JP2831369B2 - Information recording / reproducing method and system - Google Patents

Description

The present invention relates to an information recording / reproducing method and system.
In particular, the present invention relates to an information recording / reproducing method and system capable of improving the utilization efficiency of an information recording medium and reducing the number of read / write accesses to the information recording medium.

2. Description of the Related Art Conventionally, as a method of using an information recording medium such as a write-once optical disk memory as a large-capacity file memory, for example, a method described in JP-A-61-22488,
-156936.

In the former method, a data file is recorded on a write-once optical disc memory and a file directory (data file management information) is recorded, and read / write is performed in file units. In the latter method, the write-once optical disc memory is divided and managed in a new data recording area, an updated data recording area, and an updated data list recording area, and a file is read / written in block units.

[Problem to be Solved by the Invention] In the prior art described in the above-mentioned Japanese Patent Application Laid-Open No. 61-22488, the start address of the data file is indicated as the address information of the data file among the contents of the file directory record. However, there is a problem in that the data file has only the size of the data file, and new registration / update of the file must be performed in a sequential file unit.

In the prior art described in JP-A-56-156936, instead of writing update data to the same block on a write-once optical disc, data is written to an update data recording area, and the update information is updated. File access in block units is realized by writing to the list recording area. In this method, a non-volatile memory is provided in the external control system body, and the update data list is recorded at an appropriate time. For this reason, there has been a problem that the system must constantly monitor the replacement of the optical disk medium, the disconnection of the power supply, and the like.

[Means for Solving the Problems] In order to solve the above-mentioned problem, in the present invention, the information recording medium is divided and managed into a data file recording area and a file directory recording area, and are scattered as random blocks on the information recording medium. The file management information including the address information of the data file is recorded in the head unrecorded block of the file directory recording area. Using the file directory data recorded in the file directory recording area, a virtual block device that can be randomly accessed is constructed in the system main body memory. The virtual random block device referred to here is a file entry table in which file entries of a size necessary and sufficient for performing a file search are collected, and blocks in a file to be read / written are scattered at any position on the virtual device. And a data file address table indicating which address block of the information recording medium on which information is actually recorded / reproduced corresponds to each block on the virtual device. It is composed.

All file recording is done through a virtual device. The data file is sequentially written to the first unrecorded block of the data file recording area of the information recording medium, and all the file management information of the data file scattered on the information recording medium is processed on the virtual device, and when the file is closed Collects all the management information (corresponding to the file out of the three table data of the virtual device) of the file and records it in the first unrecorded block of the file directory recording area of the information recording medium. Therefore, the file directory data has not only the file address information on the information recording medium but also the corresponding data of the block address between the information recording medium and the virtual device.

All reading of the file is performed through the virtual device. All of the file search and address acquisition on any block information recording medium of the file are processed on the virtual device, and the data of the target block can be read.

[Operation] All recording of files is performed through a virtual device. Virtual device has three tables as described above
It consists of a block link table, a file entry table, and a data file address table, and each operates as follows.

The block link table of the virtual device indicates not only the connection state of each block of the file on the virtual device but also the use / unused status of the block of the virtual device.
The size of the block link table is determined by the total number of blocks of the virtual device.

In the file entry table of the virtual device, search information of all files recorded on the information recording medium is aggregated, and in addition to searching for a file name, file entry data indicating a state such as file deletion and file update. Can also be set. When file close entry data indicating the end of file recording is written to the file entry table, data of three tables (block link table, file entry table, and file data address table) relating to the file are aggregated. , In the file directory recording area of the information recording medium. The size of the file entry table is determined by the total number of file entries of the virtual device.

The file address table of the virtual device is a table for recording the correspondence between the block address of the virtual device and the block address of the information recording medium. By updating the address correspondence data, the file address table of the information recording medium is actually recorded. Even if data is additionally written in an unrecorded block in the area, it can be seen that the data is apparently updated in the same block. The size of the file address table is determined by the total number of blocks of the virtual device.

The initialization of the above three tables is performed when the power of the system body is turned on or when the information recording medium is inserted, and only the relevant file-related portions of the table data updated by file recording or the like are updated on the basis of file close. Therefore, the power supply can be turned off and the information recording medium can be exchanged arbitrarily from the point in time when writing of all the files is completed. If all the files are finally closed, a plurality of files can be opened at the same time to read / write to an arbitrary block of an arbitrary file.

Embodiment Hereinafter, an embodiment in which the present invention is mainly applied to a write-once optical disc memory will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing system blocks of a write-once optical disc system to which the present invention is applied.

