Management method and apparatus for a mini disc having recorded index audio data Number:7,426,158 from the United States Patent and Trademark Office (PTO) owispatent

Title: Management method and apparatus for a mini disc having recorded index audio data

Abstract: The track information table has: decrypting information corresponding to each track; file pointer information showing one of a plurality of files with headers; and index information showing positions in the files. A function for adding the header to the track of the index information is provided. The decrypting information corresponding to the selected track, the file pointer information, and the index information are read out from the track information table. The header of the file with the header is read out on the basis of the file pointer information. Position information in the file corresponding to the index information is detected from the header. The latter half data of the file is read out on the basis of the position information and added to the track in which coupling has been instructed, thereby newly forming a file with a header.

Patent Number: 7,426,158 Issued on 09/16/2008 to Kii,   et al.

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Inventors:	Kii; Manabu (Tokyo, JP), Ohbi; Seiji (Tokyo, JP), Kawakami; Takashi (Tokyo, JP), Hattori; Masato (Kanagawa, JP)
Assignee:	Sony Corporation (Tokyo, JP)
Appl. No.:	10/476,189
Filed:	March 31, 2003
PCT Filed:	March 31, 2003
PCT No.:	PCT/JP03/04078
371(c)(1),(2),(4) Date:	November 06, 2003
PCT Pub. No.:	WO03/083869
PCT Pub. Date:	October 09, 2003

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Foreign Application Priority Data

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Apr 01, 2002 [JP]			2002-099295
Jun 28, 2002 [JP]			2002-190806

Current U.S. Class:	369/30.09 ; 711/111
Current International Class:	G11B 7/085 (20060101)
Field of Search:	369/30.09,30.08 711/221,165,111

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References Cited [Referenced By]

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U.S. Patent Documents

5016277	May 1991	Hamilton
5706262	January 1998	Yokota et al.
5815730	September 1998	Kim
5995471	November 1999	Saoyama et al.
6212097	April 2001	Kihara et al.
6226618	May 2001	Downs et al.
6370316	April 2002	Yamada et al.
6434103	August 2002	Shitara et al.
6757480	June 2004	Moon et al.
6898159	May 2005	Kudo
6915377	July 2005	Hitotsui
7089271	August 2006	Kihara et al.
7215627	May 2007	Taira et al.
7286446	October 2007	Ohbi et al.

Foreign Patent Documents

	1055994		Nov., 2000		EP
	1103974		May., 2001		EP
	7-57436		Mar., 1995		JP
	2000-83217		Mar., 2000		JP
	2000-293973		Oct., 2000		JP
	2001-28722		Jan., 2001		JP
	2001-52465		Feb., 2001		JP
	2001-75869		Mar., 2001		JP
	2001-157145		Jun., 2001		JP
	2001-238169		Aug., 2001		JP

Other References

MAT (machine assisted translation) of paragraphs 12-19 of JP 2001-052465. cited by examiner.

Primary Examiner: Psitos; Aristotellis M
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C.

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Claims

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The invention claimed is:

1. A management method of data recorded on a disc-shaped recording medium such that a plurality of data each divided into a plurality of index audio data is managed, the recording medium including first and second recording areas, the first recording area used only for management of the second recording area, the second recording area formatted in a file allocation table (FAT) format and including management data as a file in a FAT file system, and the index audio data includes a header as a file in the FAT file system, the method comprising: reading out index audio data management information for managing recording positions of said index audio data, track management information in which track index file information of said data are managed as track information in association with the data, and play order management information for managing play order of said data; and editing said play order management information on the basis of information for designating the data to be edited such that first index audio data in a first audio file and second index audio data in a second audio file is combined by adding a header to the first index audio data to immediately precede the first index audio data, deleting index data to the second index audio data from the header, and adding the second index audio data to the first index audio data.

2. A management method of data according to claim 1, wherein upon editing of said play order management information, the association with the track index file information which is managed in said track management information associated with said play order management information is edited.

3. A management of data according to claim 1, wherein the first index audio data, before the combining, is in a first track and the second index audio data, before the combining, is in a second track.

4. A management method according to claim 1, wherein the combined first index audio data and second index audio data is on one track and includes index data for the first index audio data in the header and does not include index data for the second index audio data in the header.

5. A management device of data recorded on a disc-shaped recording medium such that a plurality of data each divided into a plurality of index audio data is managed, the recording medium including first and second recording areas, the first recording area used only for management of the second recording area, the second recording area formatted in a file allocation table (FAT) format and including management data as a file in a FAT file system, and the index audio data includes a header as a file in the FAT file system, the device comprising: means for reading out index audio data management information for managing recording positions of said index audio data, track management information in which track index file information of said data are managed as track information in association with the data, and play order management information for managing play order of said data; and means for editing said play order management information on the basis of information for designating the data to be edited such that first index audio data in a first audio file and second index audio data in a second audio file is combined by adding a header to the first index audio data to immediately precede the first index audio data, deleting index data to the second index audio data from the header, and adding the second index audio data to the first index audio data.

6. A management device of data according to claim 5, wherein upon editing of said play order management information, the association with the track index file information which is managed in said track management information associated with said play order management information is edited.

7. A management device of data according to claim 5, wherein the first index audio data, before the combining, is in a first track and the second index audio data, before the combining, is in a second track.

8. A management device according to claim 5, wherein the combined first index audio data and second index audio data is on one track and includes index data for the first index audio data in the header and does not include index data for the second index audio data in the header.

