JP2016009965A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of adjusting a drive sound level difference caused by variations or a secular change in a driving unit.SOLUTION: An imaging device comprises: driving means for moving an optical system; voice inputting means for outputting a voice signal; a memory which stores a gain parameter; a filter for taking out a prescribed frequency component when the driving means is driven from an input voice signal; gain setting means for setting a gain on the basis of the gain parameter stored in the memory and the detection results from signal level detecting means; level control means for controlling the level of the voice signal on the basis of the gain set by the gain setting means; and correction level setting means for comparing the output level of the filter between the specific period in which the driving means is driven and the period before the driving means is driven, and corrects the gain parameter when an input voice level falls below a predetermined threshold value.

Description

  The present invention relates to an imaging apparatus.

  2. Description of the Related Art Conventionally, an imaging apparatus that records an image signal and an audio signal is known. In these imaging apparatuses, a function of reducing noise mixed in sound recorded together with an image is known (Patent Document 1).

Japanese Patent Laid-Open No. 07-193548

  The lens barrel constituting the zoom lens or the like has a level difference in driving sound during driving due to individual variations and aging. Therefore, it is necessary to correct the parameters of the sound reduction processing when driving the lens barrel in accordance with the level difference.

  In Patent Document 1, it is impossible to detect the level by extracting only the driving sound of the lens barrel. That is, it is impossible to distinguish between the sound excluding the driving sound of the lens barrel and the driving sound of the lens barrel. Therefore, the sound level difference due to individual variation of the lens barrel and the sound level difference due to secular change cannot be detected unless the ambient sound is as low as possible, for example, in a silent environment such as an anechoic room or an anechoic box.

  Therefore, the present invention is not limited to a limited environment such as a quiet environment, but also in an environment where a certain amount of sound exists, the level difference or secular change of the driving sound at the time of driving the lens barrel due to individual variation of the lens barrel An object of the present invention is to provide an audio signal processing apparatus capable of correcting a level change of a driving sound at the time of driving a lens barrel.

  The configuration of the imaging apparatus according to the present invention includes an imaging unit having an optical system, a driving unit for moving the optical system, an audio input unit that acquires audio and outputs an audio signal, and audio of the audio signal A signal level detecting means for detecting a level; a memory storing a gain parameter; a filter for extracting a predetermined frequency component when the driving means is driven from the audio signal; a gain parameter stored in the memory; Gain setting means for setting a gain based on a detection result from the signal level detection means; Level control means for controlling the level of the audio signal based on the gain set by the gain setting means; and the audio level When the value falls below a predetermined threshold, the output level of the filter is compared between a specific period during which the driving means is driving and a period before driving. , Characterized in that it comprises a correction level setting means for correcting the gain parameter.

  According to the present invention, it is possible to adjust the level difference of driving sound caused by individual variation of driving units and aging.

It is a block diagram of an imaging device. It is a block diagram which shows the detailed structure of an imaging part and an audio | voice input part. It is an ALC diagram. It is an ALC correction diagram for correction calculation of a correction level setting unit. It is an ALC diagram which shows the correction process of a correction level setting part.

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

  In this embodiment, an imaging apparatus will be described with reference to FIGS. FIG. 1 is a block diagram illustrating the configuration of the imaging apparatus 100 according to the first embodiment.

  In FIG. 1, an imaging unit 101 converts an optical image of a subject captured by a photographing lens into an image signal by an imaging element, performs analog-digital conversion, image adjustment processing, and the like, and generates image data. The taking lens may be a built-in lens or a detachable lens. Further, the imaging element may be a photoelectric conversion element typified by a CCD, a CMOS or the like. The sound input unit 102 collects sound around the imaging apparatus 100 with a built-in microphone or connected via a sound terminal, and performs analog-digital conversion, sound processing, and the like to generate sound data. The microphone may be directional or omnidirectional, but in this embodiment, an omnidirectional microphone is used. The memory 103 temporarily stores the image data obtained by the imaging unit 101 and the audio data obtained by the audio input unit 102.

  The display control unit 104 displays a video related to the image data obtained by the imaging unit 101, an operation screen of the imaging device 100, a menu screen, and the like on the display unit 105 or an external display via a video terminal (not shown). . The encoding processing unit 106 reads out image data and audio data temporarily stored in the memory 103, performs predetermined encoding, and generates compressed image data, compressed audio data, and the like. Further, the audio data may not be compressed. The compressed image data is, for example, MPEG2 or H.264. It may be compressed by any compression method such as H.264 / MPEG4-AVC. The compressed audio data may also be compressed by a compression method such as AC3, AAC, ATRAC, ADPCM. The recording / reproducing unit 107 records the compressed image data, compressed audio data or audio data, and various data generated by the encoding processing unit 106 on the recording medium 108, and reads out from the recording medium 108. Here, the recording medium 108 includes all types of recording media such as a magnetic disk, an optical disk, and a semiconductor memory as long as image data, audio data, and the like can be recorded.

