JPH1027350A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce recorded data as in the case of a reproduction exclusive standard optical disk such as a DVD-ROM for reproducing data from an optical disk in which new data in a DVD-RAM or the like is written. SOLUTION: A header part 27 is pre-formatted in the head position of each sector 24, and the format of a data part 28 continuous therefrom is set equal to that of the sector 23 of a reproduction exclusive standard optical disk. By performing data reproduction not for the header part 27 but for only the data part 28, this is performed in the same way as the reproduction of the sector 23 of the standard optical disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a DVD (Digital V)
The present invention relates to an optical disk such as an (ideo disk) -RAM (random access memory), and an optical disk device that records and reproduces information on and from such an optical disk.

[0002]

2. Description of the Related Art In recent years, an optical disk medium has been developed as a large-capacity recording medium.
ct Disk) has been put to practical use. This is a read-only recording medium that records audio signals as digital data,
At present, CD-WO that can add additional digital data
(Write Once), CD with digital data rewritable
-RAMs and the like are also in practical use.

[0003] Such various types of CDs are different from the original CDs for audio reproduction in many parts, but all use the basic technology of the CDs. It is easy to reproduce such various CDs. For example, in these various CDs, digital data is recorded on a track, and the track is divided into a plurality of sectors. To search for desired digital data at high speed,
Addresses are assigned to the sectors and tracks.

[0004] Optical discs using such a CD are:
Although the recording capacity is large compared to conventional magnetic disks, etc.,
Still, the recording capacity is insufficient to reproduce a long moving image with high quality. In order to solve this, a DVD has been developed as a next-generation optical disk. This achieves a recording capacity several times larger than that of a conventional CD by reviewing the recording / reproducing hardware and the compression method of digital data. This DVD is a read-only medium like the above-mentioned CD, but it is a DVD-WO or DVD like the CD.
-Development of RAM is required.

Currently, a read-only DVD-ROM (Read On
ly Memory) standard format has been announced. In this DVD-ROM format, a track is divided into a plurality of sectors, and various areas are arranged in each sector. That is, a header portion is formed at the head position of the sector, and a data portion is formed so as to be continuous with the header portion. The header section includes an ID (I
dentification) portion, and the address data of the sector is recorded in this ID portion. Various data such as computer programs are recorded in the data section, and such various data are collectively recorded as pre-pits on the DVD-ROM.

[0006] As described above, the format standard is determined for the DVD-ROM, but the format standard is not determined for the DVD-RAM. So, DV
Considering the format of the D-RAM, in order to perform data recording in a predetermined sector, it is necessary to preformat at least a header portion having an ID portion at the head position of the sector, The user records new data in the section.

As described above, new data recorded in a large number of data portions of a DVD-RAM cannot be synchronized with each other unlike recording data formed collectively on a DVD-ROM. It is necessary to preformat a VFO (Variable Frequency Oscillator) section for synchronizing data reproduction at the head of the header section. However, in this case, the format of the sector of the DVD-RAM is different from that of the DVD-ROM, and it is difficult to reproduce these two types of DVDs with one optical disk device.

In this respect, PD which is one of the optical disk devices is
Drives are PDs and CDs with possibly different formats
And both data can be reproduced. This PD drive has one disk drive unit, one optical head, one data reproducing circuit, and the like. Each data reproducing circuit 1 has a CD reproducing unit and a PD reproducing unit as shown in FIG. And two data reproducing units 2 and 3 are provided.

That is, these data reproducing units 2 and 3
Binarization circuits 4 and 5, PLL (Phase Locked Loop) circuits 6 and 7, demodulation circuits 8 and 9, ECC (Error Correcting Co
des) The circuits 10 and 11 are respectively provided, and these processing operations are specialized for CD and PD. These data reproducing units 2 and 3 are commonly connected to one buffer manager 12, and a host I / F (Interface) 13 is connected to this buffer manager 12.
A data processing device (not shown) such as a host computer is connected to the host I / F 13.

[0010] In the PD, an SM is added at the beginning of each sector.
A (Sector Mark) section is formed, and an SM detection circuit (not shown) for detecting the SM section is also connected to the data reproduction section 3 for PD.

