JP2017195558A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of selecting one of an imaging mode that gives priority to a shake correction function to a sound collection function and an imaging mode that gives priority to the sound collection function to the shake correction function during imaging.SOLUTION: The imaging apparatus includes an optical system including a lens, an imaging part for capturing a subject image through the optical system, a shake correction part for correcting shakes during imaging, a sound collecting part for collecting sounds, and a control part for controlling the optical system, the imaging part, the shake correcting part and the sound collecting part. The control part selects and executes one of a first mode and a second mode as an imaging mode. When the control part selects the first mode, the control part controls to degrade qualities of sounds collected by the sound collecting part than in the second mode; and when the control part selects the second mode, the control part controls to degrade the shake correction function by the shake correcting part than the first mode.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to an imaging apparatus having a camera shake correction function and a sound collection function.

  Patent Document 1 discloses an arrangement of an image pickup unit that captures a moving image, a camera shake correction unit that corrects camera shake at the time of moving image capture, and an audio signal collected by a plurality of microphones and a plurality of microphones at the time of moving image capture. A sound source position detecting unit for detecting a sound source position on the moving image based on the information, and a display position for correcting the display position of the sound source position detected on the moving image according to the camera shake correction amount corrected by the camera shake correcting unit. Disclosed is an imaging apparatus including a correction unit and a display processing unit that displays a moving image corrected by a camera shake correction unit on a moving image while displaying a sound source position corrected by a display position correction unit on a moving image. .

JP2013-141090A

  The present disclosure provides an imaging apparatus that can select and shoot either a shooting mode that prioritizes a camera shake correction function over a sound collection function or a shooting mode that prioritizes a sound collection function over a camera shake correction function. .

  An imaging apparatus of the present disclosure includes an optical system including a lens, an imaging unit that captures a subject image via the optical system, a camera shake correction unit that corrects camera shake at the time of imaging, a sound collection unit that collects sound, An optical system, an imaging unit, a camera shake correction unit, and a control unit that controls the sound collection unit. The control unit selects and executes either the first mode or the second mode as the shooting mode, and when the first mode is selected, the quality of the sound collected by the sound collection unit than in the second mode. When the second mode is selected, the camera shake correction function by the camera shake correction unit is controlled to be lower than that in the first mode.

  According to the imaging device of the present disclosure, it is possible to select and shoot either a shooting mode in which the camera shake correction function is given priority over the sound pickup function or a shooting mode in which the sound pickup function is given priority over the camera shake correction function. It is possible to perform photographing according to the user's request.

1 is a front perspective view of a digital camera according to Embodiment 1. FIG. Rear view of the digital camera according to Embodiment 1 1 is a block diagram showing an electrical configuration of a digital camera according to Embodiment 1. FIG. 8 is a flowchart showing a flow of operation for selecting frequency filter processing of an audio signal of the digital camera according to the first embodiment. The figure which shows the example of the directivity synthetic | combination process of the audio | voice signal of the digital camera which concerns on Embodiment 1. FIG. 8 is a flowchart showing a flow of operations for selecting directivity synthesis processing of audio signals of the digital camera according to the first embodiment. The figure which shows the example of the gain filter process of the audio | voice signal of the digital camera which concerns on Embodiment 1. FIG. 8 is a flowchart showing a flow of operations for selecting gain filter processing of an audio signal of the digital camera according to the first embodiment.

  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, detailed descriptions of already well-known matters and repeated descriptions for 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 accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[Embodiment 1]
Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS. In the following description, the direction toward the subject is “front”, the direction opposite to the subject is “rear”, the vertical upper direction is “upward”, based on an imaging device in a normal posture (hereinafter also referred to as landscape orientation). The vertically downward direction is expressed as “downward”, the right direction when facing the subject as “right”, and the left direction when facing the subject as “right”.

[1. Constitution〕
FIG. 1 is a front perspective view of a digital camera 100 according to the first embodiment. The digital camera 100 includes a digital camera body 102 and an interchangeable lens 301. Further, the digital camera 100 includes an operation unit 180 such as a release button 181, a power switch 183, and a mode dial 184 on the upper surface.

  The digital camera 100 also includes a microphone unit 111 on the top surface. The microphone unit 111 includes two microphones, a microphone 111L and a microphone 111R. Among these, the microphone 111 </ b> L and the microphone 111 </ b> R are positioned side by side in the left-right direction on the upper surface of the digital camera body 102. Further, the digital camera 100 includes an HDMI (registered trademark) output terminal 105 on a side surface thereof.

  FIG. 2 is a rear view of the digital camera 100 according to the first embodiment. The digital camera 100 includes operation units 180 such as a center button 185 and a cross button 186 on the back surface thereof. The digital camera 100 also includes a display unit 190 and a viewfinder 191 on the back surface.

  FIG. 3 is a block diagram showing an electrical configuration of the digital camera 100 according to the first embodiment. The digital camera 100 includes a digital camera body 102 and an interchangeable lens 301. The digital camera body 102 includes a CCD image sensor 143, an AFE (analog front end) 144, an audio input system 110, a digital image / audio processing unit 120, a controller 130, a BIS processing system 149, a RAM 150, an external storage medium 160, and a ROM 170. , An operation unit 180, a display unit 190, a viewfinder 191, a body mount 340, and an HDMI output terminal 105.