  The control unit 109 can control each block of the imaging apparatus 100 by transmitting a control signal to each block of the imaging apparatus 100, and includes a CPU, a memory, and the like for performing various controls. The memory used by the control unit 109 is a ROM for storing various control programs, a RAM for arithmetic processing, and the like, and includes a memory external to the control unit 109. The operation unit 110 includes buttons, a dial, and the like, and transmits an instruction signal to the control unit 109 according to a user operation. In the image pickup apparatus of the present embodiment, a shooting button for instructing start and end of moving image recording, a zoom lever for instructing optically and electronically enlarging and reducing an image, a cross key for performing various adjustments, and a determination It consists of keys. The audio output unit 111 outputs the audio data and compressed audio data reproduced by the recording / reproducing unit 107 or the audio data output by the control unit 109 to the speaker 112 and the audio terminal. The external output unit 113 outputs the compressed video data, compressed audio data, audio data, and the like reproduced by the recording / reproducing unit 107 to an external device. The data bus 114 supplies various data such as audio data and image data and various control signals to each block of the imaging apparatus 100.

  Here, the normal operation of the imaging apparatus 100 of the present embodiment will be described. The imaging apparatus 100 according to the present embodiment supplies power to each block of the imaging apparatus from a power supply unit (not illustrated) in response to an instruction to turn on the power by operating the operation unit 110 by the user. . When the power is supplied, the control unit 109 confirms which mode the mode change switch of the operation unit 110 is in, for example, a shooting mode, a reproduction mode, or the like by an instruction signal from the operation unit 110. In the moving image recording mode, the image data obtained by the imaging unit 101 and the audio data obtained by the audio input unit 102 are stored as one file. In the reproduction mode, the compressed image data recorded on the recording medium 108 is reproduced by the recording / reproducing unit 107 and displayed on the display unit 105.

  In the moving image recording mode, first, the control unit 109 transmits a control signal to each block of the imaging apparatus 100 so as to shift to the shooting standby state, and performs the following operation.

  The imaging unit 101 converts an optical image of a subject captured by a photographing lens into an image signal by an imaging element, performs analog-digital conversion, image adjustment processing, and the like, and generates image data. Then, the obtained image data is transmitted to the display processing unit 104 and displayed on the display unit 105. The user prepares for shooting while viewing the screen displayed in this way.

  The audio input unit 102 digitally converts analog audio signals obtained by a plurality of microphones and processes the obtained digital audio signals to generate multi-channel audio data. Then, the obtained audio data is transmitted to the audio output unit 111 and is output as audio from the connected speaker 112 or an unillustrated earphone. The user can also adjust the manual volume to determine the recording volume while listening to the sound output in this way.

  Next, when a shooting start instruction signal is transmitted to the control unit 109 by the user operating the recording button of the operation unit 110, the control unit 109 transmits a shooting start instruction signal to each block of the imaging apparatus 100. Then, the following operation is performed.

  The imaging unit 101 converts an optical image of a subject captured by a photographing lens into an image signal by an imaging element, performs analog-digital conversion, image adjustment processing, and the like, and generates image data. Then, the obtained image data is transmitted to the display processing unit 104 and displayed on the display unit 105. Further, the obtained image data is transmitted to the memory 103.

  The audio input unit 102 digitally converts analog audio signals obtained by a plurality of microphones and processes the obtained digital audio signals to generate multi-channel audio data. Then, the obtained audio data is transmitted to the memory 103. If there is only one microphone, the obtained analog audio signal is digitally converted to generate audio data, and the audio data is transmitted to the memory 103.

  The encoding processing unit 106 reads out image data and audio data temporarily stored in the memory 103, performs predetermined encoding, and generates compressed image data, compressed audio data, and the like.

  Then, the control unit 109 synthesizes these compressed image data and compressed audio data, forms a data stream, and outputs the data stream to the recording / reproducing unit 107. When the audio data is not compressed, the control unit 109 synthesizes the audio data stored in the memory 103 and the compressed image data, forms a data stream, and outputs the data stream to the recording / reproducing unit 107.

  The recording / playback unit 107 writes the data stream to the recording medium 108 as one moving image file under the management of a file system such as UDF or FAT. The above operation is continued during shooting.

  When the user operates the recording button of the operation unit 110 and a shooting end instruction signal is transmitted to the control unit 109, the control unit 109 transmits a shooting end instruction signal to each block of the imaging apparatus 100. The following operations are performed.

  The imaging unit 101 and the audio input unit 102 stop generating image data and audio data, respectively. The encoding processing unit 106 reads the remaining image data and audio data stored in the memory, performs predetermined encoding, and stops the operation when generation of compressed image data, compressed audio data, and the like is completed. When the audio data is not compressed, the operation is naturally stopped when the generation of the compressed image data is finished. Then, the control unit 109 synthesizes the last compressed image data and the compressed audio data or audio data, forms a data stream, and outputs the data stream to the recording / reproducing unit 107.

  The recording / playback unit 107 writes the data stream to the recording medium 108 as one moving image file under the management of a file system such as UDF or FAT. When the supply of the data stream is stopped, the moving image file is completed and the recording operation is stopped. When the recording operation stops, the control unit 109 transmits a control signal to each block of the imaging apparatus 100 so as to shift to the shooting standby state, and returns to the shooting standby state.