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Description

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TECHNICAL FIELD

The invention relates to editing method and apparatus which are suitable to be used in the case where data is recorded and reproduced into/from a recording medium obtained by expanding a magnetooptic disc used in an existing MD system to thereby realize compatibility with the existing MD system and into/from a recording apparatus.

BACKGROUND ART

As a recording medium for recording or reproducing digital audio data, a mini disc (MD) as a magnetooptic disc having a diameter of 64 mm and enclosed in a cartridge has widely been spread.

In an MD system, ATRAC (Adaptive TRansform Acoustic Coding) is used as a compression system of the audio data. ATRAC is a technique such that the audio data fetched at a predetermined time window is compression-coded by using MDTC (Modified Discrete Cosine Transform). Music data is compressed into 1/5 to 1/10 by ATRAC.

A convolutional code called ACIRC (Advanced Cross Interleave Reed-Solomon Code) is used as an error correction system and EFM (8 to 14 Modulation) is used as a modulation system. ACIRC is a convolutional code for executing error correction coding doubly to a C1 series (vertical direction) and in an oblique direction (C2 series) and a powerful error correcting process can be executed to sequential data such as audio data. In the case of the convolutional code, however, a sector for linking is necessary at the time of rewriting the data. ACIRC system and EFM similar to those for the existing compact disc (CD) are fundamentally used.

U-TOC (User TOC (Table Of Contents)) is used for management of the music data. That is, an area called U-TOC is provided for an inner rim of a recordable area on the disc. In the existing MD system, U-TOC is management information which is rewritten in accordance with order of music pieces, recording, erasure, or the like of tracks (audio tracks/data tracks) and manages a start position, an end position, and a mode with respect to each track (parts constructing the track).

The disc of the MD system is small and low-priced and has excellent characteristics as a medium for recording and reproducing the audio data. The MD system, therefore, has widely been spread.

However, some improvements have been needed in the existing MD system as a result of the passage of time. One of them is affinity with computers.

That is, music distribution for distributing the audio data on a network has extensively been performed owing to the spread of personal computers and the networks. There is a case where the personal computer is used as an audio server and the user downloads his favorite music pieces into a portable player and reproduces music. In the existing MD system, since the data is managed by using U-TOC, the affinity with the personal computers is insufficient. Therefore, for example, it is demanded to introduce a general management system such as an FAT system or the like and raise the affinity with the personal computers.

Since the audio data can be easily copied when the affinity with personal computers rises, necessity of protecting the copyright of the audio data increases. It is, therefore, demanded to encrypt the audio data and record it to thereby further enhance the protection of the copyright.

Further, a recording capacity of the disc of the existing MD system is equal to about 160 MB and such a capacity is no longer large. Therefore, it is demanded to increase the recording capacity while keeping the compatibility with the existing MD.

SUMMARY OF THE INVENTION

It is, therefore, an object of the invention to provide editing method and apparatus which can efficiently manage audio data.

To solve the foregoing problems, there is provided an editing method of data recorded on a recording medium in a manner such that a plurality of data each divided into a plurality of parts is serially managed as a single file into a plurality of recording areas each having a predetermined capacity, comprising the steps of:

reading out parts management information in which parts information for managing recording positions of the parts is managed, track management information in which coding information of the data and parts information of the data are managed as track information in association with the data, and play order management information for managing play order of the data; and

editing the play order management information on the basis of information for designating the data to be edited.

Also, there is provided an editing method comprising the steps of:

reading out decrypting information corresponding to a selected track, file pointer information, and index information from track information having the decrypting information corresponding to each track, the file pointer information showing one of a plurality of files with headers, and the index information showing positions in the files;

reading out the headers of the files with the headers on the basis of the file pointer information;

detecting position information in the file corresponding to the index information from the headers;

setting an index to a dividing point of new data for the file and recording new index information into the header of the file; and

forming the track information having the decrypting information corresponding to each track, the file pointer information showing one of the plurality of files with the headers, and the index information showing the positions in the files.

Also, there is provided an editing method comprising the steps of:

reading out decrypting information corresponding to a selected track, file pointer information, and index information from track information having the decrypting information corresponding to each track, the file pointer information showing one of a plurality of files with headers, and the index information showing positions in the files;

reading out the headers of the files with the headers on the basis of the file pointer information;

removing an index set to a dividing point of the file and recording new index information into the header of the file; and

forming the track information having the decrypting information corresponding to each track, the file pointer information showing one of the plurality of files with the headers, and the index information showing the positions in the files.

Also, there is provided an editing method comprising the steps of:

reading out decrypting information corresponding to a selected track, file pointer information, and index information from track information having the decrypting information corresponding to each track, the file pointer information showing one of a plurality of files with headers, and the index information showing positions in the files;

reading out the headers of the files with the headers on the basis of the file pointer information;

detecting position information in the file corresponding to the index information from the headers;

reading out latter half data of a latter half portion of the file on the basis of the position information;

newly forming a file with a header in which coupling data excluding the header of the file with the header corresponding to the track in which coupling with the latter half data has been instructed and the latter half data are used as a data portion; and

newly forming the track information having the decrypting information corresponding to each track, the file pointer information showing one of the plurality of files with the headers, and the index information showing the positions in the files.

Also, there is provided an editing apparatus comprising:

means for reading out decrypting information corresponding to a selected track, file pointer information, and index information from track information having the decrypting information corresponding to each track, the file pointer information showing one of a plurality of files with headers, and the index information showing positions in the files;

means for reading out the headers of the files with the headers on the basis of the file pointer information;

means for detecting position information in the file corresponding to the index information from the headers;

means for setting an index to a dividing point of new data for the file and recording new index information into the header of the file; and

means for forming the track information having the decrypting information corresponding to each track, the file pointer information showing one of the plurality of files with the headers, and the index information showing the positions in the files.