  The digital camera 100 generates image information and an audio signal from information obtained from the outside. The image information is generated by the image input system 140. The audio signal is generated by the audio input system 110. The generated image information and audio signal are A / D converted, processed by the digital image / audio processing unit 120, and then recorded on an external storage medium 160 such as a memory card. The generated image information and audio signal are A / D converted, each processed by the digital image / audio processing unit 120, and then output from the HDMI output terminal 105. The image information recorded in the external storage medium 160 is displayed on the display unit 190 and / or the viewfinder 191 in response to an operation of the operation unit 180 by the user. Image information and audio signals recorded in the external storage medium 160 are output from the HDMI output terminal 105.

  The details of each unit shown in FIGS. 1 to 3 will be described below.

  The image input system 140 includes an interchangeable lens 301, a CCD image sensor 143, and an AFE 144, and the CCD image sensor 143 and AFE 144 are provided in the digital camera body 102.

  The digital camera body 102 includes a BIS processing system 149 as a configuration for realizing a BIS function (a function for correcting camera shake by shifting the CCD image sensor 143). The BIS processing system 149 further includes a gyro sensor 148 that detects shake of the digital camera body 102, and a BIS processing unit 147 that controls generation of a shake correction signal and shake correction processing based on the detection result of the gyro sensor 148. Furthermore, the digital camera body 102 includes a CCD drive unit 145 that moves the CCD image sensor 143 and a position sensor 146 that detects the position of the CCD image sensor 143. The CCD drive unit 145 can be realized by a magnet and a flat coil, for example. The position sensor 146 is a sensor that detects the position of the CCD image sensor 143 in a plane perpendicular to the optical axis of the optical system. The position sensor 146 can be realized by a magnet and a Hall element, for example. The BIS processing unit 147 controls the CCD driving unit 145 on the basis of the signal from the gyro sensor 148 and the signal from the position sensor 146, and uses the CCD image sensor 143 as an optical axis so as to cancel the shake of the digital camera body 102. Shift in a vertical plane. Here, the image sensor provided in the digital camera body 102 is a CCD image sensor, but another image sensor such as a CMOS image sensor may be used. The CCD driving unit 145 may use other actuators such as a stepping motor and an ultrasonic motor. When a stepping motor is used as the actuator, open control can be performed, and accordingly, a position sensor can be dispensed with. When the position of the CCD image sensor 143 is shifted by the BIS processing system 149, the generated sound and vibration increase when the movement is fast or large. Further, the flatter the frequency characteristics of the motion (frequency response of the BIS function with respect to hand vibration), the larger the generated sound and vibration.

  The interchangeable lens 301 is an optical system having a plurality of lenses. The interchangeable lens 301 includes an optical system including a lens controller 320, a lens mount 330, a focus lens 310, an OIS lens 318, and a zoom lens 312, a focus lens driving unit 311, a zoom lens driving unit 313, an aperture 316, an aperture driving unit 317, and an operation. A ring 315, an OIS control unit 319, a DRAM 321, a flash memory 322, and the like are provided.

  The lens controller 320 controls the entire interchangeable lens 301. The lens controller 320 can control the zoom lens driving unit 313 so as to drive the zoom lens 312 in response to an operation by the user of the operation ring 315. The lens controller 320 can control the focus lens driving unit 311 to drive the focus lens 310. The lens controller 320 can control the OIS control unit 319 to drive the OIS lens 318. The lens controller 320 can control the aperture driving unit 317 to drive the aperture 316.

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

  The lens mount 330 is a connection member for mechanically and electrically connecting the interchangeable lens 301 and the digital camera body 102 together with the body mount 340 included in the digital camera body 102. When the interchangeable lens 301 and the digital camera body 102 are mechanically and electrically connected, the lens controller 320 and the controller 130 can communicate with each other.

  The DRAM 321 is used as a work memory for various controls by the lens controller 320. The flash memory 322 stores programs, parameters, lens data, and the like used for various controls by the lens controller 320.

  The focus lens 310 is a lens that changes the focus state of a subject image that is incident on the optical system of the interchangeable lens 301 and formed on the CCD image sensor 143. The lens configuration of the focus lens 310 may be any number or any number of groups. The focus lens driving unit 311 drives the focus lens 310 so as to advance and retract along the optical axis of the optical system based on a control signal notified from the lens controller 320. The focus lens driving unit 311 can be realized by, for example, a stepping motor, a DC motor, an ultrasonic motor, or the like.

