JP2002344787A - Sound collecting device for video image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound collection device for a video imaging recording device that cancels a detected signal of vibration of a zoom lens drive mechanism section by a sound pickup microphone, using an inverted-phase signal from a vibration detector installed separately from the microphone, so as to prevent decrease in the level of audio signal and production of distortion in the audio signal, caused by the sound collection device operating normally. SOLUTION: The sound collecting device is provided with a subtractor, that subtracts the inverted phase component of an output signal from a vibration detection means from the output signal of the microphone, a microcomputer 7 controls the gain of an amplifier amplifying the output signal of the vibration detection means which is applied to the subtractor, depending on an operation of a zoom lens for increase the gain, only during the period when vibration noise is produced, thereby eliminating noise components due to vibration from the audio signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a sound pickup device of a video imaging and recording device.

[0002]

2. Description of the Related Art In a video imaging / recording apparatus (hereinafter referred to as a camera-integrated video) in which a video camera unit for recording video and an audio recording unit including a microphone for recording audio are housed in one housing, the video and the video are recorded. When recording audio simultaneously, vibrations generated from a video recording mechanism and vibrations generated from a mechanism such as a zoom lens of an optical lens system are transmitted to a sound pickup microphone. This vibration is often detected and recorded by a microphone as audio noise. In order to prevent this, a vibration detector is provided separately from the microphone for sound pickup, and the detection signal of the vibration detector is subtracted from the sound signal of the detection output of the microphone for sound pickup to remove noise due to vibration. It has been known. FIG. 3 is a block diagram of a conventional camera-integrated video sound pickup apparatus provided with such a noise removal apparatus.

In FIG. 3, a sound signal detected by a sound collecting microphone 1 for detecting sound to be recorded and a detection signal of a vibration detection unit 2 mounted on a camera-integrated video housing and detecting vibration are subtracted. Applied to the vessel 3. In the subtracter 3, a detection signal due to the vibration detected by the vibration detection unit 2 is made to have the same magnitude and an opposite phase to the audio signal, and then mixed with the audio signal output from the microphone 1. Thereby, the noise component due to the vibration included in the audio signal is canceled and removed. The audio signal from which the noise component has been removed is amplified by the audio amplifier 4 into a signal of a predetermined magnitude, and then recorded by the audio recording unit 5.

FIG. 4A is a waveform diagram of an audio signal 20 output from the microphone 1, and a waveform 21 in a portion surrounded by a dotted line is a noise component due to vibration. FIG. 4B shows a detection signal waveform 22 of the vibration detection unit 2. The phase of the detection signal waveform 22 is opposite to the phase of the noise component waveform 21, and the amplitudes thereof are almost the same. FIG. 4 (c)
The waveform 23 is the output waveform of the subtractor 3 and shows the waveform of the audio signal from which the vibration noise component has been removed.

[0005]

In the sound pickup device using the above-mentioned conventional vibration noise removing device, the vibration detecting unit 2
Is always running. Therefore, the vibration detection unit 2
Detects a vibration generated in the housing by voice and outputs a detection signal. This detection signal is applied to the subtractor 3 and is subtracted from the audio signal detected by the microphone 1. As a result, there arises a problem that the level of the audio signal detected by the microphone 1 is lowered or the audio signal is distorted.

[0006]

According to the present invention, there is provided a sound pickup apparatus for a video image pickup / recording apparatus, provided in the video image pickup / recording apparatus, for detecting sound and outputting a sound detection signal, and the video pickup / recording apparatus. A vibration detector that is provided in the device and detects a vibration generated during operation of the video imaging and recording device and outputs a vibration detection signal; the sound detection signal and the vibration detection signal are input; and the vibration detection is performed from the sound detection signal. A subtraction unit that reduces a signal, a detection unit that detects that a zoom lens driving unit that drives a zoom lens of the video imaging and recording device is operating, and outputs a detection signal, and the subtraction unit based on a detection signal of the detection unit. Has a control unit for performing the above operation. The operation and effect of the present invention are as follows. When the zoom lens driving section is operating, the vibration detection signal is applied to the subtraction section to subtract from the audio detection signal. This allows
Vibration generated when the zoom lens driving section is operating is detected by the microphone, and is prevented from being superimposed as noise on the audio detection signal. When the zoom lens driving unit is not operating, the vibration detection signal is not applied to the subtraction unit, so that the vibration detection signal based on the vibration of the housing caused by the voice does not affect the voice detection signal.

