JPH07182720A - Disk recording device and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the formation of an unnecessary link sector on a disk in the disk recording/reproducing device. CONSTITUTION:Data inputted via an interface l is supplied to a packing circuit 31 and a synchronizing signal is supplied to a synchronization detector 2. When the synchronizing signal is detected by the synchronization detector 2, the detected output is supplied to a linking sector position detecting circuit 33. In the linking sector detecting circuit 33, what data the synchronizing signal is inputted for is detected. Also, how many sectors of data on a disk format the amount of data is equivalent to is calculated and based on this calculated value, data is divided for each sector. A link sector outputted from a link sector generating circuit is added to data outputted from the packing circuit 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc recording device and a reproducing device such as a mini disc.

[0002]

2. Description of the Related Art For example, disk recording / recording such as mini disk
In the reproducing apparatus, ACIRC (Advanc
ed Cross Interleave Reed-Solomon Code) is used. In ACIRC, double error correction is applied. That is, 4 bytes of C2 parity in the diagonal direction is added to 24 bytes of data, and 4 bytes is added to 28 bytes of data in the recording direction.
Byte C1 parity is added. One frame is composed of 32 bytes. In this way, the error correction processing can be performed strongly against the burst error by applying the error correction to the input signal dually in the oblique direction and the recording direction.

In FIG. 10, 98 frames of data for one frame composed of ACIRC in the recording system are collected,
It is a figure shown in units of sectors (blocks). One sector has (24 bits x 98 frames) worth of frame sync signals,
(14 bits x 98 frames) subcode and (3
2 bytes x 14 bits x 98 frames) of data. By recording in such a sector unit, the error resistance becomes stronger against burst errors and the error correction capability is improved because the error correction is doubled. Further, the hardware can be downsized as compared with the product code completed in the block, and since the product code is not completed in the block, the decoding can be started from any frame when the sync signal is detected. Further, it has a higher degree of freedom than the product code.

FIG. 11 shows a data array when ACIRC interleaving is performed. Note that interleaving in this case is interleaving that is not completed in blocks (completes in cluster units). A cluster is a recording unit when writing data. In FIG. 11, one cluster includes a data sector consisting of 33 sectors and a link sector consisting of 3 sectors. More specifically, 0.5 sub-data sectors indicating the beginning and end of each data sector are provided at the front and the end of the 33-sector data sector. 1.5 before and after that
A link sector of sectors is provided. As a result, the error correction is completed on a cluster basis, and the data is rewritten on a cluster basis. Also, rewriting of data is always performed by an integral multiple of one cluster. The link sector is an ECC (Error Correction Cod).
This is a margin area provided before and after the data in order to remove the effect of interleaving in e). EC is used even when the data before and after is rewritten by the link sector.
It becomes possible to solve C.

[0005]

By the way, in rewriting on a cluster-by-cluster basis, even if rewriting is not performed on one cluster, there is always an wasted area of 3 sectors out of 33 sectors. Further, when the rewriting unit required for the signal to be recorded is not equal to the data for n clusters, the number of clusters is adjusted to the rewriting unit, and the useless area is further increased. In particular, when recording variable-length data, this useless increase of the area becomes remarkable.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a disc recording apparatus and a reproducing apparatus capable of preventing a wasteful area from being formed on a disc.

[0007]

SUMMARY OF THE INVENTION According to the present invention, in a disk recording apparatus, a link sector is added to the end portion of data with respect to input data, and the data and the link sector are provided on the disk. Is a disk recording device in which a cluster unit, which is a recording unit of, is variable according to the length of data.

Further, the present invention provides a variable disc reproducing apparatus in which a link sector is added to the end portion of the data with respect to the input data, the data and the link sector are provided on the disc, and the data is reproduced. It is a disc reproducing device for reproducing data provided on a disc in units of long clusters.

