JPH08255430A - Disc recording/reproducing apparatus - Google Patents

Abstract

PURPOSE: To solve a problem of making a listener feel uneasy by reducing the generation of different sounds during the reproduction of an audio data. CONSTITUTION: An audio signal is digitized while being divided into several blocks of data to be put in time series order so that it is recorded into a recording track of a disc-shaped recording medium 1 and the data is read by an optical head 12 tracing the recording track to be stored into a memory 7 for preventing impact. The data are read by a specified amount out of the memory 7 for preventing impact to perform a reproduction processing. A non-sound data outputting means 18a is provided to add a non-sound data with a required length to the data read out of the memory 7 for preventing impact. When the reading of the data with the optical head 12 is interrupted, a control 18 is performed so that the non-sound data with a range of time corresponding to the period of the interruption up to the resumption of the reading starting from the interruption of the reading is outputted to be added to the data at the moment of the interruption as read out of the memory 7 for preventing impact while resuming the reading.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc recording / reproducing apparatus for optically recording / reproducing digital data on / from a disc, and more particularly to disc tracks in which digital audio data is divided into blocks and time-sequentially ordered. The present invention relates to a disc recording / reproducing apparatus for recording.

[0002]

2. Description of the Related Art A compact disc (CD) on which digital data is optically recorded is for reproduction only, but recently, a rewritable disc having a size smaller than that of the CD has become popular. This disc is a mini disc (M
D), and digital data is recorded or reproduced by a disk recording / reproducing apparatus adopting a magneto-optical recording system.

This disc recording / reproducing apparatus quantizes an audio signal to form digital audio data at a predetermined transfer rate and sends it to a data compression / expansion unit. The data compression / decompression unit compresses the digital audio data to about 1/5 and sends it to the earthquake-resistant memory controller.

When the seismic resistant memory controller sends digital data to the buffer memory at a predetermined transfer rate for storage, the seismic resistant memory controller records the digital data by dividing the digital data into a certain number of clusters.

That is, in this cluster, 32 main data recording sectors in which the digital data are recorded, 3 linking sectors for connecting the main data recording sectors to each other, and 1 Each sub-data sector is composed of 36 sectors, which is one recording unit. Then, when the data thus stored exceeds a certain amount, it is read out in a burst by a predetermined amount and is sent to the EFM / CIRC unit together with the catalog information at a predetermined transfer rate.

The EFM / CIRC section performs bit conversion of digital data and error correction processing on the data, and sends it as recording data to the magnetic head side. Then, the magnetic head applies a modulation magnetic field according to the recording data to the MD, and the laser light is emitted from the optical head, whereby the data is recorded by thermomagnetic recording.

On the other hand, in the reproducing operation, the optical head traces the recording track of the MD with the laser beam to read the data. Then, this data is binarized and then supplied to the EFM / CIRC unit.

The EFM / CIRC section performs a decoding process and an EFM decoding process for error correction processing,
It is transmitted to the earthquake-proof memory controller as reproduction data. Also, this EFM / CIRC unit is the U of the MD.
-From the U-TOC data read from the TOC area,
The song number of the song recorded on the track in the data area, the track number of the song, address data indicating the start and end positions of each song, and the like are sent to the system controller.

This system controller is based on the U / T
The seismic resistant memory controller is controlled on the basis of the OC data, the reproduction position is managed, and control is performed to display the music number, title, etc. of the music number designated by the operation of the key input unit on the display unit.

The seismic resistant memory controller sends the reproduced data to the memory at a predetermined transfer rate and stores it therein. Even if a disturbance or the like occurs during the recording, the input data is continuously recorded in the data writing area. to continue. Then, when the amount of data stored in the memory exceeds a certain amount, the reproduction data is burst-read by a predetermined amount and sent to the data compression / expansion unit at a predetermined transfer speed.

The data compression / expansion unit bit-expands the digital data and sends it to the D / A converter, contrary to the above-mentioned compression. This D / A converter converts digital audio data into an analog audio signal and outputs it from an output terminal. As a result, the audio signal is reproduced and becomes audible.

