JP2002334521A - Reproduction control circuit for disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the reproduction control circuit of a disk player in which a pause function can be realized with simple constitution and also a response corresponding to the operation of a pause key is instantly performed. SOLUTION: When the digital audio compressed data recorded on an optical disk 2 are read out and the audio compressed data are reproduced, a reproduced audio output signal instantly can not be obtained by stopping the reading of the audio compressed data from a memory 22 in accordance with the operation of the pause key in a key entry operating part 8 and, also, when the memory 22 is fully occupied, the reading of the audio compressed data from the optical disk 2 is stopped and the disk player is controlled to be in a standby state. When the pause is released, the reading operation from the memory 22 is resumed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing method in which compressed data of a digital audio signal is read from a recording medium on which the compressed data is recorded, written to a memory, and read from the memory at a constant data rate. The present invention relates to a reproduction control circuit of the device.

[0002]

2. Description of the Related Art The applicant of the present invention has previously disclosed a technique for compressing an input digital audio signal into bits and recording the digital audio signal in a burst with a predetermined data amount as a recording unit, for example, as disclosed in Japanese Patent Application No. 2-169977. , Japanese Patent Application No. 22-22136
4, Japanese Patent Application No. 2-221365, Japanese Patent Application No. 2-2228
No. 21, Japanese Patent Application No. 2-282323, drawings and the like.

[0003] This technique uses a magneto-optical disk or the like as a recording medium and uses, for example, AD (adaptive difference) PCM audio data defined in the audio data format of a so-called CD-I (CD-interactive) or CD-ROM XA. Alternatively, digital audio data bit-compressed and encoded according to another format is recorded and reproduced. This bit-compressed digital audio data has a predetermined data amount as a recording unit, and
For example, for every 32 sectors, a connecting sector (linking sector) is added before and after in consideration of interleaving with data of an adjacent sector, and the sector is recorded continuously in a burst (intermittent) manner. .

Here, for example, a so-called straight PC which is obtained by simply linearly quantizing data of a standard CD (compact disk) format (CD-DA format) or an analog audio signal.
Consider a case in which M audio data is recorded and reproduced with approximately 1/4 bit compression. The playback time (play time) of the disc recorded with the bit compression of approximately 1/4 is approximately four times that of recording the straight PCM data before compression, for example, the data of the CD-DA format. Become. This is the standard one for smaller discs
Since the same recording and reproduction time as that of a 2 cm CD can be obtained, the size of the apparatus can be reduced. Also, the (instantaneous) bit rate of recording / reproduction is set to the standard CD-D
By using the same format as the A format, the time required for actually performing recording and reproduction can be reduced to approximately 1/4, so that the remaining approximately 3/4 time can be allocated to so-called retries. it can. Specifically, for example, at the time of data recording, a confirmation (verify) operation of whether or not recording was normally performed, a rewrite operation at the time of not successfully performing recording, and the like.
This is a re-read operation when the error rate of reproduced data is high. Accordingly, recording and reproduction can be performed more reliably even under bad conditions in which the mechanical unit vibrates due to disturbance and focus, tracking, and the like are lost, and application to a small portable device becomes possible.

[0005] In order to record and reproduce such digital audio data that has been bit-compressed by approximately 1/4,
A buffer memory for recording and / or reproducing compressed data is required. In this memory, during recording, compressed data is continuously written at a constant rate, and is read out in bursts or intermittently at approximately four times the speed. One data amount at the time of this burst reading is a predetermined data amount serving as the recording unit, for example, 32 sectors. As described above, several sectors for linking are added before and after, and spatially on the disk. It is recorded continuously (following the previous recording part). At the time of reproduction, the data of the data amount of the predetermined recording unit (for example, 32 sectors + several sectors for linking) is reproduced from the disk at a speed of about 4 times in a burst or intermittent manner. Are written to the buffer memory. The compressed data is continuously read from the memory at the constant rate.

[0006] Here, when the total storage capacity of the buffer memory for the recording and / or reproducing the M _T, the amount of data that is not read yet in the compressed data is written as (unread data volume), the sum of the remaining storage capacity (writable capacity) of the writable memory without destroying the unread data becomes M _T. The control of writing and reading to and from such a memory will be described below.