[0009]

The sync signal in the input signal is supplied to the sync detector 2. When the sync signal is detected by the sync detector 2, the detection output from the sync detector 2 is supplied to the link sector position detection circuit 33. The link sector position detection circuit 33 detects the data rewriting unit by detecting how many data each sync signal is.
At the same time, how many sectors on the disk format the data amount corresponds to is calculated. Further, the link sector generation circuit 32 adds link sectors before and after the sector for the rewrite unit. As a result, interleaving is completed for each rewriting unit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk recording / reproducing apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a circuit block diagram of a disk recording / reproducing apparatus according to the present invention. The configuration and operation of the recording system of the disc recording / reproducing apparatus will be described below. As the disc, for example, a magneto-optical disc is used. The audio data input via the interface 1 is supplied to the sync detector 2 and the packing unit 3. The sync detector 2 detects a frame synchronization signal indicating frame synchronization. Further, the type of the supplied data, the rewriting unit, etc. are detected or calculated. The frame synchronization signal detected by the sync detector 2 is supplied to the packing unit 3. The packing section 3 converts the frame synchronization signal and the audio data into a format suitable for the magneto-optical disk. Along with this, a link sector corresponding to the rewriting unit is added. In this way, the audio data is packed.

The output of the packing unit 3 is supplied to the RAM control unit 4. In the RAM control unit 4,
The RAM 5 is connected. RAM control unit 4 and R
The output data of the packing unit 3 is converted from the input signal rate to the recording signal rate by the AM5. In addition,
At this time, the input signal rate is smaller than the recording signal rate. The output of the RAM control unit 4 is supplied to the ECC encoder 6, the ID / subcode generator 8, and the system control unit 25. The ECC encoder 6 performs ACIRC encoding. The output of the ECC encoder 6 is supplied to the channel coding modulator 7. On the other hand, the ID and subcode generator 8 generates data IDs and subcodes. These signals are supplied to the channel coding modulator 7.

In the channel coding modulator 7, the supplied data is channel coded and then EFM (8-14) modulated. The output of the channel coding modulator 7 is supplied to the laser driver 9 and the head driver 27. The output of the head driver 27 drives the magnetic head 28 provided near the magneto-optical disk 11. Further, a control signal is supplied from the system control unit 25 to the laser driver 9. The output of the laser driver 9 is the optical head 10.
Is supplied to the magneto-optical disk 11, so that the laser light is irradiated onto the magneto-optical disk 11. A control signal is supplied from the servo unit 12 to the optical head 10. Thereby, the intensity of the laser beam with respect to the magneto-optical disk 11 is controlled.

A control signal is supplied to the optical head 10 from the servo section 12 via a slide motor 13. As a result, the optical head 10 can be moved in the radial direction with respect to the magneto-optical disk 11. The servo unit 12 is connected to the system control unit 25. Further, a spindle motor 14 is connected to the servo section 12. The magneto-optical disk 11 is rotated at a predetermined speed by the spindle motor 14.

The structure and operation of the reproducing system of the magneto-optical disk recording / reproducing apparatus will be described below. The optical head 10 irradiates the magneto-optical disk 11 with laser,
The data recorded on the magneto-optical disk 11 is read. This data is transmitted via the optical head 10.
It is supplied to the RF amplifier 15. The data is RF amplifier 1
After being amplified by 5, the servo unit 12, ADIP (ADdress
In Pre-groove) demodulator 16 and equalizer 19
Is supplied to. The ADIP demodulator 16 is connected to the spindle control unit 17 and the ADIP decoder 18. The spindle control unit 17 generates a control signal for making the rotation of the magneto-optical disk 11 CLV (constant linear velocity). This control signal is sent to the servo unit 1
2 is supplied.

Further, the wobbled pre-groove is preformed on the magneto-optical disk 11,
By applying FM modulation to this, the magneto-optical disk 1
The address of 1 is recorded in sector units. ADIP
In the decoder 18, the address of the magneto-optical disk 11 is decoded from the pre-groove previously formed on the magneto-optical disk 11. The output of the ADIP decoder 18 is supplied to the system control unit 25.

In the equalizer 19, the data supplied from the optical head 10 is waveform-equalized. The output of the equalizer 19 is the detector 20 and the PLL circuit (Phas
e Locked Loop) 21. In the PLL circuit 21, the clock is regenerated based on the supplied data. This clock is supplied to the detector 20. The detector 20 uses this clock to equalize 19
The data supplied from is latched and made into binary digital data. The detector 20 also decodes digital data.

The decoded digital data is supplied to the channel coding demodulator 22. The digital data is channel-decoded by the channel coding demodulator 22 and then demodulated by EFM (8-14). The output of the channel coding demodulator 22 is supplied to the ID and subcode reader 23 and the ECC decoder 24.
The ID and subcode reader 23 detects the ID and subcode in the data. ID and sub code reader 2
The output of 3 is supplied to the system control unit 25 and the RAM control unit 4.