In this PD drive, a CD, which is a read-only optical disk, and a PD, which is a rewritable optical disk, are removably mounted on a disk drive unit, and an optical head photoelectrically converts data recorded on the optical disk. When the photoelectrically converted recording data is input to the data reproducing circuit 1, the CD recording data is reproduced by the data reproducing unit 2, and the PD recording data is reproduced by the data reproducing unit 3. Since the recorded data of the CD and the PD are reproduced in the same form by the data reproducing units 2 and 3, the data processing device to which the reproduced data is input must handle the input data without being aware of the CD or the PD. Can be.

[0012]

In the above-mentioned PD drive, data can be reproduced from both CDs and PDs whose formats are probably different.

However, this PD drive uses a CD and a PD.
Dedicated data reproducing units 2 and 3 are provided, and each of these data reproducing units 2 and 3 requires a large number of components, so that the total number of components is large and it is difficult to reduce the size and weight and improve productivity. It is.

Similarly to the PD drive, if the DVD drive is provided with a dedicated data reproducing unit for the DVD-ROM and the DVD-RAM, both of these two types of DVDs can be used for data reproduction. The number increases, and it is difficult to reduce the size and weight and improve the productivity.

[0015]

According to the optical disk of the present invention, a header portion having at least an address portion at a head position of each sector is pre-formatted, and new data is stored at a position following the header portion of the sector. A data portion to be recorded was formed, and the format of the data portion was set to be the same as the format of a sector in which a header portion and a data portion of an optical disk of a reproduction-only standard were continuous. Therefore, since the address portion is preformatted in each sector, new data is recorded in the data portion of each sector corresponding to the address data. Since the format of the new data recorded in the data portion is the same as the sector of the standard optical disk for reproduction only, the recorded data is reproduced in the same manner as the data reproduction of the sector of the standard optical disk.

According to a second aspect of the present invention, there is provided an optical disk in which a header portion having at least an address portion at a head position of a sector group of an error correction execution unit is preformatted, and new data is recorded in each sector. To form
The format of the data portion was set to be the same as the format of the sector in which the header portion and the data portion of the optical disc of the read-only standard were continuous. Accordingly, since the address portion is preformatted at the head position of the sector group of the error correction execution unit, new data is recorded in the data portion of the sector group of the error correction execution unit corresponding to the address data. Since the format of the new data recorded in the data portion is the same as the sector of the standard optical disk for reproduction only, the recorded data is reproduced in the same manner as the data reproduction of the sector of the standard optical disk.

An optical disk device according to a third aspect of the present invention comprises:
3. A disk drive unit in which the optical disk according to claim 1 is removably mounted, and a data unit of the optical disk, which has a format identical to a sector in which a header portion and a data portion of a read-only standard optical disk are continuous. A data recording unit for recording data. Therefore, when the optical disk according to claim 1 or 2 is loaded into the disk drive unit, the data recording unit records new data in the data unit corresponding to the address data of the address unit of the optical disk. At this time, new data is recorded in the data portion of the optical disk in the same format as the sector of the read-only standard optical disk, so that the recorded data is reproduced in the same manner as the data reproduction of the sector of the standard optical disk. You.

An optical disk device according to a fourth aspect of the present invention comprises:
3. A disk drive unit in which the optical disk according to claim 1 or 2 and a read-only standard optical disk are removably mounted, and data reproduction is performed by excluding a header portion preformatted from the reproduction data of the optical disk. And a data reproducing unit to be executed. Therefore, claim 1 or 2
When the optical disk described above is loaded into the disk drive, the data reproducing unit reproduces the recorded data in the data part of the optical disk. At this time, the format of the recording data in the data portion of the optical disk is the same as that of the sector of the standard optical disk for reproduction only. Therefore, the recording data is reproduced in the same manner as the data reproduction of the sector of the standard optical disk.

According to a fifth aspect of the present invention, in the optical disk device of the fourth aspect, when the data reproducing section detects the head of the preformatted header section, the data reproducing section suspends the data reproduction for a predetermined time. Therefore, when the data reproducing unit reproduces the recorded data of the optical disc, when the head of the preformatted header is detected, the data reproduction is interrupted for a predetermined period of time. Only the recorded data of the set is reproduced.

