JP2002325219A - Analog voice signal processing circuit and recording reproduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To share a common configuration in a different type analog voice signal processing circuit, for instance, applied to a camera integrated video tape recorder, concerning analog voice signal processing circuit and a recording reproduction device. SOLUTION: The processing object of the output system of a voice signal is changed over, and an input voice signal is output so as to correspond to a processing system with two systems.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analog audio signal processing circuit and a recording / reproducing apparatus, and can be applied to, for example, a camera-integrated video tape recorder. According to the present invention, by switching the processing target of the output system of the audio signal, and by outputting the input audio signal so as to correspond to the two processing systems, the analog audio signal processing circuits of different systems can be used. Configuration that can be shared.

[0002]

2. Description of the Related Art Conventionally, in a video tape recorder integrated with a camera, various products based on a DV system, an 8 mm system, and the like have been provided. The DV system is a digital recording system in which a video signal and an audio signal are converted into digital signals and recorded on a magnetic tape. On the other hand, the 8 mm system is an analog recording system in which a low-frequency-converted chroma signal, a frequency-modulated luminance signal, and a frequency-modulated audio signal are multiplexed and recorded on a magnetic tape.

In such a camera-integrated video tape recorder, an analog audio signal processing circuit that performs analog signal processing on an audio signal obtained from a microphone or the like, performs analog signal processing on a reproduced audio signal, and outputs the analog signal.
An audio signal output from the analog audio signal processing circuit is recorded on a magnetic tape together with a video signal, and a recording / reproducing circuit for processing the reproduced signal obtained from the magnetic tape and reproducing the audio signal is provided by a dedicated integrated circuit. It is made to be composed.

[0004] In recent years, there is a DV type camera-integrated video tape recorder configured to be able to reproduce even a magnetic tape recorded by a conventional 8 mm system. In such a DV camera-integrated video tape recorder having an 8 mm playback function, the DV
In addition to the analog audio signal processing circuit and the recording / reproducing circuit by the system, the analog audio signal processing circuit by the 8 mm system,
A reproduction circuit corresponding to the analog audio signal processing circuit is mounted.

[0005]

Problems to be Solved by the Invention
In a DV camera-integrated video tape recorder having a mm reproducing function, an analog audio signal processing circuit based on the DV system and an analog audio signal processing circuit based on the 8 mm system have a common configuration. If such a common configuration can be shared by the two systems, the whole can be integrated into a circuit so as to support such different systems, and the configuration of this integrated circuit can be simplified. Also, it is considered that the overall configuration of the camera-integrated video tape recorder as a whole can be simplified, and the man-hours for development and maintenance can be reduced accordingly.

The present invention has been made in view of the above points, and it is an object of the present invention to propose an analog audio signal processing circuit and a recording / reproducing apparatus which can share a common configuration in analog audio signal processing circuits of different systems. Is what you do.

[0007]

According to the first aspect of the present invention, there is provided an analog audio signal processing circuit for processing an analog audio signal by using an integrated circuit. An input signal processing means of a recording system for processing the audio signal obtained in step 1 and outputting the audio signal so as to be compatible with a recording system by digital signal processing and a recording system by analog signal processing; and a reproduction system by at least digital signal processing. Selecting means for selecting an audio signal to be processed based on an audio signal obtained from the audio signal and an audio signal obtained from a reproduction system by analog signal processing; and output signal processing for processing the audio signal to be processed and outputting the processed signal to the outside Means.

According to a ninth aspect of the present invention, an audio signal output from an analog audio signal processing circuit formed as an integrated circuit is recorded on a predetermined recording medium, and the audio signal recorded on the recording medium is converted into an analog audio signal. When applied to a recording / reproducing device that outputs from a signal processing circuit, an analog audio signal processing circuit processes at least an audio signal acquired by a microphone, and outputs an audio signal corresponding to a recording system by digital signal processing and an analog signal processing. An input signal processing means of the recording system for outputting by an audio signal corresponding to the recording system by the audio signal obtained from the reproduction system by at least digital signal processing and an audio signal obtained by the reproduction system by analog signal processing. Selecting means for selecting an audio signal to be processed, and output signal processing means for processing the audio signal to be processed and outputting the processed signal to the outside So as to prepare for the.