[0007] During recording, the write controlling the compressed data at a predetermined data rate to said buffer memory, when the unread data volume becomes equal to or greater than the predetermined amount M _K, at a faster readout rate than the write data rate It is controlled so that data is read out in bursts for each predetermined recording unit (for example, 32 sectors + several sectors) and recorded on a recording medium such as a disk. Data not yet recorded on the recording medium is regarded as the unread data on the memory. Here, when the recording operation on the recording medium is interrupted due to disturbances such as vibrations or when recording cannot be performed normally, the amount of unread data in the memory does not decrease, and the amount of unread data in the memory is reduced. when close to the total storage capacity M _T may be the unread data be destroyed by the compressed data written at a constant rate. With this in mind, the writable capacity of the buffer memory _(M T _-M K)
Recording on a recording medium at a stage lower than the above, that is, by providing a margin in the storage capacity of the writable area, the above-described case where the recording on the medium is interrupted or cannot be performed normally. This prevents destruction of unread data. The (M T _{-M K),} assuming the time required for restoration and re-recording or the like of the suspended state of the recording on the medium, may continue to operate for writing compressed data in the memory at the fixed data rate by this time period It should just be set to about.

At the time of reproduction, control is performed so that compressed data read from a recording medium in a burst manner is written to a memory and read at a constant data rate. At this time, the amount of unread data in the memory is reduced. a predetermined amount _{M L}
When the value is less than the threshold value, control is performed such that data is read out from the recording medium in a burst manner and written into the memory. This is because even if data reading from a recording medium such as a disc cannot be performed normally due to disturbance or the like, the remaining unread data amount M
_L can be read continuously, so that the read operation at a constant rate is not interrupted and the reproduction is not interrupted. The unread data volume M _L, for example a compressed data at the time an amount corresponding to the predetermined rate required for reading the recorded data again to the recording medium may be set to a degree that may continue operation of reading from the memory.

[0009]

In a general so-called CD (compact disk) player,
A pause function for temporarily stopping a reproduction operation, a music selection reproduction function for selecting and reproducing a desired music, a single music or a disc, by making the best use of the accessibility of using a disc. One song / all song repeat function to repeatedly play all songs, and B from any point A
Many have an A / B repeat function or the like for repeatedly reproducing up to a point. By using these functions, not only can the operation time be saved, but also how to enjoy the audio can be expanded.

When such a function is to be added to a recording / reproducing apparatus or a reproduction-only apparatus for compressed data as described above, the audio signal currently being reproduced is used because the buffer memory for reproduction is used. There is a time lag between the audio signal being read from the disc and
There is a problem in responsiveness. Further, it is desirable that the configuration for adding these functions be simple.

The present invention has been made in view of such circumstances, and has a simple configuration and a playback control circuit of a disk playback apparatus capable of realizing a pause function of temporarily stopping the playback operation. For the purpose of providing.

[0012]

According to the present invention, there is provided a disk reproducing apparatus comprising:
The playback control circuit of the playback device
Playback means for performing playback, and data obtained by the playback means.
Memory for storing data and data obtained from the reproducing means.
Data is incremented at the first data rate.
Write to the memory by the
Data stored at the second data transfer rate
Read by the read pointer that is
The amount of unread data in the
Predetermined amount M _L By the above light pointer until
The writing is stopped, and the unread data amount reaches a predetermined amount M_L 
When the following conditions occur, the reproducing means is set to the reproducing state and the
Write with the pointer and input the pause key
Stop reading by the above read pointer in conjunction with
To the read pointer in conjunction with the pause release operation.
Control means for restarting readout by
Thus, the above-mentioned problem is solved.

[0013]

When the pause key is input, the audio reproduction is stopped by stopping the reading of data from the memory, and even if the reading of the recording data from the recording medium progresses and the data cannot be written to the memory, the memory control is stopped. Accordingly, data reading from the recording medium is stopped, and a standby state is realized. When the pause is released, data reading from the memory is resumed, so that data can be written to the memory, and data reading from the recording medium is resumed.