Under the control of the read / write control unit 23, the optical disc drive 22 records and reproduces a data file and a file directory of the data file on the write-once optical disc memory 21 that constitutes the write-once optical disc system 20. The interface control unit 24
By controlling the write control unit 23, the write-once optical disc memory 21
And data transfer between the external control system 25.

FIG. 1A is an explanatory view schematically showing a recording state and a virtual device structure in a write-once optical disc memory (information recording medium) according to an embodiment of the present invention. First
FIG. 2B shows the relationship between each file and the data contained therein.

As shown in FIG. 1A, a file directory recording area and a data file recording area are formed from the head (in this embodiment, the inner circumference side) of the recordable area in the optical disk memory. Each area is a fixed length area, and recording in each area is always performed on the head unrecorded block.

On the other hand, the virtual random block device is provided on the system main body memory in the external control system 25 and is constructed from a file directory recorded in a file directory recording area. This virtual device includes three tables: a block link table, a file entry table, and a data file address table. (Though the three tables are arranged in the above order in the present embodiment, they may be arranged in any other order.) Of these, the first two tables (block link table and file entry table) in the virtual device File directory recording part, file entry table contains file directory entry data including file name and data file start block address, and block link table contains data file files consisting of blocks randomly scattered on the virtual device. Chain data is respectively recorded. The data file address table placed last is a data file recording portion in the virtual device, and records the correspondence between the block address of the virtual device and the block address of the optical disk medium.

The file directory data of the optical disk memory used to construct the above three tables is the file directory entry data for file search (the same as the one recorded in the file entry table of the virtual device, the file name and the data file start block address). And file management information including file block chain data of files scattered and recorded on the optical disk memory and the virtual device.
This file directory data is written to the head unrecorded block of the file directory recording area of the optical disk memory when the file is closed.

Therefore, until the file is closed, the data file is simply added to the optical disk memory, and all the file management information is processed on the virtual device. Even if the file is recorded, the actual access to the optical disk memory is limited to the data file write and the file directory write when the file is closed, and the access time is shortened. In addition, the size of the system main memory required for opening a plurality of files is fixedly determined by the size of the virtual device and is not related to the number of files, so that the system main memory can be used effectively. .

FIG. 3 is an explanatory diagram in which the recording state in FIG. 1 according to one embodiment of the present invention is applied to a write-once optical disc.

In FIG. 3, the write-once optical disc memory 31 is divided into an inner peripheral non-recordable area 32, an outer peripheral non-recordable area 33, and a recordable area sandwiched between these areas. Is divided into two areas, a file directory recording area 38 and a data file recording area 39, from the innermost circumference to the outermost circumference. In both areas, data recording is performed from the beginning (in the present embodiment, on the inner circumference side).
The file directory unrecorded area 35, the latter is a recorded data file group 36, and the data file unrecorded area
37 each. In the present embodiment, two areas, the file directory recording area 38 and the data file recording area 39, are secured with a fixed length. During writing, one or both areas remain and the unrecorded area disappears, and writing cannot be performed. If the error occurs, the disk full error processing is executed and the write operation is interrupted. Hereinafter, an embodiment will be described without considering a disk full error.

Hereinafter, the sequence of the write-once optical disc system when actually operating will be described with reference to the flowcharts shown in FIGS.

FIG. 4 is a flowchart showing a sequence at the time of turning on the power (at the time of startup) or at the time of replacing the optical disk medium, that is, a sequence of an initialization routine. FIG. 4 will be described below for each step.

Step 401: Initialize a virtual random block device. That is, the data of the block link table and the data file address table are all filled with SPACE indicating a blank block, and the data of the file entry table are all filled with no entry indicating no entry.

Step 402: The directory data is sequentially read from the head unread block of the file directory recording area of the optical disk memory and stored in the system buffer.

Step 403: If directory data is stored in the system buffer, the process proceeds to step 404 to construct a virtual device using the data.If not, all file management information is reflected in the virtual device. Therefore, the process proceeds to step 406 and ends.

Step 404: Among the file directory data stored in the system buffer, data (file name, file creation date and time, final size,
The file start block address, etc.) is stored in the first free entry area (the area containing no entry data) of the file entry table.

Step 405: Of the upper file directory data,
The file chain data indicating which blocks on the optical disk memory or the virtual device are scattered in the data file is taken out, the block chain data on the virtual device is stored in the block link table, and the block of the virtual device is The corresponding data of the block of the optical disk memory is stored in the data file address table.