According to another aspect of the present invention, a sound pickup device of a video pickup / recording device is provided in a video pickup / recording device, and detects a sound and outputs a sound detection signal. An angular velocity sensor provided for detecting a movement of the video imaging and recording apparatus due to shaking or moving the apparatus and outputting a detection signal when the video imaging and recording apparatus is held by a user with a hand; A band-pass filter that outputs an output signal obtained by extracting a signal in an audible audio band of the detection signal, an output signal of the audio detection signal and the output signal of the band-pass filter,
A subtraction unit that subtracts the output signal of the band-pass filter from the audio detection signal, a detection unit that detects that a zoom lens driving unit that drives a zoom lens of the video imaging and recording device is operating, and outputs a detection signal; And a control unit for causing the subtraction unit to operate according to the detection signal of the detection unit. According to the present invention, in addition to the above-described effects, the detection signal of the vibration in the audible voice band detected by the angular velocity sensor is removed from the voice signal, and the detection signal due to the vibration can be prevented from affecting the voice signal.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described with reference to FIGS. << First Embodiment >> A sound pickup device of a video imaging and recording device (hereinafter, referred to as a camera-integrated video) according to a first embodiment of the present invention will be described with reference to FIG. In FIG. 1, a microphone 1 for collecting sound for detecting a sound to be recorded is connected to one input terminal of a subtractor 3. The vibration detection unit 2 attached to the camera-integrated video casing is connected to one input terminal of an amplifier 6 whose gain can be externally controlled. The output terminal of the amplifier 6 is connected to the other input terminal of the subtractor 3. A zoom detector 9 that detects that the user is operating the zoom lens 8 and outputs a detection signal.
A microcomputer 7 for controlling the zoom lens 8
It is provided in. The microcomputer 7 is connected to the zoom lens 8 including the control unit and to the other input terminal of the amplifier 6. The output terminal of the subtractor 3 is connected to the input terminal of the audio amplifier 4 and
Is connected to the input terminal of the audio recording unit 5.

The operation of the sound pickup apparatus according to the present embodiment having the above-described structure will be described below. A voice signal converted into an electric signal by the microphone 1 and a signal having the same phase and the opposite phase as the vibration detection signal detected by the vibration detection unit 2 and converted into the electric signal are applied to the subtractor 3. The other is subtracted from either one. The output of the subtracter 3 is amplified to a predetermined size by the audio amplifier 4 and recorded on the internal magnetic tape or the like by the audio recording unit 5. When the user who is taking an image with the camera-integrated video is not operating the zoom detection unit 9 (hereinafter, referred to as a normal operation), the gain of the amplifier 6 is extremely low under the control of the microcomputer 7. Therefore, even if the vibration detection unit 2 detects vibration due to voice and applies a detection output to the amplifier 6, the amplifier 6 does not apply an output to the subtractor 3. Therefore, the audio signal detected by the microphone 1 is directly amplified by the audio amplifier 4 and recorded by the audio recording unit 5.

When the user operates the zoom detector 9 to perform the zoom operation of the zoom lens 8, the microcomputer 7 detects the operation and operates the zoom lens 8 in the direction specified by the user. At this time, the vibration generated from the mechanical components driving the zoom lens 8 and the noise accompanying the vibration are transmitted to the microphone 1 and detected and superimposed on the audio signal. This vibration is also transmitted to the vibration detection unit 2, and a detection signal due to the vibration is generated.

When the zoom detector 9 is operated, the microcomputer controls the gain of the amplifier 6 to increase.
Thereby, the amplified detection output of the vibration detection unit 2 is applied to the subtractor 3. In the subtractor 3, the detection signal component due to the vibration of the mechanical component included in the audio signal detected by the microphone 1 is subtracted from the audio signal and canceled, and only the audio signal passes through the audio amplifier 4 and is recorded on the magnetic tape of the audio recording unit 5. Will be recorded.

Second Embodiment A camera-integrated video sound collecting apparatus according to a second embodiment of the present invention will be described with reference to FIG. The camera-integrated video of the present embodiment shown in FIG.
The camera-integrated video includes an angular velocity sensor 10 for detecting movement of the apparatus due to camera shake when the camera shakes or moves. Angular velocity sensor 10
Is connected to the input terminal of the amplifier 11. The output end of the angular velocity sensor 10 is also connected to a camera shake preventing device (not shown). However, since the camera shake preventing device is not directly related to the purpose of the present embodiment, the description is omitted. The output terminal of the amplifier 11 is connected to the input terminal of a bandpass filter (BPF) 12. The BPF 12 allows signals in the audible audio band of the detection output of the angular velocity sensor 10 to pass. BP
The output terminal of F12 is connected to one input terminal of the amplifier 6. The other configuration is the same as that of the first embodiment shown in FIG.