Also, there is provided an editing apparatus comprising:

means for reading out decrypting information corresponding to a selected track, file pointer information, and index information from track information having the decrypting information corresponding to each track, the file pointer information showing one of a plurality of files with headers, and the index information showing positions in the files;

means for reading out the headers of the files with the headers on the basis of the file pointer information;

means for removing an index set to a dividing point of the file and recording new index information into the header of the file; and

means for forming the track information having the decrypting information corresponding to each track, the file pointer information showing one of the plurality of files with the headers, and the index information showing the positions in the files.

Also, there is provided an editing apparatus comprising:

means for reading out decrypting information corresponding to a selected track, file pointer information, and index information from track information having the decrypting information corresponding to each track, the file pointer information showing one of a plurality of files with headers, and the index information showing positions in the files;

means for reading out the headers of the files with the headers on the basis of the file pointer information;

means for detecting position information in the file corresponding to the index information from the headers;

means for reading out latter half data of a latter half portion of the file on the basis of the position information;

means for newly forming a file with a header in which coupling data excluding the header of the file with the header corresponding to the track in which coupling with the latter half data has been instructed and the latter half data are used as a data portion; and

means for newly forming the track information having the decrypting information corresponding to each track, the file pointer information showing one of the plurality of files with the headers, and the index information showing the positions in the files.

According to the invention, music data is enclosed in the audio data file. A header is provided for the audio data file. A title, decrypting key information, and copyright management information are recorded in the header and the index information is also provided. As for the index, a music piece of one track is divided into a plurality of music pieces.

A track information file is a file in which various information for managing the music data stored in the audio data file has been described. The track information file comprises: a play order table (reproducing order table); a programmed play order table; a group information table (group information table); a track information table (track information table); and a name table.

The play order table is a table showing play order defined by a default. Information showing a link destination to a track descriptor of the track information table regarding each track number (music piece number) has been stored in the play order table.

Information regarding each music piece has been described in the track information table. The track information table comprises a track descriptor of each track (every music piece). A file pointer, an index number, an artist name, a title name, an original music piece order information, recording time information, and the like of the audio data file in which the music piece has been stored have been described in each track descriptor.

When the number of the track to be reproduced is designated by the play order table, the track descriptor of the link destination is read out. The file pointer and the index number of the music piece, pointers of the artist name and the title name, the original music piece order information, the recording time information, and the like are read out from the track descriptor.

The audio data file is accessed from the file pointer of the music piece and the information of the header of the audio data file is read out. If the audio data has been encrypted, the key information read out from the header is used. The audio data file is reproduced. At this time, if the index number is designated, the position of the designated index number is detected from the information of the header and the reproduction is started from the position of this index number.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram for use in explanation of a disc of specifications of a next-generation MD1 system.

FIG. 2 is a diagram for use in explanation of a recording area of the disc of the specifications of the next-generation MD1 system.

FIGS. 3A and 3B are diagrams for use in explanation of a disc of specifications of a next-generation MD2 system.

FIG. 4 is a diagram for use in explanation of a recording area of the disc of the specifications of the next-generation MD2 system.

FIG. 5 is a diagram for use in explanation of error correction coding processes of a next-generation MD1 and a next-generation MD2.

FIG. 6 is a diagram for use in explanation of the error correction coding processes of the next-generation MD1 and the next-generation MD2.

FIG. 7 is a diagram for use in explanation of the error correction coding processes of the next-generation MD1 and the next-generation MD2.

FIG. 8 is a perspective view for use in explanation of generation of an address signal using wobbles.

FIG. 9 is a diagram for use in explanation of an ADIP signal in the existing MD system and the next-generation MD1 system.

FIG. 10 is a diagram for use in explanation of the ADIP signal in the existing MD system and the next-generation MD1 system.

FIG. 11 is a diagram for use in explanation of an ADIP signal in the next-generation MD2 system.

FIG. 12 is a diagram for use in explanation of the ADIP signal in the next-generation MD2 system.

FIG. 13 is a diagram showing a relation between the ADIP signal and frames in the existing MD system and the next-generation MD1 system.

FIG. 14 is a diagram showing a relation between the ADIP signal and the frames in the next-generation MD1 system.

FIG. 15 is a diagram for use in explanation of a control signal in the next-generation MD2 system.

FIG. 16 is a block diagram of a disc drive apparatus.

FIG. 17 is a block diagram showing a construction of a media drive unit.

FIG. 18 is a flowchart showing an initializing process of an example of the disc according to the next-generation MD1.

FIG. 19 is a flowchart showing an initializing process of an example of the disc according to the next-generation MD2.

FIG. 20 is a diagram for use in explanation of a signal recording bit map.

FIG. 21 is a flowchart showing a reading process of an FAT sector.

FIG. 22 is a flowchart showing a writing process of the FAT sector.

FIG. 23 is a flowchart showing a reading process of the FAT sector in a single apparatus.

FIG. 24 is a flowchart showing a writing process of the FAT sector in the single apparatus.

FIG. 25 is a flowchart for use in explanation of creation of the signal recording bit map.

FIG. 26 is a flowchart for use in explanation of the creation of the signal recording bit map.

FIG. 27 is a flowchart for use in explanation of the creation of the signal recording bit map.

FIG. 28 is a diagram for use in explanation of the first example of a management system of audio data.

