 include various buttons (see FIG. 1) for inputting information, a touch panel, and the like.

[0018] The imaging device 42 includes, for example, an optical system such as a lens housed in the lens barrel 12 and an imaging element. Examples of the imaging element include a global shutter CMOS (Complementary Metal Oxide Semiconductor) image sensor and a CCD (Charge Coupled Device) image sensor. The imaging element photoelectrically converts imaging light focused via the optical system on an imaging surface basis to generate a predetermined analog signal, and then digitally converts the analog signal to generate image data as a digital signal. The image data is color signals such as R (red), G (green), and B (blue). The image data generated by the imaging device 42 is supplied to the output signal generation unit 43.

[0019] The output signal generation unit 43 performs signal processing to adjust and improve image quality, such as correction of peripheral light loss in each frame of image data supplied from the imaging device 42, predetermined interpolation, filtering, shading, and white balance processing. The output signal generation unit 43 also performs well-known image processing, such as color adjustment, brightness compression, and gamma correction, on the image data supplied from the imaging device 42, to appropriately generate a video signal to be input to a predetermined display device. The output signal generation unit 43 outputs the generated video signal to the signal output unit 44.

[0020] The output signal generation unit 43 also performs known audio processing on the audio data supplied from the microphone 46. For example, the output signal generation unit 43 converts the audio data supplied from the microphone 46 into digital audio data and performs frequency characteristic correction processing, gain adjustment processing, etc. on the converted audio data. The output signal generation unit 43 then outputs the audio signal that has been subjected to various audio signal processing to the signal output unit 44.

[0021] The signal output unit 44 is an interface that outputs video signals and audio signals (hereinafter, sometimes abbreviated as video signals, etc.) generated by the output signal generation unit 43. For example, the video signals, etc. are output to a recording device via the signal output unit 44. The recording device has a recording unit and a driver that records the video signals in the recording unit and reproduces the video signals, etc. from the recording unit. Examples of the recording unit include magnetic storage devices such as HDDs (Hard Disk Drives), semiconductor storage devices, optical storage devices, and magneto-optical storage devices, and the driver has a configuration corresponding to the configuration of the recording unit. The recording device records the video signals, etc. supplied from the signal output unit 44 in the recording unit.

[0022] Furthermore, for example, a video signal is supplied to a display device via a signal output unit 44. The display device has a display unit and a driver that drives the display unit to display the video signal. The display device displays the video signal supplied from the signal output unit 44 on the display unit. Furthermore, an audio signal is reproduced in synchronization with the reproduction of the video signal and is played from a speaker (not shown).

[0023] In this way, the video signal or the like output via the signal output unit 44 may be recorded, played back, or both recorded and played back. The recording device or display device may be a device included in the imaging device 100, or may be an external device connected to the imaging device 100 via a wired or wireless connection.

[0024] The video signal or the like output via the signal output unit 44 may be supplied via a network such as the Internet to a device (a server device or a personal computer) connected to the network, and the video signal or the like may be reproduced or recorded in the device connected to the network.

[0025] The operation unit 45 is a general term for components that are used to input operations, such as buttons (see FIG. 1 ) and a touch panel provided on the imaging device 100. The operation unit 45 may be a remote controller that remotely controls the imaging device 100. Various settings for the imaging device 100 are made using the operation unit 45.

[0026] The microphone 46 is a microphone that picks up sounds around the imaging device 100. Analog audio data picked up and generated by the microphone 46 is supplied to the output signal generation unit 43 via the bus B. Note that, as will be described in detail later, the microphone 46 constitutes part of the audio input unit 31 provided in the housing 10 of the imaging device 100.

[0027] [Regarding the Audio Input Unit] Next, the audio input unit according to this embodiment will be described with reference to Figs. 3 to 7. Fig. 3 is a diagram for explaining an example of the configuration of the audio input unit 31, Fig. 4 is an enlarged partial cross-sectional view of a portion of the imaging device 100 to which the audio input unit 31 is attached, Fig. 5 is an exploded perspective view of the audio input unit 31, Fig. 6 is a half cross-sectional view of Fig. 5, and Fig. 7 is a cross-sectional view of the entire audio input unit 31. Note that in the following description, the audio input unit 31 provided on the left side surface 14B, which is one side surface of the convex portion 14, will be described, but the audio input unit provided on the right side surface 14C, which is the other side surface of the convex portion 14, also has a similar configuration.

