Patent Publication Number: US-2010131576-A1

Title: Information reproduction method and information reproduction apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to an information reproduction method and an information reproduction apparatus for reproducing data recorded on a disk medium, and more specifically to an information reproduction method and an information reproduction apparatus for reproducing data having a broken directory structure. 
     BACKGROUND ART 
     Data is recorded on a disk media for a variety of uses such as for use in a PC (Personal Computer) and for use in an AV (Audio and Visual). In such a case, a logical file system is generally used, and in the logical file system, recorded data is managed as files and a directory hierarchy is built. Examples of the logical file systems include a widespread FAT system, a UDF (Universal Disk Format) introduced into a DVD and the like. A storage medium such as a disk medium and a memory card on which data is recorded under the industry organization standard, the format standard complying with the global standard, the UDF standard and the like, can be reproduced in a method complying with the format standard concerned. 
       FIG. 11  illustrates an information reproduction apparatus  900  of a conventional art. In  FIG. 11 , the information reproduction apparatus  900  includes a control section  10 , a data read section  11 , and a display section  12 . The data read section  11  reads data recorded on a disk medium  20 . The control section  10  reproduces data read by the data read section  11  based on a reproduction method complying with a format standard. The display section  13  displays a directory and a file reproduced by the control section  10 . 
     Here, the directory structure in the logical file system will be described in detail.  FIG. 12  illustrates the directory hierarchy. As illustrated in  FIG. 12 , data recorded on the disk medium is managed as a file in each hierarchy in which directories are built.  FIG. 13  illustrates the directory structure in the logical file system. In  FIG. 13 , by using logical addresses indicated by pointers of a File Entry (FE) and a File Identifier Descriptor (FID), each directory hierarchy is built in the logical file system. 
     For example, a case of an access to a file  111  will be described. Initially, an FE of a root directory  0  is referenced. The FE of the root directory  0  includes FIDS of directories  1  and  2 , and a file  3 . Based on the FID of the directory  1 , an FE of the directory  1  under the root directory  0  is referenced. The FE of the directory  1  includes FIDS of a directory  11 , and files  12  and  13 . Based on the FID of the directory  11 , an FE of the directory  11  under the directory  1  is referenced. The FE of the directory  11  includes FIDS of the file  111  and a file  112 . Based on the FID of the file  111 , an FE of the file  111  under the directory  11  is referenced. Based on the FE of the file  111 , data of the file  111  can be accessed. 
     As described above, in the logical file system such as the UDF, except the root directory, the FID, the FE, and actual data are accessed in order, respectively, by using the FID and the FE as pointers. 
     In addition, there is an apparatus using management information (directory management information) related to the directory structure complying with the format standard for the above-described logical file system (e.g., see Patent Document 1). This is the apparatus which makes any directory look like the root directory for a user in order to visually display only any directories, which correspond to the processing apparatus concerned, in the directory structure recorded on the disk medium. 
     Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-182122 
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, when directory management information is broken for some reasons, a part of or all of directories and files become unable to be reproduced in the method complying with the format standard. For example, as to a video camera using a disk medium, which has been widespread in recent years, it may be considered that the recording surface is damaged due to the careless dropping. In this case, when directory management information of a directory including a video data file is broken, even though filmed video data fully remains, the video data file becomes unable to be read, so that video images cannot be reproduced at all. In this manner, when the directory management information is broken, a file may not be reproduced even though recorded data remains. 
     Specifically, when a directory structure is damaged, even though data recorded on a disk medium remains, the data is not displayed on the display section  13 .  FIG. 14  illustrates a state of the directory structure which is partially damaged. When the directory structure is damaged between the root directory  0  and the directory  1 , the directory  11  and the files  12 ,  13 ,  111  and  112  under the directory  1  cannot be reproduced even though the data thereof remains in the disk medium. Similarly, when the directory structure around the directory  2  is damaged, a directory  22 , and files  3 ,  21 ,  221  and  222  cannot be reproduced. 