According to a sixth aspect of the present invention, in the optical disk device of the fifth aspect, the data reproducing section detects the head of the preformatted header section based on the reflectance. Therefore, the reflectivity of the preformatted portion is substantially different from the non-preformatted portion, and the head of the preformatted header portion is detected based on this difference in reflectivity.

According to a seventh aspect of the present invention, in the optical disk device according to the fourth aspect, when the data reproducing section detects the end of the data section, the data reproducing section suspends the data reproduction for a predetermined time.
Therefore, when the data reproducing unit reproduces the recorded data of the optical disc, when the end of the data portion is detected, the data reproduction is interrupted for a predetermined time. Only the recorded data is reproduced.

According to an eighth aspect of the present invention, in the optical disk device according to the fifth, sixth or seventh aspect, the data reproducing section holds the synchronous control of the data reproduction from the start to the end of the interruption of the data reproduction. Therefore, the synchronization state secured before the start of the interruption of the data reproduction is maintained until the end of the interruption, so that the data reproduction is restarted in the synchronous state immediately after the end of the interruption.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, the optical disk system according to the present embodiment includes a plurality of optical disks and a DVD drive which is one optical disk device. The plurality of optical disks are classified into two types: a read-only DVD-ROM and a rewritable DVD-RAM. Become.

These DVDs have a track 21,
22 is formed in a spiral shape,
2 is divided into a plurality of sectors 23 and 24. In a read-only DVD-ROM, as shown in FIG. 1B, an ID section 25 which is an address section is located at the beginning of each sector 23, and a data section 26 is located immediately following the ID section 25. doing.

In the DVD-RAM, as shown in FIG. 1A, a header section 27 is located at the head of each sector 24, and a data section 28 is located so as to be continuous with the header section. The header section 27 includes an SM section 29, a VFO section 3
0 and an ID section 31, which is an address section, are arranged in order, and are preformatted in the DVD-RAM.

The data section 28 is made of, for example, an AgInSbTe-based recording material having good overwrite characteristics, and new data is rewritably recorded. The data recording of the data section 28 is performed according to a predetermined format, and this format is set to be the same as the format of the sector 23 of the DVD-ROM. In addition,
Since data recording in the data section 28 is executed in anticipation of a jitter error, a gap 32 is generated at the beginning and end of the data section 28.

The DVD drive has a disk drive unit, a data recording unit, and a data reproduction unit.
M can record new data and DVD-RAM
And DVD-ROM recorded data can be reproduced. The disk drive has a turntable and a drive motor, and two types of DVDs are detachably loaded. The data recording section has an optical head and a data recording circuit, and a DVD-ROM
New data is recorded in the same format as that of the sector 23. The data reproducing unit has an optical head and a data reproducing circuit 41 shared with the data recording unit, and reproduces two types of DVD recorded data.

More specifically, the data reproducing circuit 41
Represents a binarizing circuit 42 and a PLL circuit 4 as shown in FIG.
3, a demodulation circuit 44, an ECC circuit 45, a buffer manager 46, a host I / F 47, and the like, which are connected in order. The data reproducing circuit 41
Also has an SM detection circuit 48 and a controller 49, and the controller 49 is connected to the circuits 44 and 45.

The SM detection circuit 48 includes a DVD-RAM
, The head of the preformatted header section 27 is detected. The SM unit 29
Is, for example, extremely long recording data compared to other recording data. Therefore, the SM detection circuit 48 accurately detects the SM section 29 with a simple logic circuit.

The controller 49 has a timer function. When the SM detection circuit 48 detects the head of the header section 27, data reproduction by the circuits 44 and 45 is interrupted for a predetermined time. Since this time is set as the time required for the optical head to pass through the header section 27, the data reproducing circuit 41
The data reproduction is executed by removing the preformatted header section 27 from the reproduction data in the RAM.

In such a configuration, in the DVD system according to the present embodiment, new data is
It can be recorded by VD drive, DVD-RO
The data recorded in the M and the DVD-RAM can be reproduced by a DVD drive.

When recording new data, a DVD-RA
In M, the header portion 27 is preformatted at the head position of each sector 24, and the address of the sector 24 is recorded in the ID portion 31 of the header portion 27. Therefore, the DVD drive can operate the desired sector of the DVD-RAM. New data can be satisfactorily recorded in the 24 data sections 28. In this case, in the DVD-RAM, the format of the data section 28 is set to be the same as the sector of the DVD-ROM.
New data is recorded in the same format as the sector of the DVD-ROM.