Next, the operation of the sound pickup device of the present embodiment will be described. During normal operation, the gain of the amplifier 6 is extremely low under the control of the microcomputer 7. Therefore, the detection signal of the angular velocity sensor 10 input to the amplifier 6 via the amplifier 11 and the BPF 12 is not applied to the subtractor 3. The audio signal detected by the microphone 1 is amplified as it is by the audio amplifier 4 and recorded by the audio recording unit 5. As a result, even if a detection output is generated in the angular velocity sensor 10 due to the vibration in the audible audio band, the detection output is not applied to the subtractor 2 and does not affect the audio signal recorded by the audio recording unit 5 at all.

When the user operates the zoom detecting section 9, the microcomputer 7 detects the operation and operates the zoom lens 8 in a direction intended by the user. At this time, the vibration generated from the mechanical component for driving the zoom lens 8 is transmitted to the microphone 1 and superimposed on the audio signal. This vibration is also transmitted to the angular velocity sensor 10 to generate a detection signal.
The microcomputer 7 is operated by operating the zoom detection unit 9.
Increases the gain of the amplifier 6. For this reason, the detection signal of the angular velocity sensor 10 whose level has risen to the same level as the audio signal is applied to the subtractor 3. As a result, the component of the detection signal due to the vibration included in the audio signal is subtracted from the audio signal and canceled, and only the audio signal is recorded on the magnetic tape of the audio recording unit 5 via the audio amplifier 4. It should be noted that the specific configurations shown in the embodiments of the present invention and the drawings are merely examples for embodying the present invention, and the technical scope of the present invention is limited by these. is not.

[0015]

As described in detail in the above embodiments, according to the camera-integrated video sound pickup apparatus of the present invention,
Noise removal due to vibration during operation of the zoom lens is performed only while the zoom detection unit is being operated. Thus, it is possible to prevent the audio signal from being distorted due to vibration during the operation of the zoom lens. Further, since noise due to vibration is not removed when the zoom lens is not operating, distortion of an audio signal can be prevented by a detection output generated by the vibration in the vibration detection unit or the angular velocity sensor.

[Brief description of the drawings]

FIG. 1 is a block diagram of a sound pickup device of a video imaging and recording device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a sound pickup device of the video imaging and recording device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a sound pickup device of a video imaging and recording device according to the related art.

4 (a) to 4 (c) are waveform diagrams showing the operation of a conventional sound collecting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microphone 2 Vibration detection unit 3 Subtractor 4 Audio amplifier 5 Audio recording unit 6 Amplifier 7 Microcomputer 8 Zoom lens 9 Zoom detection unit 10 Angular velocity sensor 11 Amplifier 12 BPF

Claims (2)

[Claims] 1. A sound pickup microphone that is provided in a video imaging and recording device and detects sound and outputs an audio detection signal. The microphone that is provided in the video imaging and recording device and detects vibration generated during operation of the video imaging and recording device. A vibration detector that outputs a vibration detection signal by performing the above operation; a subtraction unit that receives the audio detection signal and the vibration detection signal and subtracts the vibration detection signal from the audio detection signal; and drives a zoom lens of the video imaging and recording device. A sound pickup device for a video imaging and recording device, comprising: a detection unit that detects that a zoom lens driving unit is operating and outputs a detection signal; and a control unit that causes the subtraction unit to operate based on the detection signal of the detection unit. . 2. A sound pickup microphone that is provided in the video imaging and recording device and detects sound and outputs an audio detection signal. The user is provided in the video imaging and recording device, and the user holds the video imaging and recording device by hand. An angular velocity sensor for detecting a motion of the video imaging and recording apparatus due to shaking or moving hand shake and outputting a detection signal; A band-pass filter that outputs the audio detection signal and the output signal of the band-pass filter, and subtracts the output signal of the band-pass filter from the audio detection signal, and drives a zoom lens of the video imaging and recording device. A detection unit that detects that the zoom lens driving unit is operating, and outputs a detection signal, and a detection signal of the detection unit. Sound pickup device of the video imaging recording apparatus having a control unit for the operation of the subtraction unit.