According to the first aspect of the present invention, the present invention is applied to an analog audio signal processing circuit which is integrated into a circuit and processes an audio signal based on an analog signal, and at least processes an audio signal acquired by a microphone. An input signal processing means of a recording system for outputting an audio signal to a recording system by digital signal processing and a recording system by analog signal processing; and at least an audio signal obtained from a reproduction system by digital signal processing and a reproduction system by analog signal processing. With the obtained audio signal, the input signal processing unit and the output signal are provided by including a selection unit that selects an audio signal to be processed and an output signal processing unit that performs signal processing on the audio signal to be processed and outputs the processed signal to the outside. The processing means can be shared by the two systems, which is common to analog audio signal processing circuits of different systems. Can be shared configuration that.

According to the configuration of the ninth aspect, it is possible to obtain a recording / reproducing apparatus in which a common configuration is shared by analog audio signal processing circuits of different systems.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings as appropriate.

(1) First Embodiment (1-1) Configuration of First Embodiment FIG. 2 is a block diagram showing a camera-integrated video tape recorder according to a first embodiment of the present invention. It is. The camera-integrated video tape recorder 1 is a DV type camera-integrated video tape recorder having an 8 mm playback function.

This camera-integrated video tape recorder 1
In the analog audio signal processing circuit 11, the microphone 2
The audio signals S1R and S1L obtained from R and 2L are signal-processed and output by two systems corresponding to a recording system based on the 8 mm system which is analog signal processing and a DV system which is digital signal processing. Also, an audio signal S obtained from a reproduction system based on the 8 mm system, which is analog signal processing.
4. Selectively process audio signals S2R and S2L obtained from a reproduction system based on the DV system, which is digital signal processing, and output them from a jack 3 which is a line output, and output from a headphone 4 and a speaker 5. The analog audio signal processing circuit 11 outputs a monitor output of a recording system from the jack 3, the headphone 4, and the speaker 5 instead of such a reproduction signal.

An analog-to-digital converter (A / D),
The digital-to-analog conversion circuit (D / A) 6 receives the audio signals S3R and S3L corresponding to the DV-based recording system from the analog audio signal processing circuit 11, performs analog-to-digital conversion processing, and outputs them. Conversely, the digital audio signal output from the digital audio signal processing circuit 7 is subjected to digital-to-analog conversion processing, and the audio signals S2R and S2L obtained from the DV system reproduction system are output to the analog audio signal processing circuit 11. .

The digital audio signal processing circuit 7 includes an analog / digital conversion circuit, a digital / analog conversion circuit 6
The digital audio signal output from the digital audio signal is subjected to digital signal processing in a format suitable for recording on a magnetic tape and output. On the contrary, at the time of reproduction, the recording / reproducing amplifier 8
Of the digital audio signal. In these processes, the digital audio signal processing circuit 7 inputs and outputs digital audio signals and the like to and from an external device via the DV terminal.

The recording / reproducing amplifier 8 drives the magnetic head 9 based on video data obtained from a video signal processing system (not shown) and output data from the digital audio signal processing circuit 7, whereby an audio signal and a video signal are recorded on a magnetic tape. Record During reproduction, the reproduction signal obtained from the magnetic head 9 is amplified and output to the digital audio signal processing circuit 7 and a digital video signal processing circuit (not shown).

When a magnetic tape on which video and audio signals are recorded by the 8 mm system is loaded into the camera-integrated video tape recorder 1, the reproducing amplifier 10
The operation is started based on the detection result by the predetermined detection mechanism, and the reproduction signal obtained from the magnetic head 9 is amplified and the like.
The analog audio signal processing circuit 11 outputs the signal to a video signal processing circuit (not shown). Thus, the camera-integrated video tape recorder 1 can record and reproduce an audio signal and a video signal by the DV system, and reproduce an audio signal and a video signal recorded by the 8 mm system.

