JPH076507A - Digital recording and reproducing device - Google Patents

Abstract

PURPOSE:To extend the life of a battery. CONSTITUTION:A compressed digital audio signal is read out of a magneto- optical disk 2 by an optical head 3. Servo control is applied by a servo control circuit 6 to the optical head 3 to read out the compressed digital audio signal from a recording track of the magneto-optical disk 2. Selecting operation of a recording or reproducing mode in an input key operation part 8 is discriminated by a system controller 7. An A/D converter 16 is stopped when the reproducing mode is discriminated by the system controller 7. A D/A converter 34 is stopped when the recording mode is discriminated by the system controller 7, provided an input signal is an analog signal. Consequently, useless power is not consumed by the A/D converter 16 and the D/A converter 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital recording / reproducing apparatus for compressing a digital audio signal to write it on a recording medium and reading the compressed data for reproduction.

[0002]

2. Description of the Related Art The applicant of the present application has previously proposed a technique in which an input digital audio signal is bit-compressed and burst-recorded with a predetermined data amount as a recording unit.

In this technique, a magneto-optical disk or the like is used as a recording medium, and AD (adaptive difference) PCM audio data defined in an audio data format such as so-called CD-I (CD-interactive) or CD-ROM, Alternatively, the digital audio data bit-compressed and encoded according to another format is recorded and reproduced. The bit-compressed digital audio data has a predetermined amount of data as a recording unit, for example, every 32 sectors, a connecting sector (linking sector) is added to the front and the back in consideration of interleaving with data of an adjacent sector. , Sectors are recorded in bursts (intermittently).

Here, for example, a so-called straight PC obtained by simply linearly quantizing data in a so-called standard CD (compact disc) format (CD-DA format) or an analog audio signal.
Consider a case where M audio data is bit-compressed to approximately 1/4 and recorded and reproduced.

The reproduction time (play time) of a disc which is bit-compressed to approximately 1/4 and recorded is approximately 4 when the straight PCM data before compression, for example, data in the CD-DA format is recorded. Doubled. This means that the recording / reproducing time can be obtained on a smaller disc as much as a standard 12 cm CD, so that the device can be miniaturized. Further, by setting the (instantaneous) bit rate of recording / reproducing to the same as that of the standard CD-DA format, the time required to actually perform recording / reproducing can be about 1/4. Therefore, the remaining approximately 3/4 of the time can be allocated to so-called retries. Specifically, for example, when recording data, it is a confirmation (verify) operation of whether or not recording was normally performed, a rewriting operation when recording is not normally performed, etc. This is a re-reading operation when the data error rate is high. As a result, recording / reproduction can be performed more reliably even under adverse conditions in which the mechanism section vibrates due to disturbance, and the focus, tracking, etc. are deviated, and application to a small portable device has become possible.

In the small portable digital recording / reproducing apparatus to which the above technique is applied, the power source is a battery. The battery life (battery life) is limited, and it is necessary to extend the battery life.

Here, the digital recording / reproducing apparatus performs signal processing on the digitized audio signal. Therefore, if the input audio signal is an analog audio signal, it is necessary to convert it into a digital audio signal using an analog / digital (A / D) converter. Further, since the digital audio signal subjected to the digital signal processing cannot drive the headphone, the speaker, etc. in order to hear the sound as it is, an analog signal is obtained by using the digital / analog (D / A) converter. It needs to be converted into an audio signal.

[0008]

By the way, in the conventional digital recording / reproducing apparatus, the above A /
Electric power was consumed by the D converter and the D / A converter.

However, when recording an analog input audio signal, for example, the power consumed by the D / A converter is wasted. Further, the power consumed by the A / D converter is wasted during reproduction and recording of a digital input audio signal.

These useless power consumption has been a factor of shortening the battery life of the small portable digital recording / reproducing apparatus as described above.

The present invention has been made in view of the above circumstances, and is a digital recording / reproducing apparatus that does not consume unnecessary power to the A / D converter and the D / A converter and thus extends the battery life. For the purpose of provision.

[0012]

A digital recording / reproducing apparatus according to the present invention is provided with an A / D converter and a D / A converter in a recording system and a reproducing system, and a signal from the recording system and a signal to the reproducing system are provided. In a digital recording / reproducing apparatus for performing digital signal processing on a disc, a mode discriminating section for discriminating between a recording mode and a reproducing mode, and an A / D converting section is stopped when the reproducing mode is discriminated by the mode discriminating section. The above problem is solved by having a control unit for controlling.