[0028] 3, a microphone support portion 31A, a restricting member 31B, a frame-shaped member 31C, a volume expansion portion 31D, and an opening member 31E, which constitute the voice input portion 31, are provided on the left side surface 14B of the protrusion 14. Each of these components is made of resin, metal, or the like.

[0029] 4, the housing 10 of the imaging device 100, specifically, the microphone support portion 31A, the restricting member 31B, the frame-shaped member 31C, the volume expansion portion 31D, and the opening member 31E are provided in this order from the inside of the protrusion 14 toward the left side surface 14B. Therefore, the opening member 31E is disposed on the surface of the left side surface 14B.

[0030] 5 and 6, the various components of the voice input unit 31 will be described in detail. The microphone support unit 31A is generally shaped like a thin plate, with a rectangular main surface. The microphone support unit 31A has a circular hole 51 near the center. The microphone 46 is inserted into and supported by this hole 51. This positions the microphone 46 within the internal space of the housing 10.

[0031] The restricting member 31B is generally shaped like a thin plate, and has a rectangular main surface. The restricting member 31B has a circular hole 52 near the center. The hole 52 is slightly larger than the hole 51 of the microphone support 31A. The restricting member 31B restricts unnecessary movement of the microphone 46 by, for example, pressing against the circumferential surface of the microphone 46 supported by the microphone support 31A.

[0032] The frame member 31C has a generally thin plate-like shape and a rectangular main surface. The frame member 31C is a member that connects the restricting member 31B and the volume expansion portion 31D. The frame member 31C has a rectangular hole 53A near the center. The size of the hole 53A is larger than the size of the hole 52, for example, and is approximately the same size as a hole 54A of the volume expansion portion 31D, which will be described later.

[0033] The volume expansion section 31D has a box-like shape. The volume expansion section 31D has an internal space SP therein. The volume expansion section 31D has a function of expanding the volume of the internal space in which the microphone 46 is housed relative to the opening area of ​​the opening member 31E. Here, the volume of the internal space in which the microphone 46 is housed refers to the volume of the internal space from an opening (opening 55 described below) to the microphone 46. Specifically, the volume is defined by the sum of the volume of the opening 55 described below, the volume of the internal space SP, the volume of the hole 53, the volume of the hole 52, and the volume of the hole 51. Note that the largest volume of the voice input section 31 (in this embodiment, the volume of the volume expansion section 31D) may be the volume of the internal space from the opening 55 to the microphone 46.

[0034] In this manner, in this embodiment, the volume of the internal space is expanded by providing the volume expansion portion 31D. As will be described in detail later, by expanding the internal space compared to the conventional art, it is possible to reduce wind noise contained in the sound picked up by the microphone 46. A rectangular hole 54A is formed in the bottom surface of the volume expansion portion 31D, and the top surface opposite the bottom surface is an open end 54C defined by a rectangular outer edge portion 54B.

[0035] The opening member 31E has a generally thin plate-like shape and a rectangular main surface. The opening member 31E has a track-shaped opening 55. In this embodiment, the area of ​​the opening 55 (the area of ​​the opening exposed to the outside of the housing 10) corresponds to the area of ​​the opening in the claims.

[0036] 7, the voice input unit 31 is configured by stacking the components in the following order from the inside of the housing 10: microphone support portion 31A, restriction member 31B, frame-shaped member 31C, volume expansion portion 31D, and opening member 31E. The components are integrated by being attached with double-sided tape, adhesive, or the like at locations where they come into contact in the vertical direction (the up-and-down direction in FIG. 7).

[0037] When the components are integrated, the openings and holes are connected in the vertical direction. Specifically, the hole 51 in the microphone support portion 31A, the hole 52 in the restricting member 31B, the hole 53 in the frame member 31C, the internal space SP of the volume expansion portion 31D, the hole 54A in the bottom surface and the open end 54C in the top surface of the volume expansion portion 31D, and the opening 55 in the opening member 31E are connected in the vertical direction. With this configuration, the microphone 46 can pick up sound input through the opening 55 in the opening member 31E.