When reproducing the data recorded on the DVD-ROM, the DVD drive has an ID portion 25 formed at the head position of each sector 23.
-The recorded data in the data section 26 of the desired sector 23 of the ROM can be reproduced. In this case, DVD-ROM
The recording data of the data section 26 is photoelectrically converted by the optical head and input to the data reproducing circuit 41. The data reproducing circuit 41 digitizes the analog reproduced data by the binarizing circuit 42. Further, the PLL circuit 4
3, a synchronous clock is extracted from the reproduced data, a demodulation circuit 44 demodulates the reproduced data, and an ECC circuit 45 corrects an error in the reproduced data. The timing of the reproduced data processed in this manner is adjusted by the buffer manager 46, and is output from the host I / F 47 to a higher-level data processing device.

As described above, the DVD drive for reproducing the data recorded on the DVD-ROM also reproduces the recorded data on the DVD-RAM. However, since the DVD-RAM has the header 27 at the head position of each sector 24, This sector 2
4 is different from the sector 23 of the DVD-ROM. However, DVD drives are not compatible with DVD-RA
For M, only the recorded data of the data section 28 is reproduced without reproducing the recorded data of the header section 27, and the format of the data section 28 is the same as that of the sector 23 of the DVD-ROM. -ROM
Is performed in the same way as

More specifically, in the DVD-RAM, since the SM section 29 is formed at the head position of each sector 24,
When reproducing the recorded data of each sector 24, the DVD drive first detects the SM unit 29 by the SM detection circuit 48. Then, the controller 49 sets the demodulation circuit 44
And the ECC circuit 45 are stopped for a predetermined period of time, and during this stop, the optical head moves the header 27 of the DVD-RAM.
Pass through. Next, at the timing when the optical head enters the data section 28 of the DVD-RAM, the controller 49 restores the demodulation circuit 44 and the ECC circuit 45.
Only the recorded data in the data section 28 of the VD-RAM is reproduced. Since the format of the data section 28 of the DVD-RAM is the same as the sector 23 of the DVD-ROM,
The recorded data is reproduced in the same manner as in the case of a DVD-ROM.

As described above, the DVD-R according to the present embodiment
AM means that the format of the data section 28 is a standard DV format.
Since the format is the same as the format of the sector 23 of the D-ROM,
The recorded data in the data section 28 can be reproduced in the same manner as a DVD-ROM.

The DVD drive according to the present embodiment
Since new data can be recorded in the data section 28 of the DVD-RAM in the same format as the sector 23 of the DVD-ROM, the DVD-RAM uses D
It can be reproduced in the same manner as a VD-ROM. further,
In the DVD drive according to the present embodiment, the data recorded in the header 27 of the DVD-RAM is not
8, since only the recorded data is reproduced, this data
It can be executed similarly to the VD-ROM.

That is, DVD-ROM and DVD-RAM
Therefore, it is not necessary to provide two systems of data reproducing circuits, and the data reproducing circuit 41 can be realized only by adding the controller 49 to the data reproducing circuit of the conventional DVD-ROM. With good productivity.

The present invention is not limited to the above-described embodiment, but allows various modifications. For example, in the above embodiment, the header section 27 is provided at the head position of each sector 24 of the DVD-RAM, but as shown in FIG.
The header section 27 can be provided at the head position of a predetermined number of sector groups 51. That is, the standard DVD-
In the ROM, error correction is performed with 16 sectors 23 as one unit, and data recording / reproduction is also performed in this unit. Therefore, in the DVD-RAM, if the header section 27 is preformatted at the head position of the sector group 51 of the unit of execution of error correction, the recording / reproduction can be executed in the same manner as the DVD-ROM.

A data section in which new data is recorded is formed in each sector, and the format of this data section is set to DV.
The format is set to be the same as the format of the sector 23 of the D-ROM. Therefore, since the ID portion is preformatted at the head position of the sector group of the error correction execution unit, new data is recorded in the data portion of the sector group of the error correction execution unit corresponding to the address data. The format of the new data recorded in the data section in this way is DVD-
Since this is the same as the ROM sector, the recorded data is reproduced in the same manner as the data reproduction of the standard DVD-ROM sector.