  The zoom lens 312 is a lens for changing the magnification of a subject image formed by the optical system of the interchangeable lens 301. The lens configuration of the zoom lens 312 may be any number or group. The zoom lens driving unit 313 drives the zoom lens 312 so as to advance and retreat along the optical axis of the optical system based on a control signal notified from the lens controller 320. The zoom lens driving unit 313 can be realized by, for example, a stepping motor, a DC motor, an ultrasonic motor, or the like. The OIS lens 318 is a lens for correcting blurring of a subject image formed by the optical system of the interchangeable lens 301. Specifically, the OIS lens 318 corrects the blur of the subject image caused by the blur of the digital camera 100. The OIS lens 318 moves in a direction that cancels out the shake of the digital camera 100, thereby reducing the relative shake between the CCD image sensor 143 and the subject image. Specifically, the OIS lens 318 moves in a direction that cancels out the blur of the digital camera 100, thereby reducing the blur of the subject image on the CCD image sensor 143. The OIS lens 318 is composed of one or a plurality of lenses. The OIS control unit 319 drives the OIS lens 318 in a plane perpendicular to the optical axis of the optical system.

  The diaphragm 316 is configured to be able to open and close a plurality of mechanical blades. The diaphragm 316 is an adjustment member that can adjust the amount of light incident on the optical system of the interchangeable lens 301. The aperture driving unit 317 drives to change the open / close state of the mechanical blades of the aperture 316 based on the control signal notified from the lens controller 320. The aperture driving unit 317 can be realized by, for example, a stepping motor, a DC motor, an ultrasonic motor, or the like.

  The operation ring 315 is an operation member provided on the outer surface of the interchangeable lens 301. The operation ring 315 is configured to rotate relative to the interchangeable lens 301. The rotation position and rotation speed of the operation ring 315 are detected by a detection unit (not shown) and notified to the lens controller 320. The lens controller 320 can supply a drive control signal to the drive unit of the zoom lens 312 based on the notified rotation position and rotation speed of the operation ring 315. The lens controller 320 supplies a drive control signal to the zoom lens driving unit 313 so as to drive the zoom lens 312 by operating the operation ring 315.

  The body mount 340 is a connecting member for mechanically and electrically connecting the interchangeable lens 301 and the digital camera body 102 together with the lens mount 330 included in the interchangeable lens 301. When the interchangeable lens 301 and the digital camera body 102 are mechanically and electrically connected, the lens controller 320 and the controller 130 can communicate with each other. The body mount 340 notifies the lens controller 320 of the exposure synchronization signal and other control signals received from the controller 130 via the lens mount 330. The body mount 340 notifies the controller 130 of a signal received from the lens controller 320 via the lens mount 330.

  The CCD image sensor 143 captures a subject image formed through the interchangeable lens 301 and generates image information. On the light receiving surface of the CCD image sensor 143, a large number of photodiodes are arranged two-dimensionally (in a matrix). In addition, R (red), G (green), or B (blue) primary color filters are arranged corresponding to each photodiode. The primary color filters for R, G, and B are arranged in a predetermined arrangement structure. The light from the subject to be imaged passes through the interchangeable lens 301 and then forms an image on the light receiving surface of the CCD image sensor 143. The formed subject image is converted into color information classified into R, G, or B according to the amount of light incident on each photodiode. As a result, image information indicating the entire subject image is generated. Each photodiode corresponds to a pixel of the CCD image sensor 143. However, the color information actually output from each photodiode is R, G, or B primary color information. Therefore, the color to be expressed in each pixel is the primary color information (color, light amount) output from the photodiode corresponding to each pixel and the surrounding photodiode in the digital image / sound processing unit 120 in the subsequent stage. Generated based on The CCD image sensor 143 can generate image information of a new frame at regular intervals when the digital camera 100 is in the shooting mode.

  In the AFE 144, noise suppression by correlated double sampling for the image information read from the CCD image sensor 143, amplification to the input range width of the A / D converter by an analog gain controller, and A / D conversion by the A / D converter Is given. Thereafter, the AFE 144 outputs the image information to the digital image / sound processor 120.

  The audio input system 110 includes a microphone unit 111 and an analog audio processing unit 115. The microphone unit 111 includes microphones 111L and 111R. The microphone unit 111 converts an acoustic signal into an electrical signal by each microphone and inputs the electrical signal to the analog sound processing unit 115. The analog audio processing unit 115 performs A / D conversion on the processed audio signal by an A / D converter, and outputs it to the digital image / audio processing unit 120.

  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 / sound 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.

  The digital image / sound processor 120 performs a filtering process and a directivity synthesis process by performing an arithmetic process on the sound signal that is the output of the microphone unit 111. A detailed description of the sound signal filtering and directivity synthesis processing will be given later.

