JPH11178087A - Recording and reproducing device, image-pickup recording and reproducing device, and computer-readable storage medium thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control so as to raise a loudspeaker sound volume by detecting a surrounding noise level, employing a microphone used for recording, when the surrounding noise is high in of sound reproduction of a video camera. SOLUTION: A matrix circuit 8 is controlled to give prescribed directivity to a microphone 7 in recording. The matrix circuit 8 is de-energized in the case of reproduction to make the microphone 7 ominidirectional, so as to facilitate detecting the surrounding noise. A reproduced sound signal is fed to a loudspeaker 3 via an amplifier circuit 2, and subtracted from the entire sound signal fed from the microphone 7 at an adder 10 through a phase inversion circuit 4 and a correction circuit 5. The subtracted output level is detected by a sound level detector 11, and a microcomputer 12 controls the amplification factor of the amplifier circuit 2 depending on the detection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for recording / reproducing sound on / from a recording medium, an imaging / recording / reproducing apparatus such as a video camera for recording an image and a voice on a recording medium, and a computer-readable storage medium used for these. It is about.

[0002]

2. Description of the Related Art A conventional automatic volume control device for automatically controlling the volume of a loudspeaker is disclosed in JP-A-5-30588.

This device includes a first amplifier circuit for amplifying an input audio signal to drive a speaker, a control microcomputer for controlling the amplification of the first amplifier circuit to control the volume of the speaker, A microphone for collecting sound from the loudspeaker and ambient noise, a second amplifier circuit for amplifying an output signal from the microphone, and a phase inversion for inverting a phase of an audio output signal from the first amplifier circuit Circuit, and a level correction for each frequency of the audio signal from the phase inverting circuit so that the audio signal from the speaker and the audio signal from the phase inverting circuit among the signals output from the second amplifier are mutually canceled. And a correction circuit that performs phase delay correction, an addition circuit that adds a signal from the second amplification circuit and a signal from the correction circuit to extract only a noise component, An integrating circuit a signal smoother than the adder circuit, and an A / D converter for inputting a signal from the integrating circuit as converted into a digital signal loudness correction signal to the control microcomputer.

Accordingly, by using this device in, for example, a television receiver or the like, it is possible to increase the volume of a speaker when ambient noise increases during reception.

[0005]

However, in the above-mentioned conventional automatic volume control device, the directional characteristics of the microphone that collects the sound from the loudspeaker and the surrounding noise are fixed. In an imaging recording / reproducing apparatus such as a video camera capable of recording video, a mounted microphone usually has directivity in order to obtain a stereo feeling at the time of recording. When used as a sound collecting microphone for controlling the volume, there is a problem that effective sound collecting becomes difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to enable proper control of speaker volume during reproduction.

[0007]

In a recording and reproducing apparatus according to the present invention, an audio signal collected by a microphone is recorded on a recording medium, and a reproduced audio signal reproduced from the recording medium is emitted from a speaker. In the recording / reproducing device, a change unit that changes the directivity of the microphone between the recording and the reproduction, and a control unit that controls a volume of the speaker in accordance with an audio signal collected by the microphone during the reproduction. Provided.

[0008] In the imaging recording / reproducing apparatus according to the present invention, an image signal captured by an imaging means and an audio signal collected by a microphone are recorded on a recording medium, and a reproduced audio signal reproduced from the recording medium is output from a speaker. In the imaging recording / reproducing apparatus configured to emit sound, changing means for changing the directivity of the microphone between the recording time and the reproducing time, and the volume of the speaker according to a sound signal collected by the microphone during the reproducing time. And control means for controlling the

In a computer readable storage medium according to the present invention, a process of changing the directivity of a microphone between recording and reproduction, and adjusting a volume of a speaker according to an audio signal collected by the microphone during the reproduction. A program for executing the controlling process is stored.

[0010]

FIG. 1 shows a first embodiment of the present invention, and shows an automatic volume control device used in a recording / reproducing apparatus. In FIG. 1, reference numeral 1 denotes an audio signal processing unit for processing an audio signal, reference numeral 2 denotes an amplifier circuit for amplifying and outputting a reproduced audio signal from the audio signal processing unit 1, and reference numeral 3 denotes an audio signal output from the amplifier circuit 2. 4 is a phase inversion circuit for inverting the phase of the output signal from the amplifier circuit 2, and 5 is a correction circuit for performing level correction and phase delay correction for each frequency of the output signal of the phase inversion circuit 4. .

