JPH09167443A - Digital recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital recording and reproducing device which effectively utilizes the recording area of recording medium. SOLUTION: A level judging section 42 periodically judges whether the input level of sound data exceeds a criterion level during a special recording condition. When the level exceeds the criterion level, a sound companding section 13 starts compression of sound data in accordance with the indication of a sound compression controlling section 41 to store the compressed data into a DRAM 15. After this compressed data is read out by a memory controller 14 for each cluster, it is recorded into an MD(mini disk). When the input level is less than the criterion level over an allowed period T during recording, a level judging section 42 suspends the sound companding section 13 through the section 41. The DRAM 15 holds the compressed data not satisfying one cluster during the suspension of recording until the restarting time of recording. This compressed data is recorded into the MD together with the compressed data after the restart of recording.

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 audio data in the time axis direction and recording the compressed audio data on a recording medium, and particularly to a recording medium for recording audio data whose input level varies. The present invention relates to a digital recording / reproducing apparatus which can effectively use the recording area of

[0002]

2. Description of the Related Art In recent years, for example, a mini disk, which is a magneto-optical disk (Mini Disk: hereinafter referred to as MD)
A digital recording / reproducing apparatus for converting an audio signal into a digital signal for recording, such as an MD device using
Widespread. In these digital recording / reproducing apparatuses, a method of compressing and recording a digital signal is widely used in order to record high-quality sound for a long time in a limited recording capacity.

For example, the MD device compresses a digital audio signal to about ⅕ using an audio compression technique and then records it in an MD. As a result, a high-quality audio signal can be recorded on an MD having a diameter of 64 mm and a small diameter for about 74 minutes.

Here, the operation of the MD device at the time of starting or stopping recording on the MD will be briefly described. When the user presses a recording key or the like to instruct to start recording, the audio compression / expansion unit starts compression of an input digital audio signal (hereinafter referred to as audio data).
The compressed data compressed by the audio compression / decompression unit is, for example, a DRAM (Dynamic R
After being temporarily stored in the andom access memory), it is written to the MD in units of one cluster. The speed at which the audio compression / decompression unit writes to the DRAM and the speed at which the voice is transferred from the DRAM to the MD are different from each other, and writing to the DRAM and transfer from the DRAM are performed asynchronously.

On the other hand, when the user presses the stop key,
When the recording stop instruction is given, the audio compression / expansion unit stops the compression, and of the data stored in the DRAM, the data not recorded in the MD is written in the MD. Further, when the data stored in the DRAM is less than one cluster, the MD device adds 0 data, aligns the data into one cluster, and then writes the data in the MD. In addition, these 0
The area in which data is written is called a trash area and does not contribute to actual recording or reproduction.

[0006]

However, in the above-mentioned conventional MD device, since recording is continued unless a user's instruction is given, a silent portion having a low input level of audio data is also recorded, and MD recording is performed. The problem is that the area is wasted.

In addition, in order to effectively use the recording area, it is necessary for the user to instruct the recording to be interrupted each time there is no sound and to start the recording each time when there is a sound. is there. As a result, the operation becomes complicated, and there is a problem that the operation time delay or the operation error is likely to occur. Furthermore, since the volume is determined and the operation is performed, during the recording period, the user can
Must be operated on the device side.

Further, in the MD device, MD is used in cluster units.
Since it is written in, a trash area that does not contribute to recording or reproduction is generated when recording is stopped or interrupted.
Therefore, when recording is frequently interrupted, the ratio of the trash area to the recording area of the MD increases, and the effective recording area may decrease.

The present invention has been made in view of the above problems, and an object of the present invention is to realize a digital recording / reproducing apparatus capable of automatically interrupting recording and effectively utilizing a recording area of a recording medium. It is in.

[0010]

In order to solve the above-mentioned problems, a digital recording / reproducing apparatus according to the invention of claim 1 comprises a data compression means for compressing input audio data in a time axis direction, for example, a DRAM. (Dynamic Random access M
a temporary storage unit configured to temporarily store the compressed data compressed by the compression unit, and compressed data stored in the temporary storage unit for each predetermined writing unit such as a cluster unit. A digital recording / reproducing apparatus having a recording means for recording on a recording medium such as a magnetic disk is characterized by taking the following means.

That is, in the special recording state in which recording is intermittently performed according to the input level of the audio data, the detecting means for measuring the input level of the audio data to detect the recording start point, and the instruction of the detecting means. The compression control means stops the compression of the audio data by the data compression means until the recording start time and starts the compression of the audio data from the recording start time.

In the above construction, for example, when the user gives an instruction to shift to the special recording state by pressing a particular key, the detecting means measures the input level to determine whether or not the recording start time has come. To determine. In this state, the data compression means has not compressed the audio data, and the audio data in the meantime is not recorded.

For example, when the detection means determines that the recording start time has come, for example, by detecting that the input level of the audio data exceeds a predetermined determination level, the compression control means determines the data compression based on this. Causes the means to start compressing the audio data. Therefore, the compressed data corresponding to the audio data after the recording start time is stored in the temporary storage means. When the compressed data stored in the temporary storage means exceeds the writing unit, the recording means writes the compressed data in the recording medium for each writing unit.

As a result, the digital recording / reproducing apparatus is
Even if there is no user on the spot, recording can be started when the input level becomes high. Therefore, it is possible to prevent the recording of the silent portion until the recording is started. As a result, the labor of the user can be reduced and the recording area of the recording medium can be effectively used.

According to a second aspect of the present invention, there is provided a digital recording / reproducing apparatus according to the first aspect of the present invention, wherein in the configuration of the first aspect of the invention, the detecting means is the data compressing means in the special recording state. While compressing the audio data, the input level of the audio data is measured to detect the recording interruption time point, and the compression control means stops the compression of the audio data by the data compression means after the recording interruption time point, The recording unit records, on the recording medium, the compressed data that is less than the writing unit among the compressed data stored in the temporary storage unit at the time of the recording interruption. Further, the digital recording / reproducing apparatus is characterized by including invalid data generating means for generating invalid data to be added to the compressed data when recording the compressed data less than the writing unit on the recording medium.

In the above structure, after the start of recording, the data compressing means compresses the audio data, and while the digital recording / reproducing apparatus is recording, the detecting means measures the input level and becomes the recording interruption time. It is determined whether or not.

For example, when the detection means detects the recording interruption point because the input level is lower than the judgment level for the grace period T or more, the compression control means stops the data compression means. In this state, the data compression unit does not write new compressed data to the temporary storage unit, and recording of the audio data is suspended.

Further, when the temporary storage means stores compressed data that is less than the write unit at the time of the recording interruption, the recording means reads the compressed data from the temporary storage means and invalidates the portion which is short of the write unit. The invalid data generated by the data generating means is supplemented and written in the recording medium.

While the data compression means is not compressing the audio data, the detection means measures the input level to detect the recording start time. When the input level rises to the start point, the data compression means starts compression of the audio data,
The digital recording / reproducing apparatus resumes recording of audio data.

While recording invalid data, that is,
While writing the trash area, the recording means
Compressed data is not read from the temporary storage means. Therefore, even if the input level of the audio data rises immediately after the interruption, the compressed data corresponding to the audio data is not mixed with the compressed data before the interruption. As a result, the recording means can properly and surely write the respective compressed data to the recording medium.

As a result, even if a silent portion is generated after the recording is started, the digital recording / reproducing apparatus can prevent the recording of the silent portion without receiving an instruction from the user. Therefore, the labor of the user can be further reduced, and the recording area of the recording medium can be used more effectively.

According to a third aspect of the present invention, there is provided a digital recording / reproducing apparatus according to the first aspect of the present invention, wherein in the configuration of the first aspect of the invention, the detecting means is in the special recording state and the data compressing means. While the audio data is being compressed, the input level of the audio data is measured to detect the recording interruption time point, and the compression control means stops the compression of the audio data by the data compression means after the recording interruption time point.
Further, the recording means is characterized in that the compressed data written to the temporary storage means after the recording is restarted and the compressed data before the recording interruption are combined into a writing unit and written to the recording medium.

In the above arrangement, at the time of recording interruption, the compression control means stops the data compression means according to the instruction of the detection means. Further, the temporary storage means holds the compressed data that is less than the writing unit at the time of the recording interruption. Further, the recording means does not record the compressed data on the recording medium.

When the data compression means restarts the compression of the audio data at the recording start time, the compressed data is newly written in the temporary storage means. The recording unit writes the compressed data on the recording medium when the compressed data before the interruption and the compressed data after the restart are combined into a writing unit.