[0038] [Function] The following describes the function of the audio input unit 31 of the imaging device 100. Sound (such as human voices and surrounding environmental sounds) during video shooting is input to the audio input unit 31 through the opening 55 of the opening member 31E. The sound propagated into the housing 10 through the opening 55 is input to and picked up by the microphone 46 via the hole 54A of the volume expansion portion 31D, the hole 53 of the frame-shaped member 31C, the hole 52 of the restricting member 31B, and the hole 51 of the microphone support portion 31A.

[0039] Not only necessary ambient sounds but also wind is input to the audio input unit 31. This wind noise is a pseudo-sound source generated by fluid turbulence. Possible winds in the case of the imaging device 100 include wind that propagates along the surface of the lens barrel 12 and is picked up by the front surface 10A of the housing 10 before being input to the audio input unit 31, wind that flows from the front of the convex portion 14 around the left side surface 14B of the convex portion 14 before being input to the audio input unit 31, and wind that is directly input to the audio input unit 31. These winds become turbulent (air (wind) vortices) within the imaging device 100, causing wind noise. These wind noises have a frequency band of approximately 500 Hz, i.e., a low frequency range.

[0040] Wind noise picked up by the microphone 46 reduces the quality of the captured video, etc. For this reason, a windshield member called a windscreen or the like has conventionally been attached to the imaging device, but this increases costs and requires the effort of attaching the windshield member.

[0041] Therefore, in this embodiment, the volume expansion section 31D expands the internal space in which the microphone 46 is disposed, thereby reducing wind noise reaching the microphone 46. Wind enters the space expanded by the volume expansion section 31D (internal space SP in this example) through the opening 55. In a typical configuration (a configuration in which the volume is not expanded), wind vortices are generated inside, and the resulting wind noise is picked up. However, in this embodiment, because the volume of the internal space SP of the volume expansion section 31D is expanded compared to a typical configuration, even if a vortex is generated in the internal space SP by the intruding wind, the energy of the vortex can be dispersed. This reduces the sound pressure of the wind noise picked up by the microphone 46.

[0042] Incidentally, the opening 55 of the opening member 31E needs to be at least a certain size in order to pick up sounds outside the imaging device 100. On the other hand, if the size of the opening 55 is made too large, not only will the design of the imaging device 100 be impaired, but there is also a risk that noise will be more likely to be picked up. Therefore, the area of ​​the opening 55 is set to, for example, 7 mm ２ From 9mm ２ It is preferable to set it within the range of

[0043] Furthermore, as described above, although the sound pressure of wind noise can be reduced by expanding the volume of the internal space within the audio input unit 31 using the volume expansion unit 31D, if the volume of the internal space is expanded more than necessary, there is a risk that it will interfere with other components arranged within the housing 10, and there is also a risk that the overall size of the imaging device 100 will increase. Therefore, the inventors of the present disclosure measured and determined the optimal value for the volume of the internal space relative to the area of ​​the opening.

[0044] [Measurement Results] First, the area of ​​the opening 55 was set to 8.2 mm ２Measurements were conducted to determine how wind noise is reduced when the volume of the interior space is significantly changed. Figure 8 shows the results of the measurements. In the graph of Figure 8, the horizontal axis represents frequency, and the vertical axis represents sound pressure (dB). Line L1 in the figure shows the measurement results when the value obtained by dividing the volume of the interior space by the area of ​​the opening (hereinafter also referred to as the calculated value) is small (specifically, when the calculated value is 2). Line L2 in the figure shows the measurement results when the calculated value is large (specifically, when the calculated value is 8.9).

[0045] 8, in the frequency band where wind noise is particularly dominant (the area around 500 Hz surrounded by a dotted line), the sound pressure of line L2 is significantly lower than the sound pressure of line L1. This result shows that the sound pressure of wind noise can be reduced by increasing the volume of the internal space.

[0046] Next, we measured how the sound pressure around 500 Hz, where wind noise is dominant, changes when the volume of the interior space is changed while keeping the area of ​​the opening constant, in other words, when the value obtained by dividing the volume of the interior space by the area of ​​the opening is changed. Figures 9A to 9C show the results of this measurement. In each of the graphs in Figures 9A to 9C, the horizontal axis represents the value obtained by dividing the volume of the interior space by the area of ​​the opening, and the vertical axis represents sound pressure (dB). Furthermore, line L3 in Figures 9A and 9C represents the measurement results when the wind speed was 2 m / s, and line L4 in Figures 9B and 9C represents the measurement results when the wind speed was 5 m / s.