  Next, in the playback mode, the control unit 109 transmits a control signal to each block of the imaging apparatus 100 so as to shift to the playback state, and performs the following operation.

  The recording / playback unit 107 reads a moving image file composed of compressed image data and compressed audio data recorded on the recording medium 108, and sends the read compressed image data and compressed audio data to the encoding processing unit 106. The encoding processing unit 106 decodes the compressed image data and the compressed audio data and transmits them to the display control unit 104 and the audio output unit 111, respectively. The display control unit 104 causes the display unit 105 to display the decoded image data. The audio output unit 111 outputs the decoded audio data from an external speaker built in or attached.

  As described above, the imaging apparatus 100 according to the present embodiment can record and reproduce images and sounds. In the present embodiment, the audio input unit 102 performs processing such as level adjustment processing of the audio signal obtained by the microphone when obtaining the audio signal. This process may always be performed after the apparatus is activated, may be performed after the shooting mode is selected, or may be performed after a mode related to audio recording is selected. . Further, in a mode related to audio recording, the above processing may be performed in response to the start of audio recording. In this embodiment, it is assumed that the above processing is performed at the timing when moving image shooting is started.

  FIG. 2 is a block diagram illustrating detailed configurations of the imaging unit 101 and the audio input unit 102 of the imaging apparatus 100 according to the present exemplary embodiment.

  The imaging unit 101 includes an optical system such as a lens 201 that captures an optical image of a subject, and an imaging element 202 that converts the optical image of the subject captured by the lens 201 into an electrical signal (image signal). The image processing unit 203 further converts an analog image signal obtained by the image sensor 202 into a digital image signal, performs image quality adjustment processing, forms image data, and transmits the image data to a memory. Furthermore, it has a lens control unit 204 having a known drive mechanism such as a position sensor for moving the lens 201 and a motor. In this embodiment, it is described that the imaging unit 101 includes the lens 201 and the lens control unit 204, but these may be detachable interchangeable lenses.

  For example, when a user operates the operation unit 110 to input instructions such as zoom operation and focus adjustment, the control unit 109 transmits a control signal (drive signal) for moving the lens to the lens control unit 204. In response to this control signal, the lens control unit 204 confirms the position of the lens 201 with a position sensor, and moves the lens 201 with a driving unit such as a motor. In addition, when the control unit 109 confirms the image obtained by the image processing unit 203 and the distance to the subject and automatically adjusts the distance, a control signal for driving the lens is transmitted. Further, when a so-called image stabilization function for preventing image blurring is provided, the control unit 109 outputs a control signal for moving the lens 201 based on vibration detected by a vibration sensor (not shown). This is transmitted to the lens control unit 204.

  At this time, the imaging apparatus 100 according to the present embodiment generates driving noise due to movement of the lens 201 and driving noise of a motor for moving the lens 201. In the present embodiment, the lens control unit 204 drives the lens in response to a control signal for driving the lens from the control unit 109. That is, the control unit 109 can know (detect or determine) the timing at which drive noise occurs.

  In this embodiment, the lens 201 can optically perform enlargement and reduction, for example, 6 times at the maximum and 1 time at the minimum. This is called optical zoom in this embodiment. In the optical zoom, in response to an instruction from the control unit 109, the lens control unit 204 moves the lens 201 to enlarge the optical image of the subject. Further, the image processing unit 203 has an electronic zoom (enlargement) function for outputting an image signal obtained by enlarging a part of the image signal obtained by the image sensor 202. In addition, an electronic zoom (reduction) function is provided for outputting an image signal in which an image range obtained by the image sensor 202 is widened and the image processing unit 203 reduces the image size.

  The voice input unit 102 also has a microphone 205 that converts voice vibration into an electrical signal and outputs the voice signal, and an AD converter 206 that converts an analog voice signal obtained by the microphone 205 into a digital voice signal. . Furthermore, an auto level controller (hereinafter referred to as ALC) 207 for suppressing the amplitude of the audio signal to a predetermined level, and an audio processing unit 208 that performs predetermined processing on the audio signal to form audio data and transmit it to the memory 103 are provided. Yes. In addition, the level detection unit 209 detects the level of the digital audio signal and outputs the detection result, and the gain setting unit 210 sets the gain (amplification factor) in the ALC 207 based on the detection result of the level detection unit 209. Yes. Here, the level of the audio signal indicates a peak value during which the audio signal is converted into an absolute value and the amplitude once becomes substantially zero and then becomes almost zero. The voice input unit 102 also has a gain memory 211 that stores parameters for determining a gain to be set in the ALC 207 based on the detection result of the level detection unit 209 by the gain setting unit 210.