  The display unit 190 is disposed on the back surface of the digital camera 100. In the present embodiment, display unit 190 is a liquid crystal display. The display unit 190 displays an image based on the image information processed by the digital image / sound processing unit 120. The images displayed by the display unit 190 include a through image, a reproduction image, a control selection screen, a warning screen, and a power end screen. A through image is an image of a frame that is continuously generated by the CCD image sensor 143 at regular intervals. Normally, when the digital camera 100 is set to the shooting mode and is in a standby state where still image shooting is not performed or a moving image shooting state, the digital image / audio processing unit 120 generates the CCD image sensor 143. A through image is generated from the image information. The user can photograph the subject while confirming the composition of the subject by referring to the through image displayed on the display unit 190. The playback image is generated by the digital image / audio processing unit 120 when the digital camera 100 is in the playback mode. The reproduced image is an image obtained by reducing a high-pixel recorded image recorded in the external storage medium 160 or the like to a low pixel in accordance with the size of the display unit 190. The high-pixel image information recorded in the external storage medium 160 is received by the digital image / audio processing unit 120 based on the image information generated by the CCD image sensor 143 after the release button 181 receives a predetermined operation by the user. Generated. The control selection screen includes a menu screen for the user to select and determine various settings. Among various settings that can be selected and determined on the menu screen, there is a BIS control mode selection for selecting a control mode of the BIS processing system 149. Details of the BIS control mode selection will be described later. The menu screen is displayed, for example, when the user operates the operation unit 180 during through image display. A mode in which a still image or a movie is being shot is called a shooting mode. A mode in which the display unit displays a through image when a still image or a moving image is not being captured is referred to as a live mode. A mode in which the display unit 190 displays a playback image is referred to as a playback mode. A mode in which the display unit 190 displays the menu screen is called a menu mode. The display content displayed by the display unit 190 can also be displayed by the viewfinder 191.

  The controller 130 controls the overall operation of the digital camera 100.

  The ROM 170 is a program for performing overall control of the entire operation of the digital camera 100 in addition to programs related to auto focus control (AF control), automatic exposure control (AE control), strobe light emission control, etc., which are executed by the controller 130. Is stored. The ROM 170 stores various conditions and settings regarding the digital camera 100. In the present embodiment, the ROM 170 is a flash ROM.

  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. The ROM 170 does not need to exist outside the controller 130 (as a separate body from the controller 130), and may be incorporated in the controller 130.

  The RAM 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 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 an external memory having a nonvolatile recording unit such as a flash memory. The external storage medium 160 can record data such as image information and audio signals processed by the digital image / audio processing unit 120.

  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 release button 181, the power switch 183, the mode dial 184, the center button 185 and the cross button 186 shown in FIGS. 1 and 2 correspond to this. When receiving an operation by the user, the operation unit 180 notifies the controller 130 of signals for instructing various operations.

  The release button 181 is a push-down button that transitions into two stages, a half-pressed state and a fully-pressed state. When the release button 181 is half-pressed by the user, the controller 130 executes AF (Auto Focus) control and / or AE (Auto Exposure) control, etc., and determines the photographing condition. In the AF control, the digital image / sound processing unit 120 calculates a contrast value in a predetermined area of the image information, and based on this, the controller 130 drives the interchangeable lens 301 to perform feedback control so that the contrast value is maximized. Do. As a result of the AF control, the controller 130 can obtain the focal distance to the subject to be AF controlled. As a result of the AF control, the interchangeable lens 301 can form a subject image to be controlled by the AF on the CCD image sensor 143. Subsequently, when the release button 181 is fully pressed by the user, the controller 130 records image information captured at the timing of the full press in the external storage medium 160 or the like.

  The power switch 183 is a slide switch for turning on / off the power supply to each part of the digital camera 100. When the power switch 183 is slid to the right by the user when the power is OFF, the controller 130 supplies power to each part of the digital camera 100 and activates each part. When the power switch 183 is slid leftward by the user when the power is turned on, the controller 130 stops the power supply to each part of the digital camera 100.

  The mode dial 184 is a rotary dial. When the mode dial 184 is rotated by the user, the controller 130 switches the operation mode of the digital camera 100 to an operation mode corresponding to the current rotation position of the mode dial 184. The operation mode is, for example, an auto shooting mode, a manual shooting mode, a scene selection mode, or the like. Note that the auto shooting mode, manual shooting mode, and scene selection mode are collectively referred to as a shooting mode.

  The center button 185 is a push button. When the center button 185 is pressed by the user when the digital camera 100 is in the shooting mode or the playback mode, the controller 130 displays a menu screen on the display unit 190. The menu screen is a screen for allowing the user to set various shooting conditions and playback conditions. When the center button 185 is pressed while the setting item value of various conditions is selected by the user on the menu screen, the setting item is determined to be that value. The determined setting is stored in the ROM 170.

  The cross button 186 includes four push buttons provided in the vertical and horizontal directions. The user can select values of setting items for various conditions displayed on the menu screen by pressing a button in any direction of the cross button 186.

[2. BIS control mode selection)
When shooting in an environment where the shake of the digital camera body 102 is large, such as in a moving train or in a situation where the camera is not fixed with a tripod, the BIS processing system is used so that the shake does not significantly affect the shot image. It is desirable that the movement of the position shift of the CCD image sensor 143 by 149 is as fast as necessary and as large as necessary. Further, it is desirable that the frequency characteristic of the movement is flat. Thus, the BIS control mode that maximizes the BIS function is called a “BIS priority mode”.