On the other hand, in the ECC decoder 24, the ACIR
C is decoded. The error-corrected data is R
It is supplied to the RAM 5 via the AM control unit 4.
The data stored in the RAM 5 is sequentially read by the control signal of the RAM control unit 4, and the depacking unit 2
6 is supplied. The RAM 5 is called a so-called shock proof memory, which allows normal data to be output even if a large shock is applied to the magneto-optical disk recording / reproducing device during data reproduction of the magneto-optical disk. It becomes possible. That is, for example, even if the digital signal on the magneto-optical disk cannot be read due to vibration or the like,
The reproduction signal continues to be output by the data stored in the RAM 5. During this time, the optical pickup is re-accessed to the original position and the signal is read again, so that the occurrence of sound skip can be prevented. The depacking unit 26 performs the reverse process of the packing unit 3. The output data of the depacking unit 26 is output via the interface 1.

The addition of link sectors to data will be described below with reference to FIGS. 2 and 3. FIG. 2 shows a detailed circuit block diagram of the packing unit 3 and its periphery. Further, FIG. 3 shows a data array before the link sector is added and a data array after the link sector is added. Various digital data are input to the interface 1. A sync signal indicating a data delimiter is added to the head of the data for each unit of rewriting as each format. This sync signal is detected by the sync detector 2. On the other hand, the data is supplied to the packing circuit 31 of the packing unit 3.

When the sync signal is detected, the sync detector 2 supplies a detection signal to the link sector position detection circuit 33. The link sector position detection circuit 33 detects how much data the synchronization signal is input. At the same time, the number of sectors of data on the disk format is calculated, and the data is divided into sectors based on the calculated value. Here, when the rewriting unit is not an integral multiple of the sector, the data of the last sector is left over. So for this data,
Dummy data is added.

The link sector generation circuit 32 adds link sectors before and after the sector for rewriting.
As a result, interleaving is completed in units of rewriting. At this time, if information indicating that the sector is a link sector is included in the header of the sector, it becomes possible to distinguish it from valid data during reproduction. In addition, by inserting a parameter indicating a rewriting unit in the header of the interface 1, a circuit for detecting the rewriting unit can be omitted.

By the way, in the present invention, 1 cluster = n
The sector is a sector (n is any positive integer), and if the link sector is K sector, the redundancy by the link sector K is redundancy = K / n.

On the other hand, conventionally, the rewriting unit (cluster) is 1 cluster = N sectors (N is a positive fixed integer) with respect to the address unit (sector) on the disk. When link sector = K sector, the redundancy by link sector K is redundancy = K / N.

As can be seen from the above, when n> N, the redundancy due to the link sector K can be reduced. Further, when n <N, conventionally, the dummy data is added to the data of the rewriting unit and apparently recorded as the data of N sectors, whereas in the present invention, the dummy data is added in the unit of the sector. Therefore, the redundancy can be reduced.

FIG. 4 is a diagram showing a specific method of managing link sectors. In FIG. 4, the numbers below each sector are sector addresses. It is attached to each sector. Along with this, one link sector and one data sector are taken as one unit, and the address 5 in FIG.
1 to address 74 is data sector n, data sector n is one data sector n−1, and data sector n is one data sector n + 1.
Recorded in the (User Table Of Contents) area. UT
As shown in FIG. 5, the OC area is provided inside the magneto-optical disk 11 and is an area recorded by the user.

FIG. 6 shows actually recorded data and UTO.
It is a figure which shows the relationship with C area. In FIG. 6A, data 1 is stored in areas A to B and addresses C to D are stored.
Data 2 is recorded in the area No. 3 and data 3 is recorded in the areas E to F. In the UTOC area, these addresses and their data numbers are recorded so as to correspond to each other.

For the recording of the data shown in FIG. 6A,
When data 1 is erased and new data (data 1 ') longer than data 1 is inserted, as shown in FIG. 6B, data 1'is stored in the areas of addresses A to B and data 1'of addresses C to D. Data 2 is recorded in the areas, data 3 is recorded in the areas of addresses E to F, and data 1'is recorded in the areas of addresses G to H. On the other hand, in the UTOC area, data 1'is assigned to addresses A to B and G to H,
Data 2 is at addresses C to D, data 3 is at addresses E to
It is recorded that each is recorded in F. By thus recording the position information of the data in the UTOC area, it is possible to easily manage how the data is continuously reproduced even when the data is rewritten.