Further, the digital recording / reproducing apparatus according to the present invention is provided with an A / D converter and a D / A converter in the recording system and the reproducing system, and performs digital signal processing on the signal from the recording system and the signal to the reproducing system. In a digital recording / reproducing apparatus for performing the above, a mode discriminating section for discriminating a recording or reproducing mode, an input discriminating section for discriminating whether a signal input to the recording system is a digital signal or an analog signal, and the mode discriminating section Section determines the recording mode and the input determination section determines the digital signal, the A / D conversion section is stopped,
The above problem is solved by having a control unit that stops the D / A conversion unit when the recording mode is determined by the mode determination unit and the analog signal is determined by the input determination unit.

Here, the analog signal may be a microphone input audio signal or a line input audio signal.

Further, in order to solve the above problems, the digital recording / reproducing apparatus according to the present invention has an output discriminating section for discriminating whether the signal outputted from the reproducing system is a digital signal or an analog signal. The control unit stops the A / D conversion unit when the output determination unit determines that the signal is an analog signal, and the A / D converter when the output determination unit determines that the signal is a digital signal. Converter and the above D / A
The conversion units may be stopped together.

[0016]

The A / D converter and the D / A converter used in the recording system and the reproducing system are stopped when they are unnecessary, so that the battery life can be extended without wasting power.

[0017]

Embodiments of the digital recording / reproducing apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block circuit diagram showing a schematic configuration of a digital audio signal recording / reproducing apparatus which is an embodiment of a digital recording / reproducing apparatus according to the present invention.

In this embodiment, an A / D converter 16 is provided in a recording system showing a signal flow by an arrow R _EC and a D / A converter 34 is provided in a reproducing system showing a signal flow by an arrow P _B in the figure. , Digital signal processing is performed on the signal from the recording system and the signal to the reproducing system. When the system controller 7 determines the recording or reproduction mode selection operation on the input key operation unit 8, and when the system controller 7 determines the reproduction mode, the A / D converter 16 is set to the system controller 7 To stop.

In this embodiment, the system controller 7 determines whether the signal input to the recording system, which indicates the signal flow by the arrow R _EC , is an analog signal or a digital signal. When the recording mode is determined and the analog signal is determined, the D / A
The converter 34 is stopped by the system controller.
At this time, when the system controller 7 determines the recording mode and the digital signal, the A /
The D converter 16 is stopped.

Further, in this embodiment, the system controller 7 discriminates whether the signal output from the reproducing system, which shows the signal flow by the arrow P _B , is a digital signal or an analog signal, and the system controller 7 When it is determined that the signal is an analog signal, the A / D converter 16 is stopped, and when the system controller 7 determines that the signal is a digital signal, both the A / D converter 16 and the D / A converter 34 are stopped. Let

In this embodiment, AD (adaptive difference) PCM audio data or a digital audio signal bit-compressed according to another format is recorded on a magneto-optical disk 2 which is a recording medium, and this recording signal is recorded by an optical head 3. Predetermined recording unit (eg 32 sectors +
Each sector (several sectors) is read in a burst manner, bit-compressed audio data is obtained through a decoder 31 for descramble and error correction decoding, and this compressed data is stored in a RAM.
An audio signal is written to a memory 22 such as a (random access memory) and read from the memory 22 at a constant data rate, and a decoder 33 for decompressing (decompressing) the bit compression process on the recording side for decoding. Play.

The magneto-optical disk 2 rotatably driven by the spindle motor 1 is a recordable recording medium. The optical head 3 for performing recording and / or reproduction with respect to the magneto-optical disk 2 includes, for example, a laser light source such as a laser diode, an optical component such as a collimator lens, an objective lens, a polarization beam splitter, and a cylindrical lens, and a predetermined component. It is composed of a photodetector or the like having a light receiving portion of a pattern. The optical head 3 is provided at a position facing the magnetic head 4 with the magneto-optical disk 2 interposed therebetween. When recording data on the magneto-optical disk 2,
The magnetic head 4 is driven by the recording system head drive circuit 22 described later to apply a modulation magnetic field according to the recording data, and the optical head 3 irradiates a target track of the magneto-optical disk 2 with laser light to generate a magnetic field. Thermomagnetic recording is performed by the modulation method. Further, the optical head 3 detects the reflected light of the laser light applied to the target track, detects a focus error by, for example, a so-called astigmatism method, and detects a tracking error by, for example, a so-called push-pull method. When reproducing data from the magneto-optical disk 2, the optical head 3 detects the focus error and the tracking error, and at the same time, detects the difference in the polarization angle (Kerr rotation angle) of the reflected light from the target track of the laser light and reproduces it. Generate a signal.

