JPH07168749A - Information managing method, data recording medium, data recording method, information retrieving method, and information retriever - Google Patents

Abstract

PURPOSE:To perform quick access. CONSTITUTION:The data track of a magneto-optical disk is separated to a volume management area and an extent area, and the data of a file is recorded on the extent area, and directory managing information and file managing information on the volume management area. The volume management area is constituted of 32 clusters. The data allocation unit of the volume management area is set at 2k bytes, and that of the extent area at 8k bytes. A relative recording position in the volume management area of a subdirectory is recorded on the volume management area as directory information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information management method and a data recording medium suitable for managing information recorded on an information recording medium having a relatively slow access speed such as a magneto-optical disk or an optical disk. , A data recording method, an information retrieval method, and an information retrieval device.

[0002]

2. Description of the Related Art At present, in MS-DOS (trademark), which is widely used as an operating system for personal computers, directory management information and file data are recorded in the same area in the same recording unit. This method has the advantage that a hierarchical directory file system can be constructed without distinguishing between the file management method and the directory management method.

In the UNIX (trademark) method, the recording areas are Data Block and Super Block.
and k. A directory file, a subdirectory file, and a data file are recorded in the Data Block, and i- is recorded in the Super Block.
The node list is recorded.

In the directory file, the name of the file belonging to the directory and the i-node number are described. The i-node list is made up of a plurality of i-nodes assigned a predetermined number, and each i-node
e is Data of subdirectory or data file
The recording position in Block is described.

Further, for example, US Pat. No. 4,945,4
75, the method of Macintosh (trademark) disclosed in JP-A-63-116232, etc.
All the directory management information is hierarchically managed in the catalog file (Catalog File) using the B-Tree structure. That is, B-Tree
All files and directories are collectively managed by the key of the record (combination of parent directory identification number and file name). This catalog file is
Actually, it is recorded in a concentrated area. In order to search the data file, the hierarchical information of the directory is not directly used, but this B-Tree is used to indirectly search the file in the hierarchical directory.

[0006]

However, MS-
In the hierarchical directory file system of DOS, the information of each directory is distributed and recorded on the recording medium, so that the files existing in the lower layer of the hierarchical directory are spread over the entire recording medium for directory search. There is a possibility that it will be necessary to seek, and if the recording medium has a slow access speed, the file access speed will drop significantly.

As described above, when the directory management information is distributed and recorded, the number of physical writes and reads for updating the directory is increased as compared with the case where the directory management information is recorded in a concentrated manner. The information buffer utilization efficiency also deteriorates.

In addition, the UNIX method can reduce the number of physical writes of the Super Block by performing buffering, but the i-node itself is a method (i-node) independent of the directory hierarchy.
List), so these in
This management method is not effective for a small device such as a personal computer as well as a high-performance workstation because the management method of the node becomes complicated.

Further, the management by the B-Tree is extremely complicated, and the sub-directory is indirectly accessed instead of the direct access to the sub-directory by using the directory hierarchy information. , B-Tree node trees need to be searched.

B-Tree has the same distance (number of steps) from the root of the tree to all the leaves, and the search is performed efficiently. However, this distance (number of steps) is three steps when the number of directories and files increases. The number of accesses is increased to four, and the number of accesses tends to increase substantially as compared with the case where the directory position is directly indicated. Therefore, this method
It is inefficient and not suitable for small equipment.

The present invention has been made in view of such a situation, and can search a predetermined directory file in a hierarchical directory by a simple method, speed up the file search, and updates the directory. It is intended to reduce the number of times of physical reading and writing. Moreover, the directory information can be updated in a short time.

[0012]

An information management method according to a first aspect of the present invention is an information management method for managing information recorded on a recording medium, in which a file data is recorded (for example, FIG. 2). Of the first magneto-optical disk 804) (for example, the extent area of FIG. 4) to the first area.
The second area on the recording medium, which is managed by the first allocation unit (for example, allocation block) by using the management information (for example, volume space bitmap (VSB) in FIG. 6), and which is distinguished from the first area. (For example, the volume management area in FIG. 4) is converted into a first area using the second management information (for example, the management table (MT) in FIG. 7).
Of the second allocation unit (for example, management block) independent of the allocation unit of (1), and is configured by at least one second allocation unit within the second area (for example, the directory record block (DRB of FIG. 5). ))
The subdirectory information (for example, directory record for the directory in FIG. 8) therein includes information indicating the position in the second area of the second allocation unit configuring the subdirectory (for example, Index to DRB in FIG. 8). It is characterized by

The second allocation unit may be smaller than the first allocation unit.

When one file is composed of a plurality of first allocation units located at different positions, the data recorded in the second area is such that one file is stored in the first area. File extent information (for example, the extent record index (ER) of FIG. 14 including the extent record index of FIG. 15 and the extent descriptor of FIG. 16) can be included.

The file information corresponding to one file in the directory (for example, the directory record for the file in FIG. 8) is information indicating the position of the second allocation unit including the file extent information in the second area (for example, FIG. 8 Index to ER).

When one file is composed of a continuous first allocation unit, the file information (for example, the directory record for the file in FIG. 8) corresponding to one file in the directory is File position information indicating which first allocation unit of the first area is configured (for example, Extent Start in FIG. 8).
Localization) can be included.

When one directory is composed of a plurality of second allocation units, the second management information is link information (indicating that the plurality of second allocation units are connected to each other). For example, the Index ton of FIG.
ext DRB) may be included.

The data recorded in the second area may include information indicating the position of the root directory in the second area (for example, the volume descriptor (VD) in FIG. 5).

The data recording medium according to claim 8 is a data recording medium (for example, a magneto-optical disk 804 in FIG. 2) in which data having a hierarchical directory structure is recorded.
Data of a file is recorded in a first allocation unit (for example, an allocation block) in a first area (for example, the extent area in FIG. 4), and a second area (for example, in FIG. 4) distinguished from the first area is recorded. A second allocation unit (for example, management block) in which a plurality of directories are independent of the first allocation unit in the volume management area)
The subdirectory information (for example, the directory record for the directory in FIG. 8) recorded in each directory is information indicating the position in the second area of the second allocation unit forming the subdirectory (for example, in FIG. 8). Index DRB) is included.

The second allocation unit may be smaller than the first allocation unit.

When one file is composed of a plurality of first allocation units located at different positions, the data recorded in the second area is such that one file is stored in the first area. File extent information (for example, the extent record (ER) in FIG. 14) indicating whether or not the allocation unit is included.

The file information corresponding to one file in the directory (for example, the directory record for the file in FIG. 8) is information indicating the position of the second allocation unit including the file extent information in the second area (for example, FIG. 8 Index to ER).

When one file is composed of a continuous first allocation unit, the file information (for example, the directory record for the file in FIG. 8) corresponding to one file in the directory is File position information indicating which first allocation unit of the first area is configured (for example, Extent Start in FIG. 8).
Localization) can be included.

When one directory is composed of a plurality of second allocation units, the management information in the data recorded in the second area is information in which the plurality of second allocation units are connected to each other. It is possible to include the link information (for example, Index to next DRB in FIG. 10) indicating that

The data recorded in the second area may include information indicating the position of the root directory in the second area (for example, the volume descriptor (VD) in FIG. 5).

According to a fifteenth aspect of the present invention, there is provided a data recording method for recording data having a hierarchical directory structure on a recording medium (for example, the magneto-optical disk 804 in FIG. 2). 4 extent area), file data is recorded in a first allocation unit (for example, allocation block), and a plurality of files are recorded in a second area (for example, volume management area in FIG. 4) that is different from the first area. The first directory
Is recorded in a second allocation unit (for example, a management block) independent of the allocation unit, and subdirectory information (for example, the directory record for the directory in FIG. 8) in each directory is recorded in the second allocation unit. It is characterized by including information (for example, Index to DRB in FIG. 8) indicating the position of the allocation unit in the second area.

The second allocation unit may be smaller than the first allocation unit.

When one file is composed of a plurality of first allocation units at different positions, the data recorded in the second area is one file in which the first area of the first area is recorded. File extent information (for example, the extent record (ER) in FIG. 14) indicating whether or not the allocation unit is included.

File information corresponding to one file in the directory (for example, the directory record for the file in FIG. 8) is information indicating the position of the second allocation unit including the file extent information in the second area (for example, FIG. 8 Index to ER).

When one file is composed of a continuous first allocation unit, the file information (for example, the directory record for the file in FIG. 8) corresponding to one file in the directory is File position information indicating which first allocation unit of the first area is configured (for example, Extent Start in FIG. 8).
Localization) can be included.

When one directory is composed of a plurality of second allocation units, the management information in the data recorded in the second area is information in which the plurality of second allocation units are connected to each other. It is possible to include the link information (for example, Index to next DRB in FIG. 10) indicating that

The data recorded in the second area can include information indicating the position of the root directory in the second area (for example, the volume descriptor (VD) in FIG. 5).

According to a twenty-second aspect of the information retrieval method, the first area (for example, the extent area in FIG. 4) on the recording medium (for example, the magneto-optical disk 804 in FIG. 2) on which the file data is recorded is The first allocation unit (for example, allocation block) is managed by using one management information (for example, volume space bitmap (VSB) of FIG. 6), and the second area on the recording medium is distinguished from the first area. Area (for example, the volume management area in Figure 4)
By using the second management information (for example, the management table (MT) in FIG. 7), the second allocation information independent of the first allocation unit is used.
Sub-directory information (for example, directory record for the directory in FIG. 8) in a directory that is managed by each allocation unit (for example, management block) and is configured by at least one second allocation unit in the second area.
Is information indicating the position in the second area of the second allocation unit that constitutes the subdirectory (for example, In in FIG. 8).
In an information retrieval method for retrieving a desired file from a recording medium configured to include dexto DRB),
The root directory is accessed based on predetermined position information (for example, the volume descriptor in FIG. 5) in the data recorded in the second area, and file information corresponding to a desired file in the root directory (for example, FIG. 8). File location information (eg, Ext in FIG. 8) indicating which first allocation unit of the first area the desired file in the directory record for
based on ent Start Location)
It is characterized in that a desired file on a recording medium is accessed.