[0047] 9A and 9C, when the wind speed is weak, the sound pressure of the wind noise itself is small, but when the calculation value is "3," the sound pressure of the wind noise can be reduced by about 1 dB compared to when the calculation value is "1" or "2." On the other hand, even when the calculation value is increased beyond "3," the sound pressure of the wind noise does not decrease significantly.

[0048] 9B and 9C, when the wind speed is strong, the sound pressure of wind noise can be reduced more effectively by about 10 dB when the calculation value is "3" compared to "1" or "2." On the other hand, even when the calculation value is greater than "3," the sound pressure of wind noise does not decrease significantly.

[0049] From the above results, from the viewpoint of effectively reducing the sound pressure of wind noise, it is preferable that the value obtained by dividing the volume of the internal space by the area of ​​the opening be equal to or greater than 3. Furthermore, considering that an excessively large volume of the internal space does not significantly improve the effect of reducing the sound pressure of wind noise, and considering the recent demand for miniaturization of imaging devices, it is more preferable that the value obtained by dividing the volume of the internal space by the area of ​​the opening be equal to or less than 6.

[0050] As described above, according to this embodiment, the structure of the imaging device effectively reduces the sound pressure of wind noise. Cutting the low-frequency range where wind noise dominates using signal processing techniques results in cutting low-frequency sounds other than wind noise. However, this embodiment is configured to suppress the generation of vortices caused by wind using an expanded volume, while allowing the sound itself, which is air vibration, to reach the microphone 46. Therefore, the sound pressure of wind noise can be reduced without cutting low-frequency sounds. Furthermore, the sound pressure of wind noise can be reduced using a relatively simple method compared to signal processing techniques. Therefore, the signal processing load of the imaging device 100 is not increased. Furthermore, because loss of low-frequency sounds is suppressed, the user's discomfort with the sound during playback can be minimized. This embodiment eliminates the need for a windshield component, thereby suppressing increases in costs and eliminating the user's need to install a windshield component.

[0051] Second Embodiment Next, a second embodiment will be described. In the description of the second embodiment, the same or similar components as those in the above description will be denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, matters described in other embodiments can be applied to the second embodiment.

[0052] Fig. 10 is a diagram for explaining an example of the configuration of an audio input unit (audio input unit 61) of an imaging device (imaging device 100A) according to the second embodiment, Fig. 11 is a partial cross-sectional view enlarging a portion of imaging device 100A to which audio input unit 61 is attached, Fig. 12 is an exploded perspective view of audio input unit 61, and Fig. 13 is a half cross-sectional view of Fig. 12. Note that in the following explanation, the audio input unit 61 provided on the left side surface 14B of convex portion 14 will be described, but the audio input unit provided on the right side surface 14C of convex portion 14 has a similar configuration.

[0053] In the voice input unit 61, an aperture member 62 is further disposed outside the aperture member 31E described above. That is, the aperture member 62 is located on the outermost side. The aperture member 62 has a generally thin plate-like shape, and has a rectangular main surface. As shown in FIGS. 12 and 13 , the aperture member 62 has a plurality of holes 62A. Each of the plurality of holes 62A has, for example, a circular shape, but may have other shapes such as a rectangular shape. In this embodiment, the plurality of holes 62A constitutes an aperture in the claims. That is, the aperture in this embodiment has a mesh-like shape including the plurality of holes 62A. Furthermore, in this embodiment, the area of ​​the aperture in the claims is defined by the sum of the areas of the plurality of holes 62A.

[0054] The operation of the voice input unit 61 according to this embodiment will be described with reference to Fig. 14. As shown schematically in Fig. 14, in the area after passing through the multiple holes 62A of the opening member 62, wind collides and cancels out each other as indicated by the arrows, suppressing the generation of vortices. Furthermore, by reducing the area through which the wind enters (the area of ​​one hole 62A in this embodiment), it becomes more difficult for wind to enter the voice input unit 61, thereby suppressing the generation of vortices. This reduces the sound pressure of wind noise. Note that, even in this example, sound, which is air vibration, propagates within the voice input unit 61.