Unlike the CD, the MD is a rewritable recordable area between the lead-in area and the lead-out area. This area is U ・ TO
It is composed of a C area and a data area, and digital audio data is recorded in this data area. Also, U ・ TO
In the area C, table of contents (TOC: Table Of Contents) information indicating the data recording position of the data area is recorded, and it is possible to manage all the music pieces recorded in the data area.

[0013]

By the way, in the above-mentioned conventional disk recording / reproducing apparatus, when a shock is applied during the recording or reproducing operation and a so-called tracking error is caused which causes the optical head to be out of the track, the tracking is re-executed. Then, recording or reproduction is restarted. If the recording track is damaged during the reproducing operation, the optical head cannot read the data. Therefore, after the interruption, the recording track is accessed again to restart the data reading.

For example, as shown in FIG. 4A, when the reading from the recording track is started and the data d1 ... Are sequentially stored in the memory by the seismic memory controller, the reading of the data is interrupted. When it occurs at the time of Ts, a part of the data block d4 is missing. Then, the data reading is restarted, and Te
When it becomes possible at the point of time, the data block d5 is lost during the interrupting period T, and a part of the data block d6 is followed by the next data block d7.

As described above, when the seismic resistant memory controller sequentially stores the data string including the partially omitted data block in the memory, when a predetermined amount is read out in burst form from this memory, FIG. As shown in (1), one data block d5 disappears, and a data string sandwiching the data blocks d4 and d6 partially interrupted is formed.

When this data string is converted into an audio signal, the discontinuity before and after the discontinuity becomes discontinuous, so that a reproduced sound is mixed with an abnormal sound and is emitted. If such an abnormal sound is emitted while listening to a rhythmic reproduced sound such as music, the listener will feel uncomfortable and uncomfortable, which is extremely detrimental.

The present invention has been made in view of the above circumstances, and provides a disk recording / reproducing apparatus capable of reducing the occurrence of abnormal noise during reproduction of audio data and avoiding the problem of giving a listener a feeling of strangeness. It is an object.

[0018]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is directed to a disk-shaped storage medium in which an audio signal is digitized and divided into several blocks of data so as to be time-sequentially ordered. A disc recording / reproducing apparatus for recording on a recording track, reading the data by an optical head tracing the recording track, storing the data in an impact prevention memory, and then performing a reproduction process by reading a predetermined amount from the impact prevention memory. In the above, in a silent data output means for adding silent data of a required length to the data read from the shock prevention memory, and when the reading of data by the optical head is interrupted, the reading is restarted and the reading is interrupted. Silence data of the time width corresponding to the interruption period from the point of time to the point at which reading is resumed The silence data output by the output from the means is characterized in that a, and a control means for controlling to be added to the data of the interruption time to be read out from the shock preventing memory.

[0019]

In the present invention, the digital audio data recorded on the recording track of the disk-shaped storage medium is
After being read by the optical head tracing this recording track and stored in the shockproof memory, it is read from this shockproof memory and reproduced. When the data reading of the optical head is interrupted due to a scratch on the recording track or a tracking error during the reproducing operation, the control means immediately restarts the reading of the optical head. Further, the silent data output means outputs the silent data having a time width corresponding to the interruption period. Then, following the voiced data after the start of reading, silence data is added to the portion where the voiced data is interrupted, and the voiced data at the time point when re-reading becomes possible continues. For this reason, when all the data including the portion where the reading is interrupted is reproduced and the audio signal is reproduced, the generation of the abnormal noise due to the interruption of the voiced data is reduced.

[0020]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an electrical block diagram of a disk recording / reproducing apparatus according to the present invention. This disc recording / reproducing apparatus is a rewritable mini disc having a diameter smaller than that of a CD (commonly called MD-MO: Mini Disc-Magn).
et Optical) 1 is used for a recording disc.

In this disk recording / reproducing apparatus, the optical head 1 is rotated while the MD 1 is rotated by the spindle motor 11.
A modulation magnetic field corresponding to the recording data is applied from the magnetic head 2 in the state where the laser beam is irradiated by 2 to record the data along the recording track. The optical head 12 traces the recording track of the MD1 with a laser beam to reproduce data.