FIG. 1 is a block diagram showing the analog audio signal processing circuit 11. The analog audio signal processing circuit 11 is entirely constituted by an integrated circuit, and is adapted to be able to process an audio signal based on an analog signal by being applied to a camera-integrated video tape recorder of the 8 mm system and the DV system.

In this analog audio signal processing circuit 11, automatic volume control circuits (ALC) 13R and 13L
The microphones 2R and 2L respectively receive the right-channel and left-channel audio signals S1R and S1L, and correct and output the signal levels. When the analog audio signal processing circuit 11 is applied to a DV video tape recorder, the selection circuits 14R and 14L are provided with audio signals S2R and S2L output from a digital / analog conversion circuit of a reproduction system, an automatic volume adjustment circuit 13R, 13L
Are received at the respective contacts, and these signals are selected and output. The low-pass filters (LPF) 15R and 15L limit the bands of the output signals of the selection circuits 14R and 14L.

In the analog audio signal processing circuit 11, the output signals of the low-pass filters 15R and 15L can be output to the analog-to-digital conversion circuit of the DV recording system via the selection circuits 17R and 17L. As a result, the analog audio signal processing circuit 11 is applied to a DV video tape recorder and outputs the output signals S3 of the selection circuits 17R and 17L.
Audio signal S1 input from a microphone or the like by R and S3L
L and S1R can be recorded. Further, by switching the selection circuits 14R and 14L, the audio signals S2R and S2L reproduced from the preceding recording track can be fed back to the recording system to execute processing such as after recording.

The band-pass filters (BPF) 18M and 18S receive the frequency-multiplexed audio signal S4 reproduced by the 8 mm video tape recorder, and have a center frequency of 1.5 [MHz] and a center frequency of 1.7, respectively. [M
[Hz]. Demodulation circuit (DEM
OD) 19M and 19S demodulate the output signals of the band-pass filters 18M and 18S, respectively,
The main and sub audio signals S4M and S4S represented by (L + R) / 2 and (LR) / 2 are reproduced and output.

The selection circuits 20R and 20L receive at their contacts the output signals of the automatic volume control circuits 13R and 13L and the output signals of the demodulation circuits 19M and 19S, respectively, and select and output these signals. Low-pass filter (LPF) 11
R and 11L output the signals output from the selection circuits 20R and 20L after band limitation. Selection circuits 22R and 22
L switches contacts in conjunction with the selection circuits 20R and 20L, and outputs the input signal to the matrix circuit (MATRIX) 24 when the audio signals S1R and S1L input from the microphones are selected in the selection circuits 20R and 20L. On the other hand, when the output signals of the demodulation circuits 19M and 19S are selected by the selection circuits 20R and 20L, the output signals of the low-pass filters 21R and 21L are output to the noise reduction circuits (NR) 23M and 23S.
As a result, in the analog audio signal processing circuit 11, the audio signals S1R and S1L acquired from the microphone,
Main and sub audio signals S4M reproduced by the 8 mm system
And S4S share low-pass filters 21R and 21L. The selection circuits 20R and 20R
0L, 22R and 22L are set to a state where no contact is selected as necessary.

When the selection circuits 20R and 20L are set so as not to select any input signal, the switch circuits 26R and 26L convert the audio signals S2R and S2L obtained from the DV system reproduction system into low-pass filters 21R and 21L.
Output to Thus, in this embodiment, the audio signals S2R and S2L obtained from the DV system reproduction system also share the low-pass filters 21R and 21L.

The matrix circuit 24 includes a selection circuit 22R
, And 22L, to generate main and sub audio signals represented by (L + R) / 2 and (LR) / 2 and output them to the noise reduction circuits 23M and 23S. I do. Conversely, the main and sub audio signals output from the noise reduction circuits 23M and 23S are signal-processed to generate right and left channel audio signals, which are then selected by the selection circuits 28R and 28L, Output to 17R and 17L.