  The parameter recorded in the gain memory 211 indicates, for example, an output level (correspondence as shown in FIG. 3 described later) corresponding to the level of the audio signal input to the ALC 207. Further, this parameter may indicate a gain to be given to the input signal corresponding to the level of the audio signal input to the ALC 207. The gain setting unit 210 sets gain (amplification rate, attenuation rate) corresponding to the level of the audio signal input to the ALC 207 in the ALC 207 according to the parameters stored in the gain memory 211. The gain memory 211 of the present embodiment has, for example, an “enlargement parameter” corresponding to the movement of the lens 201 (hereinafter, enlarging drive) in order to enlarge the optical image of the subject. Further, it has a “reduction parameter” corresponding to when the lens 201 is moved (hereinafter referred to as reduction driving) in order to reduce the optical image of the subject. In the present embodiment, the case where the lens 201 is moved has been described. However, other driving units may have different parameters, and the same processing may be performed. The gain memory 211 also has normal parameters corresponding to when no drive unit including the lens 201 of the present embodiment is driven.

  FIG. 3 shows the gain given to the output level corresponding to the level of the audio signal input to the ALC 207 or the output signal corresponding to the level of the input audio signal for each parameter of the gain memory 211. 3A is a correspondence diagram showing the level of the audio signal input to the ALC 207 and the level of the audio signal output corresponding to the input level. FIG. 5B is a correspondence diagram showing the level of the audio signal input to the ALC 207 and the gain set in the ALC 207 corresponding to the input level. In the present embodiment, these are called ALC diagrams. In FIG. 3A, the horizontal axis represents the level of the audio signal input to the ALC 207, and the vertical axis represents the level of the audio signal output corresponding to the level of the input audio signal. In FIG. 3B, the horizontal axis represents the level of the audio signal input to the ALC 207, and the vertical axis represents the gain set in the ALC 207 corresponding to the level of the input audio signal.

  The gain memory 211 described above holds parameters for forming this ALC diagram. For example, an ALC diagram corresponding to normal parameters (parameters when no drive unit is driven) in the gain memory 211 shows an input level-output level correspondence relationship 301. Also, an input level-gain correspondence relationship such as 307 is shown. Further, an ALC diagram corresponding to the time when the lens 201 is driven to be magnified (magnification parameter) shows an input level-output level correspondence such as 302 and an input level-gain correspondence such as 308. . Further, an ALC diagram corresponding to the time when the lens 201 is driven to reduce (a parameter at the time of reduction) shows an input level-output level correspondence relationship such as 303, and an input level-gain correspondence relationship such as 309. Show. For example, the gain memory 211 holds a plurality of points indicating the output level corresponding to the input level as parameters in order to form this ALC diagram. Further, for example, it is held as table data indicating an output level corresponding to the input level. Further, for example, a plurality of points indicating gains corresponding to the input levels are held as parameters. Further, for example, table data indicating a gain corresponding to the input level is held.

  According to this ALC diagram, in this embodiment, for example, when a 60 dBSPL audio signal is input, a -30 dBFS audio signal is output when no drive unit is driven. However, an output audio signal of −34 dBFS is output when the lens 201 is driven to enlarge, and an output audio signal of −38 dBFS is output when the lens 201 is driven to reduce.

  In FIG. 3, a broken line 304 indicates an input level of an audio signal corresponding to driving noise generated by a driving unit such as a movement of the lens 201 and a motor that moves the lens 201 when the lens 201 is enlarged. , 50 dBSPL. That is, at the time of enlargement driving, an audio signal having a level of 50 dBSPL or more is input at least. The ALC 207 is configured to output a -40 dBFS audio signal when an audio signal of 50 dBSPL level is input during enlargement driving. A broken line 305 indicates the input level of the audio signal corresponding to the movement of the lens 201 when the lens 201 is driven to reduce and the driving noise generated by a driving unit such as a motor that moves the lens 201, for example, 56 dB. . That is, at the time of reduction driving, an audio signal having a level of at least 56 dBSPL is input. During the reduction driving, the ALC 207 outputs a -40 dBFS audio signal when an audio signal of 56 dBSPL level is input.

  A broken line 306 has a level of about 74 dBSPL, for example, and the level of the audio signal input to the ALC 207 is sufficiently higher than the driving noise of the driving unit such as the lens 201. The situation where an audio signal of this level is input is expected to be a situation where the level of the surrounding audio is high. Normally, a low level sound becomes difficult to be heard by a large level sound, so that a driving noise of about 50 dBSPL becomes difficult to hear by a surrounding sound of a higher level. Therefore, in this embodiment, the sound signal having a level higher than the level indicated by the broken line 306, which is predicted to be input with surrounding sound that makes driving noise inconspicuous, is the same as when the drive unit is not driven. I am trying to amplify to the extent. Specifically, normally, when an audio signal of 74 dBSPL level is input, an output audio signal of −15 dBFS level is output, and an output audio signal of −15 dBFS level is also output during enlargement driving and reduction driving. It is trying to output.

  Here, the audio level adjustment processing of the audio input unit 102 will be described with reference to FIGS. 2 and 3. First, an audio level adjustment process when a driving unit such as a motor for moving the lens 201 and the like is not driven (normal time) in the present embodiment will be described.