Reference numeral 7 denotes a microphone that collects sound and converts the sound into an electric signal, 8 denotes a matrix circuit that adds a directional characteristic to an audio signal output from the microphone 7, 9 denotes an amplification circuit that amplifies the audio signal from the matrix circuit 8, Reference numeral 10 denotes an adder for adding the audio signal from the amplifier circuit 9 and the audio signal from the correction circuit 5, and reference numeral 11 denotes an audio level to which an output signal of the adder 10 is input and which outputs an output signal corresponding to the signal level. The detector 12 receives the audio level signal from the audio level detector 11, controls the amplifier circuit 2 with a control signal corresponding to the level, and controls the matrix circuit 8 according to the operation mode of the recording / reproducing apparatus. Microcomputer.

Next, the operation of the above configuration will be described. When the operation mode is the recording mode, the sound collected by the microphone 7 is converted into an electric signal,
The signal is sent to the matrix circuit 8 and has a directional characteristic added thereto.
Next, the signal is amplified by the amplifier circuit 9, passed through the adder 10, sent to the audio signal processing section 1, converted into a recording signal, and recorded on a recording medium.

At this time, the microcomputer 12 sends a matrix ON control signal to the matrix circuit 8. Further, the audio signal processing unit 1 does not send a reproduction signal to the amplifier circuit 2. Therefore, in the adder 10,
There is no output signal from the correction circuit 5, and the output signal from the amplification circuit 9 is sent to the audio signal processing unit 1 as it is. Thus, in the recording mode, it is possible to perform a normal recording operation of recording an audio signal having directional characteristics on a recording medium.

Next, when the operation mode becomes the reproduction mode,
The reproduced audio signal processed by the audio signal processing unit 1 is sent to the amplifier circuit 2 and amplified, and then converted into audio by the speaker 3. At this time, the surrounding noise collected by the microphone 7 is sent to the matrix circuit 8. At this time, since a control signal for turning off the matrix is sent from the microcomputer 12 to the matrix circuit 8, the microphone 7
Is not added with the directional characteristic, that is, the audio signal is amplified by the amplifier circuit 9 and transmitted to the adder 10 while maintaining the non-directional characteristic.

On the other hand, the output signal of the amplifier circuit 2 is sent to a correction circuit 5 after its phase is inverted by a phase inversion circuit 4.
The correction circuit 5 performs level correction and phase delay correction for each frequency of the audio signal so as to remove the audio signal from the speaker 3 from the noise collected by the microphone 7. Next, the ambient noise from which the audio signal component from the speaker 3 has been removed by the adder 10 is sent to the audio level detector 11 and sent to the microcomputer 12 as an audio level signal corresponding to the audio level. The microcomputer 12 calculates a temporal average value of the audio level signal, and controls the amplifier circuit 2 using the average value as a control signal. Here, the microcomputer 12 sends the amplification circuit 2
When the temporal average value of the audio level signal is large, the amplification signal of the amplifier circuit 2 is controlled to be large, and when the temporal average value of the audio level signal is small, the control signal 2 is controlled to be small.

FIG. 2 shows a second embodiment of the present invention, and is a block diagram showing a configuration of a video camera provided with the automatic volume control device of FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals. First, the video system will be described. At the time of recording, an optical signal from the lens 13 is converted into an electric signal by a CCD 14 as an image pickup device, and then guided to a video signal processing unit 16 through a camera signal processing unit 15. One of the processed video signals is output from a video output terminal 17 and the other is sent to an electromagnetic conversion system and a recording medium 18 for recording.

At the time of reproduction, the electromagnetic conversion system and the recording medium 18
Are processed by the video signal processing unit 16 and then output to the video output terminal 17.

Next, the audio system will be described. At the time of recording, the audio signal from the microphone 7 is sent to the matrix circuit 8 and added with a directional characteristic. Then, after being amplified by the amplifier circuit 9, the signal is sent to the audio signal processing unit 1 through the adder 10 to be processed into a recorded audio signal, and then sent to the electromagnetic conversion system and the recording medium 18 for recording. At this time, a control signal for turning on the matrix is sent from the system control unit 19 to the matrix circuit 8. Also, a control signal is sent from the system control unit 19 to the audio signal processing unit 1 so that the audio signal processing unit 1 does not output the audio signal to the amplification circuit 2.

At the time of reproduction, the electromagnetic conversion system and the recording medium 18
Is sent to the audio signal processing unit 1, where the processed audio signal is amplified by the amplifier circuit 2 and then emitted by the speaker 3. The noise around the video camera collected by the microphone 7 is sent to the matrix circuit 8. At this time, the system control unit 19
Sends a control signal to the matrix circuit 8 so that the matrix is turned off. The audio signal from the microphone 7 is amplified by the amplifier circuit 9 while being non-directional without adding directivity, and guided to the adder 10.