Noise reduction circuits 23M and 23S
Are modulation circuits (MOD) 27R and 27R that emphasize the high frequencies of the audio signals output from the matrix circuit 24, respectively.
L and vice versa.
The high frequency range of the audio signal output from L is suppressed and output to the matrix circuit 24. Thereby, in the analog audio signal processing circuit 11, the demodulation circuits 19M and 19S
After the band of the main and sub audio signals according to the 8 mm method demodulated in the above is limited by the low-pass filters 21R and 21L, the noise is suppressed by the noise reduction circuits 23M and 23S, and then demodulated into the right and left channel audio signals by the matrix circuit 24. The audio signals of the right and left channels can be output to the recording system of the DV system by the selection circuits 17R and 17L.

The modulation circuits (MOD) 27M and 27S are:
The main and sub audio signals output by the noise reduction circuits 23M and 23S are frequency-modulated by a predetermined center frequency, respectively, and a subsequent addition circuit 30 adds and multiplexes the output signals of these modulation circuits 27M and 27S.
This analog audio signal processing circuit 11
A recording signal in the 8 mm system is generated by the output signal S5 of 0. As a result, in the analog audio signal processing circuit 11, the selection circuits 20R,
0L, 22R, 22L and switch circuits 26R, 26L, the audio signals S1R, S1 acquired from the microphone are set.
Audio signals S2R and S2 reproduced by the L and DV systems
L, audio signals S4M and S reproduced by the 8 mm system
4S can be recorded on a magnetic tape again by the 8 mm method.

With these configurations, the selection circuits 28R and 28L switch their operations in conjunction with the settings of the selection circuits 20R and 20L, and output signals of the low-pass filters 21R and 21L, output signals of the selection circuits 22R and 22L, and a matrix circuit. 24 output signals, selection circuits 17R and 17
The mute circuits (MUTE) 31R and 3 which follow the output signal of L
Selectively output to 1L. In this way, the selection circuits 28R and 28L include the audio signals S1R and S1L obtained from the microphone, the audio signals S2R and S2L reproduced by the DV system, and the audio signals S4M and S4 by the configuration of each unit described above.
When the right and left channel audio signals obtained by demodulating 4S are input, one of these signals is selected and output.

The silence circuits 31R and 31L are connected to the selection circuit 2
The output signals of 8R and 28L are silenced and output under the control of a control circuit (not shown). In the analog audio signal processing circuit 11, the output signals S6R and S6L of the muffling circuits 31R and 31L can be output as line outputs.

The electronic volume circuits (EVR) 32R and 32L amplify and output the output signals of the selection circuits 28R and 28L according to the gain specified by a control circuit (not shown). The analog audio signal processing circuit 11 can output the output signals S7R and S7L of the electronic volume circuits 30R and 32L as monitor outputs for stereo.

The addition circuit 34 adds the output signals S7R and S7L of the electronic volume circuits 22R and 32L, thereby outputting the addition signal S8 as a monitor output by a speaker or the like.

(1-1) Operation of First Embodiment In the above configuration, in the camera-integrated video tape recorder 1 (FIG. 2), at the time of recording, audio signals S1R and S1L obtained from the microphones 2R and 2L are recorded. An analog-to-digital conversion circuit processed by an analog audio signal processing circuit 11;
It is output to a digital-to-analog conversion circuit 6, where a digital audio signal is generated. Further, after this digital audio signal is processed by the digital audio signal processing circuit 7, it is recorded on the magnetic tape together with the video signal by the recording / reproducing amplifier 8 and the magnetic head 9.

At the time of reproduction, after the reproduction signal obtained from the magnetic head 9 is amplified by the recording / reproduction amplifier 8,
The digital audio signal is processed by the digital audio signal processing circuit 7 to reproduce the digital audio signal.
Is converted into an audio signal by an analog signal. In the camera-integrated video tape recorder 1, this audio signal is processed by the analog audio signal processing circuit 11 and output to the outside.

When a magnetic tape according to the 8 mm system is loaded, a reproduction signal obtained from the magnetic head 9 is processed by a reproduction amplifier 10 and the like, then processed by an analog audio signal processing circuit 11 and output to the outside. .