[0014]

FIG. 1 is a block circuit diagram showing a schematic configuration of a disk recording / reproducing apparatus in which an embodiment of a reproduction control circuit of a disk reproducing apparatus according to the present invention is used.

In FIG. 1, a bit-compressed digital audio signal is recorded on a recording medium such as an optical disk 2. This recording signal is read in bursts by a predetermined recording unit (for example, 32 sectors + several sectors) by the optical head 3, and bit-compressed audio data is obtained via a decoder 21 for descrambling and error correction decoding. The compressed data is written to a memory 22 such as a RAM (random access memory), read from the memory 22 at a constant data rate, and a decoder 23 for restoring (expanding) and decoding the bit compression processing on the recording side is used. The reproduction of the audio signal is carried out via this.

Here, the writing operation of the compressed data to the memory 22 is controlled by reading the compressed data from the recording medium such as the optical disk 2 when the data amount in the memory 22 becomes a certain amount or less. While the data is continually read and written while the free area in which data can be written remains in the memory 22, but when the free area becomes less than a certain value and the writing becomes impossible, that is, when the memory is substantially full. Then, reading from the recording medium is stopped, and for example, control is performed so that the optical head 3 keeps tracing the same track position on the optical disk 2 or enters a standby state near a position to be read next.

In the apparatus in which the writing control to the memory 22 is performed, when the pause (pause) key is operated by the key input operation unit 8, the system controller 7 such as the CPU performs the reading operation from the memory 22. Stop. Therefore, the audio signal output from the analog output terminal 26 disappears immediately (in an instant) in response to the key input, and the state is switched to a silent state. At this time, even if the compressed data is read from the recording medium such as the optical disc 2 and written to the memory 22,
When the free space in the storage area becomes equal to or less than the predetermined value, the data reading operation for the recording medium such as the optical disk 2 is automatically stopped and the apparatus is controlled to the standby state, so that the pause control including the servo system and the control system can be realized. In this pause state, when a pause release operation is performed by the key input operation unit 8, the system controller 7 restarts the operation of reading from the memory 22. Therefore, an audio signal output from the analog output terminal 26 can be obtained in a quick response (instantaneous) to the key operation. During the pause state, D
The mute control of the / A converter 24, the low-pass filter 25, and the like may be performed.

Therefore, the pause key input operation can be performed by using the original function provided in such a disk recording / reproducing apparatus and using a simple configuration in which the reading of the compressed data from the memory 22 is stopped in response to the pause operation. The reproduction sound is instantaneously muted in accordance with the condition (1), and a stop state is realized in the mechanical operation of the disk reproduction. Pause can be easily released.

Hereinafter, the specific configuration shown in FIG. 1 will be described in detail.

As the optical disk 2 driven to rotate by the spindle motor 1, a recordable, for example, a magneto-optical disk is used. However, in the case of reproduction only, an aluminum reflective film type optical disk similar to a normal CD (compact disk) can be used. An optical head 3 for performing recording and / or reproduction on the optical disk (for example, a magneto-optical disk) 2 includes, for example,
Laser light sources such as laser diodes, collimator lenses,
The optical system includes optical components such as an objective lens, a polarizing beam splitter, and a cylindrical lens, and a photodetector having a light receiving portion having a predetermined pattern. The optical head 3 is provided at a position facing the magnetic head 4 via the magneto-optical disk 2. When data is recorded on the magneto-optical disk 2, the magnetic head 4 is driven by a recording-system head drive circuit 16, which will be described later, to apply a modulation magnetic field according to the recorded data. By irradiating the track with laser light, thermomagnetic recording is performed by a magnetic field modulation method. The optical head 3 detects reflected light of the laser beam applied to the target track, detects a focus error by, for example, a so-called astigmatism method, and detects a tracking error by, for example, a so-called push-pull method. When reproducing data from the magneto-optical disk 2, the optical head 3 detects the focus error and the tracking error, and at the same time, detects the difference in the polarization angle (Kerr rotation angle) of the reflected light of the laser light from the target track and reproduces the data. Generate a signal.