On the other hand, the output signal of the amplifying circuit 2 is inverted in phase by the phase inverting circuit 4 and then corrected by the correcting circuit 5 so that the sound signal component from the speaker 3 is removed from the noise collected by the microphone 7. The signal is sent to the adder 10 after the level correction and the phase delay correction for each frequency of the signal are performed. Therefore, ambient noise from which the audio signal from the speaker 3 has been removed appears at the output of the adder 10. The sound level of the ambient noise signal from which the sound component from the speaker 3 has been removed is detected by the sound level detection circuit 11, and a detection signal corresponding to the sound level is sent to the system control unit 19. Here, a temporal average of the detected signal is calculated, and when the temporal average level is large, the amplification degree of the amplifier circuit 2 is large, and when the temporal average level is small, the amplification degree of the amplifier circuit 2 is small. An appropriate control signal is sent from the system control unit 19 to the amplifier circuit 2.

As described above, by switching the characteristics of the microphone 7 having directivity during recording to non-directional during reproduction, a collection of noise levels around the video camera for controlling the speaker volume during reproduction. It is possible to collect sound not only from a specific direction but from the entire surroundings, so that more accurate and effective control is possible.

[0022]

As described above, the first, fourth and seventh aspects of the present invention are described below.
According to the present invention, it is possible to effectively control the speaker volume at the time of reproduction of an imaging recording / reproduction device such as a recording / reproduction device or a video camera. According to the second, fifth and eighth aspects of the present invention, control of the speaker volume during reproduction is performed;
It is possible to properly collect the sound of the microphone at the time of recording. Further, according to the third, sixth, and ninth aspects, the control of the speaker volume during reproduction can be performed most appropriately and effectively.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 audio signal processing unit 2 amplification circuit 3 speaker 4 phase inversion circuit 5 correction circuit 7 microphone 8 matrix circuit 9 amplification circuit 10 adder 11 audio level detector 12 microcomputer 14 CCD 15 camera signal processing unit 16 video signal processing unit 18 electromagnetic conversion And recording medium 19 System control unit

Claims (9)

[Claims] An audio signal collected by a microphone is recorded on a recording medium, and a reproduced audio signal reproduced from the recording medium is emitted from a speaker. A recording / reproducing apparatus comprising: a changing unit that changes between time and a time of reproduction; and a control unit that controls a volume of the speaker in accordance with an audio signal collected by the microphone during the reproduction. 2. The recording / reproducing apparatus according to claim 1, wherein said changing means causes said microphone to have a predetermined directivity during said recording, and makes said microphone non-directional during said reproducing. And a subtracting means for subtracting a reproduced audio signal supplied to the speaker from an audio signal obtained from the microphone during the reproduction, and a detecting means for detecting a subtracted output level. 2. The recording / reproducing apparatus according to claim 1, wherein the volume is controlled according to the detected level. 4. An image recording / reproducing apparatus which records an image signal imaged by an image pickup means and an audio signal collected by a microphone on a recording medium, and emits a reproduced audio signal reproduced from the recording medium from a speaker. In the above, there are provided changing means for changing the directivity of the microphone between the recording and reproduction, and control means for controlling the volume of the speaker in accordance with an audio signal collected by the microphone during the reproduction. An imaging recording / reproducing apparatus characterized by the above-mentioned. 5. The apparatus according to claim 4, wherein said changing means causes said microphone to have a predetermined directivity during said recording, and makes said microphone non-directional during said reproduction. 6. A subtracting means for subtracting a reproduced audio signal given to the speaker from an audio signal obtained from the microphone at the time of the reproducing, and a detecting means for detecting a subtracted output level are provided. The imaging recording / reproducing apparatus according to claim 4, wherein the volume is controlled in accordance with the detected level. 7. A program for executing processing for changing the directivity of a microphone between recording and reproduction, and processing for controlling the volume of a speaker in response to an audio signal collected by the microphone during reproduction. A computer-readable storage medium that stores the information. 8. The computer-readable computer according to claim 7, wherein the changing process includes giving the microphone a predetermined directivity at the time of the recording, and making the microphone non-directional at the time of the reproduction. Storage medium. 9. A program for executing a process of subtracting a reproduced audio signal supplied to the speaker from an audio signal obtained from the microphone and a process of detecting a subtracted output level during the reproduction, The computer-readable storage medium according to claim 7, wherein the controlling process controls the sound volume according to the detected level.