The output of the optical head 3 is supplied to the RF amplifier circuit 5. The RF amplification circuit 5 extracts the focus error signal and the tracking error signal from the output of the optical head 3 and supplies them to the servo control circuit 6, and binarizes the reproduction signal to supply it to a reproduction system decoder 31 described later. To do.

The servo control circuit 6 is composed of, for example, a focus servo control circuit, a tracking servo control circuit, a sled servo control circuit and the like. The focus servo control circuit controls the focus of the optical system of the optical head 3 so that the focus error signal becomes zero. Further, the tracking servo control circuit controls the tracking of the optical system of the optical head 3 so that the tracking error signal becomes zero. Further, the spindle motor servo control circuit controls the spindle motor 1 so as to rotate the magneto-optical disk 2 at a predetermined rotation speed (for example, a constant linear speed). Further, the sled servo control circuit causes the optical head 3 to move to the target track position of the magneto-optical disk 2 designated by the system controller 7.
And the magnetic head 4 is moved. The servo control circuit 6 that performs such various control operations supplies the system controller 7 with information indicating the operating state of each unit controlled by the servo control circuit 6.

A key input operation unit 8 and a display unit 9 are connected to the system controller 7. The system controller 7 controls the recording system and the reproducing system in the operation mode designated by the operation input information from the key input operation unit 8. Further, the system controller 7 traces the optical head 3 and the magnetic head 4 on the basis of the address information in sector units reproduced from the recording track of the magneto-optical disk 2 by the header time, the Q data of the subcode, or the like. Manages the recording position and playback position on the recording track. Information on the recording position or the reproducing position, information on the function selected by the key operation, and the like are displayed on the display unit 9 as necessary.

Next, the recording system of this embodiment will be described. A microphone input signal A _INM , which is an analog audio signal, is input from the input terminal 10. The microphone input signal A _INM is amplified by the amplifier 12 and supplied to the selected terminal a of the changeover switch 13. Also, the input terminal 11
From the line that is an analog audio signal (LINE)
The input signal A _INL is input and supplied to the selected terminal b of the changeover switch 13.

The changeover switch 13 is controlled by the system controller 7 to change over the switch piece c, and the microphone input signal A _INM or the line input signal A _INL is input to the low-pass filter (LP) according to the operation of the key input operation unit 8.
F) 14 is selectively supplied.

The LPF 14 has a changeover switch 13
Limits the high-frequency component of the analog audio signal of the microphone input signal A _{IN M} or line input signal A _INL supplied from. The analog audio signal with the high frequency component limited is supplied to the automatic gain control (AGC) circuit 15 to adjust the gain.

One of the output signals whose gain is adjusted by the AGC circuit 15 is supplied to an analog / digital (A / D) converter 16. The other of the output signals is the selected terminal a of the changeover switch 36 surrounded by the broken line in the figure.
Is supplied to.

The A / D converter 16 quantizes the analog audio signal and converts it into a digital audio signal. This digital audio signal is so-called straight PCM data that is not subjected to compression processing, and as a specific example, the sampling frequency is 44.1 KHz, similar to the standard CD (compact disc) format (CD-DA format). And the number of quantization bits is 1
It is 6-bit PCM data. This 16-bit audio PCM data is, for example, AD (adaptive difference) PCM.
Is supplied to the encoder 19 for high efficiency encoding processing such as. The encoder 19 is also supplied with a digital audio signal (audio PCM data) via the input terminal 17 and the digital input interface circuit 18.

The encoder 19 is an audio PCM.
The data is subjected to high efficiency bit compression processing and supplied to the memory 20.

The memory 20 is a buffer for writing and reading data controlled by the system controller 7, temporarily storing the bit-compressed data supplied from the encoder 19, and recording it on the disk as necessary. It is used as a memory. That is, for example, in the 1/4 bit compression mode, the standard C
Compressed data of a constant bit rate, which is reduced to approximately 1/4 of the data transfer rate (bit rate) of the D-DA format, is continuously written in the memory 20. When this compressed data is recorded on the magneto-optical disc 2, it is recorded in a burst or discrete manner at the same data transfer rate under the same disc rotation speed (constant linear velocity) as the standard CD-DA format. There is. That is, the time during which the signal is actually recorded in the recording mode is approximately 1/100 of the whole.
4 and the remaining 3/4 of the time is the rest time during which recording is not performed. However, on the magneto-optical disk 2, the next recording is performed following the area recorded immediately before the rest period,
Continuous recording is performed on the surface of the medium. As a result, for example, the same recording density and storage pattern as in the standard CD-DA format are recorded.