More specifically, the optical head 1 will be described.
2 is arranged in an optical pickup 13 including a laser light source, optical parts, a photodetector, etc.
It is provided at a position facing the magnetic head 2 with a gap between them. The optical head 12 is a feed motor 14 controlled by a servo control circuit 15 described later when recording data in a data area (main data recording area) of the MD 1.
To move in the radial direction. Then, when the magnetic head 2 is driven by the head driving unit 3 of the recording system, the target track of the MD 1 to which the modulation magnetic field according to the recording data is applied is irradiated with laser light to record the data by thermomagnetic recording. It is like this.

Further, the optical head 12 detects the reflected light of the laser light applied to the target track,
For example, detecting the focus error by the astigmatism method,
A tracking error is detected by a so-called push-bull method, and at the time of reproducing data from the MD1, a reproduction signal is generated by detecting a difference in polarization angle (Kerr rotation angle) of reflected light from a target track. It is configured to do.

The reproduction output from the optical head 12 is supplied to the RF amplifier 4. This RF amplifier 4
Extracts the focus error signal and tracking error signal from the reproduction output and supplies them to the servo control circuit 15, and binarizes the reproduction signal to reproduce the EFM / CIR of the reproduction system.
It is supplied to the C section 5 and the address decoder 5a.

The servo control circuit 15 comprises a focus servo control section, a tracking servo control section, a spindle motor servo control section, etc., and the optical head 12
Focus control and tracking control of the optical system. Further, the spindle motor is controlled so that the MD1 is rotationally driven at a predetermined rotational speed. Further, the system controller 18 is configured to control the movement of the optical head 12 and the magnetic head 2 to a target track position of MD1 designated by the system controller 18.

The system controller 18 controls the operation of the entire apparatus, and also controls the operation of the recording system and the reproducing system in the operation mode designated by the key input unit 17, and displays the operation content, the operation state and the like on the display unit 16. To display. In addition, the EFM / CIRC unit 5, the earthquake-proof memory controller 6, the memory 7, the TOC memory 18a, the data compression / decompression unit 8 and the like are controlled to perform signal processing of main data, and a skip guard is provided at the time of recording / reproducing data. It is configured to do.

The recording system of the disc recording / reproducing apparatus includes an A / D converter 9 to which an audio signal is inputted via an input terminal. The A / D converter 9 quantizes the audio signal to form digital audio data having a predetermined transfer rate, and transmits the digital audio data to the data compression / decompression unit 8.

The data compression / decompression unit 8 performs data compression processing and data decompression processing corresponding to the 2-channel stereo mode in the CD system.
C (Adaptive Transform Acou
Stic Coding) encoder and decoder. The encoder bit-compresses the digital audio data, which is the main data quantized by the A / D converter 9, to about 1/5, for example, and sends it to the earthquake-proof memory controller 6.

The earthquake-proof memory controller 6 stores the digital data from the data compression / expansion unit 8 in the memory 7.
The data is sent to and stored in the (buffer memory) at a predetermined transfer rate. When the amount of data thus stored exceeds a certain amount, the digital data is burst-read by a predetermined amount and EFM / CIRC is added together with the catalog information.
It is sent to the unit 5 at a predetermined transfer rate.

Further, this earthquake-proof memory controller 6
Is controlled so that the memory 7 always secures a data write area of a predetermined amount or more, and the system controller 18 detects that a track jump has occurred due to disturbance or the like, and the recording operation to the MD 1 is interrupted. Even in the case of being input, the input data is continuously written in the data writing area of a predetermined amount or more. Since the return processing operation is performed during this period, it is possible to continuously record the input data on the recording track of the MD1.

As shown in FIG. 2, the digital data stored in the memory 7 is clustered into a fixed number of sectors (blocks), and the clusters are connected to each other to form a data string. ing. That is, the cluster C includes 32 main data recording sectors S0 to S31.
And three linking (connection) sectors F0 to F2 which are laser heating start points at the time of recording, and sub-data sector F3 used for a reserved area or the like. A total of 36 sectors including the individual sectors S0 to S31 are set as one recording unit.

The catalog information is U.multidot., Which indicates the recording position of the audio data recorded in the data area of MD1.
The TOC (user list) data is composed of the song number of a song recorded on a track in the data area, the track number of the song, and address data indicating the start and end positions of each song. This U / TOC data is stored in the U / TOC memory 18a, but it is sent to the EFM / CIRC unit 5 after being expanded in the U / TOC format formed at the time of recording, reproducing and erasing the data. become.