In the information retrieval method according to the twenty-third aspect, the first area (for example, the extent area in FIG. 4) on the recording medium (for example, the magneto-optical disk 804 in FIG. 2) on which the file data is recorded is changed to the first area. The first allocation unit (for example, allocation block) is managed by using one management information (for example, volume space bitmap (VSB) of FIG. 6), and the second area on the recording medium is distinguished from the first area. Area (for example, the volume management area in Figure 4)
By using the second management information (for example, the management table (MT) in FIG. 7), the second allocation information independent of the first allocation unit is used.
Sub-directory information (for example, directory record for the directory in FIG. 8) in a directory that is managed by each allocation unit (for example, management block) and is configured by at least one second allocation unit in the second area.
Is information indicating the position in the second area of the second allocation unit that constitutes the subdirectory (for example, In in FIG. 8).
In an information retrieval method for retrieving a desired file from a recording medium configured to include dexto DRB),
Based on the first position information (for example, the volume descriptor in FIG. 5) in the data recorded in the second area, the root directory is accessed and the second position information in the root directory and the parent directory (for example, in FIG. 8) is accessed. Of I
The subdirectory containing the file information corresponding to the desired file is accessed based on the index to DRB), and the desired information in the file information corresponding to the desired file in the subdirectory (for example, the directory record for the file in FIG. 8) is accessed. File information indicating which first allocation unit of the first area is configured in the first area (for example, Extent Start Locat in FIG. 8).
Ion) to access the desired file on the recording medium.

According to a twenty-fourth aspect of the information retrieval method, the first area (for example, the extent area in FIG. 4) on the recording medium (for example, the magneto-optical disk 804 in FIG. 2) on which the file data is recorded is changed to the first area. The first allocation unit (for example, allocation block) is managed by using one management information (for example, volume space bitmap (VSB) of FIG. 6), and the second area on the recording medium is distinguished from the first area. Area (for example, the volume management area in Figure 4)
By using the second management information (for example, the management table (MT) in FIG. 7), the second allocation information independent of the first allocation unit is used.
Sub-directory information (for example, directory record for the directory in FIG. 8) in a directory that is managed by each allocation unit (for example, management block) and is configured by at least one second allocation unit in the second area.
Is information indicating the position in the second area of the second allocation unit that constitutes the subdirectory (for example, In in FIG. 8).
In an information retrieval method for retrieving a desired file from a recording medium configured to include dexto DRB),
Based on the first position information (for example, the volume descriptor in FIG. 5) in the data recorded in the second area, the root directory is accessed and the second position information in the root directory and the parent directory (for example, in FIG. 8) is accessed. Of I
based on the index to DRB), the subdirectory containing the file information corresponding to the desired file is accessed, and the file information corresponding to the desired file in the subdirectory (for example, the directory record for the file in FIG. 8) is accessed. 3 position information (for example, Ind in FIG. 8)
Ex to ER), the desired file is first
File extent information (for example, extent record (ER) in FIG. 14) indicating which first allocation unit of the area is configured to access the desired file on the recording medium based on the file extent information. It is characterized by doing.

The data recorded in the second area is read from the recording medium, the read data recorded in the second area is stored in the memory (for example, RAM 18 in FIG. 1), and access to the root directory is performed. Access to sub-directories and / or file extent information may be performed using data stored in memory.

According to a twenty-sixth aspect of the present invention, there is provided an information retrieving apparatus in which a first area (eg, extent area of FIG. 4) on a recording medium (eg, magneto-optical disk 804 of FIG. 2) on which file data is recorded The first allocation unit (for example, allocation block) is managed by using one management information (for example, volume space bitmap (VSB) of FIG. 6), and the second area on the recording medium is distinguished from the first area. Area (for example, the volume management area in Figure 4)
By using the second management information (for example, the management table (MT) in FIG. 7), the second allocation information independent of the first allocation unit is used.
Sub-directory information (for example, directory record for the directory in FIG. 8) in a directory that is managed by each allocation unit (for example, management block) and is configured by at least one second allocation unit in the second area.
Is information indicating the position in the second area of the second allocation unit that constitutes the subdirectory (for example, In in FIG. 8).
In an information retrieval device for retrieving a desired file from a recording medium configured to include dexto DRB),
Means for accessing the root directory (for example, step S2 in the flowchart of FIG. 18) based on predetermined position information (for example, volume descriptor in FIG. 5) in the data recorded in the second area, and File position information indicating which first allocation unit of the first area the desired file in the file information corresponding to the desired file (for example, the directory record for the file in FIG. 8) (for example, FIG. 8). And a means for accessing a desired file on the recording medium (for example, step S13 in the flowchart of FIG. 20) based on the Extent Start Location of FIG.

The information retrieving apparatus according to a twenty-seventh aspect is arranged such that the first area (for example, the extent area in FIG. 4) on the recording medium (for example, the magneto-optical disk 804 in FIG. 2) on which the file data is recorded is the first area. The first allocation unit (for example, allocation block) is managed by using one management information (for example, volume space bitmap (VSB) of FIG. 6), and the second area on the recording medium is distinguished from the first area. Area (for example, the volume management area in Figure 4)
By using the second management information (for example, the management table (MT) in FIG. 7), the second allocation information independent of the first allocation unit is used.
Sub-directory information (for example, directory record for the directory in FIG. 8) in a directory that is managed by each allocation unit (for example, management block) and is configured by at least one second allocation unit in the second area.
Is information indicating the position in the second area of the second allocation unit that constitutes the subdirectory (for example, In in FIG. 8).
In an information retrieval device for retrieving a desired file from a recording medium configured to include dexto DRB),
Means for accessing the root directory (eg, step S2 in the flowchart of FIG. 18) based on the first position information (eg, volume descriptor of FIG. 5) in the data recorded in the second area, and the root directory and parent Second position information in the directory (see, for example, FIG. 8).
And the file information corresponding to the desired file in the subdirectory (for example, step S3 in the flowchart of FIG. 18) based on the Index to DRB of the subdirectory, and the subdirectory including the file information corresponding to the desired file. File position information (eg, Extent Start Lo of FIG. 8) indicating which first allocation unit of the first area the desired file in the file directory record of FIG. 8 is composed of.
(step S13 in the flow chart of FIG. 20) for accessing a desired file on the recording medium based on the above.

According to a twenty-eighth aspect of the present invention, there is provided an information retrieving apparatus in which a first area (for example, extent area in FIG. 4) on a recording medium (for example, magneto-optical disk 804 in FIG. 2) on which file data is recorded is The first allocation unit (for example, allocation block) is managed by using one management information (for example, volume space bitmap (VSB) of FIG. 6), and the second area on the recording medium is distinguished from the first area. Area (for example, the volume management area in Figure 4)
By using the second management information (for example, the management table (MT) in FIG. 7), the second allocation information independent of the first allocation unit is used.
Sub-directory information (for example, directory record for the directory in FIG. 8) in a directory that is managed by each allocation unit (for example, management block) and is configured by at least one second allocation unit in the second area.
Is information indicating the position in the second area of the second allocation unit that constitutes the subdirectory (for example, In in FIG. 8).
In an information retrieval device for retrieving a desired file from a recording medium configured to include dexto DRB),
Means for accessing the root directory (eg, step S2 in the flowchart of FIG. 18) based on the first position information (eg, volume descriptor of FIG. 5) in the data recorded in the second area, and the root directory and parent Second position information in the directory (see, for example, FIG. 8).
Index to DRB), a means for accessing a subdirectory containing file information corresponding to a desired file (for example, step S3 in the flowchart of FIG. 18), and a file information corresponding to the desired file in the subdirectory. Third position information (eg, FIG. 8)
Means for accessing the file extent information (for example, extent record (ER) in FIG. 14) indicating which first allocation unit of the first area the desired file is based on (Index to ER). For example, it is characterized by including a step S10) of the flowchart of FIG. 19 and a means for accessing a desired file on the recording medium based on the file extent information (for example, step S15 of the flowchart of FIG. 20).

Means for reading the data recorded in the second area from the recording medium (for example, the optical pickup 80 in FIG. 2)
6) and a memory (for example, RAM 18 in FIG. 1) for storing the data recorded in the read second area, and further, access to the root directory, access to the subdirectory, and / or file extent information. The data can be accessed using the data stored in the memory.

In the information management method according to the thirtieth aspect, a recordable area in which information can be recorded (for example, a recordable area in FIG. 23) and a non-rewritable area in which information once recorded cannot be rewritten. (For example, the premastered area in FIG. 23), and an information recording medium (for example, in FIG. 2) in which the directory management information is recorded in the non-rewritable area.
3 hybrid type disc), the directory management information (for example, FIG. 23) recorded in the non-rewritable area when the recordable area is initialized.
The volume management area (VMA) is copied to the recordable area, and thereafter the information is managed based on the directory management information of the recordable area.

In the information recording medium, an optically reproducible read-only area in which information is pre-recorded as pre-pits (for example, the pre-mastered area in FIG. 23) and a magneto-optically rewritable recording are provided. A hybrid disc having an area (for example, the recordable area in FIG. 23) can be used, and the directory management information can be recorded in a reproduction-only area.