The output of the optical head 3 is supplied to an RF circuit 5. The RF circuit 5 extracts the focus error signal and the tracking error signal from the output of the optical head 3 and supplies the focus error signal and the tracking error signal to the servo control circuit 6 and binarizes the reproduction signal and supplies it to a reproduction system decoder 21 described later. .

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

A key input operation unit 8 and a display unit 9 are connected to the system controller 7. The system controller 7 controls a recording system and a reproduction system in an operation mode specified by operation input information from the key input operation unit 8. The functions realized by the key operation include a pause function for temporarily stopping a reproduction operation, an automatic music selection function for selecting and reproducing a desired music, and a music / single reproduction for repeatedly reproducing one music or all music on a disc. All song repeat function,
An A / B repeat function for repeatedly reproducing an arbitrary point A to point B is exemplified. Also, the system controller 7
Indicates the recording on the recording track traced by the optical head 3 and the magnetic head 4 based on the address information in sector units reproduced from the recording track of the magneto-optical disk 2 by the header time, the Q data of the subcode, and the like. Manage position and playback position. The display unit 9 displays information on the recording position or the reproduction position, information on the function selected by the key operation, and the like as necessary.

Next, a recording system of the disk recording / reproducing apparatus will be described.

The analog audio input signal _{A IN} from the input terminal 10 is supplied to the A / D converter 12 through a low-pass filter 11. A / D converter 12 quantizes the analog audio input signal A _IN, a digital audio signal obtained, for example AD (adaptive differential)
It is supplied to an encoder 13 for high-efficiency encoding processing such as PCM. Further, an external digital audio signal may be supplied to the encoder 13 via a digital input interface circuit (not shown). The digital audio PCM signal input to the encoder 13 is so-called straight PCM data that has not been subjected to compression processing or the like, and as a specific example, a standard CD (compact disk) format (CD
-DA format), the sampling frequency is 44.1 kHz and the number of quantization bits is 16 bits.
Data. The input audio PCM data is subjected to a high-efficiency bit compression process by the encoder 13 such that the bit rate becomes, for example, approximately 1/4.

Next, the memory 14 is controlled by the system controller 7 to write and read data. The memory 14 temporarily stores bit-compressed data supplied from the encoder 13 and records it on a disk as needed. Is used as a buffer memory. That is, for example, in the 1/4 bit compression mode, compressed data of a constant bit rate reduced to approximately 1/4 of the data transfer rate (bit rate) of the standard CD-DA format is continuously stored in the memory 14. Is written. When this compressed data is recorded on the magneto-optical disk 2, it is recorded in a burst or discrete manner at the same data transfer speed under the same disk rotation speed (constant linear speed) as the standard CD-DA format. I have. In other words, the time during which the signal is actually recorded in the recording mode is approximately 1
/ 4, and the remaining 3/4 of the time is a pause period during which recording is not performed. However, on the magneto-optical disk 2, the next recording is performed following the area recorded immediately before the pause period, and continuous recording is performed on the medium surface. As a result, for example, recording of the same recording density and storage pattern as in the standard CD-DA format is performed.

For this reason, the compressed data is read out from the memory 14 in a burst at a bit rate corresponding to the data transfer rate of the standard CD-DA format.
The read compressed data is supplied to an encoder 15 for performing an interleaving process, an error correction coding process, an EFM modulation process, and the like. Here, in the data string supplied from the memory 14 to the encoder 15, one cluster composed of a predetermined plurality of sectors (for example, 32 sectors) is a unit that is continuously recorded in one recording, and when this is encoded, The data amount is obtained by adding several sectors for cluster connection to the data amount for one cluster. The cluster connection sector is set to be longer than the interleave length in the encoder 15 so that even if interleaved, data in other clusters is not affected.

The details of the recording in cluster units will be described later with reference to FIG.