Step 406: end.

FIG. 5 and FIG. 6 are flowcharts showing a sequence when writing a data file. Less than,
5 and 6 will be described for each step.

Step 501: Search whether a file name identical to the write file name has already been entered in the file entry table of the virtual device.

Step 502: If there is an entry with the same file name, it means that the file is updated. Therefore, the process proceeds to step 503 to apparently delete the old file (delete the entry on the virtual device). If the same name does not exist, the process proceeds to 505 to write the data file.

Step 503: Obtain the file start block address of the old file from the corresponding file entry data, sequentially read data from the corresponding block link table,
The table contents are filled with SPACE data until EOF (end of file) data indicating the end of the file is read. As a result, all blocks on the virtual device occupied by the old file can be reused.

Step 504: Store noeytry data instead of the corresponding file entry data. As a result, the file entry area occupied by the old file can be reused.

Step 505: The data of the block link table is sequentially read, and if SPACE data is obtained, it indicates that the block is writable, so that the block is set as a write block of the data file in the virtual device.

Step 506: Write a data file in the first unrecorded block of the data file recording area of the optical disk memory.

Step 507: The address of the block actually written in the optical disk memory is stored as data in the block of the data file address table corresponding to the write block in the virtual device set in step 505.

Step 508: If there is an unwritten data file, go to step 509; otherwise, go to step 510.

Step 509: The block number having the next SPACE data is stored as data in the block of the block link table corresponding to the write block in the virtual device set in step 505, and the process proceeds to step 505.

Step 510: Since all data files have been written, the EOF data indicating the end of the file is stored in the block of the block link table corresponding to the write block in the virtual device set in step 505.

Step 511: The data of the file entry table is sequentially read, and if no entry data is obtained, the entry area is usable, so that file directory data such as the file name of the written file and the file start block address are stored.

Step 512: The data of the block of the written file is acquired from the block link table and the data file address table, and file chain data composed of a chain of [virtual device block, optical disk memory block] is created.

Step 513: The file directory data stored in step 511 and the file chain data created in step 512 are written in the head unrecorded block of the file directory recording area of the optical disc memory.

Step 514: End.

FIG. 7 is a flowchart showing a sequence for reading a data file. Hereinafter, FIG. 7 will be described for each step.

Step 701: Read the file entry table of the virtual device and search for a file name identical to the read file name.

Step 702: If the same file name exists, the process proceeds to step 703; otherwise, the process proceeds to step 707.

Step 703: A file start block that can be obtained from the file directory data of the file is set as a read block.

Step 704: Obtain the block address of the optical disk memory from the data of the corresponding block in the data file address table, and read the data file.

Step 705: The number of the next block in the chain is acquired from the corresponding block data in the block link table, and is set as the next read block.

Step 706: If there is a data file that has not been read yet, proceed to step 704; otherwise, proceed to step 708.

Step 707: Since there is no corresponding file, an error processing that there is no corresponding file is performed.

Step 708: End.

Each routine shown in FIGS. 4 to 7 is an example, and preferably, a virtual device of a fixed size is formed from data in the file directory recording area.
The data file satisfies the three points of writing to the data file recording area for each data write command of the host system, and writing the file management information updated on the virtual device to the first unrecorded block of the file directory recording area when the file is closed. Then, any method may be used.

FIG. 8A schematically shows a recording state in a write-once optical disc memory according to a second embodiment of the present invention, and FIG. 8B shows a relationship between a file and data. Things.

In FIG. 8 (a), an FI that distinguishes a data file from a directory based on whether the file is a file having a data file or a file having file entry data of one or a plurality of files, respectively.
By setting file attributes LE and DIR and giving them to file directory data, a directory hierarchical structure is formed. The top layer of this hierarchical structure is called a root directory, and the layers below it are called subdirectories.

In order to record files in a subdirectory, a subdirectory must be created in advance. Subdirectories have DI as their file attribute
Reading and writing can be performed in the same sequence as a normal data file except that it has R data.
However, the data file must be file directory entry data written in the same format as the file entry table. When creating a new subdirectory, all data files are no ent
It must be filled with ry data.

On the other hand, the root directory indicates the file entry table, and is automatically created at the time of initialization.

The files directly contained in the root directory are necessary to configure the file entry table at initialization. On the other hand, the files included in the sub-directory are irrelevant to the configuration of the file entry table. Therefore, the file directory data recorded in the file directory recording area of the optical disk memory includes a ROOT that distinguishes between a file in the root directory and a file in the sub-directory. , SUB file attributes. The data file address table also has DIR, FI so that it can be distinguished whether the data file to be written is a normal data file or directory entry data.
Give LE attribute.