FIG. 29 is a diagram for use in explanation of an audio data file according to the first example of the management system of the audio data.

FIG. 30 is a diagram for use in explanation of a track index file according to the first example of the management system of the audio data.

FIG. 31 is a diagram for use in explanation of a play order table according to the first example of the management system of the audio data.

FIG. 32 is a diagram for use in explanation of a programmed play order table according to the first example of the management system of the audio data.

FIGS. 33A and 33B are diagrams for use in explanation of a group information table according to the first example of the management system of the audio data.

FIGS. 34A and 34B are diagrams for use in explanation of a track information table according to the first example of the management system of the audio data.

FIGS. 35A and 35B are diagrams for use in explanation of a parts information table according to the first example of the management system of the audio data.

FIGS. 36A and 36B are diagrams for use in explanation of a name table according to the first example of the management system of the audio data.

FIG. 37 is a diagram for explaining a process of an example according to the first example of the management system of the audio data.

FIG. 38 is a diagram for explaining that a plurality of name slots in the name table can be referred to.

FIGS. 39A and 39B are diagrams for use in explanation of a process for erasing parts from the audio data file in the first example of the management system of the audio data.

FIG. 40 is a diagram for use in explanation of the second example of a management system of audio data.

FIG. 41 is a diagram showing a structure of an audio data file according to the second example of the management system of the audio data.

FIG. 42 is a diagram for use in explanation of a track index file according to the second example of the management system of the audio data.

FIG. 43 is a diagram for use in explanation of a play order table according to the second example of the management system of the audio data.

FIG. 44 is a diagram for use in explanation of a programmed play order table according to the second example of the management system of the audio data.

FIGS. 45A and 45B are diagrams for use in explanation of a group information table according to the second example of the management system of the audio data.

FIGS. 46A and 46B are diagrams for use in explanation of a track information table according to the second example of the management system of the audio data.

FIGS. 47A and 47B are diagrams for use in explanation of a name table according to the second example of the management system of the audio data.

FIG. 48 is a diagram for explaining a process of an example according to the second example of the management system of the audio data.

FIG. 49 shows the second example of the management system of the audio data and is a diagram for explaining that data of one file is divided into a plurality of index areas by indices.

FIG. 50 shows the second example of the management system of the audio data and is a diagram for use in explanation of coupling of tracks.

FIG. 51 shows the second example of the management system of the audio data and is a diagram for use in explanation of coupling of tracks according to another method.

FIGS. 52A and 52B are diagrams for explaining that management authority is shifted in accordance with a type of data to be written in a state where a personal computer and a disc drive apparatus are connected.

FIGS. 53A, 53B, and 53C are diagrams for explaining a series of check-out procedures of the audio data.

FIG. 54 is a schematic diagram conceptually showing a state of coexistence of the next-generation MD1 system and the existing MD system in the disc drive apparatus.

FIG. 55 is an external view of an example of a disc drive apparatus constructed in a portable type.

FIG. 56 is a flowchart showing the operation of an example of the disc drive apparatus in the case where the disc is unformatted.

FIG. 57 is a flowchart showing another example of a formatting process in the case where a disc as a virgin disc has been inserted into the disc drive apparatus.

FIG. 58 is a flowchart showing the operation of an example of the disc drive apparatus in the case of recording audio data onto the disc.

FIG. 59 is a flowchart showing a process of an example in which a format of the disc is changed from a format according to the next-generation MD1 system to a format according to the existing MD system.

BEST MODE FOR CARRYING OUT THE INVENTION

1. Outline of Recording System

In a recording and reproducing apparatus to which the invention is applied, a disc similar to that used in an MD (mini disc) system or a magnetooptic recording disc which conforms with the disc used in the MD system is used as a recording medium, and contents data such as audio data is recorded and reproduced by using an FAT (File Allocation Table) system as a file management system so as to obtain affinity with the existing personal computer. By improving an error correction system and a modulation system for the existing MD system, a recording capacity of data is increased and reliability of the data is raised. Further, the contents data is encrypted and illegal copy is prevented, thereby protecting copyright of the contents data.

As recording/reproducing formats, there have been proposed: specifications of the next-generation MD1 in which a disc that is substantially similar to the disc used in the existing MD system is used; and specifications of the next-generation MD2 in which, although a disc whose outer shape is similar to that of the disc used in the existing MD system is used, a recording density in the linear recording direction is raised by using a magnetically induced super resolution (MSR) technique, thereby further increasing a recording capacity.

In the existing MD system, a magnetooptic disc having a diameter of 64 mm and enclosed in a cartridge is used as a recording medium. A thickness of disc is equal to 1.2 mm and a center hole having a diameter of 11 mm is formed at the center. The cartridge has a shape in which a length is equal to 68 mm, a width is equal to 72 mm, and a thickness is equal to 5 mm.

In both of the specifications of the next-generation MD1 and the specifications of the next-generation MD2, all shapes of those discs and shapes of those cartridges are the same, respectively. A start position of a lead-in area of each of the discs of the specifications of the next-generation MD1 and the specifications of the next-generation MD2 starts from 29 mm and is similar to that of the disc used in the existing MD system.

It is being examined that a track pitch is set to a value in a range from 1.2 .mu.m to 1.3 .mu.m (for example, 1.25 .mu.m) in the next-generation MD2 system. On the other hand, in the next-generation MD1 using the disc of the existing MD system in common, a track pitch is set to 1.6 .mu.m. A bit length of the next-generation MD1 is set to 0.44 .mu.m/bit and that of the next-generation MD2 is set to 0.16 .mu.m/bit. A redundancy of each of the next-generation MD1 and the next-generation MD2 is equal to 20.50%.