According to a thirty-second aspect of the information management method of the present invention, a write-once type information recording disc capable of recording information only once (for example, a write-once type disc of FIG. 25).
The information management method of FIG.
File 3) and the directory management information for managing data (for example, volume management area (VMA) in FIG. 25) in the first area (for example, session 2 in FIG. 25), and then new data (for example, FIG. 25). When recording the files 4 and 5) in the second area (for example, the session 3 in FIG. 25), new directory management information including the directory management information recorded in the first area is recorded in the second area. It is characterized in that the data is recorded and thereafter the data is managed based on the directory management information in the second area.

[0044]

An information management method according to claim 1 and claim 1
In the data recording method described in 5, the sub-directory information in the volume management area indicates the position in the volume management area.
It is recorded including to DRB. Therefore, the number of times of physical reading and writing for updating the directory can be reduced, and a predetermined directory file in the hierarchical directory can be searched easily and at high speed. Also, the directory information can be updated in a short time.

In the data recording medium according to the eighth aspect, subdirectory information is recorded in the volume management area. Then, the sub-directory information includes Index to DRB indicating the position in the volume management area. Therefore,
It becomes possible to realize a data recording medium that can be searched easily and at high speed.

In the information retrieving method according to the twenty-second aspect and the information retrieving apparatus according to the twenty-sixth aspect, the root directory is accessed from the volume descriptor, and the Extent Start in the root directory is accessed.
The file is accessed based on the Location.

In the information retrieving method according to the twenty-third aspect and the information retrieving apparatus according to the twenty-seventh aspect, the root directory is accessed from the volume descriptor and In in the root directory and the parent directory is accessed.
The sub-directory is accessed based on the dex to DRB. And Ext in the subdirectory
The file is accessed based on the ent Start Location.

In the information retrieving method according to the twenty-fourth aspect and the information retrieving apparatus according to the twenty-eighth aspect, the root directory is accessed from the volume descriptor, and In in the root directory and the parent directory is accessed.
The sub-directory is accessed based on the dex to DRB. And Ind in the subdirectory
The extent record is accessed based on the ex to ER, and the file is accessed based on the extent record.

Therefore, in either case, simple and quick access is possible.

In the information management method according to the thirtieth aspect, when the recordable area is initialized, the volume management area recorded in the non-rewritable area is copied to the recordable area, and thereafter the recordable area is recorded. Information is managed based on the volume management area. Therefore, it becomes possible to centrally manage the information in the recordable area and the non-rewritable area.

In the information management method according to the thirty-second aspect, when recording data in a new session, a new volume management area including the volume management area recorded in the old session is recorded. Information is managed based on the volume management area. Therefore, it becomes possible to centrally manage old information and additional information.

[0052]

FIG. 1 shows the configuration of an embodiment of an information processing apparatus to which the information management method of the present invention is applied. The input device 10 is
Data and commands corresponding to key operations by the operator are supplied to a microcomputer (hereinafter, abbreviated as microcomputer) 12.

The microcomputer 12 has a main CPU 14 and an R in which a program used by the CPU 14 is stored in advance.
OM16 and RAM18 used as a work area
And a timer 19 for generating time information, and an input / output interface 20 for exchanging various data between the CPU 14 and external peripheral devices.

The magneto-optical recording / reproducing apparatus 8 records the data supplied from the main CPU 14 via the input / output interface 20 in the loaded disc in the recording mode, and reproduces the data from the disc in the reproducing mode. The main C via the input / output interface 20
Output to PU14.

FIG. 2 shows an example of the structure of the magneto-optical recording / reproducing apparatus 8 shown in FIG. The magneto-optical recording / reproducing apparatus (M
DXD) 8 is a read (playback) -only type optical disc having a diameter of 64 mm, and a read / write type, that is, a rewritable MO.
Information is recorded on or reproduced from a recording medium in which a (magneto-optical) disc or a hybrid (partial ROM) disc having a read / write (that is, rewrite) region and a read-only region is contained in a cartridge.

Data is recorded on the MO disc and the hybrid disc by the magnetic field modulation overwrite recording method. In the case of a read-only type optical disc, the reproduction signal is detected by utilizing the diffraction phenomenon of light in the pit row of the target track, and in the case of a read / write type magneto-optical disc, the polarization angle of the reflected light from the target track (car The reproduction signal is detected by detecting the difference in the rotation angle.
In the case of a hybrid disc, the read signal is detected in the read-only area by utilizing the light diffraction phenomenon in the pit row of the target track, and the polarization angle of the reflected light from the target track (Kerr rotation) is detected in the read / write area. This is to detect the reproduction signal by detecting the difference in angle.

Such a magneto-optical recording / reproducing apparatus 8 may be a part of an MD (mini disk (trademark)) system developed for personal audio equipment (portable type, stationary type, vehicle type). it can. In the MD system, in the process of development as a personal audio device, the integration of each circuit element and the optimization of each mechanical component have been achieved, the overall size and weight of the device have been reduced, and low power consumption has been achieved. Battery operation is possible. Furthermore, in addition to the characteristics that it has almost the same storage capacity (140 Mbytes) as the existing 3.5-inch MO disk drive, and the recording medium can be replaced, and due to the effect of mass production, compared to other MO disk drives, It is possible to reduce the manufacturing cost of the device body and recording media,
From the track record of use as a personal audio device,
Reliability is also well proven.

In FIG. 2, a magneto-optical disk 804 rotatably driven by a spindle motor 802 applies a modulation magnetic field according to recording data by a magnetic head 808 while irradiating a laser beam from an optical pickup 806. Magnetic field modulation overwrite recording is performed along the recording track of the magneto-optical disk 804, and the recording track of the magneto-optical disk 804 is recorded by the optical pickup 80.
Data is reproduced magneto-optically by tracing with laser light by 6.

The optical pickup 806 includes, for example, a laser light source such as a laser diode, optical components such as a collimator lens, an objective lens, a polarization beam splitter, and a cylindrical lens, and a photodetector divided into a predetermined shape. Magnetic disk 804
It is positioned by a feed motor 810 at a position facing the magnetic head 808 with the pinch in between.

When data is recorded on the magneto-optical disk 804, the magnetic head drive circuit 809 drives the magnetic head 80.
8 is driven, and the modulation magnetic field according to the recording data is applied to the magneto-optical disk 804. Optical pickup 806
Irradiates a target track of the magneto-optical disk 804 with laser light to perform data recording by thermomagnetic recording.

Further, the optical pickup 806 detects a focus error by, for example, an astigmatism method and a tracking error by, for example, a push-pull method by detecting the laser light applied to the target track. When reproducing data from the magneto-optical disk 804, the polarization angle of the reflected light from the target track (Kerr rotation angle)
The difference is detected and a reproduction signal is generated.

The output of the optical pickup 806 is supplied to the RF circuit 812. The RF circuit 812 extracts the focus error signal and the tracking error signal from the output of the optical pickup 806, and the servo control circuit 814.
And the reproduced signal is binarized and supplied to the address decoder 816. Address decoder 816
Decodes the address from the supplied binarized reproduction signal and outputs it to the EFM / CIRC encoder / decoder 818. Also, the binarized reproduction data other than the binarized reproduction data related to the address is also processed by the EFM / CIRC. It is supplied to the encoder / decoder 818.

The servo control circuit 814 is composed of, for example, a focus servo control circuit, a tracking servo control circuit, a spindle motor servo control circuit and a sled servo control circuit.

The focus servo control circuit controls the optical pickup 806 so that the focus error signal becomes zero.
The focus control of the optical system is performed. The tracking servo control circuit controls the feed motor 810 (or the tracking actuator) of the optical pickup 806 so that the tracking error signal becomes zero.

Further, the spindle motor servo control circuit drives the spindle motor 80 so as to rotate the magneto-optical disk 804 at a predetermined rotation speed (for example, a constant linear speed).
Control 2 Further, the sled servo control circuit causes the magnetic head 808 to move to the target track position of the magneto-optical disk 804 designated by the system control CPU 820.
And the optical pickup 806 is moved by the feed motor 810.

EFM / CIRC encoder / decoder 8
Reference numeral 18 denotes an encoding process for error correction, that is, a CI for the data supplied via the interface 800.
RC (Cross Interleave Reed-
In addition to performing the encoding process of Solomon code, the modulation process suitable for recording, that is, EFM (Eight)
to Fourteen Modulation) encoding processing is performed.

EFM / CIRC encoder / decoder 8
The encoded data output from 18 is supplied to the magnetic head drive circuit 809 as recording data. The magnetic head drive circuit 809 drives the magnetic head 808 so as to apply a modulation magnetic field according to the recording data to the magneto-optical disk 804.

When the system control CPU 820 receives a write command via the interface 800, it controls the recording position on the disk 804 so that the recording data is recorded on the recording track of the magneto-optical disk 804. This recording position is controlled by EFM / C
The recording position of the encoded data output from the IRC encoder / decoder 818 on the magneto-optical disk 804 is managed by the system control CPU 804, and the magneto-optical disk 804 is controlled by the system control CPU 820.
The servo control circuit 814 is supplied with a control signal designating the recording position of the recording track.

During reproduction, the EFM / CIRC encoder / decoder 818 performs EFM demodulation processing and CIRC decoding processing for error correction on the input binarized reproduction data, and the interface 800 is operated. Output through.

Further, the system control CPU 820
When receiving a read command via the interface 800, controls the reproduction position with respect to the recording track of the magneto-optical disk 804 so that the reproduction data can be continuously obtained. The control of the reproduction position is performed by changing the position of the reproduction data on the disc to the system control CPU 82.
The servo control circuit 8 controls a control signal for designating the reproduction position on the recording track of the magneto-optical disk 804.
By feeding to 14.

FIG. 3 shows a rewritable magneto-optical disk 804.
Shows an example in which audio data and computer data are recorded. As shown in the figure, in the information area (Information area) from the innermost circumference (left side in the figure) to the outermost circumference (right side in the figure), the lead-in areas are respectively provided on the innermost circumference side and the outermost circumference side. (Lead-in area) and a lead-out area (Lead-out area) are provided. In the lead-in area and lead-out area, TOC (T
“Able of Contents” data and the like are recorded as necessary. A general user cannot record information in these areas.