       FIG. 15  illustrates the directory structure in the logical file system where the directory management information is broken. As illustrated in  FIG. 13 , when the file  111  is to be accessed, the FE of the root directory  0  is initially referenced. Here, since directory management information is broken, the FIDS included in the FE of the root directory  0  cannot be read, so that a directory and a file under the root directory  0  cannot be referenced. Accordingly, unlike the manner illustrated in  FIG. 13 , the file  111  cannot be sequentially accessed based on pointers of the FE and the FID. As a result, data of the file  111  cannot be reproduced even though the data remains in a disk medium as recorded data. 
     Therefore, an object of the present invention is to provide an information reproduction method that allows the recorded data remaining in the disk medium to be reproduced even though the directory management information is broken. 
     Solution to the Problems 
     To achieve the above objects, the information reproduction method of the present invention for reproducing data which is recorded on an information storage medium based on a logical file system where a directory structure is constructed by using logical addresses and a storage location of the data is indicated based on a root directory executes: in the case where the recorded data becomes unable to be reproduced in a method based on the logical file system, a virtual root directory creation step of reading the recorded data by using a physical address, extracting, based on information related to the directory structure and included in the read data, every directory whose higher-order directory is not found, and setting all of the extracted directory as the root directory; and a reproduction step of reproducing, in the method based on the logical file system, a file under the virtual root directory based on the virtual root directory. 
     It is preferable that the virtual root directory creation step executes: a read-in-units step of reading data recorded on the information storage medium from which the recorded data has become unable to be reproduced in the method based on the logical file system, in units of a plurality of sectors as sector data; a directory structure determination step of determining whether or not a plurality of pieces of the sector data read in the read-in-units step are information related to the directory structure; a directory location determination step of determining a hierarchy and positional relation of a directory among directories based on at least one piece of the sector data which is determined in the directory structure determination step as the information related to the directory structure; and a virtual root directory allocation step of allocating, as the virtual root directory, the directory which is determined in the directory location determination step as the directory whose higher-order directory is not found. 
     It is further preferable that the information reproduction method further executes a reproduction start determination step of determining whether or not to perform the information reproduction method in accordance with an input by one of a user and settings. 
     To achieve the above object, the information reproduction apparatus of the present invention for reproducing data which is recorded on an information storage medium based on a logical file system where a directory structure is constructed by using logical addresses and a storage location of the data is indicated based on a root directory includes: a virtual root directory creation section for reading, in the case where the recorded data becomes unable to be reproduced in a method based on the logical file system, the recorded data by using a physical address, extracting, based on information related to the directory structure and included in the read data, every directory whose higher-order directory is not found, and setting all of the extracted directory as the root directory; and a reproduction section for reproducing, in the case where the recorded data becomes unable to be reproduced in a method based on the logical file system, a file under the virtual root directory based on the virtual root directory, in the method based on the logical file system. 
     It is preferable that the virtual root directory creation section includes: a read-in-units section for reading data recorded on the information storage medium from which the recorded data has become unable to be reproduced in the method based on the logical file system, in units of a plurality of sectors as sector data; a directory structure determination section for determining whether or not a plurality of pieces of the sector data read by the read-in-units section are information related to the directory structure; a directory location determination section for determining a hierarchy and positional relation of a directory among directories based on at least one piece of the sector data which is determined by the directory structure determination section as the information related to the directory structure; and a virtual root directory allocation section for allocating, as the virtual root directory, the directory, which is determined by the directory location determination section as the directory whose higher-order directory is not found. 
     It is further preferable that the information reproduction apparatus further includes a reproduction start determination section for determining whether or not to perform the information reproduction method in accordance with an input by one of a user and settings. 
     A series of information reproduction method, as described above, executed by the information reproduction apparatus may be provided as a program causing a computer to execute the process steps as described above. The program may be implemented in a computer in the form of being recorded on a computer-readable storage medium. 