In the disc of the specifications of the next-generation MD2 system, the recording capacity in the linear density direction is improved by using the magnetically induced super resolution technique. The magnetically induced super resolution technique uses a principle such that when the disc reaches a predetermined temperature, a cut layer enters a magnetically neutral state, and a magnetic wall transferred to a reproducing layer moves, so that a micro mark seems large in a beam spot.

That is, in the disc of the specifications of the next-generation MD2 system, at least a magnetic layer serving as a recording layer for recording information, the cut layer, and a magnetic layer for reproducing the information are laminated onto a transparent substrate. The cut layer becomes a layer for adjusting an exchange coupling power. When the disc reaches the predetermined temperature, the cut layer enters the magnetically neutral state and the magnetic wall transferred to the recording layer is transferred to the magnetic layer for reproduction. Thus, the micro mark can be seen in the beam spot. Upon recording, the micro mark can be formed by using a laser pulse magnetic field modulation technique.

In the disc of the specifications of the next-generation MD2, to improve a detrack margin, a crosstalk from a land, a crosstalk of a wobble signal, and a leakage of focusing, a groove is made deeper and an inclination of the groove is made more sharp. In the disc of the specifications of the next-generation MD2, the depth of groove lies within a range from, for example, 160 nm to 180 nm, the inclination of the groove lies within a range from, for example, 60.degree. to 70.degree., and a width of groove lies within a range from, for example, 600 nm to 700 nm.

With respect to optical specifications, in the specifications of the next-generation MD1, a laser wavelength .lamda. is set to 780 nm and a numerical aperture NA of an objective lens of the optical head is set to 0.45. Also with respect to the specifications of the next-generation MD2, a laser wavelength .lamda. is set to 780 nm and a numerical aperture NA of the optical head is set to 0.45.

As a recording system, a groove recording system is used in both of the specifications of the next-generation MD1 and the specifications of the next-generation MD2. That is, the groove (the groove on the surface of the disc) is used as a track for recording and reproduction.

As an error correction coding system, the convolutional code according to the ACIRC (Advanced Cross Interleave Reed-Solomon Code) has been used in the existing MD system. However, in the specifications of the next-generation MD1 and the specifications of the next-generation MD2, the code of a block completion type in which an RS-LDC (Reed Solomon--Long Distance Code) and a BIS (Burst Indicator Subcode) are combined is used. By using the error correction code of the block completion type, a linking sector becomes unnecessary. According to the error correction system in which the LDC and the BIS are combined, when a burst error is caused, an error location can be detected by the BIS. Erasure correction can be made by the LDC code by using the error location.

As an address system, a wobbled groove system in which after a groove according to a single spiral is formed, wobbles serving as address information are formed on both sides of the groove is used. Such an address system is called ADIP (Address in Pregroove). In the specifications of the existing MD system and the specifications of the next-generation MD1 and the next-generation MD2, linear densities are different. In the existing MD system, the convolutional code called ACIRC is used as an error correction code. Since the code of the block completion type in which the LDC and the BIS are combined are used in the specifications of the next-generation MD1 and the next-generation MD2, redundancies differ and a relative positional relation between the ADIP and the data is changed. Therefore, in the specifications of the next-generation MD1 using the disc of the existing MD system in common, a method of handling the ADIP signal is set to be different from that in the existing MD system. In the specifications of the next-generation MD2, the specifications of the ADIP signal are changed so as to be matched more with the specifications of the next-generation MD2.

With respect to the modulating system, while the EFM (8 to 14 Modulation) is used in the existing MD system, an RLL (1, 7) PP (RLL: Run Length Limited, PP: Parity Preserve/Prohibit rmtr (repeated minimum transition runlength)) (hereinafter, referred to as 1-7pp modulation) is used in the specifications of the next-generation MD1 and the next-generation MD2. As a detection system of the data, a Viterbi decoding system using Partial Response PR (1, 2, 1) ML is used in the next-generation MD1 and a Viterbi decoding system using Partial Response PR (1, -1) ML is used in the next-generation MD2.

A CLV (Constant Linear Verocity) or a ZCAV (Zone Constant Angular Verocity) is used as a disc driving system. Its standard linear velocity is set to 2.4 m/sec in the specifications of the next-generation MD1 and set to 1.98 m/sec in the specifications of the next-generation MD2. In the specifications of the existing MD system, it is set to 1.2 m/sec in the disc of 60 minutes and set to 1.4 m/sec in the disc of 74 minutes.

In the specifications of the next-generation MD1 using the disc which is used in the existing MD system as it is in common, the total recording capacity of data per disc is equal to about 300 Mbytes (in the case where the disc of 80 minutes is used). By changing the modulation system from EFM to 1-7pp modulation, a window margin is changed from 0.5 to 0.666, so that 1.33 times as high density can be realized in this respect. By changing the error correction system from the ACIRC system to the combination of the BIS and the LDC, data efficiency is raised, so that 1.48 times as high density can be realized in this respect. Overall, the data capacity which is about two times as large as that of the existing MD system is realized by using substantially the same disc.

In the disc of the specifications of the next-generation MD2 using the magnetically induced super resolution, the further high density in the linear density direction is realized and the total data recording capacity is equal to about 1 Gbytes.

A data rate as a standard linear velocity is equal to 4.4 Mbits/sec in the next-generation MD1 and is equal to 9.8 Mbits/sec in the next-generation MD2.