In the analog audio signal processing circuit 11 (FIG. 1), the audio signals S1R and S1L obtained from the microphones 2R and 2L are adjusted in volume by the automatic volume adjustment circuits 13R and 13L, and then the low-pass filters 15R and 15L.
, And is output to the analog-to-digital conversion circuit 6 from the selection circuits 17R and 17L. Thus, in the camera-integrated video tape recorder 1, a recording system can be driven by an output signal of the analog-to-digital conversion circuit to record an audio signal on a magnetic tape.

The output signals of the selection circuits 17R and 17L are input to the muffling circuits 31R and 31L via the selection circuits 28R and 28L, and the line outputs S6R and S6L and the stereo monitor output are provided through the muffling circuits 31R and 31L. S7R and S7L, monaural monitor output S8
Is obtained, whereby the sound being recorded can be monitored.

On the other hand, during the reproduction of the DV system, the audio signals S2R and S2L output from the digital-to-analog conversion circuit 6 are switched to the switch circuits 26R and 26L.
Are input to the low-pass filters 21R and 21L through the bandpass filter, where the band is limited.
The signal is input to the muffling circuits 31R and 31L via L. Thus, the audio signals S2R and S2L reproduced from the magnetic tape can be monitored.

The audio signals S2R and S2L are input to the low-pass filters 15R and 15L via selection circuits 14R and 14L, are band-limited here, and are then converted to analog-digital conversion circuits via selection circuits 17R and 17L. Is output to Thus, in the DV system, the audio signal S reproduced from the preceding recording track
Processing such as editing the 2R and S2L as necessary and re-recording it on a magnetic tape can be executed.

The audio signal S2 thus obtained is
In R and S2L, the output signals of the low-pass filters 21R and 21L are input to the matrix circuit 24 via the selection circuits 22R and 22L, where they are converted into main and sub audio signals. Further, the frequency characteristics of the main and sub audio signals are changed by the noise reduction circuits 23M and 23S.
After the correction, the signals are frequency-modulated by the modulation circuits 27M and 27S, added by the addition circuit 30, and frequency-multiplexed. As a result, a modulation signal S5 of an audio signal according to the 8 mm system is generated from the audio signals S2R and S2L reproduced according to the DV system, and the audio signals S2R and S2L reproduced according to the DV system are output to the recording system according to the 8 mm system and recorded. It becomes possible.

On the other hand, when the present invention is applied to a video tape recorder of the 8 mm system, the volume of the audio signals S1R and S1L obtained from the microphone is adjusted by the automatic volume control circuit 13.
R, 13L, the low-pass filter 21R,
The band is limited by 21L, and is input to the matrix circuit 24 via the selection circuits 22R and 22L. Further, after the frequency characteristics of the main and sub audio signals output from the matrix circuit 24 are corrected by the noise reduction circuits 23M and 23S, the modulation circuits 27M and 27S
, And are added by the addition circuit 30 to be frequency-multiplexed. This makes it possible to generate a modulation signal S5 of the audio signal in the 8 mm format from the audio signals S1R and S1L obtained from the microphone, and record the signal on the magnetic tape in the 8 mm format.

In this case, in the audio signals S1R and S1L thus input, the output signals of the low-pass filters 21R and 21L are connected to the selection circuits 28R and 2R.
The sound is input to the muffling circuits 31R and 31L via 8L, whereby the sound being recorded can be monitored also in this case.

On the other hand, in the reproduction signal S4 of the 8 mm system, the band is limited by the band-pass filters 18M and 18S, respectively, and then the demodulation circuits 19M and 1
9S, the main and sub audio signals S4M and S4S are reproduced. Further, the main and sub audio signals S4M and S4S are supplied to selection circuits 20R and 20L.
Are input to the low-pass filters 21R and 21L, and are band-limited here.
The signal is input to the noise reduction circuits 23M and 23S via L. After the frequency characteristics of the main and sub audio signals are corrected by the noise reduction circuits 23M and 23S, the main and sub audio signals are converted into right channel and left channel audio signals by the matrix circuit 24, and the audio signals are supplied to the selection circuits 28R and 28L. Silencer circuits 31R and 31L via
Is input to This makes it possible to monitor the audio signal recorded by the 8 mm method.