  In this case, the analog audio signal obtained by the microphone 205 is converted into a digital audio signal by the AD conversion unit 206 and transmitted to the ALC 207 and the level detection unit 209. The level detection unit 209 detects the level of the input audio signal and transmits it to the gain control unit 210. When the control signal indicating that the driving unit such as the lens 201 is being driven is not received from the control unit 109, the gain control unit 210 reads normal parameters from the gain memory 211. An ALC diagram corresponding to a normal parameter (a parameter when no drive unit is driven) has an input level-output level correspondence such as 301 and an input level-gain correspondence such as 307. . The gain control unit 210 determines the gain (amplification rate, attenuation rate) in the ALC 207 based on the level of the audio signal input to the ALC 207 detected by the level detection unit 209 and the normal parameters read from the gain memory 211. Set. That is, the gain in the ALC 207 is set so as to have a correspondence relationship between the input level and the output level of the audio signal as indicated by 301 in FIG. Alternatively, a gain corresponding to the input level as shown by 307 in FIG.

  Then, the ALC 207 amplifies or attenuates the audio signal input with the gain set by the gain control unit 210 and transmits it to the audio processing unit 208. The audio processing unit 208 performs predetermined processing on the audio signal, forms audio data, and transmits the audio data to the memory 103.

  Next, an audio level adjustment process when the lens 201 is moved by the driving unit of the lens control unit 204 will be described. A case will be described in which the lens 201 moves (enlargement drive) in order to enlarge the optical image of the subject by the operation of the operation unit 110 by the user.

  When the operation unit 110 is magnified by the user, the control unit 109 transmits a control signal to the lens control unit 204 so that the lens moves in the direction of enlarging the optical image of the subject. In response to this control signal, the lens control unit 204 drives a motor or the like so that the lens 201 moves in the direction of enlarging the optical image of the subject. At this time, while the lens 201 is moved by the drive of the drive unit, the control unit 109 transmits a control signal indicating that the lens 201 is enlarged and driven to the gain setting unit 210.

  The analog audio signal obtained by the microphone 205 is converted to a digital audio signal by the AD conversion unit 206 and transmitted to the ALC 207 and the level detection unit 209. The level detection unit 209 detects the level of the input audio signal and transmits it to the gain control unit 210. Since the gain control unit 210 receives a control signal indicating that the lens 201 is enlarged and driven from the control unit 109, the gain control unit 210 reads the enlargement parameter from the gain memory 211. As described above, the ALC diagram corresponding to the enlargement drive (enlargement parameter) has an input level-output level correspondence such as 302 and an input level-gain correspondence such as 308. The gain control unit 210 determines the gain (amplification rate, attenuation rate) in the ALC 207 based on the level of the audio signal input to the ALC 207 detected by the level detection unit 209 and the expansion parameter read from the gain memory 211. Set. That is, the gain in the ALC 207 is set so as to have a correspondence relationship between the input level and the output level of the audio signal as indicated by 302 in FIG. Alternatively, a gain corresponding to the input level as shown by 308 in FIG. 3 is set as the gain of the ALC 207.

  Then, the ALC 207 amplifies or attenuates the audio signal input with the gain set by the gain control unit 210 and transmits it to the audio processing unit 208. The audio processing unit 208 performs predetermined processing on the audio signal, forms audio data, and transmits the audio data to the memory 103.

  Similarly, when the lens 201 is moved (reduction driving) in order to reduce the optical image of the subject by the operation of the zoom key of the operation unit 110 by the user, the lens 201 is driven by the motor of the lens control unit 204 or the like. A control signal is transmitted while moving. This control signal is a control signal indicating that the control unit 109 drives the gain setting unit 210 to reduce the lens 201.

  Since the gain control unit 210 receives a control signal indicating that the lens 201 is driven to reduce, the gain control unit 210 reads the reduction parameter from the gain memory 211. As described above, the ALC diagram corresponding to the time of reduction driving (reduction parameter) has an input level-output level correspondence such as 303 and an input level-gain correspondence such as 309. The gain control unit 210 determines the gain (amplification rate, attenuation rate) in the ALC 207 based on the level of the audio signal input to the ALC 207 detected by the level detection unit 209 and the reduction parameter read from the gain memory 211. Set. That is, the gain in the ALC 207 is set so as to have a correspondence relationship between the input level and the output level of the audio signal as indicated by 303 in FIG. Alternatively, a gain corresponding to the input level as shown by 309 in FIG. 3 is set as the gain of the ALC 207.

  Then, the ALC 207 amplifies or attenuates the audio signal input with the gain set by the gain control unit 210 and transmits it to the audio processing unit 208. The audio processing unit 208 performs predetermined processing on the audio signal, forms audio data, and transmits the audio data to the memory 103.

  Further, in this embodiment, when the driving unit shifts from the non-driven state to the driven state, the gain in the ALC 207 is gradually changed over a period of several ms.