Hereinafter, the sequence of the write-once optical disc system using the hierarchical directory will be described with reference to the flowcharts of FIGS.

FIG. 9 is a flowchart showing a sequence at the time of turning on the power or replacing the optical disk memory, that is, a sequence at the time of initialization. Hereinafter, FIG. 9 will be described for each step.

Step 901: Initialize a virtual random block device. That is, all data in the block link table and data file address table are filled with SPACE, and all data in the file entry table are filled with no entry.

Step 902: Unread data in the file directory recording area is sequentially read and stored in a buffer of the system main body.

Step 903: If there is file directory entry data in the buffer, go to step 904; otherwise go to step 908.

Step 904: If there is SUB in the file attribute of the file directory entry data in the buffer, go to step 906, otherwise go to step 905.

Step 905: Since the file attribute is ROOT and the file entry table needs to be constructed, the directory entry data including the file name, the file start block, and the file attribute (the attribute of FILE or DIR) from the file directory entry data Is stored in the first free entry area of the file entry table.

Step 906: Take out the file chain data from the file directory entry data and construct a block link table.

Step 907: The file chain data is taken out of the file directory entry data, and a file attribute (FILE or DIR) is added to construct a data file block table.

Step 908: End.

Next, a description will be given of a file read / write sequence. At this time, a file name is specified in the following format.

＼SUB1＼SUB2＼… ＼SUBN＼FILE1 ＼ (backslash) is a separator that indicates the delimitation of the directory name or file name, SUB1, SUB2,…, S
UBN indicates a subdirectory name, and FILE1 indicates a file name. Here, the part {SUB1} SUB2} ... {SUBN} is called the path name part, and the part {FILE1} is called the file name part.

In reading / writing a file, a path name portion is searched one by one in order to search for the file.

FIG. 10 to FIG. 12 are flow charts showing the sequence when reading a data file. Among these, there is a routine called "single-layer file read subroutine", which is a routine for searching for a file having a given read file name from a given search target buffer and reading a data file. This routine is used when the path name part is searched by dividing it by each subdirectory name.

 10 to 11 will be described for each step.

Step 1001: The file entry table of the virtual device is set in the file name search target buffer.

Step 1002: If there is a path name portion in the read file name, the process does not proceed to step 1003, which means that the analysis of the path name portion has been completed. Therefore, the process proceeds to step 1008 to read the target file.

Step 1003: In the path name portion, the first path name (backslash with directory name) is set as a temporary read file name.

Step 1004: Delete the leading path name from the path name part.

Step 1005: Execute the single-layer file read subroutine (see the description of FIG. 12 for details) using the already set search target buffer and the temporary read file name as arguments, and obtain the presence or absence of an error and the data file in the buffer. .

Step 1006: If the subroutine executed in step 1005 returns an error, it means that there is no corresponding path name, so the flow shifts to step 1012 to perform error processing.

Step 1007: Since the contents of the buffer obtained in the subroutine of step 1005 are a file directory entry data group having a path name, this is newly set as a file name search target buffer, and the process proceeds to step 1002.

Step 1008: Since all the analysis of the path name part is completed, the file name part is set to the read file name.

Step 1009: A single-layer file read routine is executed by using the already set search target buffer and read file name as arguments.

Step 1010: If there is an error in the execution of the subroutine of step 1009, proceed to step 1012; otherwise, go to step 1012.
Move to 11.

Step 1011: Since the contents of the buffer obtained in the subroutine of step 1009 are the data file of the target file, this is set as the read data file.

Step 1012: Among the specified file names, since the corresponding name did not exist during the analysis of the path name portion or the file name portion, error processing without the corresponding file is collectively performed.

Step 1013: Terminate.

FIG. 12 shows a subroutine sequence for reading a file in the single-layer directory used in FIGS. 10 to 11.

 FIG. 12 is described for each step.

Step 1201: Search for a read file name from the search target buffer.

Step 1202: If there is a corresponding file name, step 120
If not, go to step 1207.

Step 1203: The file start block obtained from the file directory data of the corresponding file is set as the block to be read.

Step 1204: Obtain the block address of the optical disk memory from the data of the corresponding block in the data file address table, and read the data file.

Step 1205: Obtain the number of the next chained block from the corresponding block data in the block link table and set it as the next read block.