     EFFECT OF THE INVENTION 
     As described above, in the information reproduction method of the present invention, even when the directory management information recorded on the disk medium is broken due to an accident or a user&#39;s carelessness, and consequently a file cannot be reproduced in the method complying with the format standard, the remaining directories and the remaining files can be reproduced, based on a virtual root directory, in the method complying with the format standard, the virtual root directory being derived from the highest-order directory in a directory structure obtained by collecting and analyzing the directory management information. 
     In addition, in the information reproduction method of the present invention there is no need, for example, to preliminarily record additional information or the like aiming at protecting or restoring a directory and a file, because a directory and a file is reproduced in the method complying with the format standard. That is, the information reproduction method of the present invention is highly versatile because a directory and a file, which have become unable to be reproduced, becomes able to be reproduced without preparing a special apparatus or program in advance and without affecting an ordinary use of the medium at all. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an information reproduction apparatus  100  for executing an information reproduction method according to an embodiment of the present invention. 
         FIG. 2  is a flowchart of the information reproduction method according to the embodiment of the present invention. 
         FIG. 3  is a block diagram illustrating an apparatus executing the information reproduction method of the present invention. 
         FIG. 4  illustrates a directory structure determination step S 300  in detail. 
         FIG. 5  illustrates sector data stored in a buffer. 
         FIG. 6  illustrates a directory location determination step S 400  in detail. 
         FIG. 7  illustrates a virtual root directory allocation step S 500  in detail. 
         FIG. 8  illustrates a virtual root directory read step S 600  in detail. 
         FIG. 9  illustrates a case where the directories  1  and  22  are set as the virtual root directories, and directories and files under the virtual root directories are reproduced. 
         FIG. 10  illustrates directories and files which are displayed based on the information reproduction method according to the present embodiment. 
         FIG. 11  illustrates an information reproduction apparatus  900  of a conventional art. 
         FIG. 12  illustrates a directory hierarchy. 
         FIG. 13  illustrates a structure of a directory hierarchy in a logical file system. 
         FIG. 14  illustrates a state where the directory structure is partially damaged. 
         FIG. 15  illustrates a structure of a directory hierarchy in a logical file system of a broken medium. 
     
    
    
     DESCRIPTION OF THE REFERENCE CHARACTERS 
     
         
           10 ,  120  control section 
           11 ,  130  data read section 
           12 ,  140  display section 
           20  disk medium 
           100 ,  900  information reproduction apparatus 
           110  operation section 
           121  reproduction start determination section 
           122  virtual root directory creation section 
           123  reproduction section 
           1221  read-in-units section 
           1222  directory structure determination section 
           1223  directory location determination section 
           1224  virtual root directory allocation section 
         S 100  reproduction start determination step 
         S 101  virtual root directory creation step 
         S 102  reproduction step 
         S 200  read-in-units step 
         S 201 -S 204  detailed steps of the read-in-units step 
           5300  directory structure determination step 
         S 301 -S 305  detailed steps of the directory structure determination step 
         S 400  directory location determination step 
         S 401 -S 408  detailed steps of the directory location determination step 
         S 500  virtual root directory allocation step 
         S 501 -S 502  detailed steps of the virtual root directory allocation step 
         S 600  virtual root directory read step 
         S 601 -S 602  detailed steps of the virtual root directory read step 
       
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     An embodiment of the present invention will be described below with reference to the drawings.  FIG. 1  illustrates an information reproduction apparatus  100  for executing an information reproduction method according to the embodiment of the present invention. In  FIG. 1 , the information reproduction apparatus  100  includes an operation section  110 , a control section  120 , a data read section  130 , and a display section  140 . Further, the control section  120  includes a reproduction start determination section  121 , a virtual root directory creation section  122 , and a reproduction section  123 . Still further, the virtual root directory creation section  122  includes a read-in-units section  1221 , a directory structure determination section  1222 , a directory location determination section  1223 , and a virtual root directory allocation section  1224 . 
     When the information reproduction apparatus  100  loads a disk medium  200 , the data read section  130  reads data recorded on the disk medium  200 . The control section  120  reproduces the data read by the data read section  130  by using the reproduction method complying with the format standard or the information reproduction method according to the present invention. The display section  140  displays a directory and a file reproduced by the control section  120 . 