Therefore, the compressed data is read out from the memory 20 in a burst at a bit rate corresponding to the data transfer rate of the standard CD-DA format.
The read compressed data is supplied to the encoder 21 for performing interleave processing, error correction coding processing, EFM modulation processing, and the like. Here, in the data string supplied from the memory 20 to the encoder 21, one cluster consisting of a predetermined sector (for example, 32 sectors) is a unit to be continuously recorded in one recording, and when this is encoded, The data amount for one cluster is added with a few sectors for cluster connection. This cluster connection sector is set to be longer than the interleave length in the encoder 21, so that even if interleaved, it does not affect the data of other clusters.

The encoder 21 receives the recording data burst supplied from the memory 20 as described above.
Encoding processing for error correction (parity addition and interleave processing), EFM encoding processing, and the like are performed. The recording data encoded by the encoder 21 is supplied to the magnetic head drive circuit 22. The magnetic head 4 is connected to the magnetic head drive circuit 22,
The magnetic head 4 is driven so as to apply the modulation magnetic field according to the recording data to the magneto-optical disk 2.

Further, the system controller 7 performs the above-mentioned memory control on the memory 20, and continuously records the above-mentioned recording data read out in burst from the memory 20 on the recording track of the magneto-optical disk 2 by this memory control. The recording position is controlled as described above. The control of the recording position manages the recording position of the recording data which is burst-read from the memory 20 by the system controller 7 and outputs a control signal for designating the recording position on the recording track of the magneto-optical disk 2 to the servo control circuit. It is carried out by supplying 6 to.

Further, the system controller 7 is an A / D
The operating state of the converter 16 is controlled by the operating mode and the type of input signal (analog signal or digital signal),
Controls power consumption. Details of this power control will be described later.

Next, the reproducing system of this embodiment will be described. This reproducing system is for reproducing the record data continuously recorded on the recording track of the magneto-optical disk 2 by the above-mentioned recording system, and the recording track of the magneto-optical disk 2 is laser-lighted by the optical head 3. The recording signal is read from the magneto-optical disk 2 by tracing with. Here, the magneto-optical disk 2 is the standard CD described above.
It is driven to rotate at the same rotation speed (constant linear velocity) as in the DA format, the recording signal is read in bursts (discretely) at the same data transfer rate as in the CD-DA format, and is binary by the RF amplifier circuit 5. Decoded 3
1 is supplied.

The decoder 31 corresponds to the encoder 21 in the recording system described above, and is the RF amplifier circuit 5.
The reproduced output signal binarized by the above is subjected to processing such as deinterleaving processing, decoding processing for error correction, EFM demodulation processing, and the like to convert the above-mentioned ¼ compressed data into, for example, the standard CD-DA format described above. Output in burst at the same data transfer rate as. The reproduction data obtained by the decoder 31 is supplied to the memory 32.

In the memory 32, writing and reading of data are controlled by the system controller 7, and reproduced data which is supplied in burst from the decoder 31 at the same data transfer rate as the standard CD-DA format is written. The reproduction data written in bursts is continuously read out from the memory 32 at a constant bit rate, that is, at a data transfer rate of about 1/4 of the standard CD-DA format.

The system controller 7 performs memory control for writing / reading the reproduction data to / from the memory 32, and records the reproduction data burst-written from the memory 32 on the magneto-optical disk 2 by the memory control. The playback position is controlled so that playback is continued from the track. This playback position control is
This is performed by supplying to the servo control circuit 6 a control signal for designating the reproduction position of the above-mentioned reproduction data which is burst-read from the memory 32 by the system controller 7.

Compressed data obtained as reproduced data continuously read from the memory 32 at a transfer rate (bit rate) of about 1/4 of the standard is supplied to the decoder 33. The decoder 33 corresponds to the encoder 19 of the recording system, and, for example, expands the compressed data of 1/4 by 4 times (bit expands) to 1
Play 6-bit digital audio data. The digital audio data from this decoder 33 is
It is supplied to the D / A converter 34 and is also derived from the output terminal 41 via the digital output interface circuit 40.

The D / A converter 34 converts the digital audio data supplied from the decoder 33 into an analog signal and supplies it to the selected terminal b of the changeover switch 36 via the LPF 35.