  When shooting a moving image, there is a risk that vibrations and sounds generated when the position of the CCD image sensor 143 is shifted by the BIS processing system 149 may be recorded. Therefore, when shooting in a quiet environment where there is almost no camera shake, such as in a concert hall where the ambient noise is low, or when the vibration is fixed with a tripod and the vibration is negligible. The movement of the position shift of the CCD image sensor 143 by the BIS processing system 149 is preferably slow and small. Further, it is desirable that the frequency characteristic of the movement is such that the generated sound and vibration are smaller than flat. As described above, the BIS control mode giving priority to the moving image audio quality is referred to as an “audio priority mode” so that vibrations and sounds due to the BIS control are not greatly recorded in the moving image. In the voice priority mode, the movement of the position shift of the CCD image sensor 143 by the BIS processing system 149 is slower and smaller than in the BIS priority mode. For this reason, in the audio priority mode, there is a possibility that it is likely to be affected by camera shake in exchange for the improvement of the moving image audio quality.

  The user can operate the operation unit 180 to select the BIS priority mode or the voice priority mode for the BIS control mode and shoot a moving image.

  When the user selects the voice priority mode, the BIS processing unit 147 controls the CCD driving unit 145 so that the movement of the position shift of the CCD image sensor 143 is slower than when the BIS priority mode is selected. As a result, the camera shake correction function is lower in the voice priority mode than in the BIS priority mode.

  On the other hand, when the user selects the BIS priority mode, the BIS processing unit 147 controls the CCD driving unit 145 so that the movement of the position shift of the CCD image sensor 143 is faster than when the voice priority mode is selected. Thereby, in the BIS priority mode, the camera shake correction function is improved as compared with the voice priority mode.

  As described above, a moving image file shot in the BIS priority mode has a large vibration and sound due to BIS control at the time of shooting, as described above. As described above, a moving image file shot in the audio priority mode has relatively low vibration and sound due to BIS control at the time of shooting as described above. Therefore, it is unlikely that the sound or vibration will be harsh as reproduced sound. .

[3. Operation)
Next, an outline of the operation of the digital camera 100 in the present embodiment will be described.

  FIG. 4 is a flowchart showing a flow of operations for selecting the frequency filter processing of the audio signal of the digital camera 100 according to the first embodiment. The digital image / sound processor 120 performs frequency processing by performing arithmetic processing on the sound signal that is output from the microphone unit 111. In general, it is known that the frequency characteristic of sound is a frequency characteristic in which the frequency filter processing is flat and faithful to the original sound, so that it is desirable for high sound quality. Therefore, when the user operates the operation unit 180 to select the audio priority mode and shoots a moving image, the frequency filter processing applied to the audio signal by the digital image / audio processing unit 120 is a flat frequency characteristic that is nearly flat. It is desirable that On the other hand, it is conventionally known to use a band limiting filter for the purpose of improving the S / N ratio of an audio signal. When the user operates the operation unit 180 to select the BIS priority mode and shoots a moving image, as described above, the vibration and sound generated by the BIS control are large. It ’s not a noise but a noise. It is desirable to suppress the noise caused by these BIS drives. Therefore, when the user operates the operation unit 180 to select the BIS priority mode and shoots a moving image, the digital image / audio processing unit 120 is used for the purpose of suppressing noise caused by BIS driving recorded in the moving image file. It is desirable that the frequency filter processing applied to the audio signal uses a band limiting filter having a convex frequency characteristic in which the high sound range and the low sound range are lowered.

  An operation flow of the frequency filter processing selection of the audio signal of the digital camera 100 will be described with reference to FIG. If the user selects the BIS priority mode by operating the operation unit 180 of the digital camera 100 in step S401 for selecting the frequency filter processing of the audio signal, the process proceeds to step S402. In step S401, when the user operates the operation unit 180 of the digital camera 100 and does not select the BIS priority mode (when the voice priority mode is selected), the process proceeds to step S403. In step S402, the controller 130 controls the digital image / audio processing unit 120 so that the frequency filter processing applied to the audio signal has a convex frequency characteristic in which the high frequency range and the low frequency range are lowered, and the process proceeds to step S404. Transition. In step S403, the controller 130 controls the digital image / sound processing unit 120 so that the frequency filter process applied to the sound signal has a flat frequency characteristic that is almost flat, and the process proceeds to step S404. In step S404, when the user operates the operation unit 180 of the digital camera 100 to start shooting a moving image, the selection of the frequency filter processing of the audio signal is ended. Otherwise, the process proceeds to step S401.

  Thus, when moving image shooting is performed with the BIS priority mode selected, the frequency filter processing applied to the audio signal has a convex frequency characteristic in which the high sound range and the low sound range are lowered. For this reason, even when the audio signal of the moving image to be recorded includes noise due to BIS driving, the driving noise can be suppressed to be small, and the target sound of the audio signal can be easily heard.

  Next, directivity synthesis processing will be described. The digital image / sound processing unit 120 performs a directivity synthesis process by performing arithmetic processing on the sound signal that is the output of the microphone unit 111.

  In general, a microphone built in a digital camera itself has no directivity. The lack of directivity is called “omni-directional”.