Of the information area, the area excluding the lead-in area and the lead-out area is a recordable area, and a general user can record or reproduce data in or from the area. There is.

On the innermost side of the recordable area, the UT
An OC (User TOC) area is provided, and a program area (Program area) is provided outside thereof. In the UTOC area, UTOC data corresponding to the recording data recorded by the user in the program area is recorded. Audio data, data processed by a computer, and other data can be recorded in the program area.

In the program area, each data is discretely recorded as needed. Each of the discretely arranged regions is called a part, and the related parts form one track. In the embodiment of FIG. 3, audio data is recorded on the track Trk1. That is, this track is an audio track. This truck Trk1 has two parts (Trk1
-1, Trk1-2). The parts (tracks) Trk1-1 and Trk1-2 are formed at positions distant from each other on the disc. For example, when reproducing the data, when the reproduction of the parts Trk1-1 is completed, the optical pickup 806 is , Parts Trk1
-Seek to -2 and play there. Therefore, the reproduction data can be continuously obtained.

In addition to the above, in this embodiment, the audio tracks Trk2-1 and Trk4-1 are respectively 1
It consists of three parts, and audio data is recorded.

Further, in this embodiment, the part T
Data track T including rk3-1 to 3-3
rk3 is formed, and the data processed by the main CPU 14 is recorded therein.

EFM / CIRC encoder / decoder 8
A process 18 records and / or reproduces data (hereinafter simply referred to as recording / reproduction) in units of clusters (64 kilobytes) for each track in the program area.

The data track is a volume management area (Volume Management) in which information for managing the volume such as directory information is recorded.
entArea) and an extent area (Extent Area) in which actual file data is recorded. The volume management area is
It is formed at the beginning of the data track formed first in the program area. The extent area is an area other than that.

In this embodiment, the head of the data track formed first in the program area is the part T.
This corresponds to the beginning of rk3-1 and a volume management area is formed here.

The data allocation unit of the volume management area and the extent area is independently managed. For example, the former is 2 kilobytes and the latter is 2 kilobytes, 4 kilobytes, 8 kilobytes, 16 kilobytes, 32 kilobytes, or It is set to any value of 64 kilobytes (for example, 8 kilobytes).

The volume management area is shown in FIG.
As shown in FIG. 3, it is composed of 32 clusters. One cluster before the volume management area is the boot cluster (Boot-Cluster) for one cluster.
r) is placed.

FIG. 5 shows the format of the volume management area. Since the volume management area is composed of 32 clusters and one cluster is composed of 64 kilobytes, 1024 management blocks of 2 kilobytes are formed in the volume management area and are numbered from 0 to 10 in ascending order.
23 will be added.

In the first management block of number 0, a volume descriptor VD (Volume D)
(escriptor) is recorded. In this volume descriptor, in addition to information about the entire volume such as the volume name and creation date, for example, the number of the management block in which the root directory is recorded (any value from 0 to 1023 (in the case of this embodiment,
4)) is recorded.

The management block of No. 1 has a volume space bitmap (Volume Spa).
ce Bitmap (VSB)) is arranged. This V
Data representing the usage state of the entire magneto-optical disk 804 is recorded on the SB.

That is, the volume space bitmap manages the usage status of the entire disk (in particular, extent area) in allocation units called allocation blocks. The allocation block is 2 kilobytes, 4
The value is set to any one of kilobytes, 8 kilobytes, 16 kilobytes, 32 kilobytes, and 64 kilobytes. Since this essentially specifies the allocation unit of the extent area, as described above, this implementation In the case of the example, it is set to 8 kilobytes. All allocation blocks in the disk are assigned allocation block numbers starting from 0 in ascending order. This number identifies the absolute position on the disc.

As shown in FIG. 6, for example, the volume space bitmap is made up of 2-bit entries having numbers corresponding to the numbers of the allocation blocks, and each entry is arranged in ascending order like the allocation blocks. To be done. If one management block is insufficient to represent all allocation blocks, a plurality of management blocks form a volume space bitmap.

The 2-bit value of each entry of the volume space bitmap has the following meaning. 00 Usable 01 Used 10 Defect 11 Unusable

When the disk is initialized, a data track is created, and allocation blocks belonging to other than this data track are registered in the volume space bitmap as unusable (00). The allocation blocks of the boot cluster and volume management area are registered as used (01). Allocation block in extent area can be used (00)
Register as.

File data is registered in the extent area. When recording file data, a usable (00) allocation block is searched from the volume space bitmap, and after recording the data in the allocation block, Change the corresponding entry in the volume space bitmap to used (01). Available if file is deleted (00)
Register the entry again as the allocation block of. In this way, the extent area is managed by the volume space bitmap.

A management table (Management Table (MT)) is arranged in the management blocks of 4 kilobytes in total, which are number 2 and number 3 in FIG. In this MT, the usage status of the volume management area is recorded.

FIG. 7 schematically shows a management table composed of two management blocks numbered 2 and 3. As shown in the figure, 0 to 1
Each entry with a size of 4 bytes indicated by the number 023 is
It corresponds to the management block of 2 kilobytes indicated by the numbers 0 to 1023 in FIG. Since the four management blocks numbered 0 to 3 shown in FIG. 5 are fixed in advance by the standard, that is, fixed, the four management blocks corresponding to the four management blocks in FIG. 7 are predetermined. Fixed data is recorded (reserved).

As shown in FIG. 5, in the management blocks of number 4 and thereafter, a directory record block (Directory Records Block) is included.
(DRB)) or extent record block (E
xtent Records Block (ERB))
Are arranged.

One directory contains one or more DRBs.
The DRB is composed of directory records as shown in FIG. The directory record is composed of directory information and / or file information, and the following information is recorded in each.

Directory (Name, Ind
ex to DRB, ID, Size, Dat
e, etc. ) File (Extent Record of Fi)
le Data, Name, Index to E
R (Index to ERB, Offset of
ER), Extent Start Locati
on, Number of Blocks, ID,
Size, Date, etc. )

Extent Record of Fi
le Data is a 1-bit flag and indicates whether or not the file is indicated by using an extent record block. Name is the name of the subdirectory or file, ID is its unique number, Size is its size, and Date is its formation date.

Index to DRB (Index t
o DRB) indicates the relative position in the volume management area of the first directory record block DRB in which the contents of the subdirectory are described, with the number 0.
It is represented by one of the values 1 to 1023 (the number of the management block shown in FIG. 5).

Index to ER (Index to
ER is the index to ERB (Index t
o ERB) and offset of ER (Offset)
The index to ERB is an extent record block ERB that describes an allocation block in which data of a predetermined file is recorded.
The relative position in the volume management area of
It is represented by one of the values 0 to 1023 (the management block number shown in FIG. 5).

The offset of ER is, as will be described later,
The number from 0 to 63 indicates any one of the 64 extent records of the extent record block ERB shown in FIG.

Extent start location (Ex
“Tent Start Location” represents the start position (absolute position) of the file recorded in the extent area by the allocation block number. Number of block (Number of block)
Blocks) represents the number of allocation blocks of the file starting from the start position.

However, among the above file information, I
In index to ER, one file has multiple Ex
It is recorded only when it is composed by tent (that is, when one file is composed of a plurality of distant allocation blocks), and the Extent S
The start location is when one file is composed of one Extent (that is, 1
Only when one file consists of contiguous allocation blocks).

9 to 12 show directory record block entries (Directory Records Bl) of the management table MT for managing the recording of data in the directory record block DRB.
ock Entry) format.

FIG. 9 shows the directory record block D.
This shows the format of the directory record block entry of the management table when the RB is alone. In this case, 0 is set to the first 31st bit of the 4-byte data and the remaining 3rd bit is set.
The ID is recorded in 31 bits from 0th bit to 0th bit. For example, the directory record block entry corresponding to the management block numbered 4 in FIG. 5 has the format shown in FIG. 9 as shown in FIG. In the case of this embodiment, the ID is 0000.
0002 is recorded. This ID represents the root directory.

When the directory is composed of a plurality of directory record blocks DRB, the directory record block entry of the management table corresponding to the first DRB is composed in the format as shown in FIG. 10 and corresponds to the last DRB. 12 has a format as shown in FIG. 12, and an entry corresponding to the DRB in the meantime has a format as shown in FIG.

In the entry of FIG. 10, F0 indicating the type of entry is recorded in the first 1 byte, and the 1-byte ID on the MSB side of the 4-byte ID is recorded in the next 1 byte. . Then, in the next 2 bytes, the index (I
(index to Next DRB) is arranged.

In the entry of FIG. 11, FE indicating the type of entry is arranged in the first 1 byte, and the next 1 byte is unused. Then, the index to the DRB of the next management block is arranged in the remaining 2 bytes.

In the entry of FIG. 12, the FF indicating the type of the entry is arranged in the first 1 byte, and the 1 byte MSB recorded in the 2nd byte of FIG. 10 is excluded in the remaining 3 bytes. The remaining 3-byte ID is recorded.

The entries numbered 7, 8 and 10 in FIG. 7 are defined in the formats shown in FIGS. 10, 11 and 12, respectively. 0008 is recorded in the last 2 bytes of the entry corresponding to management block number 7. This means that the next DRB in which related data is recorded is the directory record block DRB of the management block represented by number 8. (Therefore, there is an entry with the number 8 in relation to the entry with the number 7). Also, 000A (hexadecimal) is recorded in the last 2 bytes of the entry of the block corresponding to number 8, which is the management block of number 10 (decimal value corresponding to hexadecimal A). Indicates that the directory record block of is continued (therefore, the entry of the number 10 is continued).