Step 1206: If there is a data file that has not been read yet, proceed to Step 1204; otherwise proceed to Step 1208.

Step 1207: Since there is no corresponding file, an error process is performed to determine that there is no corresponding file.

Step 1208: end.

Next, the file write sequence will be described.
Since it is the same as that shown in FIG. 6 and FIG. 6, it is omitted here. Therefore, only the file write sequence in the subdirectory will be described for each step with reference to FIGS.

Step 1301: The path name portion of the write file name is set to a temporary read file name.

Step 1302: Using the temporary read file name set in step 1301, a subroutine call is made to the file read routine shown in FIGS.

Step 1303: If an error indicating that there is no corresponding file is returned, it means that the path name part does not exist. If there is no error, the process proceeds to step 1304.

Step 1304: The data file of the read path name portion is set as a file search target buffer.

Step 1305: Search for the file name portion of the write file in the search target buffer.

Step 1306: If there is the same file name, proceed to step 1308, otherwise proceed to step 1310.

Step 1307: Perform error processing without a corresponding path name.

Step 1308: All block data of the block link table corresponding to the corresponding file name is filled with SPACE.

Step 1309: Delete the entry of the file from the search target buffer and make it no entry data.

Step 1310: Search for the first block having SPACE data in the block link table and set it as the write block.

Step 1311: Write the data file to the head unrecorded block of the data file recording area.

Step 1312: The block address of the optical disk memory written in step 1311 is stored in the corresponding block of the data file address table.

Step 1313: If there is still an unwritten data file, proceed to step 1314; otherwise, proceed to step 1315.

Step 1314: The block number having the next SPACE data is stored as data in the corresponding block of the block link table, and the routine goes to Step 1310.

Step 1315: Store EOF in the corresponding block of the block link table.

Step 1316: Store the directory entry data of the written file in the head no entry area of the search target buffer and write it to the head unrecorded block of the data file recording area.

Step 1317: The data of the data file address table corresponding to the block from which the data of the search target buffer has been read is set to the block address of the optical disk memory written in step 1316.

Step 1318: Create file chain data of the written data file from the block link table and the data file address table.

Step 1319: An attribute SUB (meaning a file created in a subdirectory) is added to the file directory entry data written in step 1316 and the file chain data created in step 1318, so that the first Write to recording block.

Step 1320: Create a file directory entry and file chain data of a file (a file represented by the last path name of the path name portion) having the block from which the data of the search target buffer has been read.

Step 1321: An attribute DIR (indicating a subdirectory file) is added to the data created in step 1320, and the data is written in the head unrecorded block of the file directory recording area.

Step 1322: End.

According to this embodiment, files can be managed in a hierarchical structure, so that even files with the same name can be managed simultaneously in different hierarchies.

ROOT / SUB, FIL is used to identify the hierarchical directory structure.
Give attribute E / DIR, the former at the time of initialization,
The latter is used when creating the file entry data and the data file address table, respectively, but the recording in the file directory recording area may be performed on the basis of writing the data directly to the block having the attribute of DIR. . In this way, the two system interfaces of data exchange between a file and a virtual device and data exchange between a virtual device and an optical disk memory can be completely separated, and a more efficient system can be designed.

FIG. 16 is a diagram schematically showing a recording state in a write-once optical disc memory according to a third embodiment of the present invention.

Since the optical disk memory is a large-capacity memory, an arbitrarily large number of block tables are required to arbitrarily access the entire capacity, and the ratio of the virtual device occupying the system main body memory increases. Here, a block of the minimum size that can be read from and written to the optical disk memory is called a sector, and a collection of a plurality of sectors is called a block (for example, one block = 32 sectors).

The optical disk memory can be read / written in sector units, and the virtual device can read / write in block units.
If writing is possible, a large capacity optical disk memory can be managed efficiently.

In FIG. 16, based on whether the sector address data sequence (address arrangement of the corresponding sectors on the optical disk memory) of the virtual block is a sequential sequence or a random sequence, SEQ, RA
The attribute N is given and stored in each block data of the data file address table.

The sector address data string of the block used in the file write is stored in a buffer in the system body called a block structure table. When the file is closed, the structure in the table is converted into a data file address table and recorded on the optical disk memory. The conversion means that in the case of a sequential column, the attribute of SEQ and the head address are stored as data address table data,
In the case of a random column, the contents of the table (random sector address data column) are recorded in the first unrecorded sector of the data file recording area, and the RAN attribute and the address recorded in the optical disk memory are stored as data address table data. Work. For the sequential file, the number of used sectors may be stored in the data file address table together with the start address.
After the completion of the conversion, the file chain data shown in FIG. 1 can be used with the attribute data of SEQ and RAN.