2. With Respect to the Disc

FIG. 1 shows a construction of the disc of the next-generation MD1. As a disc of the next-generation MD1, the disc of the existing MD system is used as it is in common. That is, the disc is formed by laminating a dielectric film, a magnetic film, a dielectric film, and a reflective film onto a transparent polycarbonate substrate. A protective film is further laminated on them.

In the disc of the next-generation MD1, as shown in FIG. 1, a P-TOC (premastered TOC (Table Of Contents)) area is provided in a lead-in area of an inner rim of the disc. This area becomes a premastered area as a physical structure. That is, control information or the like has been recorded as P-TOC information by an emboss pit.

An outer rim of the lead-in area in which the P-TOC area is provided is set to a recordable area (magnetooptically recordable area) and is a recordable/reproducible area in which a groove has been formed as a guide groove of a recording track. A U-TOC (user TOC) is provided for an inner rim of the recordable area.

The U-TOC has a construction similar to that of the U-TOC used for recording management information of the disc in the existing MD system. In the existing MD system, the U-TOC is management information which is rewritten in accordance with order of music pieces, recording, erasure, or the like of the tracks (audio tracks/data tracks) and manages a start position, an end position, and a mode with respect to each track (parts constructing the track).

An alert track is provided for an outer rim of the U-TOC. The alert track is a warning track in which an alarm sound showing that the disc is used in the next-generation MD1 system and cannot be reproduced by the player of the existing MD system has been recorded.

FIG. 2 shows a construction of the recordable area of the disc of the specifications of the next-generation MD1 shown in FIG. 1. As shown in FIG. 2, the U-TOC and the alert track are provided at the head (on the inner rim side) of the recordable area. In the area in which the U-TOC and the alert track are included, data is modulated by the EFM and recorded so that it can be reproduced also by the player of the existing MD system. An area in which the data is modulated by the 1-7pp modulation of the next-generation MD1 system and recorded is provided for an outer rim of the area in which the data is modulated by the EFM modulation and recorded. The area in which the data is modulated by the EFM and recorded and the area in which the data is modulated by the 1-7pp modulation and recorded are away from each other at a predetermined distance and a guard band is provided between them. Since such a guard band is provided, a situation such that the disc of the specifications of the next-generation MD1 is loaded into the existing MD player and inconvenience is caused is prevented.

A DDT (Disc Description Table) area and a reserved track are provided at the head (on the inner rim side) of the area in which the data is modulated by the 1-7pp modulation and recorded. The DDT area is provided for executing an alternating process to an area which is physically defective. A unique ID (UID) is further recorded into the DDT area. The UID is an identification code that is peculiar to each recording medium and is based on, for example, random numbers generated in a predetermined manner. Information to protect the contents is stored in the reserved track. Information to protect the contents is stored in the reserved track.

Further, an FAT (File Allocation Table) area is provided for the area in which the data is modulated by the 1-7pp modulation and recorded. The FAT area is an area for managing the data by an FAT system. The FAT system makes data management which conforms with the FAT system used in the general personal computer. The FAT system makes file management by an FAT chain by using a directory indicative of a file on a route or an entry point of the directory and an FAT table in which coupling information of an FAT cluster has been described.

In the disc of the specifications of the next-generation MD1, information of a start position of the alert track and information of a start position of the area in which the data is modulated by the 1-7pp modulation and recorded are recorded in the U-TOC area.

When the disc of the next-generation MD1 is loaded into the player of the existing MD system, the U-TOC area is read, the position of the alert track is known from the information of the U-TOC, the alert track is accessed, and the reproduction of the alert track is started. The alarm sound showing that the disc is used in the next-generation MD1 system and cannot be reproduced by the player of the existing MD system has been recorded in the alert track. The fact that the disc cannot be used in the player of the existing MD system is notified by this alarm sound.

As an alarm sound, a warning by words such as "this player cannot be used" can be made. Naturally, a buzzer sound can be also used.

When the disc of the next-generation MD1 is loaded into the player which conforms with the next-generation MD1, the U-TOC area is read. The start position of the area in which the data has been recorded by the 1-7pp modulation is known from the information of the U-TOC and the DDT, reserved track, and FAT area are read out. In the data area of the 1-7pp modulation, data management is made by using the FAT system without using the U-TOC.

FIGS. 3A and 3B show a disc of the next-generation MD2. The disc is formed by laminating a dielectric film, a magnetic film, a dielectric film, and a reflective film onto a transparent polycarbonate substrate. A protective film is further laminated on them.

In the disc of the next-generation MD2, as shown in FIG. 3A, control information has been recorded in the lead-in area of the inner rim of the disc by the ADIP signal. In the disc of the next-generation MD2, the P-TOC by the emboss pit is not provided for the lead-in area but the control information by the ADIP signal is used in place of it. A recordable area starts from the outer rim of the lead-in area and is a recordable and reproducible area in which the groove has been formed as a guide groove of the recording track. The data is modulated by the 1-7pp modulation and recorded in such a recordable area.

In the disc of the next-generation MD2, as shown in FIG. 3B, a layer formed by laminating a magnetic layer 101 serving as a recording layer for recording information, a cut layer 102, and a magnetic layer 103 for reproducing the information is used as a magnetic film. The cut layer 102 is a layer for adjusting an exchange coupling power. When the cut layer 102 reaches a predetermined temperature, it enters a magnetically neutral state, and a magnetic wall transferred to the recording layer 101 is transferred to the magnetic layer 103 for reproduction. Thus, a micro mark seems enlarged in a beam spot of the magnetic layer 103 for reproduction in the recording layer 101.