Here, the system controller 7 is D /
The operation state of the A converter 34 is controlled by the operation mode and the type of output signal (analog signal or digital signal),
Controls power consumption. Details of this power control will be described later.

To the selected terminal a of the changeover switch 36, the gain-adjusted analog audio signal is supplied from the AGC circuit 15 as described above. The changeover switch 36 is controlled by the system controller 7 to change over the switch piece c, and responds to the operation of the key input operation unit 8 with the analog audio signal whose high frequency component is limited by the LPF 35 or the analog audio signal from the AGC circuit 15. Output selectively.

The analog audio signal selectively output from the change-over switch 36 is derived from the output terminal 37 as a LINE OUT output signal A _OTL , amplified by the amplifier 38, and output from the output terminal 39 to the headphone. It is derived as signal A _{OT H.} The analog audio signal supplied from the AGC circuit 15 via the changeover switch 36 is a sound monitor signal at the time of recording. Further, the analog audio signal supplied from the LPF 35 via the changeover switch 36 is
It is a reproduction signal.

By the way, the magneto-optical disk 2 used in this embodiment has 60 stereo audio signals.
It is desirable to set a recording capacity of at least one minute and up to about 74 minutes. For example, when the above-mentioned 1/4 data compression rate is adopted, about 130 M bytes is required. Also, in order to construct a portable or pocket-sized recording and / or reproducing apparatus, it is desirable to use a disk having an outer diameter of 8 cm or a smaller diameter. Further, regarding the track pitch and the linear velocity, the same track pitch as the CD, 1.6 μm, and the linear velocity of 1.2 to 1.4 m /
s is desired. As a disc satisfying these conditions, for example, the disc outer diameter is 64 mm, the data recording area outer diameter is 61 mm, and the data recording area inner diameter is 3 mm.
2 mm, the inner diameter of the lead-in area is 30 mm, and the center hole diameter is 10 mm. This disc is 70
When the disc is stored in a disc caddy of mm × 74 mm, recording / reproducing can be performed on the disc with a recording / reproducing device of a pocket size. The range of the inner and outer diameters of the data recording area of the disk for enabling recording / reproducing for about 72 minutes to 76 minutes in the 1/4 data compression mode is 32 mm when the inner diameter is 32 mm. Outer diameter 60 mm ~ 6
From 2mm, the outer diameter is 71mm-73 when the inner diameter is 50mm
It may be set appropriately within the range up to mm.

In this embodiment as described above, as described above,
When the system controller 7 determines that the mode selected by the input key operation unit 8 is the reproduction mode, the A / D converter 16 is stopped and power control is performed. Also,
When the system controller 7 determines the recording mode and the input signal is an analog signal, the D / A converter 34 is stopped and the system controller 7 determines the recording mode and the digital signal. In that case, the A / D converter 16 is stopped and power control is performed. Further, the system controller 7
When the output signal is judged to be an analog signal, the above A / D
When the converter 16 is stopped and the system controller 7 determines that the output signal is a digital signal, the A / D
Both the converter 16 and the D / A converter 34 are stopped to perform power control.

Here, the system controller 7 is A /
To stop the D converter 16, the A / D converter 16
/ D power control signal, the D / A power control signal is supplied to the D / A converter 34 to stop the D / A converter 34.

Next, the control operation of the system controller 7 as described above will be described with reference to the flowchart of FIG.

First, the system controller 7 determines whether or not the mode selected by the input key operation unit 8 is the recording mode. If YES (recording mode) is determined, the process proceeds to step S2. If NO (reproduction mode) is determined, the process proceeds to step S5 and step S4, and the A / D power control signal is supplied to the A / D converter 16. The A / D converter 16 is stopped.

Next, in step S2, the system controller 7 receives the determination result (recording mode) in step S1, and at this time, the signal input to the recording system indicated by the arrow R _EC in FIG. It is determined whether or not it is an analog audio signal. As the analog audio signal, there is a microphone input signal A _INM or a line input signal A _INL which is selected by the changeover switch 13. Here, if YES (analog audio signal) is determined, the process proceeds to step S3 and the D / A converter 34
To the A / D power control signal to the A / D converter 16 when the D / A power control signal is supplied to the A / D converter 16 and the D / A converter 34 is stopped and it is determined to be NO (digital audio signal). Is supplied to the A /
D Stop the power control signal.