As described above, the size of the virtual device is determined only by the number of blocks while the data file is recorded on the optical disk memory in sector units, so that the load on the system main body memory is reduced.

Also, at the time of reading a data file, the data file can be obtained in the same manner as the read sequence shown in FIG. 1 by reversely converting the corresponding block data in the data file address table into a block structure table.

The initialization sequence can be performed in exactly the same manner as the sequence shown in FIG. 1, except that SEQ and RAN attributes are added to the file chain data.

FIGS. 17 and 18 are flowcharts showing the sequence when writing a data file. Figures 17-18
The figure will be described for each step.

Step 1701: A search is made as to whether a file name identical to the write file name has already been entered in the file entry table of the virtual device.

Step 1702: If there is an entry with the same file name, go to step 1703. Otherwise, go to step 1705.

Step 1703: Obtain the file start block of the old file from the corresponding file entry data, and fill the corresponding block link table data with SPACE.

Step 1704: Erase applicable old file entry, n
o Store the entry.

Step 1705: First SPA in block link table
Set the CE block as the write block.

Step 1706: Write the data file to the head unrecorded sector of the data file recording area of the optical disk memory.

Step 1707: The sector address actually written in step 1706 is stored as data in the first SPACE sector of the block structure table corresponding to the write block in the virtual device set in step 1705.

Step 1708: If there is still an unwritten data file, proceed to step 1709; otherwise, proceed to step 1711.

Step 1709: If there is a SPACE sector in the block structure table corresponding to the write block in the virtual device set in step 1705, the process proceeds to step 1706; otherwise, the process proceeds to step 1710.

Step 1710: A block number having the next SPACE data is stored as data in the block link table corresponding to the write block in the virtual device set in step 1705, and the process proceeds to step 1705.

Step 1711: The EOF is stored in the block link table corresponding to the write block in the virtual device set in step 1705.

Step 1712: Convert the block structure table created for writing the corresponding file and store it in the data file address table.

Step 1713: beginning of file entry table no entr
Store the file directory entry data in the y area.

Step 1714: Create file chain data of the file from the block link table and the data file address table.

Step 1715: The file directory entry data stored in step 1713 and the file chain data created in step 1714 are written in the head unrecorded block of the file directory recording area of the optical disc memory.

Step 1716: Terminate.

FIG. 19 is a flowchart showing a sequence when reading a data file. FIG. 19 is described for each step.

Step 1901: A search is made to determine whether the file entry table of the virtual device has the same file name as the read file name.

Step 1902: If there is the same file name, go to step 1903, otherwise go to step 1904.

Step 1903: Set the file start block obtained from the file directory data of the file as the block to be read.

Step 1904: Since there is no corresponding file, an error processing that there is no corresponding file is performed.

Step 1905: Invert the data file address table of the block to be read into a block structure table.

Step 1906: Data files of the optical disk memory corresponding to the read sectors are sequentially read.

Step 1907: If there is a data file that has not been read yet, go to step 1908; otherwise go to step 1910.

Step 1908: If there is a sector that has not been read yet in the read block, go to step 1906.
Move to 1909.

Step 1909: The next block number in the chain is acquired from the corresponding block data in the block link table, and is set as the next read block.

Step 1910: End.

Initialization is the same as in FIG.

As described above, reading and writing can be performed on a plurality of opened files in sector units, which is effective for data logging of a plurality of items.

FIG. 20 is a diagram schematically showing a recording state in a write-once optical disc memory according to a fourth embodiment of the present invention.

In FIG. 20, when a file is deleted, DELETE indicating that the corresponding block link table and data file address table data are all filled with SPACE as file chain data and the corresponding file in the file entry table is deleted. Is added to the file directory entry, and the file directory entry data and the file chain data are recorded in the file directory recording area. In the initialization sequence, if the data has the DELETE attribute, the corresponding file name in the file entry table is deleted and no entry is stored.

FIG. 21 is a flowchart showing a sequence when deleting (erasing) a data file. FIG. 21 is described for each step.

Step 2101: A search is made as to whether a file name identical to the write file name has already been entered in the file entry table of the virtual device.

Step 2102: If there is an entry with the same file name, go to step 2103, otherwise go to step 2104.

Step 2103: Obtain the file start block of the file to be deleted from the corresponding file entry data, and fill the corresponding block link table data with SPACE.