When actually recording the information of the link sector in the UTOC area, the information of the link sector is supplied from the packing unit 3 to the RAM control unit 4. R
The AM control unit 4 creates a table as shown in FIG. 6 based on the link sector information and the address on the magneto-optical disk. It is difficult to record this information during the recording of the data. Therefore, after the data recording is completed, the optical pickup accesses the UTOC area, and writing or rewriting of information as shown in FIG. 6 is performed. At the time of rewriting, the writing position is determined in consideration of the position of the link sector to be recorded next while reading the information of the UTOC area and searching for an empty area. Then, information is recorded at this writing position.

FIG. 7 is a circuit block diagram of a magneto-optical disk recording / reproducing apparatus for moving pictures. The output terminal 51 and the input terminal 52 are connected to the RAM control unit 4 in FIG. Further, the circuits after the RAM control unit 4 can be the same as those in FIG.

The configuration and operation of the recording system of the circuit shown in FIG. 7 will be described below. The video signal via the input terminal 40 is supplied to the frame memory 41. The frame memory 41 stores the video signal in units of one frame.
From the frame memory 41, a video signal in 1-frame units is converted into a motion-compensated inter-frame prediction unit 43 of the video encoder 42.
And the scene change detector 63. When the scene change detection unit 63 detects that the pixel value difference between the frames obtained from the frame memory 41 is equal to or larger than a predetermined value, it is detected that a scene change has occurred. In this case, from the scene change detection unit 63, the motion compensation inter-frame prediction unit 43 and the system multiplexing encoder 50 described later
Is supplied with a detection signal. As a result, the motion-compensated inter-frame prediction unit 43 processes the supplied frame as an intra frame.

In the system multiplexing encoder 50, the video data and the audio data are multiplexed, and at the same time, it is adapted to the format of the magneto-optical disk.
The data is divided into sectors. At this time, a link sector is added before the sector of the frame in which the scene change is detected. Since image rewriting is often performed at scene change, as described above, by adding a link sector at scene change, rewriting can be performed neatly in that unit.

The video data supplied to the motion-compensated inter-frame prediction unit 43 is divided into 16 × 16 pixel data, and motion compensation and inter-frame prediction are performed in this unit. Thereafter, the motion-compensated inter-frame prediction unit 43 supplies the video data to the DCT (Discrete Cosine Transform) circuit 44 and the motion vector data to the VLC (Variable Length Coding) circuit 47. In the DCT circuit 44, 8
DCT conversion is performed in block units of × 8 pixels. VL
In the C circuit 47, the motion vector data is variable length coded. The output of the VLC circuit 47 is the video multiplexing encoder 4
8 are supplied. The video data which has been subjected to the predetermined processing in the DCT circuit 44 is quantized in the quantization circuit 45. The output of the quantization circuit 45 is converted into variable length coded data in the VLC circuit 46. The output of the VLC circuit 46 is supplied to the video multiplexing encoder 48.

The video multiplexing encoder 48 multiplexes the variable length encoded video data and the variable length encoded motion vector data. The multiplexed data is supplied to the system multiplexing encoder 50 via the buffer 49. The output of the buffer 49 is also supplied to the quantization circuit 45 in order to keep the output of the quantization circuit 45 constant. The system multiplex encoder 50 multiplexes and encodes the data from the video multiplex encoder 48 and the audio data and additional data input from another system. The output of the system multiplexing encoder 50 is an output terminal 51.
Is supplied to the circuit in the subsequent stage via.

The configuration and operation of the reproducing system of the circuit shown in FIG. 7 will be described below. The data input through the input terminal 52 is separated into audio data and additional data and a video data component in the system multiplexing decoder 53. The audio data and the additional data are processed by a voice system (not shown) after being decoded. On the other hand, the video data component, after being decoded, passes through the buffer 54 and the video decoder 55.
Of the video multiplexer / decoder 56. The video multiplexing decoder 56 separates the video data component into video data and motion vector data.