Then, 00 is recorded in the second byte of the entry of number 7, and the ID of 00000005 is recorded in the second to fourth bytes of the entry of number 10, so in the end, these three It can be seen that the ID of the directory defined by the entry is 00000005.

FIG. 13 shows an extent record block entry (Extent Records Bloc) for managing the ERB of the management table shown in FIG.
kEntry) format. In this format, 80 indicating the type of the entry is arranged in the first 1 byte, the remaining 2 bytes are unused (Reserved), and the used count (Used Count) is arranged in the last 1 byte. ing. This used count is the extent record block (Extent Record) of FIG. 14 described later.
Among the records corresponding to the numbers 0 to 63 of ds Block), the number of used extent records is represented.

In the management table of FIG. 7, the entries corresponding to the management blocks represented by the numbers 5 and 11 in FIG. 5 are represented by the extent record block entry format shown in FIG. In the case of the example of number 5, the value of 04 is recorded in the last 1 byte. This is shown in FIG.
6 of 0 to 63 of the extent record block shown in
Of the extent records ER represented by 4 numbers, the number of used extent records is 4 (each extent record of number 0, 1, 2, 4 has been used)
It means that.

The extent record block ERB shown in FIG. 5 describes in which allocation block the data of the file recorded in the extent area is recorded. For example, the extent record block ERB is constructed as shown in FIG. There is. As shown in the figure, each of the 2 kilobyte extent record blocks ERB is
It is composed of 64 extent records ER represented by numbers 0 to 63 of 32 bytes.

Each extent record ER is the first 1
4 bytes data in which FFFF indicating that the extent record is an index is recorded in the byte, and seven extent record indexes (Extent Record Index) shown in FIG. 15 are collected, or alternatively, A 4-byte extent descriptor (Extent D) shown in FIG.
It is configured by collecting 8 escriptors.

As shown in FIG. 15, a logical offset (Logical Offset) is arranged in the first 2 bytes of the extent record index, and an index to ERB (Inde) is arranged in the next 10 bits.
x to ERB) is allocated, and the last 6 bits are
Offset of ER (Offset of ER) is arranged.

In the extent area, data is recorded with the allocation block as the minimum allocation unit. The logical offset indicates the position of the data indicated by the extent record index from the beginning of the file (relative position in the file), and is indicated by the relative number of the allocation block in the file. ing.

The index-to-ERB has a structure of 10 bits and has an extent record block ER.
The relative position of the B in the volume management area is represented by one of the values 0 to 1023 (the management block number shown in FIG. 5).

Further, the offset of ER is composed of 6 bits, and by any number from 0 to 63,
It indicates any one of the 64 extent records in the extent record block shown in FIG.

As shown in FIG. 16, the extent start location (Extent Start Lo) is set in the first 2 bytes of the extent descriptor.
The number of blocks of the number of blocks (Number of Blocks) is stored in the remaining 2 bytes.
Are arranged. The extent start location represents the start position (absolute position) of the file recorded in the extent area by the allocation block number. The number of blocks represents the number of allocation blocks of the file starting from the start position.

In FIG. 14, the 32-byte extent record ER represented by number 1 represents the extent record index. FFFF is recorded in the first 2 bytes of the first 4 bytes. Then, in the case of this embodiment, the first 4 are stored in the next 4 bytes.
In the byte, 0000 is arranged as a logical offset, 5 is stored as an index to ERB, and 2 is stored as an offset of ER.

The index to ERB being 5 means that the management block number of the extent record block ERB (shown in FIG. 14) is 5.

The fact that the offset of ER is 2 indicates that the extent record ER represented by the number 2 is present in FIG. The logical offset is 0000, which is represented by the extent record represented by number 2.
The number (relative number) of the first allocation block of the file in the file is 0000 (that is, the first allocation block constituting the file). Then, in the extent record ER with the number 2, for example, at the beginning (on the left side in the drawing), one in the fifteenth allocation block at the absolute position (extent start location) on the data track (number of block )
Allocation blocks are shown to exist.

It is shown that the offset of ER is 4 in the next 4 bytes of the 32-byte extent record ER represented by the number 1. This indicates that data exists in the extent record of number 4 among the extent records represented by numbers 0 to 63. In the case of this embodiment, the logical offset is 000B (11 in decimal). That is, in the embodiment of FIG. 14, the total number of allocation blocks of the extent record ER represented by the number 2 is 11 (= 1 + 1 + 2), as will be described later.
+ 1 + 1 + 1 + 3 + 1). Therefore, at the position where the extent start location is 053C as the absolute position on the magneto-optical disk 804 recorded in the extent record ER represented by the number 4, the first
There is a file starting from the second (relative allocation block number 11).

As shown in FIG. 14, in this embodiment, one extent record ER can contain only a maximum of seven extent record indexes, so that only seven extent record ER can be designated. When the extent record ER further increases, another extent record index is further generated, and an index for collecting a plurality of extent record indexes is further generated.

To use the management blocks in the volume management area, unused management blocks (00000
000 management entries), and the data in the format shown in FIGS. 9 to 13 is registered in the entry in accordance with the usage status. When the specified management block is no longer needed, 0 is added to the entry.
Register 0000000. In this way, the volume management area is managed by the management table.

FIG. 17 schematically shows the relationship between the index recorded in the extent record block ERB and the extent record ER. As shown in the figure, from the directory record (FIG. 8) for the file of the predetermined directory record block DRB (FIG. 5), the Index to ER is used to indicate the extent record ER ( 14) is designated. Then, a maximum of seven extent record indexes are recorded in the designated extent record.

Then, in the extent record ER designated by each index, the start position of a maximum of eight extents (extent start location)
And an extent descriptor, which is information of the number of allocation blocks (number of blocks) forming the extent, is recorded. In the above example, the ER number including the extent descriptor is
Although it is shown via the extent record index, if the number of Extents constituting one file is 8 or less, the Index to ER can directly indicate the ER including the extent descriptor.

As shown in FIGS. 14 and 17, allocation block numbers 0015, 0017, 023A, 00.
From each position of 16,03A2, 03B2, 04AA, 04CD, 1 (relative block number 0000), 1 (000
1), 2 (0002, 0003), 1 (0004), 1
(0005), 1 (0006), 3 (0007,000,000)
8,0009) and 1 (000A), ie 1 in total
The extent record ER of number 2 describes that one allocation block constitutes a part of one file. Furthermore, the remaining part of the file following this is 4 from allocation block number 053C (relative block number 000B000).
It is described in the extent record ER of number 4 that it is composed of an allocation block of (C, 000D, 000E). That is, in the case of this example, one file is composed of a total of 15 allocation blocks.

Next, with reference to the flow charts of FIGS. 18 to 20, the operation of searching for predetermined data in a predetermined file will be described. The data in the volume management area is read when the magneto-optical disk 804 is loaded and is already buffered in the RAM 18.

First, in step S1, the hierarchical directory path from the root directory composed of a plurality of subdirectory names, the file name, and the byte offset (Byte Off) of the data to be searched in the file.
set) is input to the main CPU 14 via the input device 10. Next, in step S2, the main CPU 14
Accesses the volume descriptor VD (FIG. 5) of the volume management area stored in the RAM 18 to obtain the address of the directory record block DRB of the root directory. That is, of the management blocks represented by the numbers 4 to 1023 in FIG. 5, the number of the directory record block DRB in which the root directory is recorded is obtained.

Next, in step S3, the main CPU 1
4 accesses the management block (directory record block DRB) of the number obtained in step S2 in the volume management area stored in the RAM 18. Then, the subdirectory recorded in the directory record block DRB is searched by that name. Next, in step S4, the main C
The PU 14 determines whether or not the directory entered in step S1 has reached the last directory of the hierarchical directory path entered in step S1, and if the directory has not reached the last directory yet. , The main CPU 14 obtains the position of the next directory record block DRB from the current directory record block DRB. Then, the process returns to step S3, and the DRB at the position obtained in step S5 is accessed.

When it is determined in step S4 that the last directory has been reached by repeatedly executing the above steps S3 to S5, the process proceeds to step S6, and the main CPU 14 makes the directory record. The directory record of the file is obtained from the name of the file in the block DRB. That is, the entry of the specified file is obtained.

Next, in step S7, the main CPU 1
4 indicates whether or not the designated file has an extent record block ERB, which is the extent record of fi of the directory record for the file.
Judge from le Data. If the specified file has the extent record block ERB, the process proceeds to step S9, and the main CPU 14 causes the Ind included in the directory record of the file obtained in step S6.
ex to ER (Index to ERB, Off
The position of the extent record ER is obtained from the set of ER). Then, in step S10, the main C
The PU 14 accesses the extent record ER obtained in step S9 in the volume management area stored in the RAM 18.

Here, the main CPU 14 determines from the contents of the obtained extent record ER whether it is the extent record index or the extent descriptor, and if it is the extent record index, the process proceeds to step S11. If it is an extent descriptor, the process proceeds to step S13.

In step S11, the main CPU 1
4 determines the extent record index having the logical offset including the data of the byte offset designated in step S1 from the extent record ER accessed in step S10 as follows.

First, the byte offset designated in step S1 is divided by the number of bytes of one allocation block (8 kilobytes in this embodiment) as the allocation unit of the extent area in which the file is recorded,
Let X be the integer of the obtained quotient. And, it is less than or equal to the obtained value X and the maximum logical offset (see FIG.
Find the extent record index with 5).

By the processing of this step S11, FIG.
The index (extent record index) shown in (3) is obtained.

Next, in step S12, the main CPU
14 is the Index to ERB and Offs in the extent record index obtained in step S11.
The position of the desired extent record ER is determined using etof ER (FIG. 15). That is, 0 shown in FIG.
The position of the extent record ER having a predetermined number out of the numbers 63 to 63 is obtained. As a result, any one of the extent records ER shown in FIG. 17 is obtained.