Step 2104: Since the corresponding file does not exist, the error processing without the corresponding file is performed.

Step 2105: Delete the corresponding file entry data and store no entry.

Step 2106: From the block link table, the data of the block related to the deleted file (all SPACE
Data) and create file chain data.

Step 2107: Create file directory entry data by adding a DELETE attribute indicating deletion to file search information including the file name of the deleted file, the deletion date and time, and the file deletion start block.

Step 2108: The file chain data created in step 2106 and the file directory entry data created in step 2107 are written to the head unrecorded block of the file directory recording area of the optical disc memory.

Step 2109: end.

When a file is deleted as described above, the file appears to be deleted from the virtual device,
Since the directory entry to which the DELETE attribute is not added is recorded in the file directory recording area of the optical disc, it is possible to completely restore the original file.

FIG. 22 is a diagram schematically showing a recording state in an erasable optical disk memory according to another embodiment of the present invention.

It is obvious that the embodiment of the write-once optical disk memory can be applied to the erasable optical disk memory as it is, but the erasable optical disk memory erases a data file that is no longer needed and writes a new data file in the same block. Therefore, the data file address table of the virtual device and the blocks of the data file recording area of the optical disk memory can be made to correspond one-to-one.

In this case, if the recording of the data file is performed on the corresponding block address of the data file recording area in the file write, the sequence becomes the same as that of the file write in the write-once optical disc memory. The read sequence and the initialization sequence are the same as in the embodiment of the write-once optical disc memory.

Thus, even in the case of an erasable optical disk memory, file search, writing of file management information, and the like are processed on the virtual device, and actual access to the optical disk memory is performed when reading / writing a data file and when closing the file. High-speed input / output of data files can be realized only by writing directory data.

In the above-described embodiment, the write-once optical disk memory can be applied to an erasable optical disk memory, a time disk medium, and a magnetic tape medium. Can be applied to magnetic disk media and magnetic tape media.

[Effects of the Invention] As described above, according to the present invention, all files are accessed through the randomly accessible virtual block device provided in the system main body memory, so that a plurality of files can be opened at the same time. Can be read from any block in the file.
You will be able to light.

In addition, since all file management information is processed on the virtual device and a table of the virtual device related to the file is recorded in the optical disk memory when the file is closed, the number of times of actually accessing the optical disk memory can be reduced. And the recording / reproducing speed can be improved. All management information of the file is reflected on the optical disk based on the file close. On the contrary, when the power is turned on or the disk is replaced, the virtual device can be initialized from the optical disk, so that the system body always controls the power on / off and disk replacement. There is no need to put it down.

Also, since each file directory data in the file directory recording area of the optical disc memory includes address information on the optical disc memory, it is particularly necessary to completely restore and read the updated old file in the write-once type information recording medium. Becomes possible.

[Brief description of the drawings]

FIG. 1, FIG. 3, FIG. 8, FIG. 16, FIG. 20, and FIG.
FIG. 2 is an explanatory view showing the information recording state of a write-once optical disc memory according to an embodiment of the present invention. FIG. 2 is a system block diagram of a write-once optical disc system to which the present invention is applied, FIG. 4 to FIG. FIG. 15, FIG. 17 to FIG. 19, and FIG. 21 are flowcharts showing a sequence for recording and reproducing data in each embodiment. 20: write-once optical disk system, 21: write-once optical disk memory, 22: optical disk drive, 23: read / write control unit, 24: interface control unit, 25: external control system, 31: write-once Type optical disk memory, 32 ... inner area non-recordable area, 33 ... outer area non-recordable area, 34 ... recorded file directory, 35 ... file directory area (unrecorded), 36 ... recorded data file, 37 ... ... Data file area (unrecorded).

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takashi Takeuchi 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (56) References JP-A-1-116819 (JP, A) JP-A Sho 62-26533 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06F 3/06 G06F 3/08 G06F 12/00 G11B 27/10

Claims (11)