  As described above, in the imaging apparatus 100 according to the present embodiment, while the drive unit is driven, the amplification is smaller as the level of the audio signal obtained by the microphone becomes lower than when the drive unit is not driven. The audio signal input at a rate is amplified. That is, as shown in FIG. 3B, the lower the level of the audio signal obtained by the microphone, the greater the difference in amplification factor between when the driving unit is not driving and when the driving unit is driving. As described above, the amplification factor when the drive unit is driven is lowered. In other words, while the drive unit is being driven, the level of the adjusted audio signal is reduced as the level of the audio signal obtained by the microphone is lower than when the drive unit is not being driven. I try to adjust it.

  According to such a configuration, when the drive unit is driven, the image pickup apparatus of the present embodiment attenuates an audio signal at a level at which drive noise is expected to be conspicuous, and a level at which drive noise is not conspicuous. It is possible to prevent the sound signal from being attenuated. In addition, it is possible to obtain an audio signal that does not give the user a sense of incongruity while reducing driving noise generated during driving of the driving unit.

  In this embodiment, when the drive unit is driven (during driving), if a sound signal with a level where drive noise is conspicuous is obtained by the microphone, compared to when the drive unit is not driven (normal time). An output audio signal with a low level is output. Furthermore, if an audio signal with a level where drive noise is not conspicuous is obtained by the microphone, an output audio signal having the same level as that when the drive unit is not driven is output. In this way, at the time of driving, an audio signal at a level where driving noise is expected to be conspicuous is attenuated, and an audio signal at a level where driving noise is expected to be inconspicuous is not attenuated.

  In the present embodiment, the ALC diagrams 302 and 303 shown in FIG. 3A are shown as an example, but other characteristics such as 310 and 311 may be used. In other words, the level of the output audio signal corresponding to the level of the input audio signal may be made smaller as the level of the input audio signal becomes lower during driving than during normal operation. Similarly, ALC diagrams 308 and 309 as shown in FIG. 3B are shown, but other characteristics such as 312 and 313 may be used.

  In this embodiment, the case where there is one microphone has been described with reference to FIG. 2, but a plurality of microphones may be used. In this case, only one ALC 207 may be provided to control the gain. However, if the ALC 207 corresponding to each microphone is individually provided, the noise reduction effect can be further enhanced. This is because it is desirable to individually reduce noise because the level of drive noise input to each microphone differs depending on the location of the microphone. At this time, the number of gain memories 211 may be one.

(Example of this case)
Next, in FIG. 2, the correction determination unit 212 receives the output results of the control unit 109 and the level detection unit 209 and determines whether to correct the parameters recorded in the gain memory 211. The filter 213 is configured to extract a specific frequency band, and performs filtering on the digital audio signal from the AD conversion unit 206. A configuration in which only a frequency band in which driving noise is conspicuous when the driving unit is driving (during driving) is extracted. In this embodiment, a band pass with a resonance frequency of 3.5 kHz and a bandwidth of 3.0 kHz to 4.0 kHz. It is a filter. A frequency band in which driving noise is conspicuous when the driving unit is driving (during driving) is used.

  The level detection unit 214 detects the level of the digital audio signal from the filter 213 for a certain period as needed, outputs the detection result to the correction level setting unit 215, and records it in the buffer 216. The correction level setting unit 215 receives the result of the correction determination unit 212, determines a correction level based on the detection result of the level detection unit 214 and the detection result recorded in the buffer 216, and the ALC 207 recorded in the gain memory 211. The parameter for determining the gain to be set is corrected.

  The gain memory 211 records correction parameters for determining the correction level based on the detection result of the level detection unit 214 and the detection result recorded in the buffer 216 by the correction level setting unit 215. Correspondence indicating a level obtained by subtracting the audio input level during the non-driving period of the driving unit from the audio input signal level during the driving period of the driving unit with respect to the audio input level during a certain period when the driving unit of the gain memory 211 is not driven FIG. 4 shows the relationship diagram. In this embodiment, this is called an ALC correction diagram, and is a parameter that the correction level setting unit 215 reads out in order to calculate the correction level.

  In FIG. 4, the horizontal axis indicates the level of an audio signal input during a certain period when the driving unit is not driven, and the vertical axis indicates the audio signal input during a certain period during which the driving unit is driven. The level is obtained by subtracting the level of the audio signal input for a certain period during which the drive unit is not driven from the level. When obtaining the above relationship, the sound pressure level [dB] is calculated as sound pressure [μPa] because it is a relative scale. The level of the audio signal input during a certain period when the driving unit is not driven, that is, the sound pressure level of the environmental sound is represented as S [dB], and the sound pressure is represented as s [μPa], and the driving unit is driven. An audio signal input for a certain period when the drive unit is not driven, that is, a sound pressure level of the drive unit drive sound is N [dB] and a sound pressure is n from a level of the audio signal input for a certain period. It is expressed as [μPa], and the level of the audio signal input for a certain period during which the driving unit is driven, that is, the sound pressure level obtained by adding the driving unit driving sound and the environmental sound is S + N [dB], and the sound pressure is s + n. Let it be expressed as [μPa]. At this time, the calculation formula described later holds.