  In general, when two microphones arranged on the left and right are used for recording, a recording method of an audio signal in moving image recording is a stereo method having two channels of a left channel (Lch) and a right channel (Rch). In general, for the purpose of obtaining a sound with a rich sense of presence, a signal having directivity on the left is Lch, and a signal having directivity on the right is Rch. In this way, during playback, the sound coming from the left side can be heard greatly from the left channel, and the sound coming from the right side can be heard from the right channel greatly, so that a sound with a rich sense of reality can be heard. Such processing for controlling directivity is called stereo processing. On the other hand, processing for controlling directivity so that Lch and Rch are the same signal is called monaural processing. The monaural processing has a low presence, but has an effect of making it easy to hear the target sound (increasing the S / N ratio), as will be described later.

  FIG. 5 is a diagram illustrating an example of the directivity synthesis processing of the audio signal of the digital camera 100 according to the first embodiment.

  FIG. 5A is a diagram showing a directivity synthesis process for obtaining an Lch output. The sound wave coming from the right side of the digital camera 100 first reaches the right microphone 111R, and then reaches the left microphone 111L after time τ1. Assuming that the distance between the microphone 111R and the microphone 111L is d and the velocity of the sound wave is c, τ1 can be expressed as in Expression (1).

τ1 = d / c (1)
First, stereo processing will be described.

  When the output of the right microphone 111R is delayed by τ1, and this result is subtracted from the output of the left microphone 111L, the output for the sound wave coming from the right side is canceled. The delay device 601 gives a delay of time τ1 to the output of the microphone 111R. Multiplier 602 multiplies the output of delay unit 601 by minus 1 (−1). That is, the multiplier 602 inverts the output. The adder 603 adds the output of the multiplier 602 to the output of the microphone 111L and outputs the result. That is, the output of the adder 603 is equal to the output of the delay unit 601 subtracted from the output of the microphone 111L. Multiplier 604 multiplies the output of adder 603 by 1 to obtain an Lch output. Through the above processing, an output for Lch having low sensitivity to sound waves coming from the right side can be obtained. Such directivity having extremely low sensitivity to sound waves from a certain direction is called “unidirectional”.

  FIG. 5B is a diagram showing directivity synthesis processing for obtaining an output for Rch. The processing is the same as in FIG. 5A except that the left and right are reversed. That is, the delay device 605 gives a delay of time τ1 to the output of the microphone 111L. The multiplier 606 multiplies the output of the delay unit 605 by minus 1 (−1). That is, the multiplier 606 inverts the output. The adder 607 adds the output of the multiplier 606 to the output of the microphone 111R and outputs the result. That is, the output of the adder 607 is equal to the output of the microphone 111R minus the output of the delay unit 605. Multiplier 608 multiplies the output of adder 607 by 1 to obtain an Rch output. Through the above processing, an output for Rch having low sensitivity to the sound wave coming from the left can be obtained.

  Since the Lch and Rch outputs obtained by stereo processing have directivity on the left and right sides as described above, it is possible to obtain a sound with a rich sense of realism. However, on the other hand, since the signal is subtracted by the adder 603 and the adder 607, the S / N ratio becomes small and it may be difficult to hear the target sound.

  Next, monaural processing will be described.

  In FIG. 5A, the delay device 601 gives a delay of time zero to the microphone 111R. That is, the delay device 601 does not delay. Multiplier 602 multiplies the output of delayer 601 by plus 1 (+1). That is, the multiplier 602 does not change the output. The adder 603 adds the output of the multiplier 602 to the output of the microphone 111L and outputs the result. That is, the output of the adder 603 is equal to the sum of the output of the microphone 111L and the output of the microphone 111R. Multiplier 604 multiplies the output of adder 603 by 0.5 to obtain an output for Lch. That is, the Lch output obtained here is an average value of the output of the microphone 111L and the output of the microphone 111R.

  In FIG. 5B, the delay device 605 gives a delay of time zero to the microphone 111L. That is, the delay unit 605 does not delay. Multiplier 606 multiplies the output of delay unit 605 by 1 (+1). That is, the multiplier 606 does not change the output. The adder 607 adds the output of the multiplier 606 to the output of the microphone 111R and outputs the result. That is, the output of the adder 607 is equal to the sum of the output of the microphone 111L and the output of the microphone 111R. Multiplier 608 multiplies the output of adder 607 by 0.5 to obtain an Rch output. That is, the Rch output obtained here is an average value of the output of the microphone 111L and the output of the microphone 111R.

  Thus, as described above, the outputs for Lch and Rch obtained by monaural processing are both average values of the output of the microphone 111L and the output of the microphone 111R. As a result, since there is no directivity on the left or right, the presence is low. However, on the other hand, since the respective signals are added by the adder 603 and the adder 607, there is an effect that the S / N ratio is increased and the target sound can be easily heard. Also, the directivity of the output for Lch and Rch obtained by monaural processing is very close to omnidirectionality. That is, the difference between stereo processing and monaural processing can be said to be a difference between unidirectionality and omnidirectionality. In FIG. 5A, the directivity between unidirectionality and omnidirectionality is changed by changing the delay amount of the delay device 601 or changing the value that the multiplier 602 multiplies the signal. You can also get it.