Then, the process proceeds to step S13 and step S1.
2 or the first extent descriptor (FIG. 16) in the extent record obtained in step S10 is sequentially obtained, and the extent descriptor near the first condition satisfying the following conditions is obtained. That is, a value obtained by modulo addition of the byte offset designated in step S1 by the number of bytes of one allocation block, that is, a remainder obtained as a result of dividing the byte offset by the number of bytes of one allocation block is obtained. Furthermore, the number of blocks (number of blocks) in the extent record ER is sequentially accumulated, and the accumulated number is multiplied by the number of bytes of one allocation block to obtain a value. Then, an extent descriptor satisfying the condition that the above-mentioned remainder is smaller is obtained from the multiplied value.

That is, in the example of FIG. 17, the extent record ER represented by the number 4, for example, is stored in step S
Called in 12. Then, in step S13, for example, the first extent descriptor of the extent record ER with the number 4 is obtained as one satisfying the above condition. That is, the process of step S13 determines whether the desired byte offset exists in the extent designated by which of the eight extent descriptors.

Next, in step S14, the main CPU
14 determines which allocation block contains the data designated by the desired byte offset, from the extent descriptor obtained in step S13 and the remainder.

Further, in step S15, the main CP
U14 is the step S for the magneto-optical recording / reproducing apparatus 8.
It instructs to access the position on the disk corresponding to the allocation block obtained in 14.

In step S7, the file to be searched is the extent record block E.
When it is determined that the RB does not exist, the main CPU 14
Advances to step S8, and from the extent start location of the directory record of the file obtained in step S6 and the byte offset input in step S1, a logical offset including the byte offset, that is, an allocation block including the byte offset, Ask for a number. Then, step S15
Then, the main CPU 14 instructs the magneto-optical recording / reproducing apparatus 8 to access the position on the disk corresponding to the allocation block. In the above embodiment, the data of the volume management area is buffered in the RAM 18 in advance,
Although the data is searched for and the directory is searched, the magneto-optical disk 804 may be accessed and the directory searched in each step.

FIG. 21 schematically shows the processing when searching for a file as described above. As shown in the figure, first, the root directory having the ID 2 is obtained from the description of the volume descriptor VD (FIG. 5). In the case of this example, this root directory is shown in FIG.
Of the numbers 0 to 1023 in the directory record block DRB of the management block represented by the number 4. Directory records for two directories are recorded in the directory record block DRB of the management block of number 4, and directory record blocks DRB in which sub directories are recorded exist in the management blocks of numbers 6 and 7. This is described by the Index to DRB (FIG. 8) in each directory record.

In the directory record block DRB of the management block with the number 6, a subdirectory with the name Sys whose ID is 3 is recorded. Number 7
In the directory record block DRB of the management block, the subdirectory with the name WORK of ID 5 is recorded.

Furthermore, in the directory record block DRB of the management block of No. 4,
The management information (file directory record) of the file whose name is Readme with ID 4 is also recorded.
Therefore, the file Readme can be immediately accessed from the root directory.

As described above, the Exte that composes the file
When nt is one, that is, when one file is composed of continuous allocation blocks, it is possible to immediately access from the directory record block DRB without going through the extent record ER.

On the other hand, the name De whose ID is 12
Since the file of the Vice is composed of a plurality of Extents, that is, a plurality of allocation blocks located at distant positions, from the directory record block DRB of the management block with the number 6 to the Index
will be searched via the ER (FIG. 8).

In addition, in this embodiment, the directory with the name WORK is not limited to the directory record block DRB of the management block with the number 7,
The description is sequentially performed in the directory record block DRB of the management blocks of number 8 and number 10. Then, the Index of the directory record block DRB of the management block of number 8
o The DRB (FIG. 8) further describes the directory record block DRB of the management block of number 12, and the directory record block DRB of the management block of number 12 has an ID of 2
The file management information (file directory record of FIG. 8) of the file M930908 which is 1 is described.

As described above, the file management information of the file M930908 is described in the directory record block DRB of the management block of number 12, and the management information of the directory record block DRB of the management block of number 12 is of number 8. Described in the directory record block DRB of the management block, the directory management information consisting of the directory record block DRB of the management block of number 8 and the directory record block DRB of the management block of number 7 is the management information of the management block of number 4. The link information of the management blocks numbered 7 and 8 is described in the directory record block DRB. It is described in T. Therefore, the position information of the file M930908 is the numbers 4, 7, 8, 1
It can be obtained via each directory record block DRB of the two management blocks.

As described above, the volume descriptor VD describes the management block number of the first DRB forming the root directory. Then, in the directory record recorded in the parent directory of the directory in the DRB of the management block number, the first D that constitutes the contents of the directory is recorded.
The management block number of RB is described.

If the directory is composed of a plurality of DRBs, the link information (Index to Index) indicating the directory record block forming the next part is added to the entries in the management tables of the first and middle DRBs.
next DRB) (FIGS. 10 and 11).

In this way, the position within the volume management area of the root directory is described by the volume descriptor VD (FIG. 5) that manages the entire volume, and the volume management area of the subdirectory is added to the root directory (parent directory). The position within is described. Such description is sequentially repeated to build a hierarchical directory structure.

For example, the volume descriptor VD
Indicates that the top DRB of the root directory is the management block 4 of FIG. 5, and the root directory is one directory record block D.
It can be seen that it consists of RB (Fig. 7). Index of some directory records in the root directory
o DRB (FIG. 8) describes the position of the subdirectory, and the first directory record of the DRB (FIG. 8) uses the management block number 6 as the recording position of the subdirectory. It can be seen that the subdirectory also consists of one DRB (Fig. 7).

The Index to DRB of another directory record in this root directory (FIG. 8)
Describes the position of the subdirectory, and indicates that the first directory record is the management block of number 7. The entry of the management block number 7 (FIG. 7) is the first directory record block, and the link information of this entry indicates 0008, that is, the management block number 8.

Further, it is found that the directory record block of the management block of No. 8 is an intermediate block, and the link information of this entry is 00.
The management block of number 10 is indicated by 0A (hexadecimal number). Then, it is understood that the directory record block of the management block of number 10 is the last directory record block (FIG. 7).

The two subdirectories correspond to the subdirectory names Sys and WORK in FIG. 21, respectively.

These directory record blocks D
As described above, the RB and the extent record block ERB are collectively recorded within the range of the volume management area composed of 32 consecutive clusters. That is, it is not recorded in the extent area. Therefore, it is possible to quickly obtain the directory management information and the file management information.

Further, since which allocation block of the extent area constitutes the file is recorded in the extent record block ERB of the volume management area as an extent descriptor (FIG. 16), this is recorded in the directory information. At the same time, buffering can be performed, and high-speed reading of file data becomes possible.

Therefore, the following effects can be obtained in this embodiment.

(1) Speed-up of hierarchical directory search Since the hierarchical directory information is recorded in a concentrated area (volume management area) and its structure is simple, the head of the magneto-optical device which occurs at the time of directory search is recorded. It is possible to search the directory at high speed by reducing the seek moving distance and the number of seeks. Therefore, for example, it is effective for a directory search in a case where the directory information of the recording medium that is frequently exchanged is configured not to be buffered in the memory when the recording medium is exchanged. Further, it is particularly effective for a recording medium having a slow seek time in a recording / reproducing apparatus.

(2) Efficient management of directory information The allocation block is made large (for example, 64 kilobytes) in order to prevent a decrease in the file read / write speed caused by recording file data in distributed allocation blocks. (However, since the usage efficiency of the capacity of the recording medium decreases, it is generally effective when the size of the file is large), and even when the directory uses only about 1 sector (2 kilobytes),
Since the file management unit (allocation block) is independent from the volume information management unit (volume management area) such as a directory, the volume management information such as a directory can be recorded in a relatively small area.

(3) High-speed writing when the minimum writing unit for recording such as MD is large In MD, the minimum writing unit (cluster) for recording is 6
This is much larger than 4 kilobytes, which is 512 bytes for hard disks. For this reason,
A buffer for one cluster is prepared in the memory, and the data for that buffer is written at once. Therefore, 1
Even when rewriting only the data of one part of the cluster,
It is necessary to once read the data for one cluster into the buffer, update part of the data in the buffer, and then write the data in the buffer.
In this case, the MD takes about 0.5 seconds to read and the writing takes about 0.5 seconds or more, so that it takes 1 second or more to write to the cluster. If the management information of the directory is distributed and recorded in a plurality of distant clusters, reading and writing of one cluster is required multiple times when updating the directory, which is very time consuming. .

However, in the management method of this embodiment,
One because the directory management information is concentrated
By reading the cluster, more directory management information can be read than in the above case. Therefore, the directory can be updated with a relatively small number of reads and writes, and thus in a short time.

Further, since the management area of the directory becomes small, the utilization efficiency of the cluster buffer in this area is improved. Therefore, a large amount of directory information is buffered at one time, and most of the directory search can be performed by using the data in the memory, so that the speed can be increased.

In the above embodiments, a rewritable disc was used as an example of the recording medium, but a hybrid disc in which a rewritable area and a non-writable area are mixed and recording is possible. However, in a write-once type optical disc (write-once type disc) that is not rewritable (recordable only once), directory information is already recorded in the unwritable area or the unwritable area. In this case, the directory information can be copied to a rewritable area or a new recording area, and thereafter, the directory information recorded in the area can be updated (rewritten) as needed and used. it can.

FIG. 22 shows a processing example of the format in such a case. First, in step S31, the main CPU 14 reads the TOC. This TOC
Is formed in advance in the premastered area of a hybrid disc, a premastered disc (playback-only disc), or a normal recordable / updateable MO disc. T
Identification information indicating the type of the disc is recorded in the OC, and whether the disc is a hybrid type disc, a premastered disc, or a normal MO disc is recorded from the TOC data. Can be recognized.