Therefore, it is possible to prevent the occurrence of a trash area when recording is interrupted. Therefore, claim 2
The recording area of the recording medium can be used more effectively than the described digital recording / reproducing apparatus.

In order to solve the above-mentioned problems, a digital recording / reproducing apparatus according to a fourth aspect of the present invention comprises a data compression means for compressing input audio data in the time axis direction and a compressed data compressed by the compression means. In a digital recording / reproducing apparatus having a temporary storage means for temporarily storing and a recording means for recording the compressed data stored in the temporary storage means on a recording medium for each predetermined writing unit, the following means are provided. There is.

That is, the data compression means always compresses the audio data during the special recording state in which recording is interrupted according to the input level of the audio data, and the input level of the audio data is changed during the special recording state. Based on an instruction from the detecting means for measuring and detecting the recording start time point, the area to be written is the same area when the data compression means writes the compressed data to the temporary storage means until the recording start time point based on the instruction of the detecting means. And a writing area control means for setting the writing area.

In the above structure, when the special recording state is entered, the data compression means always compresses the audio data and writes the compressed data in the same area of the temporary storage means according to the instruction of the writing area control means.

In this state, since the compressed data is written in the same area, the total amount of compressed data stored in the temporary storage means does not increase. As a result, the compressed data for the writing unit is not accumulated, and the recording unit does not record new audio data on the recording medium.

At the recording start time, the writing area control means cancels the setting of the writing area, and the data compression means writes the compressed data to a new area as in the case of normal recording. When the compressed data is accumulated and the write unit is reached, the recording unit writes the compressed data to the recording medium.

As a result, the digital recording / reproducing apparatus is
Even if there is no user on the spot, it is possible to prevent the recording of the silent portion until the recording is started. Therefore, the recording area of the recording medium can be used more effectively than before.

Further, since the data compressing means always compresses the audio data, the time when the writing area control means resets the writing area is between the detection of the recording start time and the start of recording. If it does not enter, the audio data immediately before the start of recording can be recorded in the recording medium. Therefore, it is possible to prevent the occurrence of headaches, and it is possible to more reliably record the audio data as compared with the digital recording / reproducing apparatus according to the first aspect of the invention.

In order to solve the above-mentioned problems, a digital recording / reproducing apparatus according to a fifth aspect of the present invention has a structure according to the fourth aspect of the invention, in which the detecting means is in the special recording state. , Measuring the input level of the audio data to detect the recording interruption point, and the writing area control means,
From the time when the recording is interrupted to the time when the next recording is started, the data compression means sets the area for writing the compressed data to the temporary storage means in the same area, and the recording means is stored in the temporary storage means at the time of the recording interruption. Among the compressed data, the compressed data that is less than the writing unit is recorded on the recording medium. Further, the digital recording / reproducing apparatus is characterized by including invalid data generating means for generating invalid data to be added to the compressed data when recording the compressed data less than the writing unit on the recording medium.

In the above construction, when the detecting means detects the recording interruption time, the writing area control means writes the compressed data in the temporary storage means by the data compression means from the recording interruption time to the next recording start time. Set the area to the same area. In this state, the total amount of compressed data stored in the temporary storage means does not increase. Therefore, the recording means
After the recording is interrupted, the newly written compressed data is not written in the recording medium, and the recording of the audio data is interrupted.

Further, when the temporary storage means stores the compressed data which is less than the writing unit at the time of the recording interruption, the recording means reads the compressed data from the temporary storage means and deletes the portion which is insufficient for the writing unit. The invalid data generated by the invalid data generating means is supplemented and written in the recording medium.

On the other hand, when the input level rises again and the recording start time is reached, the data compression means writes the compressed data in a new area of the temporary storage means, and the total amount of compressed data increases. As a result, recording of audio data is restarted. Further, since the invalid data generating means generates invalid data, recording can be resumed even if the input level rises immediately after the interruption.

Thus, the recording of the audio data can be interrupted according to the input level of the audio data, and the recording area of the recording medium can be used more effectively as compared with the digital recording / reproducing apparatus according to the fourth aspect.

Furthermore, since the data compressing means always compresses the audio data, it is possible to prevent the occurrence of head loss at the start of recording. Therefore, the audio data can be recorded more reliably as compared with the digital recording / reproducing apparatus according to the second aspect.

According to a sixth aspect of the present invention, there is provided a digital recording / reproducing apparatus for solving the above-mentioned problems, in the configuration of the fourth aspect of the invention, wherein the detecting means is in the special recording state. , Measuring the input level of the audio data to detect the recording interruption point, and the writing area control means,
From the time when the recording is interrupted to the time when the next recording is started, the data compression means sets the area where the compressed data is written in the temporary storage means to the same area. Further, the recording means is characterized in that the compressed data written to the temporary storage means after the recording is restarted and the compressed data before the recording interruption are combined into a writing unit and written to the recording medium.

In the above structure, from the recording interruption time point to the next recording start time point, the writing area control means is configured to temporarily store the compressed data by the data compression means from the recording interruption time point to the next recording start time point. The area to be written to the means is set to the same area. In this state, the total amount of compressed data stored in the temporary storage means does not increase. The recording means is
Do not write compressed data that is less than the writing unit to the recording medium. Therefore, the temporary storage means holds the compressed data while the recording is suspended.

When the input level rises again and the recording start time comes, the data compression means writes the compressed data in a new area of the temporary storage means. The recording unit combines the compressed data stored before the interruption and the compressed data after the resuming, and writes the compressed data to the recording medium for each writing unit.

Therefore, even if the recording is interrupted depending on the input level of the audio data, the trash area does not occur.
Therefore, the recording area of the recording medium can be used more effectively than the digital recording / reproducing apparatus according to the fifth aspect. Further, it is possible to prevent the occurrence of head loss at the start of recording, and it is possible to more reliably record the audio data as compared with the digital recording / reproducing apparatus according to the third aspect of the invention.

In order to solve the above-mentioned problems, a digital recording / reproducing apparatus according to a seventh aspect of the present invention comprises a data compression means for compressing input audio data in a time axis direction and a compressed data compressed by the compression means. In a digital recording / reproducing apparatus having a temporary storage means for temporarily storing and a recording means for recording the compressed data stored in the temporary storage means on a recording medium for each predetermined writing unit, the following means are provided. There is.

That is, the data compression means always compresses the audio data during the special recording state in which the recording is interrupted according to the input level of the audio data, and the compressed data is stored in the area different from the previous time in the temporary storage means. I am writing.

During the special recording state, the recording means measures the input level of the audio data to detect the recording start time, and the recording means operates until the recording start time based on the instruction of the detecting means. The address of the read area to be read from the temporary storage means is controlled to prevent the recording means from writing to the recording medium, and at the start of recording, the data compression means reads the read data according to the address of the area to which the compressed data is written. And a read area control unit for setting an address of the area.

In the above structure, when the special recording state is entered, the data compression means always compresses the audio data and writes the compressed data in the area of the temporary storage means different from the previous storage area. Therefore, new compressed data is sequentially stored in the temporary storage means. However, the read area control unit moves the read area, for example, by increasing the address of the read area by the same amount as the written area moves. As a result, the recording unit determines that the amount of compressed data stored in the temporary storage unit has not increased. Therefore, during this period, the recording unit does not record the data corresponding to the new audio data on the recording medium.

On the other hand, when the detection means detects the recording start time, the read area control means calculates the address of the read area from the address of the write area at that time, for example, to calculate the address of the read area. decide. Therefore, the recording means starts recording on the recording medium from the compressed data corresponding to the audio data slightly before the recording start time.

As a result, the digital recording / reproducing apparatus is
Even if there is no user on the spot, it is possible to prevent the recording of the silent portion until the recording is started. Therefore, the recording area of the recording medium can be used more effectively than before.

Further, the digital recording / reproducing apparatus can record the audio data slightly before the recording start time on the recording medium. Therefore, the time to start recording the audio data can be set to a predetermined time before the input level rises or the like. As a result, compared with the digital recording / reproducing apparatus according to claim 4,
The time to start recording audio data can be set more flexibly.

In order to solve the above-mentioned problems, a digital recording / reproducing apparatus according to an eighth aspect of the present invention has a structure according to the seventh aspect of the invention, wherein the detecting means is in the special recording state. , Measuring the input level of the audio data to detect the recording interruption time point, and the recording means, among the compressed data stored in the temporary storage means at the recording interruption time point,
The recording device is provided with invalid data generation means for generating invalid data to be added to the compressed data when recording the compressed data less than the writing unit on the recording medium and recording the compressed data less than the writing unit on the recording medium. It is characterized by being.