The video data is supplied to the inverse VLC circuit 57, and the motion vector data is supplied to the inverse VLC circuit 58. The inverse VLC circuits 57 and 58 respectively perform variable length decoding on the supplied data. The output of the inverse VLC circuit 57 is inversely quantized by the inverse quantization circuit 59 and then inverse DCT
The circuit 60 performs inverse DCT conversion. The output of the inverse DCT circuit 60 and the output of the inverse VLC circuit 58 are supplied to the motion compensation inter-frame prediction unit 61. Motion compensation inter-frame prediction unit 6
In No. 1, motion compensation is performed on the video data supplied from the inverse DCT circuit 60 based on the motion vector data supplied from the inverse VLC circuit 58. The output of the motion compensation inter-frame prediction unit 61 is supplied to the subsequent circuit via the output terminal 62. Like the circuit shown in FIG. 7, when a scene change is detected, a link sector is added, so that data can be properly written or rewritten.

FIG. 8 is a circuit block diagram of a magneto-optical disk recording / reproducing apparatus for moving images, as in FIG. In the circuit of FIG. 8, whether or not the link sector is added is determined according to the type of audio signal. The output terminal 83 and the input terminal 84 are connected to the RAM control unit 4 in FIG. Further, the circuits after the RAM control unit 4 can be the same as those in FIG.

The configuration and operation of the recording system of the circuit shown in FIG. 8 will be described below. The video signal transmitted through the input terminal 71 is the motion compensation inter-frame prediction unit 73 of the video encoder 72.
Is supplied to. In the motion compensation inter-frame prediction unit 73, the supplied video data is divided into data of 16 × 16 pixels, and motion compensation and inter-frame prediction are performed in this unit. Then, from the motion compensation inter-frame prediction unit 73,
The video data is supplied to the DCT circuit 74, and the motion vector data is supplied to the VLC circuit 77. DCT circuit 74
Then, DCT conversion is performed in a block unit of 8 × 8 pixels.

On the other hand, in the VLC circuit 77, the motion vector data is variable length coded. The output of the VLC circuit 77 is supplied to the video multiplexing encoder 78. The video data which has been subjected to the predetermined processing in the DCT circuit 74 is quantized in the quantization circuit 75. The output of the quantization circuit 75 is converted into variable length coded data in the VLC circuit 76. The output of the VLC circuit 76 is the video multiplexing encoder 7
8 are supplied.

The video multiplex encoder 78 multiplexes the variable length encoded video data and the variable length encoded motion vector data. The multiplexed data is supplied to the system multiplexing encoder 80 via the buffer 79. The output of the buffer 79 is also supplied to the quantization circuit 75 in order to keep the output of the quantization circuit 75 constant. The system multiplexing encoder 80 has an input terminal 8
An audio signal is input via 1. This audio signal is also supplied to the bilingual / stereo broadcast detection unit 82.

For example, C for bilingual broadcasting and stereo broadcasting
When M is supplied to the bilingual / stereo broadcast detection unit 82, the pilot signal in the signal is detected. By this detection, the input signal is determined to be CM. The detection output of the bilingual / stereo broadcast detection unit 82 is supplied to the system multiplexing encoder 80. Only when there is a detection output, the system multiplexing encoder 80 adds a link sector to the signal supplied from the buffer 79. The output of the system multiplexing encoder 80 is output to a circuit (not shown) in the subsequent stage via the output terminal 83.

Since the structure and operation of the reproducing system of the circuit shown in FIG. 8 are the same as those of FIG. 7, the description thereof will be omitted.

As described above, the bilingual / stereo broadcast detecting unit 82 detects whether or not the input signal is CM, and if it is CM, the link sector is added and the magneto-optical signal is added. By recording on the disk 11, the data recording area of the magneto-optical disk 11 can be effectively used.

Similar to FIG. 8, FIG. 9 is a circuit block diagram of a magneto-optical disk recording / reproducing apparatus for moving images. In addition,
In the circuit of FIG. 9, a link sector is externally added by the user after data recording. The configuration and operation of the circuit shown in FIG. 9 will be described below. The video signal via the input terminal 91 is supplied to the motion-compensated inter-frame prediction unit 93 of the video encoder 92. The video data supplied to the motion compensation inter-frame prediction unit 93 is divided into 16 × 16 pixel data, and motion compensation and inter-frame prediction are performed in this unit.