In the above embodiment, it is assumed that only one of the land and the groove of the DVD-RAM is used as the track 22, but as shown in FIG. 4, both the land 52 and the groove 53 are used as the track 54. It is also possible to use it. In this case, the header portion 27 to be pre-formatted is composed of the land 52 and the groove 5 serving as the track 54.
3, the recording density of the DVD-RAM can be doubled.

Further, in the above embodiment, when the data reproduction circuit 41 of the DVD drive reproduces the recorded data of the DVD-RAM, the controller 49 temporarily stops the demodulation circuit 44 and the ECC circuit 45 for the data reproduction of the header section 27. However, as shown in FIG. 5, it is also possible to form a data reproducing circuit 56 in which the controller 55 is also connected to the PLL circuit 43, and to suspend the synchronous control of the header section 27 temporarily.

That is, a plurality of sectors 2 of the DVD-RAM
In the case where new data is continuously recorded in the data section 28, the recorded data is synchronized with each other in the plurality of data sections 28, but is synchronized with the preformat header section 27 located immediately before the data section. Absent. Therefore, DVD-RA
When reproducing the recorded data of the plurality of sectors 24 of M,
If you pause and hold at the position of the header section 27,
The recorded data in the plurality of sectors 24 can be reproduced in a synchronized state.

Further, in the above embodiment, the SM section 29 is formed at the head position of the header section 27 of the DVD-RAM, and the DVD drive suspends the data reproduction of the header section 27 in response to the detection of the SM section 29. Illustrated. However, as shown in FIG. 6, since the preformatted header section has a different reflectance from the data section which is not preformatted, the header section of the DVD-RAM can be specified based on this reflectance. .

In that case, as shown in FIG.
Since the SM section 29 can be omitted from the AM header section 61,
The structure is simplified and the capacity of the data section 28 can be increased. As shown in FIG. 8, the data reproducing circuit 62 of the DVD drive may be provided with a reflectance detection circuit 63 instead of the SM detection circuit 48.
3 is realized by a simple structure for determining the light intensity with a predetermined threshold value, so that it is possible to further reduce the size and weight of the DVD drive and improve the productivity.

In the DVD-RAM, since the header section 61 and the data section 28 are alternately located, the data section 2
When the end of 8 is detected, the data reproduction of the header section 61 can be eliminated by suspending the data reproduction for a predetermined time. In this case, as shown in FIG. 9, the data reproduction circuit 64 of the DVD drive may be formed so that the controller 65 detects the end of the data section 28 based on the reproduction data of the demodulation circuit 44 and the ECC circuit 45. With such a structure, data reproduction of the header section 61 can be reliably eliminated.

Further, the above-mentioned various modifications need not be independent of each other, and can be combined within a range that does not conflict with each other. For example, it is also possible to form a DVD-RAM in a land & groove format, set an error correction execution unit to 16 sectors, and detect the header portion based on the reflectance.

[0048]

According to the first aspect of the present invention, there is provided an optical disk in which a header portion having at least an address portion at a head position of each sector is preformatted, and new data is recorded at a position continuous with the header portion of the sector. And the format of the data portion is set to be the same as the format of the sector in which the header portion and the data portion of the read-only standard optical disc are continuous, so that new data can be read from the sector of the read-only standard optical disc. Therefore, the recorded data can be reproduced in the same manner as in the case of a read-only standard optical disk.

According to a second aspect of the present invention, there is provided an optical disk in which a header section having at least an address section at a head position of a sector group of an error correction execution unit is preformatted, and new data is recorded in each sector. To form
By setting the format of this data portion to be the same as the format of the sector in which the header portion and the data portion of the read-only standard optical disc are continuous, the new data has the same format as the sector of the read-only standard optical disc. Thus, the recorded data can be reproduced in the same manner as in the case of a reproduction-only standard optical disk.

An optical disk device according to a third aspect of the present invention
3. A disk drive unit in which the optical disk according to claim 1 is detachably mounted, and new data in the same format as a sector in which a data portion of the optical disk has a header portion and a data portion of a read-only standard optical disk. And a data recording unit for recording the new data, the new data can be recorded in the data portion of the optical disk in the same format as the sector of the optical disk of the read-only standard.