When the detection means detects the recording interruption point, the recording means also reads the compressed data which is less than the writing unit from the temporary storage means. Further, the recording means supplements the portion lacking in the writing unit with the invalid data generated by the invalid data generating means and records the portion on the recording medium. While recording the invalid data, the recording unit does not read the compressed data from the temporary storage unit. Therefore, even if the input level of the audio data increases immediately after the interruption, the compressed data corresponding to the audio data does not mix with the compressed data before the interruption,
The recording means can properly and surely write the respective compressed data to the recording medium.

As a result, even if a silent portion is generated after the recording is started, the digital recording / reproducing apparatus can prevent the recording of the silent portion without receiving the instruction from the user. Therefore, as compared with the digital recording / reproducing apparatus according to claim 7,
The time and effort of the user can be further reduced, and the recording area of the recording medium can be used more effectively. Further, the time to start recording the audio data can be set more flexibly as compared with the digital recording / reproducing apparatus according to the fifth aspect.

[0053]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
The following is a description with reference to FIG. That is, as shown in FIG. 2, a mini disk device (hereinafter abbreviated as MD device) 1 according to the present embodiment is a mini disk (Mini Disk: abbreviated as MD hereinafter) 2,
It is used to record and reproduce data such as voice.

On the front panel 1a of the MD device 1, an operation section 3 and a display 4 are arranged.
The operation unit 3 includes keys such as a power key, an eject key, a play key, a pause key, a stop key, a fast-forward key, and a rewind key, and the user operates these keys to Operation can be instructed to the MD device 1. Further, the display 4 displays time information such as the total playing time of the mounted MD 2, the elapsed time of the song being played, the remaining playing time of the song being played, the remaining playing time of the whole, and the like.
The track number of the song being played is displayed. Further, the display 4 can also display the music being played and the level of the recording input signal. When a disc name or a track name is recorded on the MD 2, the display 4 can also display such information.

Further, the MD device 1 is provided with a mounting tray 5 on which the MD 2 is placed. When the eject key of the operation unit 3 is operated, the mounting tray 5 is pulled out from the front panel 1a as indicated by a two-dot chain line in the figure. Place the MD2 on this mounting tray 5 and then again
By storing the device in the device 1, the MD device 1 has an MD2
Is attached. As a result, the MD device 1 has the MD2
It becomes possible to record and reproduce.

Further, the operation unit 3 according to the present embodiment is provided with
A normal recording key 6 and a special recording key 7 for instructing recording on the mounted MD 2 are provided. When the normal recording key 6 is operated, the MD device 1 continuously records in the MD 2 from the time when it is operated as usual. On the other hand, when the special recording key 7 is operated, the MD device 1 shifts to the special recording state and can record the input signal in the MD 2 during the period in which the input sound exceeds the predetermined level.

In the MD device 1 according to the present embodiment, a digital audio signal (hereinafter simply referred to as audio data) serving as a recording source is supplied from the analog input terminal 11a to the ADC 12 as shown in FIG. , Is directly supplied from the digital audio input terminal 11b to the audio compression / decompression unit (data compression means) 13.

This voice compression / decompression unit 13 uses ATRAC
The input audio data is compressed to about ⅕ using the (Adaptive Transform Acoustic Coding) method, and then the DR is a temporary storage means via the memory controller 14.
The compressed data is stored in AM (Dynamic Random accessMemory) 15 for each sound group.

On the other hand, the memory controller 14 uses the DRA
The compressed data stored in M15 is EFM for each cluster.
-Transfer to the CIRC encoder / decoder (recording means) 16. EFM / CIRC encoder / decoder 16
Is the CIRC (Cross Interleave Reed-Solomon Code)
) Is used to perform error correction coding on the received compressed data, and then EFM (8-14 modulation) is performed.

EFM / CIRC encoder / decoder 1
The recording data formed by 6 is supplied to the recording magnetic head 22 located above the disk 2a of the MD 2 via the head drive circuit 21. As a result, the magnetic field modulated by the recording data is applied to the disk 2a rotated by the spindle motor 23. On the other hand, an optical pickup 24 is arranged below the disk 2a so as to face the recording magnetic head 22. This optical pickup 24
Irradiates the disk 2a with a laser beam. As a result, data is recorded on the disc 2a of MD2.

The optical pickup 24 comprises the feed motor 2
5, the disk 2a is moved in the radial direction. Further, the servo control circuit 26 controls the spindle motor 23.
In addition to controlling the rotation, the optical pickup 24 and the feed motor 25 are controlled to perform tracking and focus control of the laser beam. As a result, the optical pickup 24 can irradiate the laser beam to a desired position on the disc 2a of the MD2.

Further, the address decoder 27 detects the address data indicating the position on the disk 2a at the time of recording from the signal transmitted from the optical pickup 24 via the RF amplifier 28, and the EFM / CIRC encoder /
It is supplied to the decoder 16. The address data is wobble-recorded in advance in the groove formed on the disc 2a of MD2.

On the other hand, at the time of reproduction, contrary to the time of recording, MD
The data recorded on the second disc 2a is reproduced by the optical pickup 24 and then transmitted through the RF amplifier 28 to the EF.
It is transmitted to the M / CIRC encoder / decoder 16.
The EFM / CIRC encoder / decoder 16 performs EFM demodulation on this data and then performs error correction processing to restore compressed data. This compressed data is stored in the DRAM 15 via the memory controller 14. On the other hand, the memory controller 14 sequentially sends the compressed data stored in the DRAM 15 to the audio compression / decompression unit 13. The voice compression / decompression unit 13 decompresses the received compressed data into voice data. The DAC 29 converts this audio data into an analog signal and then sends it out from the audio output terminal 30.

Further, the MD device 1 is provided with the level data holding circuit 31 and can hold the peak value of the audio data inputted from the digital audio input terminal 11b and the ADC 12. Further, when reproducing the MD2, the level data holding circuit 31 uses the audio compression / expansion unit 1
The peak value of the audio data output by 3 is measured. The level data holding circuit 31 is used by the system controller 17
Clears the peak value each time is read. By this, the peak value of the audio data inputted thereafter can be measured.

Further, the system controller 17 is
At the time of recording or reproduction, the peak value is read from the level data holding circuit 31 every predetermined period, and the level meter is displayed on the display 4 based on the read peak value.
Further, the system controller 17 is responsive to instructions from the operation unit 3 to compress the audio compression / decompression unit 13 and the memory controller
4 etc., the entire MD device 1 can be controlled.

As shown in FIG. 1, the system controller 17 according to the present embodiment operates / compresses the audio compression / decompression unit 13.
Audio compression control unit (compression control means) 41 for controlling stop
And a level determination section (detection means) 42 that determines whether or not the input level exceeds a predetermined determination level and gives an instruction to the audio compression control section 41. It is configured to control the operation / stop of the compression / expansion unit 13 to intermittently record to the MD2.

When the MD device 1 shifts to the special recording state by pressing the special recording key 7 of the operation unit 3 shown in FIG. 2 or the like, the voice compression control unit 41 until the level determination unit 42 gives an instruction. The voice compression / decompression unit 13 can be stopped. As a result, recording on the MD2 can be put on standby.

On the other hand, when the MD device 1 shifts to the special recording state, the level determining section 42 outputs the level data holding circuit 31.
Is read out every predetermined read cycle c to determine whether or not the input level of the audio data exceeds the predetermined judgment level. If it exceeds, the level determination unit 42
Through the voice compression control unit 41.
To work. As a result, the MD device 1 can start recording on the MD 2.

Also, in the special recording state, the MD device 1
Even during recording in D2, the level determination unit 42 is reading the input level of the audio data, as in the standby state.
Furthermore, the level determination unit 42 determines that the predetermined grace period T or more,
When the input level is below the determination level, the voice compression control unit 41 stops the voice compression / decompression unit 13. As a result, the MD device 1 can interrupt recording on the MD2.

The voice compression control section 41 and the level determination section 42 are functional blocks realized by the system controller 17 executing a predetermined program.

By the way, when the MD device 1 records data, it is necessary to control the laser power. Also,
In the EFM / CIRC encoder / decoder 16,
The interleave length of CIRC used for error correction coding is set to 108 frames, which is longer than the length of one sector of MD2 (98 frames). As a result, a linking area is required for error correction coding.