Therefore, in step S32, the main CPU 14 determines whether or not the currently mounted disc is a premastered disc. If it is a premastered disc, it is a read-only disc and does not need to be formatted. Therefore, step S
Proceeding to 33, the main CPU 14 executes a process (error process) that the formatting cannot be performed.

On the other hand, if it is determined that the mounted disc is not the premastered disc (a hybrid disc or a normal MO disc), the process proceeds to step S34, and the main CPU 14 causes the magneto-optical recording. The playback device 8 is instructed to create the UTOC in the recordable area. The magneto-optical recording / reproducing apparatus 8 creates a UTOC on the mounted magneto-optical disk 804 based on this instruction. And step S
In 35, the main CPU 14 determines whether or not the hybrid disc is currently mounted, and when it is determined that the hybrid disc is not the hybrid disc (TOC
(When all the areas are normal MO disks formed as recordable areas except for the recording area), the process proceeds to step S36, where the main CPU 14 instructs the magneto-optical recording / reproducing apparatus 8 to set the volume management area. Instruct to create. The magneto-optical recording / reproducing apparatus 8 is
Based on this instruction, the mounted magneto-optical disk 804
Create a new volume management area in the recordable area of.

On the other hand, in step S35,
If it is determined that the hybrid disk is currently installed, the process proceeds to step S37, and the main CPU
Reference numeral 14 instructs the magneto-optical recording / reproducing apparatus 8 to copy the volume management area. The magneto-optical recording / reproducing device 8 reads a volume management area formed in advance with pre-pits from the pre-mastered area on the magneto-optical disk 804, and copies this to the recordable area.

In this way, after copying the volume management area to the recordable area,
By managing the file based on the data of the volume management area recorded in this recordable area (when recording the file in the recordable area, the management information is recorded in this volume management area) It becomes possible to centrally manage the file previously recorded in the area and the file newly recorded in the recordable area.

FIG. 23 schematically shows how a volume management area recorded in advance in a premastered area formed of prepits is copied to a recordable area in a hybrid disc.

In this embodiment, files 1 and 2 are recorded in the premastered area, and file 3 is recorded in the recordable area. In the volume management area copied to the recordable area, files 1 and 2 in the premastered area
The directory management information and the file management information are recorded in advance. By updating this to include the directory management information and the file management information of the file 3 newly recorded in the recordable area and recording it in the recordable area, the pre-mastered area can be used by using this volume management area. It becomes possible to centrally manage all files recorded in the recordable area.

FIG. 24 shows a processing example of a write-once disc (write-once disc). In this case, in step S51, a session is added. Here, a session is a unit of information recorded at one time. Next, in step S52, the volume management area recorded in the immediately preceding session is read out, and the contents thereof include the directory management information and the file management information of the file added in step S51. Added to the
Record.

FIG. 25 schematically shows the operation of additionally recording the session in this way. That is, session 1
In, file 1 and file 2 are recorded,
At this time, the volume management area including the directory management information for managing the files 1 and 2 and the file management information is simultaneously recorded in the session 1. Then, when the file 3 is recorded next in the session 2, the volume management area of the session 1 is read, the directory management information and the file management information of the file 3 are added thereto, and the data of the file 3 is recorded in the session 2. To do.

Further, in the case of recording the files 4 and 5 in the session 3, in addition to these data, the volume management area of the session 2 is read out, and the directory management information and the file management of the files 4 and 5 are read into this. Information is added and Session 3 is set as a new volume management area.
Add to.

Thus, each time a new session is formed, the volume management area is updated and newly recorded so that the file can be managed based on the volume management area of the latest session. , Can read the files of all sessions.

In the case of this embodiment, since the volume management area is recorded every time a new session is formed, the capacity for recording the original information of the disc becomes small. Therefore, in the case of this embodiment, as many files as possible are combined into one.
It is preferable to record as one session.

As described above, even when the volume management area is copied, since this volume management area is formed in one cohesive area, the copy processing is recorded with the directory management information distributed. It is possible to complete more quickly than the case where

In addition, Index to D shown in FIG.
RB, Index to ER, and Ind shown in FIG.
Since the position information such as ex to ERB is represented by the relative position (number of the management block) in the volume management area, the position information can be used as it is even in a newly copied area. In addition, by using the relative position in the volume management area in this way, the number of bits required to express the relative position is smaller than that in the absolute position including the extent area. It can be used less, and the disk usage efficiency can be improved accordingly.

As described above, the present invention is applied to a magneto-optical disk.
The case of recording or playing information has been explained as an example,
In addition, the present invention can be applied not only to an information recording medium such as a magnetic disk that has a fast access but also to an optical disk and other information recording media that have a relatively slow access.

[0180]

As described above, according to the present invention, the following effects can be obtained.

According to the information management method of the first aspect and the data recording method of the fifteenth aspect, the subdirectory information is recorded in the second area including the information indicating the position in the second area. It Therefore, the number of physical reads and writes for updating the directory is reduced,
Given a directory file in a hierarchical directory,
You can search easily and fast. Moreover, the directory information can be updated in a short time.

Further, since the relative recording position in the second area of the subdirectory is described in the directory management information, even if the directory management information is recorded in another area, the recording is performed. The position can be used as it is. In addition, the recording position is set to the second
It is possible to reduce the amount of data required to represent that position, as compared with the case where it is represented not only by the area but also by the absolute position including the first area. It is possible to increase the data capacity and improve the utilization efficiency of the recording medium.

According to the data recording medium of the eighth aspect, the subdirectory information is recorded in the second area. Then, the subdirectory information includes information indicating the position in the second area. Therefore, it is possible to realize a data recording medium that can be searched easily and at high speed.

According to the information retrieving method of the twenty-second aspect and the information retrieving apparatus of the twenty-sixth aspect, the root directory is accessed from the position information of the second area, and based on the file position information in the root directory. , The file is accessed.

According to the information search method of the twenty-third aspect and the information search apparatus of the twenty-seventh aspect, the root directory is accessed from the first position information of the second area, and the root directory and the parent directory are accessed. Second
The subdirectory is accessed based on the location information of. Then, the file is accessed based on the file position information in the subdirectory.

According to the information retrieving method of the twenty-fourth aspect and the information retrieving apparatus of the twenty-eighth aspect, the root directory is accessed from the first position information of the second area, and the root directory and the parent directory are accessed. Second
The subdirectory is accessed based on the location information of. Then, the file extent information is accessed based on the third position information in the subdirectory,
Further, the file is accessed based on the file extent information.

Therefore, in either case, simple and quick access is possible.

According to the information management method of the thirtieth aspect, when the recordable area is initialized, the directory management information recorded in the non-rewritable area is copied to the recordable area. The information is managed based on the directory management information of. Therefore, the information in the recordable area and the non-rewritable area can be centrally managed.

According to the information management method of the thirty-second aspect, when data is recorded in the second area, new directory management information including the directory management information recorded in the first area is recorded, Thereafter, information is managed based on this new directory management information. Therefore, it is possible to centrally manage old information and additional information.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an information processing apparatus to which an information management method of the present invention is applied.

FIG. 2 is a block diagram showing a configuration example of a magneto-optical recording / reproducing apparatus in the embodiment of FIG.

3 is a diagram illustrating a format of the magneto-optical disk 804 of FIG.

FIG. 4 is a diagram illustrating the format of the data track of FIG. 3;

5 is a diagram illustrating a format of a volume management area in FIG.

6 is a diagram illustrating the configuration of the volume space bitmap of FIG.

7 is a diagram showing a configuration of a management table of FIG.

8 is a diagram illustrating directory records that form the directory record block of FIG. 5. FIG.

9 is a diagram illustrating a format of a directory record block entry of the management table of FIG.

10 is a diagram illustrating a format of a directory record block entry of the management table of FIG.

11 is a diagram illustrating a format of a directory record block entry of the management table of FIG.

12 is a diagram illustrating a format of a directory record block entry of the management table of FIG.

13 is a diagram illustrating a format of an extent record block entry of the management table of FIG.

14 is a diagram illustrating a configuration of an extent record block of FIG.

15 is a diagram illustrating the format of an extent record index of FIG.

16 is a diagram illustrating a format of the extent descriptor of FIG.

FIG. 17 is a diagram illustrating a relationship between an index of an extent record block and an extent record.

FIG. 18 is a flowchart illustrating an operation of the embodiment of FIG.

FIG. 19 is a flowchart following FIG.

FIG. 20 is a flowchart following FIG. 19.

FIG. 21 is a diagram illustrating a processing operation of FIGS. 18 to 20.

FIG. 22 is a flow chart illustrating an operation at the time of formatting the magneto-optical disk.

FIG. 23 is a diagram of a hybrid disc explaining the processing shown in the flowchart of FIG. 22.

FIG. 24 is a flowchart illustrating a recording process of a write-once type disc.

FIG. 25 is a diagram illustrating a process of the flowchart of FIG. 24.