S = 10 log 10 (s ² / p ₀ ² )
N = 10 log 10 (n ² / p ₀ ² )
S + N = 10 log 10 (10 ^ (S / 10) + 10 ^ (N / 10))
※ _{p 0} is the reference value _(p 0 = _20μPa)
From the above equation, in FIG. 4, the horizontal axis indicates the level of the audio signal input during a certain period when the driving unit is not driven, and the vertical axis indicates the input during the certain period during which the driving unit is driven. The level relationship is derived by subtracting the level of the audio signal input for a certain period during which the drive unit is not driven from the level of the audio signal being input.

  The gain memory 211 described above holds parameters for forming this ALC correction diagram.

  For example, an ALC correction diagram that the imaging apparatus 100 has as a default indicates a correspondence relationship such as 501. In this embodiment, an ALC correction diagram corresponding to when the lens 201 is driven to be magnified (magnification parameter) is shown. Of course, an ALC correction diagram corresponding to the case where the lens 201 moves (reduction drive) to reduce the optical image of the subject by the user's operation of the zoom key of the operation unit 110 may be used. A correction diagram corresponding to both driving may be used.

  Here, the sound level correction processing of the sound input unit 102 in this embodiment will be described with reference to FIGS. 2, 3, 4, and 5.

  First, sound level correction pre-processing when a driving unit such as a motor for moving the lens 201 and the like is not driven (normal time) in the present embodiment will be described.

  The analog audio signal obtained by the microphone 205 is converted into a digital audio signal by the AD conversion unit 206 and transmitted to the filter 213 and the level detection unit 209. The digital audio signal filtered by the filter 213 is transmitted to the level detection unit 214. The level detection unit 214 detects the level of the input audio signal and transmits it to the buffer 216 and the correction level setting unit 215. The buffer 216 records the result from the level detection unit 214.

  Next, audio level correction processing when the lens 201 is moved by the driving unit of the lens control unit 204 will be described.

  When the lens 201 moves (enlargement drive) in order to enlarge the optical image of the subject by the operation of the operation unit 110 by the user, the control unit 109 instructs the lens 201 to the correction determination unit 212 and the correction level setting unit 215. Transmits a control signal indicating that the lens 201 is magnified while the lens is moved by driving of the driving unit.

  Then, the level detection unit 209 detects the level of the input audio signal and transmits it to the correction determination unit 212. The correction determination unit 212 receives the output results of the control unit 109 and the level detection unit 209, determines whether or not to perform the sound level correction process, and determines that the sound level correction process is performed. A control signal indicating the processing command is output to the correction level setting unit 215.

  Here, conditions for determination will be described. Condition 1 is whether or not the result of the level detection unit 209 is below a predetermined level. The predetermined level refers to the level indicated by the broken line 306 in the ALC diagram of FIG. 3, and is set so that the driving noise of the driving unit becomes inaudible due to surrounding sounds in terms of hearing.

The setting of the broken line 306 will be described. First, a broken line 304 indicates an input level of an audio signal corresponding to driving noise generated by a driving unit such as a motor that moves the lens 201 or a motor that moves the lens 201 when the lens 201 is enlarged, and is, for example, 50 dBSPL. . That is, at the time of enlargement driving, an audio signal having a level of 50 dBSPL or more is input at least. The broken line 306 is set as N times the broken line 304. In this embodiment, it is 74 dBSPL, which is 16 times.
Condition 2 is whether or not the user has performed correction processing.

  When the user instructs correction processing through the operation unit 110, the control unit 109 transmits a control signal indicating a correction processing command to the correction determination unit 212 and the correction level 215. Condition 3 is whether or not the number of driving times of the driving unit such as the lens 201 exceeds a specified number. The control unit 109 includes a counter and a memory. The control unit 109 counts and records the number of times the lens 201 is driven, and when the predetermined number of times recorded in the memory is exceeded, the correction determination unit 212 and the correction level are recorded. A control signal indicating a correction processing command is transmitted to 215.

  The control unit 109 resets the counter when the counter exceeds a specified number. Of course, the counter and the memory may be configured separately outside. The correction determination unit 212 determines whether to perform the sound level correction process when the result of the level detection unit 209 falls below a predetermined level in the condition 1 and when the user performs the correction process operation in the condition 2. I do. Further, when the result of the level detection unit 209 falls below a predetermined level in the condition 1 and when the driving frequency of the driving unit such as the lens 201 exceeds the predetermined frequency in the condition 3, the correction determination unit 212 It is determined that the sound level correction process is performed.

  The analog audio signal obtained by the microphone 205 is converted into a digital audio signal by the AD converter 206 and transmitted to the filter 213. The digital audio signal filtered by the filter 213 is transmitted to the level detection unit 214, and the level detection unit 214 detects the level of the input audio signal and transmits it to the correction level setting unit 215. When the correction level setting unit 215 receives the control signal of the sound level correction processing command from the correction determination unit 212, the correction level setting unit 215 determines the correction level based on the detection result of the level detection unit 214 and the detection result recorded in the buffer 216. A parameter for determining a gain set in the ALC 207 recorded in the gain memory 211 is corrected.