       FIG. 2  is a flowchart of the information reproduction method according to the embodiment of the present invention. In the information reproduction method according to the embodiment of the present invention, a reproduction start determination step S 100 , a virtual root directory creation step S 101 , and a reproduction step S 102  are performed. 
     In the reproduction start determination step S 100 , the reproduction start determination section  121  determines whether or not to start the information reproduction method according to the present invention. When directories and files recorded on the disk medium are reproduced, the directory management information is not usually damaged, and accordingly the reproduction section  123  reproduces data read by the data read section  130  by using a reproduction method complying with the format standard (step S 102 ). 
     In the present embodiment, a method for reproducing remaining recorded data on the disk medium will be described when the directory structures of the root directory  0  and the directory  2  are damaged as illustrated in  FIG. 14  and  FIG. 15 . 
     In the reproduction start determination step S 100 , since the directory management information is damaged as illustrated in  FIG. 14  and  FIG. 15 , the reproduction start determination section  121  determines to start the information reproduction method according to the present invention (Yes in the reproduction start determination step S 100 ). The control section  120  starts the information reproduction method according to the present invention for reproducing the remaining data in the disk medium. In addition, in the reproduction start determination step S 100 , when the information reproduction method according to the present invention is started, a user makes, at the operation section  110 , an input for starting processing, but the start of the processing may not be necessarily performed by the user&#39;s operation. For example, when a directory and a file recorded on the disk medium cannot be reproduced by the reproduction method complying with the format standard due to the directory management information being damaged, an automatic start of the information reproduction method according to the present invention may be preset. 
     In the virtual root directory creation step S 101 , the virtual root directory creation section  122  sets as a virtual root directory a directory where directory structure is not damaged and reproduction is capable. In addition, the directory set as the virtual root directory is the directory that has no reproducible parent directory to which the directory belongs. Here, processing of the virtual root directory creation step S 101  will be described in detail. 
     As illustrated in  FIG. 2 , in the virtual root directory creation step S 101 , a read-in-units step S 200 , a directory structure determination step S 300 , a directory location determination step S 400 , a virtual root directory allocation step S 500 , and a virtual root directory read step S 600  are performed. 
       FIG. 3  illustrates the read-in-units step S 200  in detail. In the read-in-units step S 200 , the read-in-units section  1221  sequentially reads all of the data recorded on the disk medium. 
     In step S 201 , the read-in-units section  1221  specifies a range of sectors in a sequential reading of all of the data recorded on the disk medium. 
     In step S 202 , the read-in-units section  1221  reads data (hereinafter, referred to as sector data), recorded on the disk medium, in sector units specified in step S 201 . 
     In step S 203 , the read-in-units section  1221  stores, in a buffer, the sector data read in step S 202 . 
     In step S 204 , the read-in-units section  1221  determines whether or not recorded data to be read from the disk medium remains. When the recorded data to be read remains in the disk medium (Yes in step S 204 ), the processing returns to step S 202 . When the recorded data to be read does not remain in the disk medium (No in step S 204 ), the process step of the read-in-units step S 200  is terminated. 
     As described above, in the read-in-units step S 200 , the read-in-units section  1221  stores in a buffer all of the data, recorded on the disk medium, as sector data, in the specified sector units. 
       FIG. 4  illustrates the directory structure determination step S 300  in detail. In the directory structure determination step S 300 , the directory structure determination section  1222  determines whether or not the sector data, which the read-in-units section  1221  has read in the read-in-units step S 200 , is directory management information. 
     In step S 301 , the directory structure determination section  1222  determines whether or not sector data to be extracted remains in the buffer. When sector data to be extracted does not remain in the buffer (No in step S 301 ), the process step of the directory structure determination step S 300  is terminated. When the sector data to be extracted remains in the buffer (Yes in step S 301 ), a process step of step S 302  described below is performed. 