[0055] Furthermore, the audio input unit 61 according to this embodiment has a volume expansion unit 31D, similar to the audio input unit 31. This allows the energy of the vortex to be dispersed, as described in the first embodiment, thereby reducing the sound pressure of wind noise caused by the vortex. That is, the sound pressure of wind noise can be reduced more effectively than in the first embodiment. Furthermore, the area of ​​the opening can be made smaller than in the first embodiment. Therefore, when the value obtained by dividing the volume of the internal space by the area of ​​the opening is set to 3 or more, the volume of the internal space can be made smaller than in the first embodiment. Therefore, the risk of the expanded volume of the internal space interfering with other components is reduced, improving the design flexibility of the imaging device 100.

[0056] <Third Embodiment> Next, a third embodiment will be described. In the description of the third embodiment, the same or similar components as those in the above description will be denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, matters described in other embodiments can be applied to the third embodiment.

[0057] In the second embodiment described above, it has been explained that the sound pressure of wind noise can be reduced by using the mesh-shaped aperture member 62 in which a plurality of holes are formed. In the second embodiment, the aperture member 62 was arranged on the outermost side (on the surface of the housing 10), but in this embodiment, a member having a shape similar to that of the aperture member 62 (hereinafter also referred to as a mesh portion as appropriate) is arranged inside the housing 10. Even when the mesh portion is arranged on the inside, the sound pressure of wind noise can be reduced using the same principle as in the second embodiment.

[0058] For example, as shown schematically in Fig. 15 , in the configuration of the voice input unit 61 described in the second embodiment, a mesh portion (mesh portion 65) may be disposed between the opening member 31E and the volume expansion portion 31D. Note that in the schematic diagram of Fig. 15 , the illustration of each component is simplified to prevent the illustration from becoming too complicated. Also, in the schematic diagram of Fig. 15 , the direction from the opening member 62 toward the microphone support portion 31A (the direction from top to bottom in Fig. 15 ) corresponds to the direction from the mesh-shaped opening toward the microphone 46. This also applies to similar schematic diagrams.

[0059] Furthermore, the mesh portion 65 may be applied to the configuration of the voice input unit 31 described in the first embodiment (a configuration without the opening member 62). For example, as schematically shown in Fig. 16 , in the configuration of the voice input unit 31, the mesh portion 65 may be disposed between the opening member 31E and the volume expansion portion 31D.

[0060] Multiple mesh portions may be arranged. For example, as schematically shown in FIG. 17A , two mesh portions (a first mesh portion 65A and a second mesh portion 65B) may be arranged between the opening member 31E and the volume expansion portion 31D. In this case, as shown in FIG. 17B , the multiple mesh portions may be stacked such that at least some of the holes of each mesh portion are located at different positions in the stacking direction (the vertical direction in FIG. 17B ). Specifically, the positions of the holes 66A of the first mesh portion 65A and the holes 66B of the second mesh portion 65B may be stacked such that they are located at different positions in the stacking direction. This allows the ends of the holes 66A of the first mesh portion 65A to be shielded by the second mesh portion 65B, thereby preventing air vortices from reaching the microphone 46 even if they are generated beyond the holes 66A. As a result, the sound pressure of wind noise can be reduced. Note that three or more mesh portions may be arranged. In addition, in the configuration shown in FIG. 17A, the opening member 62 described in the second embodiment may be disposed.

[0061] <Fourth Embodiment> Next, a fourth embodiment will be described. In the description of the fourth embodiment, the same or similar components as those in the above description will be assigned the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, matters described in other embodiments can be applied to the fourth embodiment.

[0062] The voice input unit (voice input unit 71) according to the fourth embodiment has a flow path dividing unit 73. As schematically shown in Fig. 18 , in the voice input unit 71 according to the present embodiment, the flow path dividing unit 73 is disposed between the opening member 31E and the volume expansion unit 31D.