The encoder 15 converts the recording data supplied from the memory 14 in a burst
Encoding processing (parity addition and interleaving processing) for error correction, EFM encoding processing, and the like are performed. The recording data that has been subjected to the encoding process by the encoder 15 is supplied to the magnetic head drive circuit 16. The magnetic head drive circuit 16 is connected to the magnetic head 4,
The magnetic head 4 is driven so that a modulation magnetic field corresponding to the recording data is applied to the magneto-optical disk 2.

The system controller 7 performs the above-described memory control on the memory 14 and continuously records the recording data, which is read from the memory 14 in a burst manner, on the recording track of the magneto-optical disk 2 by the memory control. The recording position is controlled so that The recording position is controlled by controlling the recording position of the recording data read out from the memory 14 in a burst manner by the system controller 7 and transmitting a control signal designating the recording position on the recording track of the magneto-optical disk 2 to a servo control circuit. 6
Is performed by supplying the

Next, a reproducing system of the disk recording / reproducing apparatus will be described.

This reproducing system is for reproducing the recorded data continuously recorded on the recording tracks of the magneto-optical disk 2 by the above-mentioned recording system. Is traced by a laser beam, whereby a recording signal is read from the magneto-optical disk 2. Here, the magneto-optical disk 2 is rotationally driven at the same rotational speed (constant linear velocity) as the standard CD-DA format, and is burst-like (discrete) at the same data transfer speed as the CD-DA format. The read signal is read by the RF amplifier circuit 5, binarized by the RF amplifier circuit 5, and supplied to the decoder 21.

The decoder 21 corresponds to the encoder 15 in the above-described recording system, and performs a deinterleaving process, a decoding process for error correction, and an EFM demodulation on the reproduced output binarized by the RF circuit 5. Processing such as processing is performed, and the above-mentioned quarter-compressed data is output in a burst at the same data transfer rate as, for example, the standard CD-DA format. The reproduction data obtained by the decoder 21 is supplied to the memory 22.

In the memory 22, writing and reading of data are controlled by the system controller 7, and reproduced data supplied in bursts from the decoder 21 at the same data transfer rate as the standard CD-DA format is written. In addition, in the memory 22, the reproduction data written in a burst is continuously read at a constant bit rate, that is, at a data transfer speed of approximately 1/4 of the standard CD-DA format.

The system controller 7 performs memory control of writing / reading of the reproduction data to / from the memory 22, and reproduces the reproduction data written in a burst from the memory 22 by the memory control. The playback position is controlled so as to continuously play back from the recording track. The reproduction position is controlled by controlling the reproduction position of the reproduction data read in a burst from the memory 22 by the system controller 7 and transmitting a control signal designating the reproduction position on the recording track of the magneto-optical disk 2 to a servo control circuit. 6.

Compressed data obtained as reproduced data continuously read from the memory 22 at a transfer rate (bit rate) of approximately 1/4 of the standard is supplied to a decoder 23. The decoder 23 corresponds to the encoder 13 of the recording system. For example, the decoder 23 expands the compressed data of 1/4 by, for example, 4 times (bit expansion) to obtain 1 data.
6-bit digital audio data is reproduced. The digital audio data from the decoder 23 is
It is supplied to the D / A converter 24.

The D / A converter 24 converts the digital audio data supplied from the decoder 23 into an analog signal, and outputs an analog audio output signal _AOUT from an output terminal 26 via a low-pass filter 25.

The magneto-optical disk 2 used in such a disk recording / reproducing apparatus desirably has a capacity capable of recording a stereo audio signal for 60 to 74 minutes. When employing a compression ratio, about 130 Mbytes are required.
In addition, a portable or pocket-sized record and / or
Or, in order to configure a reproducing apparatus, the outer diameter of the disc is 8c.
It is desirable to use a disk of m or smaller diameter. Further, the track pitch and the linear velocity are the same as those of the CD, that is, the track pitch is 1.6 μm, and the linear velocity is 1.
It is desired to be 2 to 1.4 m / s. As a disk satisfying these conditions, for example, a disk having an outer diameter of 6
4 mm, the outer diameter of the data recording area is 61 mm, the inner diameter of the data recording area is 32 mm, the inner diameter of the lead-in area is 30 mm,
The center hole diameter may be 10 mm. If this disc is stored in a disc caddy measuring 70 mm × 74 mm in length and width and supplied to the market, recording and reproduction on the disc can be performed by a recording / reproducing apparatus having a pocket size. In addition, 72 minutes or more in the above 1/4 data compression mode
The range of the inner diameter and outer diameter of the data recording area of the disk for enabling recording and reproduction for about 76 minutes is from an outer diameter of 60 mm to 62 mm when the inner diameter is 32 mm and from an outer diameter of 50 mm when the inner diameter is 50 mm. What is necessary is just to set suitably in the range of 71 mm-73 mm in outer diameter.