     In step S 302 , the directory structure determination section  1222  sequentially extracts the sector data from the buffer. 
     In step S 303 , the directory structure determination section  1222  determines whether or not the sector data extracted in step S 302  is management information. When the sector data is not the management information (No in step S 303 ), the processing proceeds to step S 305 . Then, the directory structure determination section  1222  deletes the sector data from the buffer in step S 305 , and the processing returns to step S 301 . When the sector data is the management information (Yes in step S 303 ), a process step of step S 304  described below is performed. 
     In step S 304 , the directory structure determination section  1222  further determines whether or not the sector data, which has been determined as the management information in step S 303 , is directory management information. When the sector data is not the directory management information (No in step S 304 ), the processing proceeds to step S 305 . In step S 305 , the directory structure determination section  1222  deletes the sector data, which is not determined as the directory management information, from the buffer, and the processing returns to step S 301 . When the sector data is the directory management information (Yes in step S 304 ), the processing returns to step S 301  and at that time the sector data concerned remains in the buffer. 
     In this manner, in the directory structure determination step S 300 , the directory structure determination section  1222  remains in the buffer only sector data that is the directory management information among sector data which the read-in-units section  1221  has stored in the buffer in the read-in-units step S 200 , and deletes other sector data from the buffer. 
     As described above, in the reproduction start determination step S 100  through the directory structure determination step S 300 , only the directory management information is stored in the buffer as the sector data. In the following description, for reasons of clarity, the directory management information related to each of the directories and files illustrated in  FIG. 15  is stored in the buffer as one piece of the sector data. However, the directory management information of the root directory  0  and directory  2  is not found due to destruction.  FIG. 5  illustrates the sector data stored in the buffer. As described above three pieces of the sector data, directory  1 , directory  11 , and directory  22  are stored, here, as the sector data of the directory management information. 
       FIG. 6  illustrates the directory location determination step S 400  in detail. In the directory location determination step S 400 , the directory location determination section  1223  determines the location of each directory based on the directory management information that the directory structure determination section  1222  has stored in the buffer in the directory structure determination step S 300 . 
     In step S 401 , the directory location determination section  1223  determines whether or not unchecked sector data remains in the buffer. When the unchecked sector data does not remain in the buffer (No in step S 401 ), the process step of the directory location determination step S 400  is terminated. When the unchecked sector data remains in the buffer (Yes in step S 401 ), a process step of step S 402  described below is performed. 
     In step S 402 , the directory location determination section  1223  extracts the unchecked sector data stored in the buffer, and sets the extracted sector data as a directory structure (A). 
     In step S 403 , the directory location determination section  1223  determines whether or not sector data to be compared with the directory structure (A) remains in the buffer. When sector data to be compared with the directory structure (A) does not remain in the buffer (No in step S 403 ), the processing proceeds to step S 407 . In step S 407 , the directory location determination section  1223  stores the location of the directory structure (A) in another buffer ( 2 ). Then, in step S 408 , the directory location determination section  1223  sets the sector data of the directory structure (A) as being already checked, and the processing returns to step S 401  so as to process other unchecked sector data. When sector data to be compared with the directory structure (A) remains in the buffer (Yes in step S 403 ), a process step of step S 404  described below is performed. 
     In step S 404 , the directory location determination section  1223  extracts sector data which is stored in the buffer and has not been compared with the directory structure (A), and sets the extracted sector data as a directory structure (B). 
     In step S 405 , the directory location determination section  1223  compares the directory structure (A) with the directory structure (B), and determines whether or not the directory structure (B) is a parent directory of the directory structure (A). When the directory structure (B) is not the parent directory of the directory structure (A) (No in step S 405 ), the processing returns to step S 403  so as to process other sector data that has not been compared with the directory structure (A). When the directory structure (B) is the parent directory of the directory structure (A) (Yes in step S 405 ), a process step of step S 406  described below is performed. 
     In step S 406 , the directory location determination section  1223  deletes the sector data of the directory structure (A) from the buffer, and the processing returns to step S 401  so as to process other unchecked sector data. 