[0063] FIG. 19 is a diagram illustrating an exemplary configuration of the flow path dividing section 73. The flow path dividing section 73 is a member made of, for example, resin or metal. In this embodiment, the flow path dividing section 73 is made of, for example, resin having a thickness of several millimeters to approximately 1 cm. The flow path dividing section 73 has a thin, frame-shaped base 73A. A mountain-shaped section 73B having a downwardly sloping surface is formed near the center of the base 73A, connecting two opposing sides of the base 73A. The flow path dividing section 73 also has two holes 73C and 73D located on both sides of the mountain-shaped section 73B. In this embodiment, the holes 73C and 73D are rectangular, but may be other shapes, such as circular or elliptical. The flow path dividing section 73 divides the flow path of air (specifically, wind) entering through the opening 55 of the opening member 31E into two directions.

[0064] The operation of the voice input unit 71 will now be described. For example, as shown in FIG. 20 , wind entering through the opening 55 is divided by the flow path dividing unit 73 into a path that passes through the hole 73C and a path that passes through the hole 73D. This can reduce the wind speed. Furthermore, the winds whose flow paths are divided can be canceled out by colliding with each other from different directions (opposite directions), thereby further reducing the wind speed. This operation is indicated by arrows and cross marks in FIG. 20 . By reducing the wind speed, the generation of vortices can be suppressed, which ultimately reduces the sound pressure of wind noise caused by vortices. Note that the flow path dividing unit 73 may divide the wind direction into three or more directions.

[0065] The voice input unit 71 may further include the mesh portion 65 described in the third embodiment. For example, as schematically shown in FIG. 21A , a mesh portion 65 and a flow path dividing portion 73 may be arranged in this order from the opening member 31E side between the opening member 31E and the volume expansion portion 31D. Also, as schematically shown in FIG. 21B , a flow path dividing portion 73 and a mesh portion 65 may be arranged in this order from the opening member 31E side between the opening member 31E and the volume expansion portion 31D. Also, as schematically shown in FIG. 21C , the voice input unit 71 may include the opening member 62 described in the second embodiment. Also, the voice input unit 71 may include multiple mesh portions. For example, as schematically shown in FIG. 21D , a first mesh portion 65A, a flow path dividing portion 73, and a second mesh portion 65B may be arranged in this order from the opening member 31E side between the opening member 31E and the volume expansion portion 31D.

[0066] <Fifth Embodiment> Next, a fifth embodiment will be described. In the description of the fifth embodiment, the same or similar components as those in the above description will be denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, matters described in other embodiments can be applied to the fifth embodiment.

[0067] 22 , the voice input unit (voice input unit 81) according to this embodiment includes a mesh portion 65 and a flow path dividing portion (flow path dividing portion 77). The mesh portion 65 and the flow path dividing portion 77 are integrally formed by, for example, a composite member 75.

[0068] Fig. 23A is a half cross-sectional view showing an example configuration of the composite member 75. Fig. 23B is a diagram for explaining the function of the composite member 75. The composite member 75 is, for example, a hollow columnar body whose top surface 75A and bottom surface 75B are track-shaped. A circular or elliptical hole 75C is formed in the bottom surface 75B of the composite member 75, and this hole 75C communicates with the internal space SP of the volume expansion section 31D.

[0069] A mesh portion 65 having a plurality of holes is provided near the center of an upper surface 75A of a composite member 75. Separate grooves 77A and 77B are formed around the periphery of the mesh portion 65. The grooves 77A and 77B form a flow path dividing portion 77 according to this example. The grooves 77A and 77B are connected at a bottom surface 75B.

[0070] The action of the composite member 75 will be described with reference to Figure 23B. The composite member 75 arranges a path for the wind to head toward the mesh portion 65 and a path for the wind to head toward the flow path dividing portion 77. As described above, the mesh portion 65 acts to reduce the generation of vortices in the wind that enters through the opening 55 of the opening member 31E. Furthermore, the winds that enter the groove portions 77A and 77B collide with each other at the bottom surface 75B and cancel each other out, thereby reducing the generation of vortices. Because the generation of vortices can be reduced, the sound pressure of wind noise caused by vortices can be effectively reduced.

[0071] <Modifications> Although the embodiments of the present disclosure have been specifically described above, the contents of the present disclosure are not limited to the above-described embodiments, and various modifications based on the technical ideas of the present disclosure are possible.