The EFM / CIRC section 5 performs bit conversion and error correction processing on the digital audio data, and includes an EFM section and a CIRC section. The EFM section sends a signal of 8 bits per symbol to 14 bits each.
E converted to 1-bit (4 bits per channel) data
FM (Eight to Fourteen Modu
data) is output as recording data.

The CIRC section is composed of a Reed-Solomon code which is an error correction code having a high random error correction capability, and a conversion section which converts a burst error into a random error by interleaving.
s InterleaveReed Soromon
By performing error correction processing by Code),
We try not to cause any problems in normal use.

The recording data thus encoded is sent to the head drive section 3. The magnetic head 2 is connected to the head drive unit 3 and applies a modulation magnetic field according to recording data to the MD 1 as described above. Along with this, laser light is emitted from the optical head 12, so that data recording is performed by thermomagnetic recording.

On the other hand, in the reproducing system of the disk recording / reproducing apparatus, the reproduction output from the optical head 12 is the RF amplifier 4
Then, a focus error signal and a tracking error signal are extracted from the reproduction output and transmitted to the servo control circuit 15, and the reproduction signal is binarized and supplied to the EFM / CIRC unit 5.

The EFM / CIRC unit 5 performs the decoding processing for the error correction processing and the EFM decoding processing as described above, and transmits the reproduced data to the earthquake-proof memory controller 6. Also, this EFM / CIRC section 5
Is provided with an address decoder 5a, and when receiving the U / TOC data read from the U / TOC area of the MD1, the song number of the song recorded in the track of the data area and the recording track of the song are recorded. The number, address data indicating the start and end positions of each music, and the like are sent to the system controller 18.

The system controller 18 stores the catalog information including the address data in the TOC memory 18a, controls the seismic resistant memory controller 6 based on the U / TOC data, and manages the reproduction position. For example, control is performed to cause the display unit 16 to display the music number, title, and the like of the music number specified by operating the key input unit 17.

Further, the system controller 18 is
When the recording track of MD1 is scratched and the reading of data is interrupted during the reproducing operation, the data is accessed again to restart the reading, and the silent data having a time width corresponding to the interruption period from the reading interruption point to the reading resumption point. Is added to the data read from the memory 7.

The silent data is previously stored as zero data in the TOC memory 18a, and when the required amount is read by the system controller 18, the data (voiced portion) from the memory 7 has a required length. It is to be inserted as a silent part with a. This silent data is written as zero data in the main data recording sectors S0 to S31 shown in FIG. 2 in which unit recording is performed by clustering as described above, in an amount comparable to the interruption period of reading. There is. This silent data is not read from the TOC memory 18a, but the data compression / expansion unit 8
It is also possible to generate zero data and insert the required amount into the voiced data.

The earthquake-proof memory controller 6 sends the reproduced data to the memory 7 at a predetermined transfer rate and stores it therein. It should be noted that the input data is continuously recorded in the data writing area in the data writing area even if a disturbance or the like occurs during the recording as described above. When the amount of data stored in the memory 7 exceeds a certain amount, the reproduction data is burst-read by a predetermined amount and sent to the data compression / expansion unit 8 at a predetermined transfer speed.

The data compressing / expanding unit 8 bit-expands the digital data contrary to the time of compression, and the D / A converter 1
Send to 0. The D / A converter 10 converts digital audio data into an analog audio signal and outputs it from an output terminal. As a result, the frequency characteristic is 5 to 20 kHz and the dynamic range is 1 according to human hearing.
It is possible to obtain an audio signal in which a characteristic of 05 dB, which is comparable to that of a CD, is achieved.

By the way, the MD1 has a diameter of 64 mm.
This is a magneto-optical disk of a certain degree, and a recordable area including a U / TOC area and a data area is provided between the lead-in area and the lead-out area. Music is written as digital data in the data area, but by forming grooves (pre-groups) that serve as laser spots along spiral recording tracks, it is possible to show fine points on the recording surface of the disc. The address is given in advance.