Therefore, each MD device 1 has 36
Writing to MD2 in cluster units composed of sectors, the EFM / CIRC encoder / decoder 16
The compressed data is received from the DRAM 15 for each cluster. Of the 1 cluster (36 sectors), the first 3 sectors are used as linking sectors, and the next 1 sector is reserved for sub data. The compressed data is recorded in the remaining 32 sectors.

The optical pickup 24 is about 1.4M.
It is possible to write to MD2 at a transfer rate of bits / second. Therefore, the transfer rate between the EFM / CIRC encoder / decoder 16 and the DRAM 15 is also about 1.4M.
It is set to bits per second.

On the other hand, when the digital audio signal is a stereo signal, the audio compression / expansion unit 13 compresses each 512 samples of the left and right channels to 212 bytes.
These compressed data are 424
Handled in bytes. In the following description, one unit is called a sound group. The voice compression / decompression unit 13
Transfers the compressed data to the DRAM 15 for each sound group via the memory controller 14.

In the MD device 1 according to this embodiment, the digital audio signal is represented as a 16-bit digital value sampled at 44.1 KHz. Therefore, the compressed data of one sound group is
It corresponds to a digital audio signal of about 11.6 ms. As a result, the data transfer rate between the audio compression / decompression unit 13 and the DRAM 15 is about 300 Kbit / sec. In addition, 5
The audio data of 12 samples is 2048 bytes, so the compression rate is 424/2048, that is, about 1/5.
Becomes

Between the audio compression / decompression unit 13 and the DRAM 15, the EFM / CIRC encoder / decoder 16 and the DR
The transfer rate and the transfer unit of the AM 15 are different from each other. Therefore, the respective transfers are performed asynchronously with each other, and the memory controller 14 makes the EFM / CIR during the period in which there is no transfer from the audio compression / decompression unit 13.
Transferred to the C encoder / decoder 16.

From the voice compression / decompression unit 13 to the DRAM.
When transferring data to DRAM 15, and from DRAM 15 to EFM.
The operation of the memory controller 14 when transferring to the CIRC encoder / decoder 16 will be described.

As shown in FIG. 4, the DRAM 15 is provided with an audio data area for storing compressed data from the lower limit address a to the upper limit address b. Since the DRAM 15 according to this embodiment has a storage capacity of 4 Mbits, it can store compressed data corresponding to about 10 seconds. The lower limit address a and the upper limit address b are initialized from the system controller 17 to the memory controller 14 before recording / reproducing the MD2.

Further, the memory controller 14 is provided with a pointer A and a pointer P pointing inside the audio data area. At the time of recording, the pointer A indicates the address to be written from the audio compression / decompression unit 13 to the DRAM 15, and the pointer P is the EFM / CIRC encoder /
The read address for transfer to the decoder 16 is designated. The compressed data stored at the addresses from the pointer P to the pointer A is the data that is not recorded in the MD2.

At the start of recording / reproduction, both pointers A and P are initially set to point to the same address, for example, the lower limit address a. In addition, pointer A
When P increases and exceeds the upper limit address b, the memory controller 14 causes the pointer exceeding the upper limit address b to point to the lower limit address a.

The memory controller 14 transfers the compressed data from the audio compression / decompression unit 13 to each sound group DR.
When writing to the AM 15, the pointer A moves according to the amount of written data. The voice compression / decompression unit 13 has about 1
Since one sound group (424 bytes) of compressed data is written every 1.6 ms, the average moving speed of the pointer A is about 300 Kbit / sec.

On the other hand, the memory controller 14 determines MD2 from the difference between the value indicated by the pointer A and the value indicated by the pointer P.
The amount of compressed data that has not been recorded is calculated for each cluster, and EFM.
Transfer to the CIRC encoder / decoder 16. DRA
From M15 to EFM / CIRC encoder / decoder 16
Since the data transfer rate to the pointer is set to about 1.4 Mbit / sec, the pointer P moves at about 5 times the speed of the pointer A. As a result, at the time of recording or reproduction, the distance between the pointer A and the pointer P is usually maintained to slightly exceed a maximum of one cluster.

If the desired recording address of the MD2 could not be recorded due to vibration or the like, the memory controller 1
4 returns the pointer P to the original position, and the MD device 1 accesses the desired recording address again and tries recording. During this time, the voice compression / decompression unit 13 is still compressing the voice data, and new compressed data is written in the DRAM 15. In this state, the pointer P is stopped,
The pointer A is moving as usual.

If more compressed data than the compressed data which can be stored in the audio data area is written while the recording continues to fail and the pointer A passes the pointer P, the unrecorded data to the MD2 is recorded. New compressed data is written in the portion, and some unrecorded data is lost. On the other hand, before the pointer A passes the pointer P, MD2
If the recording is successful, the audio data can be recorded without any trouble.

The DRAM 15 according to this embodiment has a storage capacity of about 4 Mbits and can store compressed data for about 10 seconds. Therefore, the audio data can be buffered for a practically sufficient time against a tracking error due to a shock at the time of recording.

Below the lower limit address a, the TOC
/ User TOC area is provided. The area is MD
Of the data recorded in 2, the TOC or the user TOC that is frequently referred to and updated at the time of recording or reproduction is stored, and the user TOC on the MD 2 can be updated by writing to the area.

The operation of each unit of the digital processing unit 18 in the special recording state in the above structure will be described below with reference to the timing chart shown in FIG. 5 or FIG.

When the user presses the special recording key 7 of the operation unit 3 shown in FIG. 2 to shift the MD device 1 to the special recording state, as shown in FIG. 1, the level determination unit 42 provided in the system controller 17 is provided. Reads the peak value of the input level of the audio data from the level data holding circuit 31 for each read cycle c, and waits until the input level reaches a predetermined determination level.

In the level determining section 42 according to this embodiment,
The read cycle c is set to 4 ms, for example. Therefore, the level determination unit 42, during the recording standby, 4
It is determined every ms whether or not the input level has reached the determination level (the period from t0 to t1 shown in FIG. 5). Since the input level is below the determination level during this period, the level determination unit 42 does not instruct the audio compression control unit 41 to operate the audio compression / decompression unit 13. Therefore, the voice compression / decompression unit 13 has not compressed the voice data, and the value indicated by both pointers A and P remains the value a set at the time t0 and remains unchanged.

When the input level of the voice data rises and exceeds the judgment level at t1, the level judgment unit 42
Next, when the peak value is read from the level data holding circuit 31 (time t2), it detects that the input level exceeds the determination level, and the audio compression / decompression unit 13 via the audio compression control unit 41. To start compressing audio data. As a result, the MD device 1 starts recording on the MD 2.

The voice compression / decompression unit 13 is shown in FIG.
As shown in, the compression of the audio data is started from time t2. Note that, in FIG. 5B, the data corresponding to the first audio data is indicated by the diagonal line to the lower right.

Further, the audio compression / expansion unit 13 issues a transfer start request to the memory controller 14 every time the audio data of one sound group is compressed. Upon receiving the transfer start request, the memory controller 14 causes the audio compression / decompression unit 1
The compressed data is received from 3, and is recorded in the DRAM 15 from the address indicated by the pointer A. Also, the pointer A
Moves according to the amount of transferred data.

As a result, the DRAM 15 has about 11.6.
Compressed data of one sound group is written every ms. The time required for one data transfer is about 0.
It is about 5 to 1.5 ms.

On the other hand, recording on the MD2 is performed in units of one cluster asynchronously with the data transfer from the audio compression / expansion unit 13 to the DRAM 15. That is, the memory controller 14 does not transfer the compressed data to the EFM / CIRC encoder / decoder 16 while the difference between the value indicated by the pointer P and the value indicated by the pointer A is less than one cluster. Therefore, during this period, the value indicated by the pointer P is constant (the period from t2 to t4). The value indicated by the pointer A is increased by 1SG for each sound group. Note that 1SG is the data amount of one sound group.

On the other hand, for example, at time t4, the pointer A points to a + C, and the pointer P points to a. Therefore, the difference between the value indicated by the pointer P and the value indicated by the pointer A, PA, has reached the data amount C for one cluster.

In this way, when one cluster of compressed data is stored in the DRAM 15, the memory controller 14
Transfers one cluster of compressed data from the address indicated by the pointer P of the DRAM 15 to the EFM / CIRC encoder / decoder 16. The value indicated by the pointer P increases according to the amount of data transferred to the EFM / CIRC encoder / decoder 16. As a result, the MD device 1
Can be recorded in MD2 in cluster units.