The optical disk device according to the fourth aspect of the present invention
3. A disk drive unit in which the optical disk according to claim 1 or 2 and a standard optical disk for reproduction only are removably loaded, and data reproduction is executed by excluding a header part preformatted from reproduction data of the optical disk. Since the optical disc according to claim 1 or 2 has a header portion, the format is different from that of a read-only standard optical disc, but the recorded data in the header portion is not reproduced. Only the data recorded in the data section can be reproduced, and since the format of this data section is the same as that of the sector of the reproduction-only standard optical disc, data can be reproduced from two types of optical discs by one type of data reproduction section.

In the optical disk apparatus according to the fifth aspect of the present invention, when the data reproducing section detects the head of the preformatted header section, the data reproducing section interrupts the data reproduction for a predetermined time, thereby reproducing the data in the header section by a simple process. Can be eliminated.

In the optical disk device according to the present invention, the data reproducing section detects the head of the preformatted header section based on the reflectance, thereby detecting the head of the header section by a simple process. Can be.

According to the seventh aspect of the present invention, when the data reproducing section detects the end of the data section, the data reproducing section suspends the data reproducing for a predetermined time, thereby eliminating the data reproducing of the header section by a simple process.

In the optical disk device according to the present invention, the data reproducing section holds the synchronous control of the data reproduction from the start to the end of the interruption of the data reproduction,
The recorded data of the plurality of data portions can be continuously reproduced in a synchronized state.

[Brief description of the drawings]

FIG. 1A is a schematic diagram showing a format of a DVD-RAM which is an optical disk according to an embodiment of the present invention;
(B) DVD which is a read-only standard optical disk
FIG. 3 is a schematic diagram showing a format of a ROM.

FIG. 2 is a block diagram showing a data reproduction circuit of a DVD drive which is an optical disk device.

FIG. 3 is a schematic diagram showing a format of a first modified example of a DVD-RAM.

FIG. 4 is a schematic diagram showing a format of a second modified example of the DVD-RAM.

FIG. 5 is a block diagram showing a data reproducing circuit according to a first modification of the DVD drive.

FIG. 6 is a characteristic diagram showing a reflectance of a DVD-RAM.

FIG. 7 is a schematic diagram showing a format of a third modification of the DVD-RAM.

FIG. 8 is a block diagram showing a data reproducing circuit according to a second modified example of the DVD drive.

FIG. 9 is a block diagram showing a data reproducing circuit according to a third modification of the DVD drive.

FIG. 10 is a block diagram showing a data reproducing circuit of a PD drive which is an optical disk device of a conventional example.

[Explanation of symbols]

 23, 24 sectors 25, 31 address part 26, 28 data part 27, 61 header part 51 sector group

Claims (8)

[Claims] 1. A header section having at least an address section at a head position of each sector is preformatted, and a data section in which new data is recorded is formed at a position following the header section of the sector. An optical disc characterized by setting the same as the format of a sector in which a header section and a data section of a read-only standard optical disc are continuous. 2. A preformatter of a header portion having at least an address portion at a head position of a sector group of an error correction execution unit, forming a data portion in which new data is recorded in each of the sectors, An optical disc, wherein a format is set to be the same as a format of a sector in which a header section and a data section of a read-only standard optical disc are continuous. 3. A disk drive unit on which the optical disk according to claim 1 is removably mounted, and a sector in which a header portion and a data portion of a read-only standard optical disk are continuous with a data portion of the optical disk. An optical disc device, comprising: a data recording unit that records new data in the same format. 4. A disk drive unit in which the optical disk according to claim 1 or 2 and a read-only standard optical disk are removably mounted, and a header part preformatted from the reproduction data of the optical disk is excluded. An optical disk device comprising: a data reproducing unit that performs data reproduction by performing a data reproduction. 5. The optical disk device according to claim 4, wherein the data reproducing unit suspends the data reproduction for a predetermined time when detecting the head of the preformatted header part. 6. The optical disk device according to claim 5, wherein the data reproducing section detects the head of the preformatted header section based on the reflectance. 7. The optical disk apparatus according to claim 4, wherein the data reproducing unit suspends data reproduction for a predetermined time when detecting the end of the data part. 8. The optical disk apparatus according to claim 5, wherein the data reproducing unit holds the synchronous control of the data reproduction from the start to the end of the interruption of the data reproduction.