[0072] [Variation 1] FIG. 24 illustrates a variation of the flow path dividing section. The flow path dividing section according to this variation includes a structure 91 that generates Helmholtz resonance in a location that serves as an airflow path. The structure 91 is a tubular member having an overall tubular shape with both ends open, and is made of resin or metal. Specifically, the structure 91 includes a tubular section 91A and multiple closed spaces 91B formed on the inner surface of the tubular section 91A. The number and shape of the closed spaces 91B are not limited to the illustrated example and can be modified as appropriate. The air that enters the structure 91 is divided into a component that passes through the tubular section 91A and a component that enters the closed spaces 91B. This disperses the wind energy, reduces the generation of vortices, and reduces the sound pressure of wind noise caused by vortices. In particular, the sound pressure of wind noise can be effectively reduced at the resonant frequency of the structure 91. Designing the resonant frequency of the structure 91 to be 500 Hz, the dominant component of wind noise, can effectively reduce the sound pressure of wind noise.

[0073] [Variation 2] Figure 25 shows another variation of the flow path dividing section. The flow path dividing section 92 according to this variation is a ring-shaped member made of resin or metal. Although not shown, the flow path dividing section 92 has a spiral groove starting from an inlet formed at a predetermined location on the upper side. An outlet for the groove is formed on the lower side of the flow path dividing section 92. As shown by the arrows in Figure 25, the wind component entering through the opening 55 of the opening member 31E is divided into a wind component WA that passes through the hole 92A inside the flow path dividing section 92 and a wind component WB that passes through the groove. The path lengths of the flow path through which the wind component WA passes and the flow path through which the wind component WB passes are different; specifically, the latter path length is longer. The wind components WA and WB collide and cancel each other out near the outlet of the groove, suppressing the generation of vortices. This reduces the sound pressure of wind noise caused by vortices.

[0074] The imaging device according to the present disclosure may have a configuration optimized for a wind speed so as to effectively reduce wind noise at a predetermined wind speed. One example of such a configuration is a mechanism (hereinafter also referred to as a wind speed control mechanism) that controls the wind speed of wind noise entering the internal space SP of the volume expansion section 31D.

[0075] An example of a wind speed control mechanism is shown in FIGS. 26A to 26D . The wind speed control mechanism is, for example, a throttle mechanism 93 having a hole 93A in the center and capable of varying the size of the hole 93A. FIG. 26A shows a state in which the size of the hole 93A is minimized, and FIG. 26B shows a state in which the hole 93A is opened to a slightly larger size from the state shown in FIG. 26A . FIG. 26C shows a state in which the hole 93A is opened to a further larger size from the state shown in FIG. 26B . FIG. 26D shows a state in which the hole 93A is opened to its largest size. The operation of the throttle mechanism 93 is controlled, for example, by the control unit 41, and the size of the hole 93A changes in accordance with this control. For example, when the wind speed of the invading wind is low, the size of the hole 93A is controlled to be small, and when the wind speed of the invading wind is high, the size of the hole 93A is controlled to be large. This allows the wind speed of the invading wind to be kept substantially constant, effectively reducing the sound pressure of wind noise.

[0076] [Variation 4] In the above-described embodiments, the mesh structure of the opening member 62 and the mesh structure of the mesh portion 65 do not necessarily have to be a solid structure with holes. For example, as shown in FIG. 27A, they may be fibrous (mesh-like), or as shown in FIG. 27B, they may be powder (indicated by circles in FIG. 27B) solidified to the extent that some space is created. They may also contain a porous foam such as a wind jammer (fur) or melamine sponge. This breaks down the wind W as shown by the thin arrows, thereby reducing the generation of vortices. This reduces the sound pressure of wind noise caused by vortices.

[0077] [Other Modifications] The position where the audio input unit is formed on the housing of the imaging device is not limited to the side surface of the protrusion. In addition, the present disclosure can also be applied to imaging devices that do not have a protrusion (imaging devices also known as compact digital cameras, etc.) and various electronic devices such as smartphones.