Further, the system controller 7 receives the determination result of NO (reproduction mode) in step S1 and determines in step S5 whether or not the reproduction output signal is an analog audio signal. . If it is determined to be YES (the output signal is an analog audio signal), the process proceeds to step S4, the A / D power control signal is supplied to the A / D converter 16, and the A / D power control signal is supplied.
When the D converter 16 is stopped and it is determined to be NO (the output signal is a digital audio signal), the process proceeds to step S3, the D / A power control signal is supplied to the D / A converter 34, and the D / A converter 34 is supplied. Is stopped and the process proceeds to step S4 to supply the A / D power control signal to the A / D converter 16 to stop the A / D converter 16.

As described above, in this embodiment, the A / D converter 16 and the D / A converter 34 used in the recording system and the reproducing system are used.
Since it is stopped when it is not necessary, it is possible to extend battery life without wasting power.

The digital recording / reproducing apparatus according to the present invention is not limited to the above embodiment, but can be applied to an apparatus in which a normal single-phase 100V is used as a power source. For example, it can be applied to a video recording / reproducing device that performs digital signal processing.

[0055]

The digital recording / reproducing apparatus according to the present invention is provided with an analog / digital converting section and a digital / analog converting section in a recording system and a reproducing system, and performs digital signal processing on a signal from the recording system and a signal to the reproducing system. In the digital recording / reproducing apparatus for performing the above, the mode discriminating unit discriminates between the recording mode and the reproducing mode, and when the discriminating result is the reproducing mode, the control unit stops the analog / digital converting unit. It is possible to extend the battery life without causing the digital conversion unit to consume useless power.

Further, the digital recording / reproducing apparatus according to the present invention is provided with an analog / digital converter and a digital / analog converter in the recording system and the reproducing system, and performs digital signal processing on the signal from the recording system and the signal to the reproducing system. In the digital recording / reproducing apparatus, the mode discriminating unit discriminates the recording or reproducing mode, and the input discriminating unit discriminates whether the signal input to the recording system is a digital signal or an analog signal. When the recording section is discriminating the recording mode and the input discriminating section discriminates the digital signal, the control section stops the A / D converting section, the mode discriminating section discriminates the recording mode and the input discriminating section. When the analog signal is discriminated, the control unit stops the digital / analog conversion unit, so the analog / digital conversion unit and the digital / analog conversion unit It is not possible to wasteful power consumption in, can stretch the battery life.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a schematic configuration of an embodiment of a digital recording / reproducing apparatus according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment shown in FIG.

[Explanation of symbols]

 2 ... Magneto-optical disk 3 ... Optical head 4 ... Magnetic head 6 ... Servo control circuit 7 ... System controller 8 ... Input key Operating unit 15 ... Automatic gain control (AGC) circuit 16 ... Analog / digital (A / D) converter 19 ... Encoder 20 ... Memory 21 ... Encoder 22 ... ..Magnetic head drive circuit 31..Decoder 32..Memory 33 .. ・ Data expansion decoder 34 .... Digital / analog (D / A) converter

Claims (4)

[Claims] 1. A digital recording / reproducing apparatus which comprises a recording system and a reproducing system having an analog / digital converting section and a digital / analog converting section and performs digital signal processing on a signal from the recording system and a signal to the reproducing system, wherein a recording mode And a reproduction mode, and a control section for stopping the analog / digital conversion section when the reproduction mode is discriminated by the mode discrimination section. apparatus. 2. A digital recording / reproducing apparatus, which comprises an analog / digital converter and a digital / analog converter in a recording system and a reproducing system, and performs digital signal processing on a signal from the recording system and a signal to the reproducing system. A mode discriminating section for discriminating a reproduction mode; an input discriminating section for discriminating whether a signal input to the recording system is a digital signal or an analog signal; When the discriminating unit discriminates the digital signal, the analog / digital converting unit is stopped, and when the mode discriminating unit discriminates the recording mode and when the input discriminating unit discriminates the analog signal, the digital / analog conversion is performed. And a control unit for stopping the unit. 3. The digital recording / reproducing apparatus according to claim 2, wherein the analog signal is a microphone input audio signal or a line input audio signal. 4. An output discriminating unit for discriminating whether the signal output from the reproducing system is a digital signal or an analog signal, and the control unit discriminates an analog signal by the output discriminating unit. The analog / digital converter is stopped when the output signal is detected, and both the analog / digital converter and the digital / analog converter are stopped when the output signal is judged to be a digital signal. Item 1 or 2
The digital recording and reproducing apparatus described.