In MD2, one cluster is composed of 32 sectors for recording compressed data, and 11 sound groups are assigned to 2 sectors.
Therefore, the memory controller 14 uses the EFM / CI
Compressed data for one cluster is transferred to the RC encoder / decoder 16 approximately every 2 seconds. The transfer time for one transfer is set to about 0.5 seconds. In addition, the transfer rate at the time of transfer is set to about 5 times the average transfer rate between the audio compression / decompression unit 13 and the memory controller 14, and every time transfer is performed to the EFM / CIRC encoder / decoder 16, a pointer is set. The difference between P and the pointer A becomes short.

In the special recording state, the MD device 1
While recording on the MD2, the MD device 1 suspends the recording when the input level of the audio data is below the determination level for the grace period T or more. Thereby, the MD device 1
It is possible to effectively use the recording area of MD2 without recording a silent portion in MD2.

That is, the system controller 17
Similar to the recording standby, the peak value of the input level is read from the level data holding circuit 31 and it is determined whether the input level of the audio data is below the determination level for a predetermined grace period T or more. .

As shown in FIG. 6A, the time when the input level of the voice data is below the judgment level (time t1).
Therefore, if the judgment level is not reached for the grace period T, the level judgment unit 42 instructs the sound compression control unit 41 to stop the sound compression / expansion unit 13 (time t2). As a result, t
Audio data after 2 is no longer recorded, and MD device 1
Shifts to the recording standby state. In this state, as shown in FIG. 5B, the input level of the audio data is judged every read cycle c until the judgment level is exceeded,
stand by.

By the way, since the compression of the audio data is stopped according to the input level, the audio compression / decompression unit 13 does not always stop the compression of the audio data at the delimiters of the clusters. Therefore, normally, when compression is stopped, (b) in FIG.
As shown in, at t2, less than one cluster of compressed data is stored in the DRAM 15. Note that, in FIG. 6, this compressed data is indicated by a diagonal line rising to the right.

In the MD device 1 according to the present embodiment, the compressed data is DR until the MD device 1 restarts recording or leaves the special recording state and stops recording.
Hold in AM15.

After the recording is interrupted at the time point t2, if the input level of the audio data exceeds the judgment level at the time point t3, the level judgment unit 42 determines the same as at the time point t2 shown in FIG. , To the voice compression controller 41.
Instruct the operation of. This causes the MD device 1 to
Restart recording.

When recording is restarted, compressed data is stored in the DRAM 15. When the accumulated compressed data becomes one cluster including the compressed data before the interruption, the memory controller 14 transfers the compressed data for one cluster to the EFM / CIRC encoder / decoder 16,
The MD device 1 writes the data in MD2. In addition,
In the figure, the compressed data after resuming is shown by a diagonal line descending to the right.

While the MD device 1 is in the special recording state, MD
When the input level of the audio data exceeds the judgment level, the device 1 starts recording, and when the performance on the recording source side has ended, the input level falls below the judgment level and the grace period T elapses. If, stop recording.

During the special recording state, the system controller 17 monitors whether or not the stop key of the operation unit 3 shown in FIG. 2 has been pressed. When the user presses the stop key, the system controller 17 stops the audio compression / decompression unit 13, acquires the cluster value, the sector value, and the sound group value at the time of the stop from the memory controller 14 and stores them. Furthermore, as shown in FIG.
These values are written as end addresses at predetermined positions in the TOC / user TOC data area provided in M15. As a result, the user TOC (sector 0) of MD2 is updated. In addition, the memory controller 14
In accordance with an instruction from the system controller 17, adds 0 data after the compressed data of less than 1 cluster to make 1 cluster and transfers it to the EFM / CIRC encoder / decoder 16.

As a result, as shown in FIG. 6B, M
Compressed data obtained by compressing audio data and 0 data are written in D2. A sector or a sound group in which 0 data is written in a cluster does not contribute to actual recording or reproduction and is called a trash area.

As described above, in the digital processing section 18 according to the present embodiment, the level determination section 42 detects that the input level of the audio data has reached the determination level, and the audio compression control section 41 detects this. Accordingly, the operation of the audio compression / decompression unit 13 is started. This allows
The MD device 1 can omit recording to the MD 2 while the input level of the audio data is low and the silent portion is useless even when recording.
As a result, the recording area of MD2 can be used more effectively.

Since the recording is started according to the input level even when the user is not present, the MD device 1 starts recording on the MD2 even when the recording start time is unknown and a timer or the like cannot be set. it can. Further, since the user's operation can be reduced, the user's operation error and operation delay can be prevented.

In addition, in the digital processing unit 18 according to the present embodiment, when the level determination unit 42 detects that the input level of the audio data is below the determination level for the grace period T or more during recording of the audio data, Voice compression controller 41
Stops the operation of the voice compression / decompression unit 13.

Therefore, during the special recording state, the MD device 1 can prevent the recording of the silent portion. As a result, MD2
The recording area of can be used more effectively. It should be noted that, since the silent part is reduced, there is a possibility that an uncomfortable feeling may occur during reproduction of the MD2. ,
Stop recording. Therefore, the input level of the audio data recorded immediately before the interruption is lower than the determination level, and no discomfort is caused.

Further, the MD device 1 interrupts the recording according to the input level without the user instructing the start or the interruption of the recording. Therefore, at the time of recording, it is possible to reduce the time and effort of the user's operation, and to prevent an operation error and a time delay.

By the way, the conventional MD device 1 cannot frequently determine whether or not to intermittently perform recording. Therefore, when there is an instruction to suspend or stop recording, the MD device 1 is operated as in the stop key input shown in FIG.
Writes the compressed data obtained by compressing the audio data and the 0 data, and writes it in MD2 in units of one cluster. As a result, when recording is frequently interrupted, the ratio of the trash area that does not contribute to the actual recording and reproduction of the audio data in the cluster increases. As a result, the ratio of the effective recording area in MD2 decreases.

However, the DRAM 15 according to the present embodiment.
When the recording is interrupted, the compressed data of less than one cluster is stored, and the MD device 1 records the compressed data in MD2 together with the compressed data after the recording is restarted. As a result, it is possible to prevent the trash area from being generated. As a result, the MD device 1
Can use the recording area of MD2 more effectively.

On the other hand, in the MD device 1 having the above-mentioned structure, since the compression of the audio data is started after the input level is detected, the audio data at the time when the input level reaches the judgment level cannot be recorded and the head is truncated. There is a problem that it occurs.

Therefore, instead of the system controller 17 shown in FIG. 1, a system controller 17a is used as shown in FIG. While the system controller 17a controls the intermittent recording by operating / stopping the audio compression / decompression unit 13, the system controller 17a controls the area for writing compressed data in the DRAM 15 so that the MD2
The record to is interrupted.

That is, the above system controller 17
The a includes a voice compression control unit 41a instead of the voice compression control unit 41 shown in FIG. This audio compression control unit 41
In a, while the audio compression control unit 41 controls the audio compression / expansion unit 13 according to the input level, the audio compression / expansion unit 13 is always operated during the special recording state regardless of the input level.

Further, the system controller 17a includes
A storage area control unit (writing area control means) 43a is newly provided to control the storage area used when the memory controller 14 transfers the compressed data to the DRAM 15 according to the input level of the audio data.

The storage area control section 43a has a memory controller each time the sound compression / expansion section 13 compresses sound data of one sound group until the input level exceeds the judgment level, that is, in the recording standby state. The value of the pointer A of 14 is reset to the same value as the previous time. As a result, the memory controller 14 writes the compressed data in the same storage area of the DRAM 15.

The operation of each section of the digital processing section 18a in the special recording state will be described below with reference to the timing charts shown in FIGS.

When the MD device 1 shifts to the special recording state by pressing the special recording key 7 shown in FIG. 2 or the like, the audio compression controller 41a provided in the system controller 17a.
Instructs the audio compression / decompression unit 13 to start compression of audio data. Thereby, as shown in FIG. 5C, the audio compression / expansion unit 13 always compresses the audio data during the special recording state.

The voice compression / decompression unit 13 transfers the voice data to the DRAM 15 for each sound group while compressing the voice data. The pointer A increases according to the transferred data amount. Then, prior to the transfer of the next sound group, the level determination unit 42 determines whether or not the input level has reached the determination level. If the determination level has not been reached, the storage area control unit 43a sets the pointer A to the same value as the previous value. As a result, when transferring the next sound group, the memory controller 14 transfers the compressed data to the same area in the DRAM 15 as the previous area.