  FIG. 6 is a flowchart showing a flow of operations for selecting directivity synthesis processing of audio signals of the digital camera 100 according to the first embodiment. As shown in FIG. 6, when the user operates the operation unit 180 of the digital camera 100 and selects the BIS priority mode in step S501 of the sound signal directivity synthesis processing selection, the process proceeds to step S502. In step S501, when the user does not select the BIS priority mode by operating the operation unit 180 of the digital camera 100 (when the voice priority mode is selected), the process proceeds to step S503. In step S502, the controller 130 controls the digital image / audio processing unit 120 so that the directivity synthesis process performed on the audio signal is a monaural process, and the process proceeds to step S504. In step S503, the controller 130 controls the digital image / audio processing unit 120 so that the directivity synthesis processing applied to the audio signal is stereo processing, and the process proceeds to step S504. In step S504, when the user operates the operation unit 180 of the digital camera 100 to start shooting a moving image, the selection of the directivity synthesis processing of the audio signal is ended. Otherwise, the process proceeds to step S501.

  As described above, when moving image shooting is performed with the BIS priority mode selected, since the directivity synthesis processing applied to the audio signal is monaural processing, the S / N ratio is increased and the target sound is easily heard. That is, even when BIS drive noise is included in the audio signal of the moving image to be recorded, the drive noise can be suppressed to a low level.

  Next, gain filter processing of the audio signal will be described.

  The level at which the audio signal collected by the microphone unit 111 is recorded in the moving image file depends on the gain (audio recording gain) of the analog audio processing unit 115 and / or the digital image / audio processing unit 120. Generally, it is known that it is desirable for high sound quality that the sound recording gain is fixed regardless of the surrounding sound pressure (maintaining linearity).

  Whether the noise caused by the BIS drive recorded in the moving image file is harsh during playback depends on the surrounding acoustic environment (ambient sound pressure) at the time of shooting. In a quiet environment, the noise caused by BIS drive is relatively conspicuous and sounds harsh. Conversely, in an environment with a high volume such as a rock concert, noise caused by BIS driving is canceled out by these loud sounds, and the harshness does not sound bad. If the sound recording gain when quiet is made smaller than the sound recording gain when the volume is high in the gain filter processing of the sound signal, the noise caused by the BIS drive recorded when the sound is quiet can be reduced to improve the harshness. I can do it. That is, when the ambient sound pressure is low and the noise due to BIS driving is conspicuous, it is desirable to reduce the voice recording gain and record the BIS driving noise to improve harshness even if there is a trade-off with linearity.

  FIG. 7 is a diagram illustrating an example of gain filter processing of the audio signal of the digital camera 100 according to the first embodiment.

  FIG. 7A is a diagram illustrating an example of the ambient sound pressure-sound recording gain characteristic by the gain filter processing of the sound signal when the sound recording gain is fixed regardless of the ambient sound pressure. Even if the ambient sound pressure changes, the audio recording gain does not change (ensure linearity).

  FIG. 7B is a diagram illustrating an example of the ambient sound pressure-sound recording gain characteristic by the gain filter processing of the sound signal when the sound recording gain is lowered when the ambient sound pressure is low. When the ambient sound pressure decreases, the sound recording gain decreases (linearity is not ensured).

  When a user operates the operation unit 180 to select a BIS priority mode and shoots a moving image, as described above, vibration and sound due to BIS control are large, but noise due to BIS driving recorded in the moving image is It is desirable not to be harsh. Therefore, when the user operates the operation unit 180 to select the BIS priority mode and shoots a moving image, the digital image / audio processing unit 120 is used for the purpose of suppressing noise caused by BIS driving recorded in the moving image file. The gain filter processing performed on the audio signal is, for example, processing for ensuring non-linearity as shown in FIG.

  When a user operates the operation unit 180 to select a voice priority mode and shoots a moving image, as described above, since vibration and sound due to BIS control are small, noise due to BIS driving recorded in the moving image is low. It is unlikely that it will be heard. Accordingly, when the user operates the operation unit 180 to select the audio priority mode and shoots a moving image, the gain filter processing that the digital image / audio processing unit 120 performs on the audio signal is, for example, FIG. The linearity securing process as shown in FIG.

  FIG. 8 is a flowchart showing a flow of operations for selecting the gain filter processing of the audio signal of the digital camera 100 according to the first embodiment. The digital image / sound processing unit 120 performs a gain filter process by calculating the sound signal that is the output of the microphone unit 111. The flow of the operation of selecting the gain filter processing of the audio signal of the digital camera 100 will be described with reference to FIG. If the user operates the operation unit 180 of the digital camera 100 and selects the BIS priority mode in step S801 for selecting the gain filter processing of the audio signal, the process proceeds to step S802. In step S801, when the user does not select the BIS priority mode by operating the operation unit 180 of the digital camera 100 (when the voice priority mode is selected), the process proceeds to step S803. In step S802, the controller 130 controls the digital image / audio processing unit 120 so that the gain filter process applied to the audio signal is, for example, a process for ensuring non-linearity as shown in FIG. The process proceeds to S804. In step S803, the controller 130 controls the digital image / audio processing unit 120 so that the gain filter processing applied to the audio signal is, for example, the process of ensuring linearity as shown in FIG. 7A, and the process proceeds to step S804. Transition. In step S804, when the user operates the operation unit 180 of the digital camera 100 to start shooting a moving image, the selection of the audio signal gain filter processing is ended. Otherwise, the process proceeds to step S801.