Whether the system is the next-generation MD1 or the next-generation MD2 can be discriminated, for example, from the information of the lead-in area. That is, if the P-TOC by the emboss pit is detected in the lead-in area, it is possible to determine that the disc is a disc of the existing MD or the next-generation MD1. If the control information by the ADIP signal is detected in the lead-in area and the P-TOC by the emboss pit is not detected, it is possible to determine that the disc is a disc of the next-generation MD1. A method of discriminating the next-generation MD1 and the next-generation MD2 is not limited to such a method but they can be discriminated from a phase of a tracking error signal in an on-track state and that in an off-track state. A detection hole or the like for identifying the disc can be also formed.

FIG. 4 shows the construction of the recordable area of the disc of the specifications of the next-generation MD2. As shown in FIG. 4, all of the data is modulated by the 1-7pp modulation and recorded in the recordable area. A DDT area and a reserved track are provided at the head (on the inner rim side) of the area in which the data is modulated by the 1-7pp modulation and recorded. The DDT area is provided as a recording area of alternating area management data for managing an alternating area for an area which is physically defective. Further, the foregoing UID is recorded in the DDT area. Information for protecting the contents is stored in the reserved track.

Further, the FAT area is provided for the area in which the data is modulated by the 1-7pp modulation and recorded. The FAT area is an area for managing the data by the FAT system. The FAT system makes data management according to the FAT system used in the general personal computer.

In the disc of the next-generation MD2, the U-TOC area is not provided. If the disc of the next-generation MD2 is loaded into the player which conforms with the next-generation MD2, the DDT, reserved track, and FAT area existing in predetermined positions are read out and the data management is made by using the FAT system.

In the disc of the next-generation MD1 and the disc of the next-generation MD2, the initializing operation which takes a long time is unnecessary. That is, in the discs of the specifications of the next-generation MD1 and the next-generation MD2, the initializing operation other than the operation to form the necessary least table of the DDT, reserved track, FAT table, and the like is unnecessary. The recording and reproduction of the recordable area can be directly executed from the unused disc.

3. Signal Format

Subsequently, signal formats of the next-generation MD1 system and the next-generation MD2 system will be described. In the existing MD system, the ACIRC as a convolutional code is used as an error correction system and a sector consisting of 2352 bytes corresponding to a data amount of the subcode block is used as an access unit of the recording and reproduction. In the case of the convolutional code, since an error correction coding series strides over a plurality of sectors, when the data is rewritten, it is necessary to prepare a linking sector between the adjacent sectors. As an address system, an ADIP as a wobbled groove system in which after a groove was formed by a single spiral, wobbles serving as address information are formed on both sides of the groove is used. In the existing MD system, the ADIP signals are arranged so as to be optimum in the case of accessing the sector consisting of 2352 bytes.

On the other hand, in the specifications of the next-generation MD1 system and the specifications of the next-generation MD2 system, the code of the block completion type in which the LDC and the BIS are combined is used and 64 kbytes are used as an access unit of the recording and the reproduction. In the code of the block completion type, the linking sector is unnecessary. Therefore, in the specifications of the next-generation MD1 system using the disc of the existing MD system in common, a way of handling the ADIP signal is changed so as to cope with a new recording system. In the specifications of the next-generation MD2 system, the specifications of the ADIP signal are changed so as to be matched more with the specifications of the next-generation MD2.

FIGS. 5, 6, and 7 are used for explaining the error correction system which is used in the next-generation MD1 system and the next-generation MD2 system. In the next-generation MD1 system and the next-generation MD2 system, an error correction coding system by an LDC as shown in FIG. 5 and a BIS system as shown in FIGS. 6 and 7 are combined.

FIG. 5 shows a construction of a coding block of the error correction coding by the LDC. As shown in FIG. 5, an error detection code EDC of 4 bytes is added to data of each error correction coding sector, and the data is two-dimensionally arranged to an error correction coding block of 304 bytes in the horizontal direction and 216 bytes in the vertical direction. Each error correction coding sector comprises data of 2 kbytes. As shown in FIG. 5, 32 error correction coding sectors each consisting of 2 kbytes are arranged in the error correction coding block consisting of 304 bytes in the horizontal direction and 216 bytes in the vertical direction. A parity of a Reed-Solomon code of 32 bits for error correction is added in the vertical direction to the data of the error correction coding block of the 32 error correction coding sectors which have two-dimensionally been arranged in a manner such that 304 bytes are arranged in the horizontal direction and 216 bytes are arranged in the vertical direction as mentioned above.

FIGS. 6 and 7 show constructions of the BIS. As shown in FIG. 6, the BIS of 1 byte is inserted every data of 38 bytes, and a total of 157.5 bytes of data of (38.times.4=152 bytes), BIS data of 3 bytes, and a frame sync of 2.5 bytes are set to one frame.

As shown in FIG. 7, the block of the BIS is constructed by collecting 496 frames each of which is constructed as mentioned above. User control data of 576 bytes, an address unit number of 144 bytes, and an error correction code of 768 bytes are included in the BIS data (3.times.496=1488 bytes).

As mentioned above, since the error correction code of 768 bytes is added to the data of 1488 bytes in the BIS data, the error correction can be powerfully made. By embedding the BIS code every 38 bytes, when a burst error occurs, an error location can be detected. Erasure correction can be made by the LDC code by using the error location.