Therefore, as in the period from t0 to t2, while the input level of the audio data does not exceed the determination level, the memory controller 14 always keeps the same address on the DRAM 15, such as the address a set at t0. Compressed data is being written from the address. During this time,
The memory controller 14 changes from the DRAM 15 to the EFM.
No data has been transferred to the CIRC encoder / decoder 16, and the value of the pointer P has not changed.

If the input level exceeds the judgment level at time t1, the level judgment unit 42 detects this at the time t2 at which the peak value is read next, and the storage area control unit 43a detects the pointer A. Cancel the setting of. As a result, the value of the pointer A increases in accordance with the amount of compressed data stored, and the memory controller 14 transfers the compressed data stored in the DRAM 15 to the EFM / CIRC encoder / decoder 16 in units of one cluster. This gives M
The D device 1 starts recording compressed data in the MD 2.

In the digital processing section 18a according to this embodiment, the audio compression / expansion section 13 constantly compresses audio data during the special recording state. Also, the voice compression / decompression unit 1
The address of the area for storing the compressed data is reset every time tc when 3 completes the compression of one sound group. As a result, the MD device 1 starts MD from the sound group including the time point t1 when the input level exceeds the determination level.
You can record to 2.

When the read cycle c is longer than one sound group, that is, when c ≧ 11.6 ms, the next level read must not be performed until the compression of the next sound group is completed. There is. In this case, new compressed data is overwritten on the compressed data at the time point t1 and a head loss occurs. However, in the present embodiment, since the read cycle c is set shorter than the transfer cycle from the audio compression / decompression unit 13, it is possible to eliminate the occurrence of head loss.

As a result, the recording to the MD2 is made to wait until the input level of the audio data reaches the judgment level, and after the judgment level is reached, the audio data is accurately recorded without cutting off. it can.

On the other hand, during recording, the level determination section 42 reads the peak value of the input level of the audio data from the level data holding circuit 31 at the read cycle c. When the read input level is below the determination level for the grace period T or more, the level determination unit 42 shifts the MD device 1 to the recording standby state. That is, the storage area control unit 43a responds to the instruction from the level determination unit 42 from t0 to t shown in FIG.
Pointer A for each sound group transfer
Reset the value of to the same value. As a result, the memory controller 14 writes the compressed data in the same area of the DRAM 15 (the period from t2 to t3 shown in FIG. 6).

At t3, when it is detected that the input level has reached the judgment level, the storage area control section 43a stops the control of the area. As a result, the pointer A is
The compressed data is moved in accordance with the amount of data written in 5, and the compressed data is stored in a new area on the DRAM 15. As a result, the MD device 1 restarts recording on the MD2.

Similar to the digital processing section 18 shown in FIG.
Also in the digital processing unit 18a according to the present embodiment, compressed data of less than one cluster is often stored when recording is interrupted (indicated by a diagonal line rising to the right in the figure). Therefore, the DRAM 15 according to the present embodiment also holds the audio data until the input level reaches the determination level next time.

After that, the recording on the MD2 is performed by combining the compressed data written in the DRAM 15 until the recording is interrupted and the compressed data after the recording is restarted (indicated by the diagonal line in the lower right of the figure). It is performed for each cluster.

By the way, in the configuration of the digital processing section 18a, since the compressed data is overwritten in the same area during the standby, when the input level exceeds the judgment level, the compressed data before the current sound group is , DRAM15
Does not exist on. Also, the read cycle c ≧ 11.6
In the case of ms, the compression completion time point tc of the audio compression / decompression unit 13 may be inserted between t1 and t2 shown in FIG.

Therefore, instead of the system controller 17a shown in FIG. 7, the system controller 17b is used as shown in FIG. 9 so that the recording can be performed shortly before the rise of the input level. While the system controller 17a controls the area to be written in the DRAM 15, the system controller 17 according to the present embodiment.
In the area b, the area read from the DRAM 15 by the memory controller 14 is controlled to intermittently perform recording on the MD2.

The system controller 17b shown in FIG.
A storage area control unit (readout area control means) 43b is provided instead of the storage area control unit 43a shown in FIG. The storage area control unit 43b can control the pointer P according to the instruction of the level determination unit 42. As a result, during recording standby, the distance between the pointer A and the pointer P can be kept substantially constant, and recording on the MD 2 can be restricted.

The operation of each section of the digital processing section 18b when recording is started in the special recording state will be described below with reference to the timing chart shown in FIG. 5 (d).

When shifting to the special recording state, the audio compression / expansion unit 13 starts the compression of the audio data based on the instruction of the audio compression control unit 41a. Therefore, during the special recording state, the audio compression / expansion unit 13 continues to compress the audio data,
The memory controller 14 stores the compressed data from the address indicated by the pointer A for each sound group in the DRAM 15
Write to Further, unlike the storage area control unit 43a shown in FIG. 7, the storage area control unit 43b does not control the pointer A. Therefore, the pointer A moves according to the amount of written data, and the compressed data is stored in the DRAM 15 from an address different from the address where the previously compressed data is stored.

In normal recording, in this case, the pointer P does not move, and as the compressed data is written, the distance between the pointer A and the pointer P increases and the compressed data is accumulated. However, the storage area control unit 43b according to the present embodiment reads the pointer A from the memory controller 14 each time the transfer of one sound group is completed during recording standby, and based on this, the pointer P of the memory controller 14 is read. Set new. As a result, the pointer P moves with the pointer A, and the distance between the pointer A and the pointer P, that is, the amount of unrecorded data to the MD2 is
Does not increase (time period from t0 to t2).

At time t2, the level judgment unit 42
Detects that the input level of the audio data has exceeded the determination level, and causes the storage area control unit 43b to stop controlling the pointer P. As a result, the pointer P is held as it is at the value at that time.

For example, both pointers A at time t2
・ The value of P is n, and the data amount of one sound group is 1SG
Then, after t2, every time the compressed data is written in the DRAM 15, the pointer A is n + 1SG, n + 2SG.
, While the pointer P remains n until the compressed data for one cluster is accumulated, and does not change (period from t2 to t3).

At time t3, when one cluster of compressed data is accumulated in the DRAM 15, the memory controller 14 extracts one cluster of compressed data from the address indicated by the pointer P of the DRAM 15 by the EFM / CIRC encoder / decoder 16. , And the pointer P increases according to the amount of transferred data.

This makes it possible to reliably record the compressed data corresponding to the audio data at the moment when the input level exceeds the judgment level. Furthermore, during the recording standby, the storage area control unit 43
When b sets the pointer P, the pointer P may be delayed from the pointer A by a fixed amount α (indicated by a broken line in FIG. 5D). As a result, the compressed data corresponding to the audio data a certain time before the input level of the audio data exceeds the determination level can be recorded in the MD2.

By the way, during the special recording state, the pointer A
When the recording standby time is long when the recording data is constantly moved, the pointer A goes around the pointer P and approaches the pointer P, and the memory controller 14 may overwrite the compressed data stored in the DRAM 15 with another compressed data. . Therefore,
The compressed data stored in the DRAM 15 needs to be recorded in the MD 2 even if it is less than one cluster.

However, as shown in FIG. 8B, when the time from the time t2 when the recording is interrupted to the time t3 until the recording is restarted is short, the compression completion time tc of the cluster including the time t2 is t3 or later. Sometimes.

In this case, DR during the period from t3 to tc
In the AM 15, the area to be written from the audio compression / decompression unit 13 and the area to be read to the EFM / CIRC encoder / decoder 16 overlap. Therefore, for example, instead of the 0 data added to the end of the cluster, another data is written, which causes a problem.

Therefore, as shown in FIG. 9, in the EFM / CIRC encoder / decoder 16 according to the present embodiment,
A 0 data generation unit (invalid data generation means) 44b is provided. The 0 data generation unit 44b sets the transfer data input group to D based on the end address designated by the level determination unit 42 provided in the system controller 17b.
The data can be supplied to the head drive circuit 21 and the like shown in FIG. 3 by switching to the RAM 15 side or the GND side that always has 0 data. As a result, when the recording is interrupted at the delimiter of the cluster, the compressed data from the DRAM 15 can be recorded in the MD2 up to the end address, and 0 data can be recorded in the MD2 after the end address.

The operation of each section of the digital processing section 18b at the time of interrupting and resuming recording in the special recording state will be described below with reference to the timing chart shown in FIG.