Also, in this way, the matrix circuit 24
The output audio signal is output via the selection circuits 17R and 17L, whereby the audio signal reproduced by the 8 mm method can be recorded by the DV method.

For recording and reproducing in this manner, in the analog audio signal processing circuit 11, the mute circuits 31R, 31L, the electronic volume circuit, which are the output systems of the audio signal, in the case of the DV system and the case of the 8 mm system. 32R, 32L, and the addition circuit 34, the selection circuit 28
The audio signals to be processed are switched by R and 28L, and the output signals of the automatic volume control circuits 13R and 13L, which are the input systems of the audio signals, are output to two processing systems, whereby the DV system and the 8 mm system are common. The common configuration is shared.

By switching the input and output of the low-pass filters 21R and 21L, the low-pass filters 21R and 21 are shared between the reproduction by the DV system and the recording and reproduction by the 8 mm system.

(1-3) Effects of the First Embodiment According to the above configuration, the processing object of the output system of the audio signal is switched by the selection circuit, and the input audio signal is processed by two systems. By outputting the signal corresponding to the system, the common configuration can be shared between the DV system and the 8 mm system. Therefore, by applying the present invention to the camera-integrated video tape recorder 1, the overall configuration can be simplified accordingly. Further, high versatility can be ensured by applying to various types of video tape recorders.

Also, by switching the input and output of the low-pass filter for band-limiting the audio signal, the low-pass filter can be shared between the reproduction by the DV system and the recording and reproduction by the 8 mm system. And the 8 mm system can share a common configuration, and the overall configuration can be simplified accordingly.

The audio signal obtained from the DV system, which is a reproduction processing system based on digital signal processing, can be output to an 8 mm recording processing system based on analog signal processing. Since the audio signal obtained from the processing system can be output to the recording system of the DV system, for example, the audio signal reproduced by the 8 mm system is subjected to digital signal processing to execute processing such as reduction of noise and wind noise. It is possible to improve the sound quality of the audio signal by the 8 mm method,
It is also possible to digitally output an audio signal reproduced by the mm system.

(2) Second Embodiment FIG. 3 is a block diagram showing a camera-integrated video tape recorder according to a second embodiment of the present invention. This camera-integrated video tape recorder 51 is configured by omitting the reproduction amplifier 10 from the camera-integrated video tape recorder 1 described in the first embodiment, and thereby records video and audio signals only by the DV system. It is configured to be playable.

According to the configuration shown in FIG.
The DV system camera-integrated video tape recorder can be configured by using the analog audio signal processing circuit 11 that shares the same configuration with the m system.

(3) Third Embodiment FIG. 4 is a block diagram showing a camera-integrated video tape recorder according to a third embodiment of the present invention. The camera-integrated video tape recorder 61 is configured to record and reproduce video signals and audio signals only by the 8 mm system.

That is, in the camera-integrated video tape recorder 61, the recording / reproducing amplifier 62 receives the frequency multiplexed signal S4 of the audio signal from the analog audio signal processing circuit 11, and the frequency multiplexed signal S4 and the video signal (not shown) The signal is multiplexed with a modulation signal based on a video signal obtained from the processing circuit. Further, the magnetic head 9 is driven by the multiplexed signal obtained as a result, and the video signal and the audio signal are recorded on the magnetic tape.

On the contrary, the reproduced signal obtained from the magnetic head 9 is amplified and output to the analog audio signal processing circuit 11 and a video signal processing circuit (not shown).

According to the configuration shown in FIG.
An 8-mm camera-integrated video tape recorder can be configured using the analog audio signal processing circuit 11 that shares the same configuration with the m system.