Next, the basic recording / reproducing operation by the disk recording / reproducing apparatus as described above will be described in more detail.

First, the recording data (read from the memory 14)
Data) is a fixed number (for example, 32) of sectors
(Or blocks).
Several sectors for cluster connection are arranged between rasters
It is in the form that was. Specifically, as shown in FIG.
Cluster C consists of 32 sectors (blocks) B0-B31
And each of these clusters C has four
Sectors L1 to L4 for connection (for linking) are
Connected to the raster. Where one cluster, example
For example, the k-th cluster C_k If you want to record
Cluster C_k Not only the 32 sectors B0 to B31,
3 sectors forward, 1 sector backward, connecting sector
Cluster C_k-1 2 for run-in block on the side
Sectors L2 and L3 and one sector L4 for sub data
And cluster C_{k + 1} Side run-out block
A total of 36 sectors including one sector L1
I try to keep a record. At this time, these 36
Data from the memory 14 to the encoder 15
The encoder 15 performs an interleave process.
As a result, up to 108 frames (about 1.1 sections)
Are sorted), but the above class
TA C_k The data in
It is well within the range of Kuta L1 ~ L4, other classes
TA C_k-1 And C _{k + 1} Has no effect on
Note that, for example, dummy data such as 0 is allocated to the sectors L1 to L3.
The auxiliary sub data is allocated to sector L4.
Of the original data due to the interleave processing.
The effect can be avoided. Here, the main data sector B0
~ B31 is 000 as an 8-bit binary number (2-digit hexadecimal number)
0 0000 (00H) to 0001 1111 (1FH) sector number
Are attached, and the sector L1 of the linking part is 001
0 0000 (20H) and 0011 1101 (3DH) for L2 to L4
[0011] Sector numbers of 1111 (3FH) are respectively added.
I have. In addition, the above-mentioned cluster includes a linking section.
For example, 36 sectors including data may be considered as one cluster.
No.

By performing such recording in cluster units, it is not necessary to consider mutual interference due to interleaving with other clusters, and data processing is greatly simplified. Also, if the recording data cannot be recorded normally at the time of recording due to defocus, tracking deviation, other malfunction, etc., re-recording can be performed in cluster units, and if effective data reading cannot be performed during reproduction, Re-reading can be performed in cluster units.

Incidentally, one sector (block) is 235.
23 bytes consisting of 2 bytes, 12 bytes for synchronization, 4 bytes for header, and data D0001 to D2336 from the beginning.
36 bytes are arranged in this order. Of the 12 bytes for synchronization in the sector structure (block structure), the first 1 byte is 00H (H indicates a hexadecimal number), followed by 10 bytes of FFH, and the last 1 byte is 00H. The next 4-byte header is composed of one byte for mode information, following the minute, second, and block address portions of one byte each. This mode information is mainly for indicating the mode of the CD-ROM, and the internal structure of the sector shown in FIG. 2 corresponds to the mode 2 of the CD-ROM format. CD-I is a standard using this mode 2.

The specific example of FIG. 2 further shows a format for recording compressed audio data. From the top of the 2336-byte area, an 8-byte sub-header, 128 bytes each, and 18 groups of sound groups SG01 to SG01 are provided. SG18, a 20-byte space area, and a 4-byte reserved area are arranged in this order. 8 above
The byte subheader has a file number, a channel number, a submode, and a data type of 1 byte, which are arranged twice.