[Explanation of symbols]

 8 magneto-optical recording / reproducing device 10 input device 12 microcomputer 14 main CPU 800 interface 802 spindle motor 804 magneto-optical disk 806 optical pickup 808 magnetic head 809 magnetic head drive circuit 820 system control CPU

Claims (32)

[Claims] 1. An information management method for managing information recorded on a recording medium, comprising: using a first management information, a first area on a recording medium in which file data is recorded. The second area on the recording medium, which is managed in the allocation unit and is distinguished from the first area, is assigned a second allocation independent of the first allocation unit by using the second management information. The sub-directory information in the directory which is managed in units and is composed of at least one of the second allocation units in the second area is the second allocation unit of the second allocation unit which constitutes the sub-directory. An information management method characterized by including information indicating a position in an area. 2. The information management method according to claim 1, wherein the second allocation unit is smaller than the first allocation unit. 3. When one file is composed of a plurality of first allocation units at a plurality of remote positions, the second allocation unit
The data recorded in the area of
The information management method according to claim 1, further comprising file extent information indicating which of the first allocation units in the first area is configured. 4. The file information corresponding to the one file in the directory includes information indicating a position of the second allocation unit including the file extent information in the second area. The information management method according to claim 3. 5. When one file is composed of consecutive first allocation units, the file information corresponding to the one file in the directory is such that the one file has the first area. The information management method according to claim 1, further comprising file position information indicating which of the first allocation units of the file position information is included. 6. One directory includes a plurality of the second directories.
2. The second management information includes link information indicating that the plurality of second allocation units are mutually linked information when configured by the allocation unit. Information management method described in. 7. The data recorded in the second area comprises:
The information management method according to claim 1, further comprising information indicating a position of the root directory in the second area. 8. A data recording medium in which data having a hierarchical directory structure is recorded, in which data of a file is recorded in a first allocation unit in a first area, and a second area is distinguished from the first area. , A plurality of directories are recorded in a second allocation unit independent of the first allocation unit, and the subdirectory information in each directory is the second allocation unit of the subdirectory. A data recording medium including information indicating a position in the second area. 9. The data recording medium according to claim 8, wherein the second allocation unit is smaller than the first allocation unit. 10. When one file is composed of a plurality of first allocation units located at a plurality of distant positions, the data recorded in the second area is stored in the one file as the first allocation unit. 9. The data recording medium according to claim 8, further comprising file extent information indicating which one of the first allocation units of the area is included. 11. The file information corresponding to the one file in the directory includes information indicating a position of the second allocation unit including the file extent information in the second area. Claim 1
The data recording medium described in 0. 12. One file is a series of the first files.
, The file information corresponding to the one file in the directory is 1
9. The data recording medium according to claim 8, wherein one file includes file position information indicating which of the first allocation units of the first area is configured. 13. When one directory is composed of a plurality of the second allocation units, the management information in the data recorded in the second area is a plurality of the second allocation units. 9. The data recording medium according to claim 8, further comprising link information indicating that the information is mutually connected. 14. The data recording medium according to claim 8, wherein the data recorded in the second area includes information indicating the position of the root directory in the second area. 15. A data recording method for recording data having a hierarchical directory structure on a recording medium, wherein data of a file is recorded in a first allocation unit in the first area, and the first area is In the distinguished second area, a plurality of directories are recorded in a second allocation unit independent of the first allocation unit, and sub-directory information in each directory is the sub-directory that constitutes the sub-directory. A data recording method including information indicating the position of the second allocation unit in the second area. 16. The data recording method according to claim 15, wherein the second allocation unit is smaller than the first allocation unit. 17. When one file is composed of a plurality of the first allocation units located at a plurality of distant positions, the data recorded in the second area is the one file is the first allocation unit. 16. The data recording method according to claim 15, further comprising file extent information indicating which one of the first allocation units of the area is included. 18. The file information corresponding to the one file in the directory includes information indicating a position of the second allocation unit including the file extent information in the second area. Claim 1
7. The data recording method described in 7. 19. One file is a continuous first file.
, The file information corresponding to the one file in the directory is 1
The data recording method according to claim 15, wherein one file includes file position information indicating which first allocation unit of the first area is configured. 20. When one directory is composed of a plurality of the second allocation units, the management information in the data recorded in the second area is a plurality of the second allocation units. The data recording method according to claim 15, further comprising link information indicating that the information is mutually connected. 21. The data recording method according to claim 15, wherein the data recorded in the second area includes information indicating a position of the root directory in the second area. 22. A first area on a recording medium in which file data is recorded is managed in a first allocation unit by using first management information, and is distinguished from the first area. The second area on the recording medium is managed in a second allocation unit that is independent of the first allocation unit using the second management information, and at least one of the second areas in the second area is managed. The subdirectory information in the directory composed of two allocation units is desired from a recording medium adapted to include information indicating the position of the second allocation unit forming the subdirectory in the second area. In the information retrieving method for retrieving the file, the root directory is accessed based on predetermined position information in the data recorded in the second area, and the desired file in the root directory is accessed. Accessing the desired file on the recording medium based on file position information indicating which of the first allocation units of the first area the desired file in the file information for Information retrieval method characterized by. 23. A first area on a recording medium in which file data is recorded is managed in a first allocation unit by using first management information, and is distinguished from the first area. The second area on the recording medium is managed in a second allocation unit that is independent of the first allocation unit using the second management information, and at least one of the second areas in the second area is managed. The subdirectory information in the directory composed of two allocation units is desired from the recording medium adapted to include the information indicating the position of the second allocation unit forming the subdirectory in the second area. In the information retrieving method for retrieving a file, the root directory is accessed based on the first position information in the data recorded in the second area, and the second directory in the root directory and the parent directory is accessed. The subdirectory containing the file information corresponding to the desired file is accessed based on the location information, and the desired file in the file information corresponding to the desired file in the subdirectory is stored in the first area. An information retrieval method, characterized in that the desired file on the recording medium is accessed based on file position information indicating which first allocation unit is configured. 24. A first area on a recording medium on which file data is recorded is managed in a first allocation unit using first management information, and is distinguished from the first area. The second area on the recording medium is managed in a second allocation unit that is independent of the first allocation unit using the second management information, and at least one of the second areas in the second area is managed. The subdirectory information in the directory composed of two allocation units is desired from a recording medium adapted to include information indicating the position of the second allocation unit forming the subdirectory in the second area. In the information retrieving method for retrieving a file, the root directory is accessed based on the first position information in the data recorded in the second area, and the second directory in the root directory and the parent directory is accessed. The subdirectory containing the file information corresponding to the desired file is accessed based on the location information, and the desired directory is accessed based on the third position information in the file information corresponding to the desired file in the subdirectory. File extent information indicating which first allocation unit of the first area is composed of the first area, and accesses the desired file on the recording medium based on the file extent information. Information retrieval method characterized by the following. 25. The data recorded in the second area is read from the recording medium, the data recorded in the read second area is stored in a memory, and access to the root directory is performed. 25. The data stored in the memory is used to access a sub-directory and / or to access the file extent information.
Information retrieval method described in. 26. A first area on a recording medium in which file data is recorded is managed in a first allocation unit using first management information, and is distinguished from the first area. The second area on the recording medium is managed in a second allocation unit that is independent of the first allocation unit using the second management information, and at least one of the second areas in the second area is managed. The subdirectory information in the directory composed of two allocation units is desired from a recording medium adapted to include information indicating the position of the second allocation unit forming the subdirectory in the second area. In the information retrieving device for retrieving the file, means for accessing the root directory based on predetermined position information in the data recorded in the second area, and the desired file in the root directory. To the desired file on the recording medium based on the file position information indicating which of the first allocation units of the first area the desired file in the file information corresponding to An information retrieving apparatus comprising: an access unit. 27. A first area on a recording medium on which data of a file is recorded is managed in a first allocation unit using first management information, and is distinguished from the first area. The second area on the recording medium is managed in a second allocation unit that is independent of the first allocation unit using the second management information, and at least one of the second areas in the second area is managed. The subdirectory information in the directory composed of two allocation units is desired from a recording medium adapted to include information indicating the position of the second allocation unit forming the subdirectory in the second area. In the information retrieving device for retrieving the file, the means for accessing the root directory based on the first position information in the data recorded in the second area, and the root directory and the parent directory. Means for accessing a sub-directory containing file information corresponding to the desired file based on the second position information; and the desired file in the file information corresponding to the desired file in the sub-directory. And a means for accessing the desired file on the recording medium based on file position information indicating which first allocation unit of the first area is configured. . 28. A first area on a recording medium in which file data is recorded is managed in a first allocation unit using first management information, and is distinguished from the first area. The second area on the recording medium is managed in a second allocation unit independent of the first allocation unit using the second management information, and at least one of the second areas in the second area is managed. The subdirectory information in the directory composed of two allocation units is desired from a recording medium adapted to include information indicating the position of the second allocation unit forming the subdirectory in the second area. In the information retrieving device for retrieving the file, the means for accessing the root directory based on the first position information in the data recorded in the second area, and the root directory and the parent directory. Means for accessing a sub-directory containing file information corresponding to the desired file based on the second position information; and third position information in the file information corresponding to the desired file in the sub-directory. A means for accessing file extent information indicating which of the first allocation units of the first area the desired file is composed of, and a means for accessing the file extent information on the recording medium based on the file extent information. An information retrieving apparatus comprising means for accessing the desired file. 29. The route further comprises means for reading data recorded in the second area from the recording medium, and memory for storing the data recorded in the second area read. 29. Accessing a directory, accessing the subdirectory, and / or accessing the file extent information is performed using data stored in the memory.
Information retrieval device described in. 30. A recordable area in which information can be recorded and a non-rewritable area in which information once recorded cannot be rewritten, and directory management information is recorded in the non-rewritable area. An information management method for an information recording medium, wherein when the recordable area is initialized, the directory management information recorded in the non-rewritable area is copied to the recordable area, and thereafter the recordable area is recorded. An information management method characterized by managing information based on the above directory management information. 31. The information recording medium comprises a hybrid disc having an optically reproducible read-only area in which information is pre-recorded as pre-pits and a magneto-optically rewritable recording area. 31. The information management method according to claim 30, wherein the directory management information is recorded in the reproduction-only area. 32. An information management method for a write-once type information recording disc capable of recording information only once, wherein predetermined data and directory management information for managing the data are recorded in a first area. After that, the second data
When recording in the area, the new directory management information including the directory management information recorded in the first area is recorded in the second area, and thereafter, the directory management in the second area. An information management method characterized by managing data based on information.