  The correction process of the correction level setting unit 215 will be described with reference to FIGS. When the correction level setting unit 215 receives the control signal of the command of the sound level correction processing from the correction determination unit 212, the correction level setting unit 215 and the detection result (hereinafter referred to as detection result α) from the level detection unit 214 are recorded in the buffer 216. A level difference (hereinafter referred to as a calculation result γ) of a new detection result (hereinafter referred to as a detection result γ) is calculated, and a parameter for determining a gain set in the ALC 207 recorded in the gain memory 211 is read and corrected. Calculate the result. The parameters are shown in FIG.

  In FIG. 4, the sound input level corresponding to the detection result β is a sound input level when not driven, and the sound input level corresponding to the calculation result γ is (when driven−not driven). A point E is obtained from each result γ, β. Next, a broken line 502 that passes through the point E and is orthogonal to the undriven audio input level axis is obtained as a point F that is the intersection of the curve 501 and the broken line 502. A curve 501 indicates an ALC correction diagram that the imaging apparatus 100 has as a default as described above. Finally, the level difference between point E and point F is obtained, and this result is the correction result (hereinafter referred to as correction level X). This correction level X is the drive noise level of the drive unit assumed by the default ALC correction diagram 501 and the drive noise level of the drive unit mounted on the actual imaging apparatus 100 due to the influence of individual variation, secular change, and the like. That is the difference.

  Next, the correction level setting unit 215 corrects the correction level X as a calculation result with respect to the parameter for determining the gain set in the ALC 207 recorded in the gain memory 211. FIG. 5 shows an example in which the correction level is corrected for the parameter for determining the gain set in the ALC 207 recorded in the gain memory 211.

  307, 308a, 309a, 304a, 305a, and 306a are the same as the relationship shown in the ALC diagram of FIG. Reference numeral 307 denotes an input level-gain relationship corresponding to when no driving unit is driven. Reference numeral 308a denotes an input level-gain relationship (enlargement parameter) corresponding to when the lens 201 is enlarged. Reference numeral 309a denotes an input level-gain relationship (reduction parameter) corresponding to the reduction driving of the lens 201. A broken line 304a indicates an input level of an audio signal corresponding to driving noise generated by a driving unit such as a motor that moves the lens 201 or a motor that moves the lens 201 when the lens 201 is enlarged, and is, for example, 50 dBSPL. A broken line 305a indicates the input level of the audio signal corresponding to the movement of the lens 201 when the lens 201 is driven to reduce and the driving noise generated by a driving unit such as a motor that moves the lens 201, and is 56 dBSPL, for example. The broken line 306a is at a level of about 74 dBSPL, for example, and the setting of the broken line 306a is the same as that of the broken line 306 described above.

  Point D1 is on 307a and represents the input level of 306a. Point A1 is on 308a and represents the point at 304a input level. Point B1 is on 309a and represents the input level of 305a. The correction level setting unit 215 corrects the respective points for the correction level X and corrects them as A2, B2, and D2, respectively. Each is complemented by a straight line, and the enlargement parameter 308a is corrected to 308b and the reduction parameter 309a is corrected to 309b. The correction result is recorded in the gain memory 211 and reflected from the subsequent audio level adjustment processing of the audio input unit 102. Through the above processing, the parameter for determining the gain to be set in the ALC 207 recorded in the gain memory 211 can be a parameter corresponding to the drive noise level of the drive unit mounted on each imaging device.

  In the present embodiment, the case where one system of audio is input has been described, but the present invention can be applied even when the number of channels is more than that.

  In the present embodiment, the imaging apparatus has been described. However, the audio processing of the audio input unit 102 according to the present embodiment is any apparatus as long as it records or inputs external audio. Can also be applied. For example, you may apply to an IC recorder, a mobile telephone, etc.

100 imaging device, 101 imaging unit, 102 voice input unit, 103 memory,
104 display control unit, 105 display unit 1, 106 encoding processing unit

Claims (3)

Imaging means having an optical system;
Driving means for moving the optical system;
Voice input means for acquiring voice and outputting voice signals;
Signal level detecting means for detecting a sound level of the sound signal;
A memory storing gain parameters,
A filter for extracting a predetermined frequency component from the audio signal when the driving means is driving;
Gain setting means for setting a gain based on a gain parameter stored in the memory and a detection result from the signal level detection means;
Level control means for controlling the level of the audio signal based on the gain set by the gain setting means;
A correction level setting means for comparing the output level of the filter between a specific period during which the driving means is driven and a period before driving when the audio level is lower than a predetermined threshold, and correcting the gain parameter; An imaging apparatus comprising:   The correction level setting means, based on the gain parameter and the correction parameter stored in the gain memory, the specific period during which the driving means is driven and the specific period immediately before the previous driving means is driven, the output level of the filter The imaging apparatus according to claim 1, wherein the gain parameters are corrected.   When correction is instructed from the operation means, or by the sum condition of the condition when the number of driving times of the driving means exceeds a predetermined number of times and the condition when the input sound level falls below a predetermined threshold, The imaging apparatus according to claim 1, further comprising: a unit that determines whether to perform correction processing.