When such sector-structured data is recorded on a disk, the encoder 15 performs encoding processing including parity addition and interleaving processing, and performs EFM (8-14 modulation) processing. FIG. 3
Recording is performed in a recording format as shown in FIG.

In FIG. 3, one block (one sector) is composed of 98 frames from the first frame to the 98th frame, and one frame has a channel clock period T
588 times (588T) of the frame synchronization pattern part of 24T (+3 connection bits) in one frame, 14T
A (+ connection bit 3T) subcode portion and a 544T data (audio data and parity data) portion are provided. The data portion of 544T is so-called EFM-modulated 12-byte (12-symbol) audio data, 4-byte parity data, 12-byte audio data, and 4-byte parity data, and audio data in one frame. Is 24 bytes (that is, one word of audio sample data is 16 bytes).
12 words). The sub-code part is obtained by subjecting 8-bit sub-code data to EFM modulation, and is divided into blocks of 98 frames, and each bit forms eight sub-code channels P to W. However, the subcode portions of the first and second frames are block synchronization patterns S _{0 and} S ₁ outside the rules of the EFM modulation (out-of-rule), and the subcode channels P to W are shifted from the third frame to the third frame. It is 96 bits each for up to 98 frames.

The above-mentioned audio data is recorded after being subjected to an interleaving process. During reproduction, the audio data is subjected to a de-interleaving process so as to be audio data having a data arrangement in a time order. Instead of this audio data,
General CD-I data and the like can be recorded.

In the disk recording / reproducing apparatus shown in FIG. 1, the system controller 7 continuously increments the write pointer W of the memory 14 at a speed corresponding to the bit rate of the compressed data, as shown in FIG. continuously writing Te, the unread data volume of the compressed data stored in the memory 14 becomes equal to or larger than a predetermined amount M _K, pursuant read pointer R of the memory 14 in the standard CD-DA format The memory control is performed such that the data is incremented in a burst at the transfer speed and read out in predetermined recording units (for example, 32 sectors). Therefore, in the memory 14, the data amount that can be written without destroying the unread data, that is, the recordable capacity is:
It will be prevented below a predetermined amount _(M T -M _K).

Here, the recording data read out from the memory 14 in a burst manner is continuously recorded on the recording track of the magneto-optical disk 2 by controlling the recording position on the recording track of the magneto-optical disk 2 by the system controller 7. The status can be recorded. Further, as described above, since a data write area of a predetermined amount or more is always secured in the memory 14, the system controller 7 detects that a track jump or the like has occurred due to disturbance or the like, and performs a recording operation on the magneto-optical disk 2. Even when the recording is interrupted, the input data is continuously written in the recordable area of the predetermined amount or more, and the return processing operation can be performed during that time, and the input data is continuously recorded on the recording track of the magneto-optical disk 2. The status can be recorded.

The magneto-optical disk 2 is recorded with header time data and the like corresponding to the physical address of the sector added to the compressed data for each sector. The catalog data indicating the recording area and the recording mode is TO TO
It is recorded in a catalog area such as the C area.

Next, in the reproducing system of the disk recording / reproducing apparatus shown in FIG. 1, the system controller 7 sets the write pointer W of the memory 22 to a standard CD as shown in FIG.
-While incrementing at a transfer rate in accordance with the DA format and writing in a burst, the read pointer R of the memory 22 is continuously incremented and read at a rate corresponding to the bit rate of the compressed data. It stops writing when caught up with the read pointer R (writable area becomes zero), so that the unread data amount stored in the memory 22 writes the equal to or less than a predetermined amount M _L Perform memory control. Accordingly, while ensuring a data read area always a predetermined amount M _L or more unread data volume in the memory 22 can be read continuously reproduced data from the memory 22.

The reproduction data written in a burst to the memory 22 is reproduced in a continuous state on the recording track of the magneto-optical disk 2 by controlling the reproduction position on the recording track of the magneto-optical disk 2 by the system controller 7. can do. Moreover, since always a predetermined amount M _L or more data read area in the memory 22 as described above is secured, with respect to the optical disk 2 to detect that the track jump or the like occurs due to disturbances such as the system controller 7 even when the interrupting playback operation, it is possible to continue the output of the analog audio signal by reading the playback data from the predetermined amount M _L or more data read area, it is possible to perform the return processing operations in the meantime.