[0078] The present disclosure may also adopt the following configurations. (1) An imaging device comprising: a housing having an opening communicating with the inside and outside; and a microphone disposed in an internal space communicating with the opening; wherein a value obtained by dividing the volume of the internal space from the opening to the microphone by the area of ​​the opening is 3 or more. (2) The imaging device described in (1), wherein the housing has a convex portion for accommodating a pentatrhythm, and the opening is formed in the convex portion. (3) The imaging device described in (2), wherein the opening is formed on each side surface of the convex portion, and the microphones include a microphone disposed in the internal space communicating with one of the openings and a microphone disposed in the internal space communicating with the other opening. (4) The imaging device described in any of (1) to (3), wherein the opening has a track shape. (5) The imaging device described in any of (1) to (3), wherein the opening has a mesh shape with a plurality of holes. (6) The imaging device according to any one of (1) to (5), wherein a mesh portion having a plurality of holes is arranged between the opening and the microphone. (7) The imaging device according to (6), wherein a plurality of mesh portions are arranged. (8) The imaging device according to (7), wherein the plurality of mesh portions are stacked such that at least a portion of the holes of each of the mesh portions are located at different positions in the stacking direction. (9) The imaging device according to any one of (1) to (8), wherein a flow path dividing portion that divides the flow path of air from the opening toward the microphone from the opening into at least two directions is arranged between the opening and the microphone. (10) The imaging device according to any one of (1) to (5), wherein a mesh portion having a plurality of holes and a flow path dividing portion that divides the flow path of air from the opening toward the microphone from the opening into at least two directions are arranged from the opening toward the microphone. (11) The imaging device according to (10), wherein a path leading to the mesh portion and a path leading to the flow path dividing portion are arranged in a direction substantially perpendicular to a direction from the opening toward the microphone.(12) The imaging device according to any one of (1) to (11), further comprising a control mechanism for controlling a flow rate of air flowing into the housing through the opening. (13) The imaging device according to (9), wherein the air flow paths divided by the flow path dividing section have different path lengths. (14) The imaging device according to (9), wherein the flow path dividing section is configured by a tubular member having a plurality of closed spaces formed on its inner surface.

[0079] REFERENCE SIGNS LIST 100: Imaging device 10: Housing 14: Convex portion 31: Audio input portion 31D: Volume expansion portion 31E: Opening member 46: Microphone 55: Opening 62: Opening member 62A: Hole portion 65: Mesh portion 73: Flow path dividing portion

Claims

1. An imaging device comprising: a housing having an opening communicating with the inside and outside; and a microphone disposed in an internal space communicating with said opening, wherein the volume of the internal space from said opening to said microphone divided by the area of ​​said opening is 3 or greater.

2. The imaging device according to claim 1, wherein the housing has a protruding portion in which a pentagon is housed, and the opening is formed in the protruding portion.

3. The imaging device of claim 2, wherein the openings are formed on each of the side surfaces of the convex portion, and the microphones include a microphone disposed in an internal space communicating with one of the openings, and a microphone disposed in an internal space communicating with the other of the openings.

4. The imaging device according to claim 1, wherein the opening has a track shape.

5. The imaging device according to claim 1, wherein the opening has a mesh shape having a plurality of holes.

6. The imaging device according to claim 1, wherein a mesh portion having a plurality of holes is disposed between the opening and the microphone.

7. The imaging device according to claim 6, wherein a plurality of mesh portions are arranged.

8. The imaging device according to claim 7, wherein the plurality of mesh portions are stacked such that at least some of the holes in each of the mesh portions are located at different positions in the stacking direction.

9. The imaging device according to claim 1, wherein a flow path dividing section is disposed between the opening and the microphone, the flow path dividing the air flowing from the opening to the microphone into at least two directions.

10. The imaging device according to claim 1, further comprising: a mesh section having a plurality of holes arranged from the opening toward the microphone; and a flow path dividing section that divides the air flow path from the opening toward the microphone into at least two directions.

11. The imaging device according to claim 10, wherein a path passing through the mesh portion and a path passing through the flow path dividing portion are arranged in a direction substantially perpendicular to a direction from the opening toward the microphone.

12. The imaging device according to claim 1, further comprising a control mechanism for controlling a flow rate of air flowing into the housing through the opening.

13. The imaging device according to claim 9, wherein the air flow paths divided by the flow path dividing section have different path lengths.

14. The imaging device according to claim 9, wherein the flow path dividing section is constituted by a tubular member having a plurality of closed spaces formed on its inner surface.

Images