(57) [Claims] 1. An information recording medium, comprising: a memory for storing a virtual random block device capable of random read / write access in block units; and recording a file on the information recording medium via the virtual random block device. An information recording / reproducing method for reproducing the data, wherein the virtual random block device has a file entry table, a block link table, and a data file address table, and records a data file on the information recording medium. When you do
The start block address of the data file on the virtual random block device and the data indicating which block of the data file is scattered on the virtual random block device are stored in the file entry table and the block link, respectively. While registering in the table, the correspondence between the address on the virtual random block device assigned to the data file and the address of the information recording medium on which the data file is recorded is registered in the data file address table, The reading of the data file recorded on the information recording medium is performed by referring to the file entry table and the block link table to specify each block constituting the data file, and to specify each of the specified blocks. An information recording / reproducing method, wherein an address of the information recording medium corresponding to an address on each of the virtual random block devices is retrieved from the file address table. 2. The information recording / reproducing method according to claim 1, wherein said information recording medium has a data file recording area for recording a data file and a file directory recording area for recording a file directory. After recording the data file in the data file recording area, file entry data, file block chain data, and address correspondence information between the virtual random block device and the information recording medium for the data file are stored in the file directory. An information recording / reproducing method characterized by recording in a recording area. 3. The information recording / reproducing method according to claim 2, wherein when a power supply of a system to which the information recording / reproducing method is applied is turned on, based on a recorded content of a file directory recording area of the information recording medium. An information recording / reproducing method for reproducing and storing the contents of a file entry table, a block link table, and a data file address table of a virtual random block device. 4. An information recording / reproducing method according to claim 2, wherein an attribute indicating a hierarchical directory structure of a file is added to said address correspondence information recorded in said file directory recording area. Playback method. 5. The information recording / reproducing method according to claim 4, wherein the attribute is for identifying whether the file is a normal data file or a directory file having a file directory as a data file. An information recording / reproducing method characterized by having a file attribute of: 6. The information recording / reproducing method according to claim 4, wherein the attribute is a file attribute for identifying in which hierarchy of the hierarchical directory the file is located. Characteristic information recording / reproducing method. 7. The information recording / reproducing method according to claim 2, wherein the blocks in the virtual random block device are obtained by collecting a plurality of sectors which are the minimum units recordable / reproducible on / from the information recording medium. An information recording / reproducing method characterized by the following. 8. The information recording / reproducing method according to claim 1, wherein, when the data file is deleted, information about the data file registered in the file entry table and the block link table is deleted. An information recording / reproducing method characterized by recording, in the file directory recording area, a file to which an attribute indicating that the attribute is added and the address correspondence information of a block that can be reused by the deletion. 9. An information recording medium having a data file storage area for rewritably recording a data file in an arbitrary block and a file directory recording area for recording a file directory of the data file, and random read / write access in block units. A memory for storing a virtual random block device capable of performing the following. An information recording / reproducing method of recording a file on the information recording medium via the virtual random block device and reproducing the file, wherein the virtual random block device Has a file entry table, a block link table, and a data file address table. When a data file is recorded in a data file recording area of the information recording medium, the virtual lander of the data file Registering the start block address on the block device and data indicating which block on the virtual random block device the data file is scattered with in the file entry table and the block link table, respectively, Registering, in the data file address table, the correspondence between the address on the virtual random block device assigned to the data file and the address of the information recording medium on which the data file is recorded, File management information including directory data, file block chain data, and address correspondence information between the virtual random block device and the information recording medium is recorded in a file directory of the information recording medium. Reading the data file recorded in the area, and reading the data file recorded on the information recording medium, by referring to the file entry table and the block link table, specifying each block constituting the data file, and An information recording / reproducing method, wherein an address of the information recording medium corresponding to an address on a virtual random block device is retrieved from the file address table. 10. An information recording medium, and a memory for storing a virtual random block device capable of random read / write access in units of blocks, wherein a file is recorded on the information recording medium via the virtual random block device. An information recording / reproducing system for performing the reproduction, wherein the virtual random block device has a file entry table, a block link table, and a data file address table, and records a data file on the information recording medium. When you do
The start block address of the data file on the virtual random block device and the data indicating which block of the data file is scattered on the virtual random block device are stored in the file entry table and the block link, respectively. Means for registering in the data file address table a correspondence between an address on the virtual random block device assigned to the data file and an address of the information recording medium on which the data file is recorded. With reference to the file entry table and the block link table, each of the blocks constituting the data file is specified, and the address of the specified block on the virtual random block device is specified. Means for reading the data file recorded on the information recording medium by retrieving the address of the information recording medium corresponding to the information from the file address table, the information recording / reproducing system comprising: . 11. The information recording / reproducing system according to claim 10, wherein the information recording medium has a data file recording area for recording a data file and a file directory recording area for recording a file directory. File entry data for the data file recorded in the data file recording area, file block chain data, and address correspondence information between the virtual random block device and the information recording medium,
An information recording / reproducing system, further comprising means for recording in the file directory recording area.