The present invention is not limited to the above embodiment. For example, the number of sectors constituting the cluster is not limited to 32. For example, an arbitrary number of sectors such as 64 sectors constitutes one cluster. May be configured. The recordable disc is not limited to a magneto-optical disc, and the present invention can be applied not only to a phase-change optical disc, an organic dye-based optical disc, a PHB (photochemical hole burning) optical disc, and the like, but also The present invention can be applied to a card-like medium, a sheet-like medium, and a tape-like medium other than the disk-like medium.

[0053]

As is apparent from the above description, according to the reproduction control circuit of the disk reproducing apparatus of the present invention, the reproducing means for reproducing the disk from the head and the data obtained from the reproducing means are provided. And writes the data obtained by the reproducing means into the memory by a write pointer incremented at a first data transfer rate, and increments the data stored in the memory at a second data transfer rate reading by the read pointer is to detect the unread data volume in the memory, the unread data volume stops writing by the write pointer until the predetermined amount or less M _L, the unread data volume is a predetermined amount when it becomes less than M _L and the playback means to playback mode to perform the writing by the write pointer, Pau Since the reading by the read pointer is stopped in conjunction with the key input, the audio playback is stopped instantaneously, and even if the reading of the recording data from the recording medium progresses and the data cannot be written to the memory, By the memory control, data reading from the recording medium is stopped, and a standby state is realized. Also, by restarting the reading by the read pointer in conjunction with the pause release operation, audio reproduction is restarted instantaneously, and data can be written to the memory by reducing unread data. Data reading is resumed. Here, the memory control operation is performed to continuously reproduce data regardless of disturbance of the servo system due to disturbance or the like. By using this memory control operation, the pause function can be easily performed. realizable.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a configuration example of a disk recording / reproducing apparatus using an embodiment of a reproduction control circuit of a disk reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing a format of a cluster structure which is a unit of recording on a recording medium.

FIG. 3 is a diagram showing a format of a frame and a sector (block) in the standard of a so-called CD (compact disk).

FIG. 4 is a diagram showing a state of a memory whose memory is controlled in a recording system of the disk recording / reproducing apparatus of FIG. 1;

FIG. 5 is a diagram showing a state of a memory whose memory is controlled in a reproducing system of the disk recording / reproducing apparatus of FIG. 1;

[Explanation of symbols]

2 magneto-optical disk, 3 optical head, 4 magnetic head, 6 servo control circuit, 7 system controller, 10 analog audio signal input terminal, 1
2 A / D converter, 13 encoder for data compression processing, 14, 22 memories, 15 encoders, 1
6 magnetic head drive circuit, 21 decoder, 23
Decoder for data decompression processing, 24 D / A converter,
26 Analog audio signal output terminal

Claims (2)

[Claims] 1. A reproducing means for reproducing data from a disk by a head, a memory for storing data obtained from the reproducing means, and a write for incrementing the data obtained from the reproducing means at a first data transfer speed. The data is written to the memory by the pointer, and the data stored in the memory is stored in the second memory.
Reading by the read pointer is incremented at a data rate of, detecting the unread data volume in the memory, it stops writing by the write pointer until the data amount out this unread becomes equal to or less than the predetermined amount M _L, the unread out when the data amount is equal to or less than the predetermined amount M _L and the playback means to playback mode to perform the writing by the write pointer, in conjunction with the pause key input, the reading by the read pointer is stopped, the pause release operation A reproduction control circuit for a disk reproduction apparatus, comprising: control means for restarting reading by the read pointer in conjunction with the control means. 2. The controller according to claim 1, wherein the controller stops the data reading operation on the disk when data is read from the disk and written to the memory at the time of the pause, so that a free space in the memory becomes a predetermined value or less. 2. A reproduction control circuit for a disk reproduction apparatus according to claim 1, wherein the control is performed in a standby state.