During the grace period T, when the input level of the audio data falls below the judgment level (at time t2), the level judgment unit 42 suspends the recording on the MD2. That is,
Based on the instruction from the level determination unit 42, the system controller 17b sets the end address at the time when the recording is interrupted to the user TOC in the same manner as when the user presses the stop key.
Write to In addition, for the memory controller 14,
Unrecorded data in the DRAM 15, that is, the pointer P
It is instructed to transfer the subsequent compressed data to the EFM / CIRC encoder / decoder 16.

Further, the system controller 17b according to the present embodiment sends the end address to the 0 data generation unit 44b based on the instruction of the level determination unit 42. 0
When transferring the cluster including the end address, the data generation unit 44b sets the transfer data input data group on the DRAM 15 side up to the received end address. As a result, compressed data of less than one cluster is recorded in MD2. On the other hand, after the end address, 0 data generation unit 4
4b switches the transfer data input group to the GND side. As a result, 0 data is written in the trash area provided at the end of the cluster regardless of the DRAM 15.

At the time of t2, the storage area control unit 43b sets the value of the pointer A to the head address of a cluster that is easy to manage, such as the next cluster, in the memory controller 14. For example, when the start address of the cluster is n at time t2, the value of the pointer A is set to n + C. Furthermore, DRA
From M15 to EFM / CIRC encoder / decoder 16
After transferring the compressed data to the storage area control unit 43b,
The value of the pointer P is set to the head address of the cluster to which the pointer A is set. As a result, from the time of t2,
It becomes a new cluster, and even if the recording is restarted immediately after the interruption, the recording can be performed on the MD2 without any trouble.

The digital processing section 1 according to the present embodiment.
In 8b, both pointers A and P are reset when the recording is interrupted, but the present invention is not limited to this. Also, E
Although the 0 data generation unit 44b is provided inside the FM / CIRC encoder / decoder 16, the present invention is not limited to this. For example, the 0 data generation unit 44b may be provided inside the memory controller 14 or between the memory controller 14 and the EFM / CIRC encoder / decoder 16. 0 to record after the end address of the cluster
If the data can be generated independently of the DRAM 15,
The same effect as that of the present embodiment can be obtained.

By the way, the digital processing section 1 shown in FIG.
8, or in the digital processing unit 18a shown in FIG.
The DRAM 15 holds less than one cluster of compressed data and does not record the compressed data in the MD 2 when recording is interrupted, but the present invention is not limited to this. Compressed data of less than one cluster may be written to MD2 when recording is interrupted. As a result, even if some trouble occurs in the MD device 1 during the interruption of the recording, the audio data up to the interruption of the recording can be surely written in the MD2.

In this case, as shown in FIG. 8B, after the recording is interrupted, the recording cannot be resumed while the trash area is being written, and the head is cut off. Like the trash area, the period of the head loss is about 2 seconds at the maximum, which is extremely longer than the period of the head loss caused by the delay time of the audio compression / decompression unit 13 in the digital processing unit 18 of FIG.

In the digital processing section 18 / 18a, the DRAM 15
There is also a method of interrupting recording after all the compressed data in the data becomes 0 data. In this method, at the time of interruption of recording, the entire voice data area of the DRAM 15 shown in FIG.
Since the data has been written, recording can be resumed immediately after the interruption. However, in this case, it is necessary to set the determination level to −∞ dB and set the grace period T sufficiently long. For example, when the DRAM 15 can store compressed data for about 10 seconds, the grace period T is set to 10 seconds or more. Since the judgment level and the grace period T are limited, recording cannot be interrupted when there is a silent portion shorter than the grace period T or when voice data of an extremely low level is input. As a result, there are many wasted portions in the recording area of the MD2.

In any case, there is a problem in terms of the presence or absence of a head cut at the recording start portion, the degree, the grace period T, the limitation of the determination level, and the like. Therefore, the digital processing unit 18
a stores M compressed data that is less than 1 cluster when recording is interrupted.
When recording to D2, the 0 data generation unit 44b shown in FIG.
To solve these problems.

As a result, the audio data compression operation and the DRAM can be performed while writing 0 data up to the cluster delimiter.
It is possible to continue the write operation to 15, and wait for the start of the next recording. Therefore, it is possible to prevent the occurrence of head loss due to the writing in the trash area, and to set the grace period T
And the judgment level can be freely set, and the 0 data generation unit 44b
The recording area of the MD2 can be used more effectively as compared with the case where is not added.

[0156]

As described above, the digital recording / reproducing apparatus according to the first aspect of the present invention measures the input level of the audio data in the special recording state in which the recording is interrupted according to the input level of the audio data. And a compression means for stopping the compression of the audio data by the data compression means until the recording start time and for starting the compression of the audio data from the recording start time based on the instruction of the detection means. And a control means.

Therefore, the digital recording / reproducing apparatus can start recording from the time when the input level becomes high even if there is no user on the spot. Therefore, it is possible to prevent the recording of the silent portion until the recording is started. As a result,
It is possible to reduce the labor of the user and to effectively use the recording area of the recording medium.

In the digital recording / reproducing apparatus according to the second aspect of the present invention, as described above, in the configuration of the first aspect of the invention, the compression control means causes the data compression means to compress the audio data after the recording interruption point. The recording means records the compressed data that is less than the writing unit among the compressed data stored in the temporary storage means at the time of the recording interruption on the recording medium and also generates invalid data to be added to the compressed data. It is the structure provided with the invalid data generating means.

Therefore, when the recording is interrupted, the compressed data up to the interruption can be surely recorded on the recording medium, and
It is possible to prepare for resuming recording immediately after the interruption. Therefore, the digital recording / reproducing apparatus can intermittently record according to the input level, and can prevent the recording of the silent portion during the special recording state. As a result, the recording area of the recording medium can be used more effectively.

In the digital recording / reproducing apparatus according to the third aspect of the present invention, as described above, in the configuration of the first aspect of the invention, the compression control means causes the data compression means to compress the audio data after the recording interruption point. The recording means is configured to stop and simultaneously write to the recording medium when the compressed data written to the temporary storage means after the recording is restarted and the compressed data before the recording interruption are combined into a writing unit.

Therefore, the digital recording / reproducing apparatus can intermittently record according to the input level, and during the special recording state,
It is possible to prevent recording of silent parts. Furthermore, it is possible to prevent the occurrence of a trash area when recording is interrupted. Therefore, as compared with the digital recording / reproducing apparatus according to the second aspect, the recording area of the recording medium can be used more effectively.

As described above, in the digital recording / reproducing apparatus according to the fourth aspect of the present invention, the data compressing means always compresses the audio data while in the special recording state in which the recording is intermittently performed according to the input level of the audio data. At the same time, up to the recording start time, when the compressed data is written in the temporary storage means by the data compression means, the writing area control means for setting the writing area to the same area is provided.

Therefore, the digital recording / reproducing apparatus can prevent the recording of the silent portion until the recording is started even if there is no user on the spot. As a result, it is possible to reduce the labor of the user and to effectively use the recording area of the recording medium as compared with the related art.

Furthermore, since the data compression means constantly compresses the audio data, it is possible to prevent the occurrence of head loss. As a result, as compared with the digital recording / reproducing apparatus according to the first aspect of the invention, there is an effect that the audio data can be recorded more reliably.

In the digital recording / reproducing apparatus according to the fifth aspect of the present invention, as described above, in the configuration of the fourth aspect of the present invention, the writing area control means is provided between the recording interruption point and the next recording start point. The data compression unit sets the area for writing the compressed data to the temporary storage unit in the same area, and the recording unit sets the compressed data that is less than the writing unit among the compressed data stored in the temporary storage unit at the time of the recording interruption. The recording medium is recorded on a recording medium, and an invalid data generating means for generating invalid data to be added to the compressed data is provided.

Therefore, when the recording is interrupted, the compressed data up to the interruption can be surely recorded on the recording medium, and
It is possible to prepare for resuming recording immediately after the interruption. Therefore, the digital recording / reproducing apparatus can intermittently record according to the input level, and can prevent the recording of the silent portion during the special recording state. As a result, in addition to the effect of the invention of claim 4,
This has the effect that the recording area of the recording medium can be used more effectively.