  As described above, when moving images are shot with the BIS priority mode selected, when the ambient sound pressure is low, the gain filter processing applied to the audio signal lowers the audio recording gain and records the noise caused by the BIS drive. The possibility of audible noise can be reduced.

[4. Correspondence with the present invention]
The digital camera 100 is an example of an imaging apparatus according to the present disclosure. The CCD image sensor 143 is an example of an imaging unit of the present disclosure. The BIS processing system 149 is an example of a camera shake correction unit according to the present disclosure. The microphone unit 111 is an example of a sound collection unit of the present disclosure. The controller 130 is an example of a control unit of the present disclosure. The BIS priority mode is an example of a first mode of the present disclosure. The voice priority mode is an example of a second mode of the present disclosure.

[Other Embodiments]
The present invention is not limited to the above embodiment, and various embodiments are conceivable. Hereinafter, other embodiments of the present invention will be described together.

  In the above-described embodiment, the digital camera 100 has been described as an example of the imaging device including the sound collection device. However, any device that can perform camera shake correction in which the position of the image sensor shifts and can shoot moving images (audio recording) may be used. That is, a video camera may be used.

  In the above embodiment, whether or not to select the BIS priority mode is selected by the user by operating the operation unit 180, but this is not necessarily the case. That is, using the output signal of the gyro sensor 148, the BIS processing unit 147 and the controller 130 may select whether to select the BIS priority mode.

  In the above-described embodiment, there are three audio signal processing selections depending on whether or not the BIS priority mode is selected: frequency filter processing selection, directivity synthesis processing selection, and gain filter processing selection. It is not necessary. In other words, the audio signal processing selection that changes depending on whether or not the mode is the BIS priority mode is any one or two of frequency filter processing selection, directivity synthesis processing selection, and gain filter processing selection. It may be.

  In the above embodiment, the options that can be taken in the directivity synthesis processing selection are monaural processing (non-directional) or stereo processing (unidirectional), but are not limited thereto. For example, the omnidirectional processing may be performed so that the characteristic is intermediate between unidirectionality and omnidirectionality.

  In the above embodiment, the digital image / sound processor 120 and the controller 130 have been described as having the functions and configurations as described above, but some of the functions and configurations of each are included in the other. It is good also as a structure.

  In the above embodiment, the CCD image sensor 143 has been described as an example of the imaging unit, but the present invention is not limited to this. That is, other image pickup devices such as a CMOS image sensor and an NMOS image sensor are applicable to the present disclosure.

  The present disclosure can be applied to an imaging apparatus such as a digital camera or a movie camera having a camera shake correction function and a sound collection function.

100 Digital Camera 102 Digital Camera Body 105 HDMI Output Terminal 110 Audio Input System 111 Microphone Unit 111L Microphone 111R Microphone 115 Analog Audio Processing Unit 120 Digital Image / Audio Processing Unit 130 Controller 140 Image Input System 143 CCD Image Sensor 145 CCD Drive Unit 146 Position Sensor 147 BIS processing unit 148 Gyro sensor 149 BIS processing system 150 RAM
160 External storage medium 170 ROM
180 Operation unit 181 Release button 183 Power switch 184 Mode dial 185 Center button 186 Cross button 190 Display unit 191 Viewfinder 301 Interchangeable lens 310 Focus lens 311 Focus lens drive unit 312 Zoom lens 313 Zoom lens drive unit 315 Operation ring 316 Aperture 317 Aperture Drive unit 318 OIS lens 319 OIS control unit 320 lens controller 321 DRAM
322 Flash memory 330 Lens mount 340 Body mount 601 Delay device 602 Multiplier 603 Adder 604 Multiplier 605 Delay device 606 Multiplier 607 Adder 608 Multiplier

Claims (4)

An optical system including a lens;
An imaging unit for imaging a subject image via the optical system;
A camera shake correction unit that corrects camera shake during imaging;
A sound collection unit for collecting sound;
A control unit that controls the optical system, the imaging unit, the camera shake correction unit, and the sound collection unit;
The controller is
As the shooting mode, select and execute either the first mode or the second mode,
If the first mode is selected, control to lower the quality of the sound collected by the sound collection unit than the second mode,
When the second mode is selected, control is performed to lower the camera shake correction function by the camera shake correction unit than the first mode.
Imaging device. The camera shake correction unit corrects camera shake by moving the imaging unit in a plane perpendicular to the optical axis.
The imaging device according to claim 1. In the first mode, the control for reducing the quality of the sound includes a control for reducing the flatness of the frequency characteristics of the sound signal, a control for making the directivity of the sound signal non-directional, and a gain filter processing of the sound signal. Is at least one of the controls that result in the process not securing
The imaging device according to claim 1. The control unit executes either the first mode or the second mode based on a user's selection.
The imaging device according to claim 1.