     As described above, in the directory location determination step S 400 , the directory location determination section  1223  determines the location of each directory based on the directory management information that the directory structure determination section  1222  has stored in the buffer in the directory structure determination step S 300 , and stores the directory structure that has no reproducible parent directory, as location data, in the other buffer ( 2 ). 
     Here, among the three pieces of sector data, which are the directory management information of the directories  1 ,  11  and  22  illustrated in  FIG. 5 , when, for example, the sector data of the directory  11  is set as the directory structure (A) initially (step S 402 ), and the sector data of the directory  22  is set as the directory structure (B) (step S 403 , step S 404 ), since the directory structure (B) is not determined as the parent directory of the directory structure (A) in step S 405  (No in step S 405 ), the processing returns to step S 403 . Next, when the sector data of the directory  1  is set as the directory structure (B) (step S 403 , step S 404 ), since the directory structure (B) is determined as the parent directory of the directory structure (A) in step S 405  (Yes in step S 405 ), the processing proceeds to step S 406 . In step S 406 , the sector data of the directory  11  that is the directory structure (A) is deleted. 
     Next, when the sector data of the directory  1  is set as the directory structure (A) (step S 402 ), the sector data of the directory  22  is set as the directory structure (B) (step S 403 , step S 404 ). In step S 405 , since the directory structure (B) is not the parent directory of the directory structure (A) (No in step S 405 ), the processing returns to step S 403 . Since sector data, which has not been compared with the directory structure (A), does not remain in the buffer in step S 403  (No in step S 403 ), the location of the directory structure (A) is stored in the other buffer ( 2 ) in step S 407 . Then, the sector data of the directory  1 , which is the directory structure (A), is set in step S 408  as already been checked. 
     Finally, when the sector data of the directory  22  is set as the directory structure (A) (step S 402 ), the sector data of the directory  1  is set as the directory structure (B) (step S 403 , step S 404 ). In step S 405 , since the directory structure (B) is not the parent directory of the directory structure (A) (No in step S 405 ), the processing returns to step S 403 . Since sector data that has not been compared with the directory structure (A) does not remain in the buffer in step S 403  (No in step S 403 ), the location of the directory structure (A) is stored in the other buffer ( 2 ) in step S 407 . Then, in step S 408 , the sector data of the directory  22 , which is the directory structure (A), is set as already been checked. 
     In this manner, the directory structures of the directories  1  and  22  are finally stored in the other buffer ( 2 ) as the location data depending on the sequential check of the sector data stored in the buffer. Note that, although in the present embodiment, directories  11 ,  1  and  22  are extracted in order, respectively, at the extraction of sector data in step S 402 , it is apparent that the same effect can be achieved even by the extraction in other orders. In addition, also in step S 404 , regardless of the extracting order the sector data, the same effect can be achieved at the end. 
       FIG. 7  illustrates the virtual root directory allocation step S 500  in detail. In the virtual root directory allocation step S 500 , the virtual root directory allocation section  1224  registers the directory structure that the directory location determination section  1223  has stored as the location data in the directory location determination step S 400  in a list as a virtual root directory. 
     In step S 501 , the virtual root directory allocation section  1224  determines whether or not the location data to be extracted remains in the buffer. When the location data to be read does not remain in the buffer (No in step S 501 ), the process step of the virtual root directory allocation step S 500  is terminated. When the location data to be extracted remains in the buffer (Yes in step S 501 ), a process step of step S 502  described below is performed. 
     In step S 502 , the virtual root directory allocation section  1224  extracts the location data stored in the buffer, and registers the location data in the list as a virtual root directory. Then, the processing returns to step S 501  so as to process the subsequent location data. 
     As described above, in the virtual root directory allocation step S 500 , the virtual root directory allocation section  1224  registers all of the directory structures that the directory location determination section  1223  has stored as the location data in the directory location determination step S 400  in the list as virtual root directories. Here, the directory structures of the directories  1  and  22  are registered in the list as the virtual root directories  1  and  2 , respectively. 