In the digital recording / reproducing apparatus according to the sixth aspect of the present invention, as described above, in the configuration of the fourth aspect of the invention, the writing area control means operates from the recording interruption point to the next recording start point. The data compressing unit sets the area where the compressed data is written to the temporary storage unit to the same area, and the recording unit combines the compressed data written to the temporary storage unit after the recording is resumed and the compressed data before the recording is interrupted in the unit of writing. When it becomes, it is configured to write to the recording medium.

Therefore, the digital recording / reproducing apparatus can interrupt recording according to the input level, and during the special recording state,
It is possible to prevent recording of silent parts. Furthermore, it is possible to prevent the occurrence of a trash area when recording is interrupted. Therefore, in addition to the effect of the fifth aspect of the invention, the recording area of the recording medium can be used more effectively.

As described above, in the digital recording / reproducing apparatus according to the seventh aspect of the present invention, during the special recording state in which the recording is interrupted according to the input level of the audio data, the data compression means always outputs the audio data. The recording medium is compressed and the compressed data is written in an area different from the previous time in the temporary storage means, and the address of the read area read from the temporary storage means by the recording means is controlled until the recording start time, and the recording medium by the recording means. And a read area control means for setting the address of the read area according to the address of the area in which the compressed data is written at the start of recording.

Therefore, the digital recording / reproducing apparatus can prevent the recording of the silent portion until the recording is started even if there is no user on the spot. Therefore, compared to the related art, it is possible to reduce the labor of the user and to effectively use the recording area of the recording medium.

Further, the data compressing means always compresses the audio data, and the recording means can write the compressed data before the recording start time onto the recording medium.
Therefore, as compared with the digital recording / reproducing apparatus according to the fourth aspect of the present invention, it is possible to more flexibly set the time to start recording the audio data.

As described above, in the digital recording / reproducing apparatus according to the eighth aspect of the present invention, in the configuration of the seventh aspect of the invention, the recording means stores the compressed data stored in the temporary storage means at the time of the recording interruption. Of the above, a configuration is provided that includes an invalid data generating unit that records compressed data that is less than the writing unit in a recording medium and that generates invalid data that is added to the compressed data when recording the compressed data in the recording medium. is there.

Therefore, when the recording is interrupted, the compressed data up to the interruption can be surely recorded on the recording medium, and
It is possible to prepare for resuming recording immediately after the interruption. Therefore, the digital recording / reproducing apparatus can intermittently record according to the input level. As a result, the effect that the recording area of the recording medium can be used more effectively, and the effect that the time to start recording the audio data can be set more flexibly are achieved together.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a block diagram showing a main configuration of a digital processing unit.

FIG. 2 is a perspective view showing an appearance of an MD device including the digital processing unit.

FIG. 3 is a block diagram showing a main configuration of the MD device.

FIG. 4 is an explanatory diagram illustrating operations of a storage area for compressed data and a pointer in a DRAM provided in the digital processing unit.

FIG. 5 is a timing chart showing an operation of the digital processing section in a waiting period from a transition to a special recording state to recording.

FIG. 6 is a timing chart showing the operation of the digital processing section from the interruption of recording to the restart of recording in the special recording state.

FIG. 7 shows another embodiment and is a block diagram showing a digital processing unit of the MD device.

FIG. 8 shows another embodiment, and is a timing chart showing the operation of the digital processing unit of the MD device from the interruption of recording to the restart of recording in the special recording state.

FIG. 9 is a block diagram showing a main configuration of the digital processing unit.

[Explanation of symbols]

1 Mini Disc Device (Digital Recording / Reproducing Device) 2 Mini Disc (Recording Medium) 13 Audio Compression / Expansion Unit (Data Compression Unit) 15 DRAM (Temporary Storage Unit) 16 EFM / CIRC Encoder / Decoder (Recording Unit) 41 Audio Compression Control Unit (Compression control unit) 42 Level determination unit (Detection unit) 43a Storage area control unit (Write area control unit) 43b Storage area control unit (Read area control unit) 44b 0 Data generation unit (Invalid data generation unit)

Claims (8)

[Claims] 1. A data compression means for compressing input audio data in a time axis direction, a temporary storage means for temporarily storing the compressed data compressed by the compression means, and a predetermined compression data stored by the temporary storage means. In a digital recording / reproducing apparatus having a recording means for recording on a recording medium for each writing unit, in the special recording state in which recording is interrupted according to the input level of audio data, the input level of audio data is measured and recorded. Detection means for detecting the start time point, and compression control means for stopping the compression of the audio data by the data compression means until the recording start time point and starting the compression of the audio data from the recording start time point based on the instruction of the detection means. A digital recording / reproducing apparatus comprising: 2. The detecting means, in the special recording state,
While the data compression means is compressing the audio data, the input level of the audio data is measured to detect the recording interruption time point, and the compression control means compresses the audio data by the data compression means after the recording interruption time point. The recording means records, on the recording medium, compressed data that is less than the writing unit among the compressed data stored in the temporary storage means at the time of the recording interruption, and compresses less than the writing unit. 2. The digital recording / reproducing apparatus according to claim 1, further comprising invalid data generation means for generating invalid data to be added to the compressed data when the data is recorded on the recording medium. 3. The detecting means, in the special recording state,
While the data compression means is compressing the audio data, the input level of the audio data is measured to detect the recording interruption time point, and the compression control means compresses the audio data by the data compression means after the recording interruption time point. The recording means stops the recording, and writes the compressed data, which is written in the temporary storage means after the recording is resumed, and the compressed data before the recording is stopped, into the recording medium when the writing unit is combined. 1. The digital recording / reproducing apparatus according to 1. 4. A data compression means for compressing input voice data in a time axis direction, a temporary storage means for temporarily storing the compressed data compressed by the compression means, and a predetermined compression data stored by the temporary storage means. In the digital recording / reproducing apparatus having a recording means for recording the recording unit for each writing unit, the data compressing means always outputs the audio data during the special recording state in which the recording is interrupted according to the input level of the audio data. While compressing, the detecting means for detecting the recording start time by measuring the input level of the audio data during the special recording state, and the data compression means until the recording start time based on the instruction of the detecting means. A writing area control means for setting the writing area to the same area when the compressed data is written to the temporary storage means. Le recording and reproducing apparatus. 5. The recording means detects the recording interruption point by measuring the input level of the audio data during the recording in the special recording state, and the writing area control section detects the recording interruption point from the recording interruption point. Up to the recording start time, the data compression means sets the area for writing the compressed data to the temporary storage means in the same area, and the recording means stores the compressed data stored in the temporary storage means at the time of the recording interruption. Of these, an invalid data generating means for generating the invalid data to be added to the compressed data when recording the compressed data less than the writing unit on the recording medium and recording the compressed data less than the writing unit on the recording medium. The digital recording / reproducing apparatus according to claim 4, wherein the digital recording / reproducing apparatus is provided. 6. The recording means detects the recording interruption point by measuring the input level of the audio data during recording in the special recording state, and the writing area control section detects the recording interruption point from the recording interruption point. Up to the recording start time, the data compression unit sets the area for writing the compressed data to the temporary storage unit to the same area, and the recording unit sets the compressed data to be written to the temporary storage unit after the recording is resumed and before the recording interruption. The digital recording / reproducing apparatus according to claim 4, wherein when the unit of writing together with the compressed data of (1) becomes a writing unit, the data is written to the recording medium. 7. A data compression means for compressing input audio data in a time axis direction, a temporary storage means for temporarily storing the compressed data compressed by the compression means, and a predetermined compression data stored by the temporary storage means. In a digital recording / reproducing apparatus having a recording means for recording on a recording medium for each writing unit, while the data recording means is in a special recording state in which recording is interrupted according to the input level of the audio data, the data compression means always outputs the audio data. While compressing and writing the compressed data in an area of the temporary storage means different from the previous time, during the special recording state, the detecting means for measuring the input level of the audio data to detect the recording start point, and the instruction of the detecting means. Based on the above, until the recording start time, the address of the read area read from the temporary storage means by the recording means is controlled so that the recording means records. In addition to preventing writing to the medium, at the start of recording, the data compression means is provided with a read area control means for setting the address of the read area in accordance with the address of the area where the compressed data is written. And a digital recording and reproducing device. 8. The detecting means measures an input level of audio data to detect a recording interruption point during recording in the special recording state, and the recording means temporarily stores at the recording interruption point. Of the compressed data stored in the means, when the compressed data that is less than the writing unit is recorded on the recording medium and the compressed data that is less than the writing unit is recorded on the recording medium, the compression data is not added to the compressed data. 8. The digital recording / reproducing apparatus according to claim 7, further comprising invalid data generating means for generating data.