As shown in FIG. 8, the ADIP signal is recorded by forming the wobbles on both sides of the single spiral groove. That is, the ADIP signal is recorded as a wobble of the groove by frequency modulating the address data.

FIG. 9 shows a sector format of the ADIP signal in the case of the next-generation MD1.

As shown in FIG. 9, 1 sector (ADIP sector) of the ADIP signal comprises: a sync of 4 bits; upper bits of the ADIP cluster number of 8 bits; lower bits of the ADIP cluster number of 8 bits; an ADIP sector number of 8 bits; and an error detection code CRC of 14 bits.

The sync is a signal of a predetermined pattern for detecting the head of the ADIP sector. In the conventional MD system, since the convolutional code is used, the linking sector is necessary. The sector number for linking is a sector number having a negative value and is one of the sector numbers "FCh", "FDh", "FEh", and "FFh" (h denotes a hexadecimal number). Since the disc of the existing MD system is used in common in the next-generation MD1, the format of the ADIP sector is similar to that of the existing MD system.

In the next-generation MD1 system, as shown in FIG. 10, the ADIP cluster is constructed by 36 sectors of the ADIP sector numbers "FCh" to "FFh" and "0Fh" to "1Fh". As shown in FIG. 10, the data of two recording blocks (64 kbytes) is arranged in one ADIP cluster.

FIG. 11 shows a construction of the ADIP sector in the case of the next-generation MD2. In the specifications of the next-generation MD2, the ADIP sector is constructed by 16 ADIP sectors. Therefore, the sector number of ADIP can be expressed by 4 bits. In the next-generation MD, since the block completion error correction code is used, the linking sector is unnecessary.

As shown in FIG. 11, the ADIP sector of the next-generation MD2 comprises: a sync of 4 bits; upper bits of the ADIP cluster number of 4 bits; middle bits of the ADIP cluster number of 8 bits; lower bits of the ADIP cluster number of 4 bits; an ADIP sector number of 4 bits; and a parity for error correction of 18 bits.

The sync is a signal of a predetermined pattern for detecting the head of the ADIP sector. As an ADIP cluster number, a total of 16 bits of upper 4 bits, middle 8 bits, and lower 4 bits are described. Since the ADIP cluster is constructed by 16 ADIP sectors, the sector number of the ADIP sector consists of 4 bits. While the error detection code of 14 bits is used in the existing MD system, the parity for error correction of 18 bits is used. In the specifications of the next-generation MD2, as shown in FIG. 12, data of one recording block (64 kbytes) is arranged in one ADIP cluster.

FIG. 13 shows a relation between the ADIP cluster and frames of the BIS in the case of the next-generation MD1.

As shown in FIG. 10, in the specifications of the next-generation MD1, one ADIP cluster is constructed by 36 sectors of the ADIP sectors "FC" to "FF" and the ADIP sectors "00" to "1F". Two data each consisting of one recording block (64 kbytes) serving as a unit of the recording and the reproduction are arranged in one ADIP cluster.

As shown in FIG. 13, one ADIP sector is separated into 18 sectors of the former half and 18 sectors of the latter half.

The data of one recording block serving as a unit of the recording or reproduction is arranged into the block of the BIS consisting of 496 frames. A preamble of 10 frames (frame "0" to frame "9") is added before frames (frame "10" to frame "505") of the data of 496 frames corresponding to the block of the BIS. A postamble of 6 frames (frame "506" to frame "511") is added after the frames of the data. The data of a total of 512 frames is arranged in the former half of the ADIP cluster in a range from the ADIP sector "FCh" to the ADIP sector "0Dh" and in the latter half of the ADIP cluster in a range from the ADIP sector "0Eh" to the ADIP sector "1Fh". The frames of the preamble before the data frames and the frames of the postamble after the data are used to protect the data upon linking with the adjacent recording block. The preamble is also used for pull-in of the PLL for data, control of the signal amplitude, control of the signal offset, and the like.

A physical address at the time of recording or reproducing the data of the recording block is designated by the ADIP cluster and a discrimination result about whether it is located before or after the cluster. When the physical address is designated upon recording or reproducing, the ADIP sector is readout from the ADIP signal, the ADIP cluster number and the ADIP sector number are read out from the reproduction signal of the ADIP sector, and whether it is located before or after the ADIP cluster is discriminated.

FIG. 14 shows a relation between the ADIP cluster and the frames of the BIS in the case of the specifications of the next-generation MD2 system. As shown in FIG. 12, in the specifications of the next-generation MD2, one ADIP cluster is constructed by 16 ADIP sectors. The data of one recording block (64 kbytes) is arranged in one ADIP cluster.

As shown in FIG. 14, the data of one recording block (64 kbytes) serving as a unit of the recording or reproduction is arranged into the block of the BIS consisting of 496 frames. A preamble of 10 frames (frame "0" to frame "9") is added before the frames (frame "10" to frame "505") of the data of 496 frames corresponding to the block of the BIS. Frames (frame "506" to frame "511") of a postamble of 6 frames are added after the frames of the data. The data of a total of 512 frames is arranged in the ADIP cluster comprising the ADIP sectors "0h" to "Fh".

The frames of the preamble before the data frames and the frames of the postamble after the data are used to protect the data upon linking with the adjacent recording block. The preamble is also used for pull-in of a PLL for data, control of a signal amplitude, control of a signal offset, and the like.

A physical address at the time of recording or reproducing the data of the recording block is designated by the ADIP cluster. When the physical address is designated upon recording or reproducing, the ADIP sector is read out from the ADIP signal and the ADIP cluster number is read out from the reproduction signal of the ADIP sector.