(4) Other Embodiments In the above-described embodiment, the case where the analog audio signal processing circuit is configured to be applicable to the 8 mm system and the DV system has been described. However, the present invention is not limited to this. In other words, when the analog audio signal processing circuit is configured to be applicable to these schemes and other schemes, and when the analog audio signal processing circuit is configured to be applicable to a plurality of other schemes, the method is widely applied. Can be.

[0055]

As described above, according to the present invention, by switching the processing target of the audio signal output system, and by outputting the input audio signal so as to correspond to the two processing systems. In addition, the configuration common to the analog audio signal processing circuits according to different systems can be shared.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an analog audio signal processing circuit applied to a camera-integrated video tape recorder according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a camera-integrated video tape recorder using the analog audio signal processing circuit of FIG. 1;

FIG. 3 is a block diagram showing a camera-integrated video tape recorder according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a camera-integrated video tape recorder according to a third embodiment of the present invention.

[Explanation of symbols]

1, 51, 61 ... video tape recorder integrated with a camera, 22 ... analog audio signal processing circuit, 13R, 13
L: Automatic volume control circuit, 14R, 14L, 17R, 1
7L, 21R, 21L, 28R, 28L ... selection circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/7826 H04N 5/782 CF term (Reference) 5C018 BA04 5C022 AA11 AC69 AC71 AC79 5C053 GB11 JA01 KA08 LA01 5D044 AB05 CC01 FG01 FG04 JJ05 JJ06 JJ07 5D080 BA01 DA01 EA01 FA03 FA08 FA11 FA54 JA06

Claims (9)

[Claims] An analog audio signal processing circuit integrated into an integrated circuit for processing an audio signal based on an analog signal, wherein at least an audio signal obtained by a microphone is processed, and a recording system and an analog signal processing by digital signal processing are provided. Input signal processing means of the recording system that outputs the audio signal in a manner compatible with the recording system according to the above, and at least an audio signal obtained from the reproduction system by digital signal processing and an audio signal obtained from the reproduction system by analog signal processing. An analog audio signal processing circuit comprising: a selection unit that selects an audio signal to be processed; and an output signal processing unit that performs signal processing on the audio signal to be processed and outputs the processed signal to the outside. 2. The analog audio signal processing circuit according to claim 1, wherein said input signal processing means is an automatic volume control circuit for correcting a signal level of said audio signal. 3. The analog audio signal processing circuit according to claim 1, wherein said input signal processing means is a low-pass filter. 4. The analog audio signal processing circuit according to claim 1, wherein said output signal processing means is a volume variable circuit for varying a volume according to the audio signal to be processed. 5. The analog audio signal processing circuit according to claim 1, wherein said output signal processing means is a muffling circuit for silencing the audio signal to be processed. 6. The apparatus according to claim 1, further comprising selection means for supplying an audio signal from said input signal processing means to said output signal processing means in place of the audio signal to be processed selected by said selection means. 3. The analog audio signal processing circuit according to 1. 7. An analog audio signal processing circuit according to claim 1, further comprising switching means for supplying an audio signal obtained from a reproduction system based on said digital signal processing to a recording system based on said analog signal processing. 8. The analog audio signal processing circuit according to claim 1, further comprising switching means for supplying an audio signal obtained from a reproduction system based on said analog signal processing to a recording system based on said digital signal processing. 9. An analog audio signal processing circuit which records an audio signal output from an integrated analog audio signal processing circuit on a predetermined recording medium and reproduces the audio signal recorded on the recording medium. In a recording / reproducing device that outputs from a circuit, the analog audio signal processing circuit processes at least an audio signal acquired by a microphone, and an audio signal corresponding to a recording system by digital signal processing;
An input signal processing means of a recording system for outputting by an audio signal corresponding to a recording system by analog signal processing; and at least an audio signal obtained from a reproduction system by digital signal processing and an audio signal obtained from a reproduction system by analog signal processing. A recording / reproducing apparatus, comprising: a selection unit that selects an audio signal to be processed; and an output signal processing unit that performs signal processing on the audio signal to be processed and outputs the processed signal to the outside.