Thereafter, the motion-compensated inter-frame prediction section 93 supplies the video data to the DCT circuit 94 and the motion vector data to the VLC circuit 97. In the DCT circuit 94, DCT conversion is performed in block units of 8 × 8 pixels. In the VLC circuit 97, the motion vector data is variable length coded. The output of the VLC circuit 97 is supplied to the video multiplexing encoder 98. The video data which has been subjected to the predetermined processing in the DCT circuit 94 is quantized by the quantization circuit 9.
Quantized by 5. The output of the quantization circuit 95 is variable length encoded data in the VLC circuit 96. VLC
The output of circuit 96 is provided to video multiplex encoder 98.

The video multiplex encoder 98 multiplexes the variable length encoded video data and the variable length encoded motion vector data. The multiplexed data is supplied to the system multiplexing encoder 100 via the buffer 99. The output of the buffer 99 is also supplied to the quantization circuit 95 in order to keep the output of the quantization circuit 95 constant. The system multiplex encoder 100 multiplexes and encodes the data from the video multiplex encoder 98 with the audio data and additional data input from another system. Further, a man-machine interface 101 is connected to the system multiplexing encoder 100. An input device such as a keyboard (not shown) is connected to the man-machine interface 101. The data input by this input device is supplied to the system multiplex encoder 100 via the man-machine interface 101.

The data supplied to the system multiplexing encoder 100 via the man-machine interface 101 is
This is for determining at which position of the data to be recorded on the magneto-optical disk the link sector is added.
For example, data relating to the position at which a link sector is to be driven later is supplied to the system multiplex encoder 100 via the man-machine interface 101 at a position where an edited break is likely to occur in the data recorded by the user. . As a result, it is possible to prevent improper operation such that effective data is erased at a break at the time of editing and waste of the data area is increased. The output of the system multiplex encoder 100 is supplied to the subsequent circuit via the output terminal 102.

Since the configuration and operation of the reproducing system of the circuit shown in FIG. 9 are the same as those in FIG. 7, their description will be omitted.

In this way, when the work such as editing is performed after the recording of the data recording, the data related to the setting of the link sector is input from the outside to prevent the erroneous deletion of the effective data and the increase of the wasteful data area. be able to.

[0049]

According to the present invention, it is possible to set a recording unit suitable for input data without changing the disc format. Therefore, the area on the disc can be used more effectively than when the rewriting unit is fixed. Further, the number of link sectors can be reduced in proportion to the increase in the rewriting unit.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a disc recording / reproducing apparatus according to the present invention.

FIG. 2 is a detailed circuit block diagram of a packing unit and its periphery.

FIG. 3 is a diagram showing a data array of a link sector.

FIG. 4 is a diagram showing a specific management method of link sectors.

FIG. 5 is a diagram showing a UTOC area on a disc.

FIG. 6 is a diagram showing a relationship between actually recorded data and a UTOC area.

FIG. 7 is a circuit block diagram of a magneto-optical disk recording / reproducing apparatus for a moving image.

FIG. 8 is a circuit block diagram of a magneto-optical disk recording / reproducing apparatus for a moving image.

FIG. 9 is a circuit block diagram of a magneto-optical disk recording / reproducing apparatus for moving images.

FIG. 10 is a diagram showing, for each sector, 98 frames of data for one frame configured by ACIRC.

FIG. 11 is a diagram showing a data array when interleaving ACIRC.

[Explanation of symbols]

 2 sync detector 3 packing unit 31 packing circuit 32 link sector generation circuit 33 link sector position detection circuit 63 scene change detection unit 82 bilingual / stereo broadcast detection unit 101 man-machine interface

Claims (3)

[Claims] 1. A disk recording apparatus in which a link sector is added to an end portion of the data with respect to input data and the data and the link sector are provided on a disk, which is a recording unit of the data. A disk recording device in which the cluster unit is variable according to the length of the above data. 2. The disc recording apparatus according to claim 1, wherein the information in units of clusters is recorded at a predetermined position on the disc. 3. A disc reproducing apparatus, wherein a link sector is added to an end portion of the data with respect to input data, the data and the link sector are provided on a disc, and the data is reproduced, a variable length A disc reproducing device for reproducing the data provided on the disc in units of clusters.