Further, in the U / TOC area, the catalog information for managing the data recording position of the data area is recorded, and for all the music recorded in the data area, the address of which music is numbered The data such as the starting address and the ending address are written. General-purpose type M
In the U / TOC area in D1, it is possible to set cue points for up to 255 songs, and the song number of each song,
The address of the start position and the address of the end position of the music are recorded as U / TOC data.

Next, a data reproducing operation by the disc recording / reproducing apparatus will be described. First, at the time of reproduction, when the optical head 12 traces a recording track of MD1 with a laser beam to read data, the seismic-resistant memory controller 6 stores and reads a data block, and then D / The audio signal is converted into an analog audio signal by the A converter 10 and reproduced from a speaker so that it can be heard.

During this reproduction, if the recording track of MD1 is damaged, the reading of data by the optical head 12 is interrupted. At this time, when the system controller 18 stops inputting data to the earthquake-resistant memory controller 6,
A command is issued to the servo control circuit 15 to access the recording track again, and data reading is restarted.

Although this reading is performed several times, when it is determined that the data cannot be read, the system controller 18 starts counting the interruption period by the built-in timer and reads the data slightly ahead on the recording track. Let out.

For example, as shown in FIG. 3A, reading from the recording track is started, and the data d1 ...
If the data reading is interrupted at the time of Ts, the data block d4 is partially lost. Then, the data reading is restarted, and Te
When it becomes possible at the point of time, the data block d5 is lost, and the next data block d7 follows a part of the data block d6 to form a continuous data string.

Here, the system controller 18 starts the reading restart time Te from the reading interruption time Ts.
The period T up to is calculated, and silent data corresponding to this interruption period T is added. At this time, as shown in FIG. 3B, the silence data M having the same time width as the interruption period T is the T
It is connected to the data block d4 at the time of the interruption, which is read from the OC memory 18a and sequentially read from the memory 7.

As a result, the earthquake-proof memory controller 6
3C, the data block d6 follows the silent data M, and becomes a data string sandwiching the silent data M and the partially interrupted data blocks d4 and d6. This data string is sent from the data compression / decompression unit 8 to the D / A converter 10, and when all the data including the portion where the reading is interrupted is converted into an audio signal, the voiced data is concatenated by the silent data M. It becomes a state.

For this reason, since the portion before and after the damaged portion of the recording track is continuous, when the digital audio data is music, the reproduced sound emitted from the speaker contains a silent sound, but an abnormal sound is emitted. It will not be done. Therefore, the trouble that gives the listener a feeling of strangeness or discomfort is significantly reduced.

[0052]

As described above, according to the present invention, when reading of data recorded by the optical head on the disk-shaped storage medium is interrupted due to scratches on a recording track or tracking error, Since the silent data of the time width corresponding to the interruption period is added to the discontinuous portion, when the digital audio data is reproduced as the audio signal, the abnormal noise caused by the interruption of the voice data is generated. This has the effect of reducing the occurrence and reducing the trouble that the listener feels uncomfortable or uncomfortable.

[Brief description of drawings]

FIG. 1 is an electrical block diagram of a disk recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a block structure of recording data.

FIG. 3 is a timing chart illustrating a reproduction process of adding silent data to voiced data read from a recording track.

FIG. 4 is a timing chart illustrating a reproduction process of voiced data read from a recording track in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disk-shaped storage medium 7 Memory for impact prevention 12 Optical head 18a Silent data output means 18 Control means

Claims (1)

[Claims] 1. An optical head which digitizes an audio signal and records it on a recording track of a disk-shaped storage medium in a time-sequential order by dividing it into several blocks of data, and by an optical head which traces this recording track. In a disk recording / reproducing apparatus for performing reproduction processing by reading a predetermined amount from the shock-preventing memory after the data has been read and stored in the shock-preventing memory, the data read from the shock-preventing memory has a required length. When the reading of data by the optical head is interrupted, the reading is resumed, and a time width corresponding to the interruption period from the reading interruption time point to the reading resumption time point. The silent data is output from the silent data output means, and the impact data is output. Disk recording and reproducing apparatus characterized by comprising a control means for controlling to be added to the data of the interruption time which is read from the memory for stop, the.