       FIG. 8  illustrates the virtual root directory read step S 600  in detail. In the virtual root directory read step S 600 , the reproduction section  123  reproduces, based on the virtual root directory that the virtual root directory allocation section  1224  has registered in the list in the directory location determination step S 500 , the recorded data in the method complying with the format standard. 
     In step S 601 , the reproduction section  123  determines whether or not a virtual root directory to be extracted remains in the list. When the virtual root directory to be extracted does not remain in the list (No in step S 601 ), the process step of the virtual root directory read step S 600  is terminated. When the virtual root directory to be extracted remains in the list (Yes in step S 601 ), a process step of step S 602  described below is performed. 
     In step S 602 , the reproduction section  123  extracts the virtual root directory in the list, and reproduces the recorded data in the method complying with the format standard, based on the extracted virtual root directory. Then, the processing returns to step S 601  so as to process the subsequent virtual root directory. Here, since the directories  1  and  22  are registered in the list as the virtual root directories, the directory  11  and the files  12 ,  13 ,  111 , and  112  under the directory  1  are reproduced, and further the files  221  and  222  under the directory  22  are reproduced. 
       FIG. 9  illustrates a case where the directories  1  and  22  are set as the virtual root directories  1  and  2 , respectively, and directories and files under the virtual root directories are reproduced. In a logical file system such as a UDF, generally, by using an FID and an FE as pointers, the FID, the FE and actual data under the root directory are accessed in order, respectively, based on the root directory. In the present embodiment, the directories  1  and  22  are set as the virtual root directories  1  and  2 , respectively, and by using the FID and the FE as pointers, the FID, the FE and actual data under the virtual root directory are accessed in order, respectively, based on the virtual root directory. 
     The display section  140  displays a directory and a file reproduced in the above-described method.  FIG. 10  illustrates the directories and files that are displayed in the information reproduction method according to the present embodiment. In the logical file system, when the directory structure is damaged, all of the directories and files cannot be reproduced in the method complying with the format standard. However, as shown in  FIG. 10 , in the information reproduction method according to the present embodiment, by setting the directory  1  as the virtual root directory  1 , the directory  1  and the files  12 ,  13 ,  111 , and  112  under the virtual root directory  1  can be reproduced. Similarly, by setting the directory  22  as the virtual root directory  2 , the files  221  and  222  under the virtual root directory  2  can be reproduced. 
     As described above, in the information reproduction method of the present invention, even when the directory management information is broken, the recorded data remaining in the disk medium is read, and the highest-order directory is set as the virtual root directory among directories at which the directory structure is not damaged, whereby the recorded data remaining in the disk medium can be reproduced. 
     Further, although in the present embodiment all of the directories and files under the virtual root directory can be reproduced, even when the directory structure under the virtual root directory is partially damaged, directories and files at which the directory structure is not damaged can be reproduced. For example, when the directory  11  under the virtual root directory  1  is damaged, the FID of the directory  11  is deleted from the FE of the directory  1  that is the virtual root directory  1 . Thus, the files  12  and  13  under the directory  1  can be reproduced. 
     Still further, although in the present embodiment all of the recorded data remaining in the disk medium are extracted as sector data to be processed in the information reproduction, all of the recorded data may not necessarily be processed in the information reproduction depending on the situation. For example, when the location of recorded data on the disk medium, which is desired by a user to reproduce, can be identified, data may be extracted as sector data by setting only the storage location including nearby areas of the recorded data that is desired by the user to reproduce as a processing target of the information reproduction. Thus, the information reproduction of the recorded data that is desired by the user can be efficiently performed. 
     Still further, although the disk medium is used for the storage medium in the present embodiment, the present invention is not limited thereto and it is apparent that other storage media can achieve the same effect in a case where directory management information is broken. 
     INDUSTRIAL APPLICABILITY 
     The information reproduction method of the present invention is applicable to an application for a personal computer, to a DVD recorder, to a digital video camera, to a digital still camera, and the like.