Patent Publication Number: US-7907478-B2

Title: Drive device

Description:
TECHNICAL FIELD 
     The present invention relates to a drive apparatus for recording data in an information recording media and for reproducing data recorded in the information recording media. 
     BACKGROUND ART 
     Recently, various types of information recording mediums are used to record digital data. For example, a rewritable optical disc or a write-once optical disc is used. In the rewritable optical disc, data can be rewritten repeatedly at the same location. In the write-once optical disc, data can be written only once at the same location, while it is inexpensive. 
     As an example of rewritable optical discs, there are DVD-RAM discs and BD-RE (Blu-ray Disc Rewritable) discs and the like. 
     As an example of write-once optical discs, there are DVD-R discs and BD-R (Blu-ray Disc Recordable) discs and the like. 
     In the rewritable optical disc, a defective management mechanism is introduced to improve the reliability of data recorded on the disc. 
     The defective management mechanism includes a slipping replacement algorithm and a linear replacement algorithm. 
     The slipping replacement algorithm is mainly performed when the disc is formatted. In the slipping replacement algorithm, all of the ECC clusters in the user data area are checked for detecting a defective cluster. When the defective cluster is found, the location of the defective cluster is registered to a primary defect list (hereinafter, “PDL”). The logical cluster corresponding to the defective cluster is shifted such that the logical cluster corresponds to a physical cluster which is next to the physical cluster corresponding to the defective cluster. 
     Thus, when the user data is recorded, it is possible to avoid recording the user data in the defective cluster registered in the PDL. As a result, it is possible to improve the reliability of the data recording. 
     The linear replacement algorithm is performed when a user data is recorded. 
     After the user data is recorded, a verify process is performed. In the verify process, the recording result is verified. If the data recording has failed, the ECC cluster including the recording location is determined as a defective cluster. Then, the location of the defective cluster is managed by a secondary defect list (hereinafter, “SDL”). 
     The user data is recorded in the spare area which is located at the inner-most periphery or the outer-most periphery on the disc, instead of the defective cluster in the user data area. 
     The verify process described above is performed during the replacement recording. If the data recording has succeeded, the location at which the user data is recorded is determined. An SDL entry which correlates the location of the defective cluster with an ECC cluster for replacement is generated. Then, the SDL entry is registered to the SDL. 
     The SDL entry is provided for each of the all ECC clusters included in the spare area. It is possible to manage whether or not each ECC cluster in the spare area is available as a replacement cluster. If the ECC cluster is an unrecorded area in the spare area, then the ECC cluster is available as a replacement cluster. If the ECC cluster is a recorded area in the spare area, then the ECC cluster is not available as a replacement cluster. The unrecorded area in the spare area is also called a spare cluster. 
     In the reproduction process, by referring to the PDL and the SDL, if necessary, the data is reproduced from the replacement cluster. 
     The PDL and the SDL are recorded in a defect management area (hereinafter, “DMA”) provided in the lead-in area on the disc. In the DMA, information indicating the size of the spare area and the like is further recorded. 
     In the rewritable optical disc, the information on the defective management is updated by rewriting the DMA. 
     In the write-once optical disc, it is possible to introduce a defective management mechanism, for example, as described in the specification of U.S. laid-open patent publication No. 2004/0076096 (hereinafter, “reference 1”). 
     FIG. 3 of the reference 1 shows a data structure of the disc. In the disc of the reference 1, the DMA is provided in the lead-in area and the lead-out area. 
     Further, a temporary defect management area (hereinafter, “TDMA”) is provided in the lead-in area and the lead-out area. 
     In the write-once optical disc, the information on the defective management is updated by additionally recording defective information in the TDMA each time the defective information is updated. 
     When the disc is closed or finalized, the data in the latest TDMA is recorded in the DMA. 
     In the TDMA, temporary defect management information (hereinafter, “TDDS”) and temporary defect information (hereinafter, “TDFL”) are recorded. 
     FIG. 5B of the reference 1 shows a data structure of the TDDS. The TDDS includes pointer information to the TDFL. The TDFL can be recorded in the TDMA a plurality of times. The pointer information is recorded for the respective TDFLs. 
     In the TDDS, a last recorded address on the write-once optical disc is recorded. As shown in FIG. 5B of the reference 1, a single write-once optical disc can have a plurality of last recorded addresses. 
     In the TDDS, a last recorded replacement address on the write-once optical disc is recorded. As shown in FIG. 5B of the reference 1, a single write-once optical disc can have a plurality of last recorded replacement addresses. 
     FIG. 6 of the reference 1 shows a data structure of the TDFL. 
     The TDFL includes information regarding defect #1, #2, . . . and the like. 
     The information regarding defect includes status information, a pointer to the defective cluster and a pointer to the replacement cluster. 
     The information regarding defect has a data structure similar to the SDL entry included in the SDL. The information regarding defect performs a function similar to the SDL entry. 
       FIGS. 33A and 33B  show a method for updating the TDFL disclosed in FIG. 9A and FIG. 9B of the reference 1. 
       FIG. 33A  shows a data structure of the TDFL #0. The TDFL #0 includes the information regarding defect #1, #2 and #3 corresponding to the defects #1, #2 and #3. 
     After the TDFL #0 is recorded, it is assumed that the defects #4 and #5 are detected as a result of performing a new data recording. In this case, the TDFL #1 shown in  FIG. 33B  is recorded on the write-once optical disc. 
     The TDFL #1 is generated by maintaining the information regarding defect #1, #2 and #3 included in the TDFL #0 and adding the information regarding defect #4 and #5 corresponding to the defects #4 and #5. 
     FIG. 10 of the reference 1 shows a data structure of the information regarding defect. 
     The information regarding defect includes status information. The status information includes information indicating that the defective area is a continuous defect block or a single defect block. 
     The information regarding defect further includes a pointer to the defective area (the location of the defective area on the disc). 
     The information regarding defect further includes a pointer to the replacement area corresponding to the defective area. 
     When the defective area is a continuous defect block, the status information indicates that a pointer to the defective area designates a start location of the continuous defect block or an end location of the continuous defect block. In this case, the status information further indicates that a pointer to the replacement area designates a start location of the replacement block or an end location of the replacement block. 
     By using these data structures, the defective management mechanism can be implemented in the write-once optical disc. 
     Further, by using the defective management mechanism described above, it is possible to implement a pseudo-overwrite recording for the write-once optical disc. 
     With reference to  FIGS. 31 and 32 , the pseudo-overwrite recording for the write-once optical disc will be described. 
     As described above, in the defective management mechanism, by using the replacement information such as the information regarding defect or the SDL entry, the physical address at which the data is actually recorded is mapped to another location which is previously allocated, without changing the logical address at which the data is recorded. 
     When it is instructed to record data at a logical address at which the data has already been recorded on the write-once optical disc, the data is recorded in a sector located at a physical address which is different from the physical address corresponding to the logical address, and the replacement information is updated to maintain the logical address. According to this process, it is possible to overwrite data in a pseudo manner. Hereinafter, such data recording is referred to as a pseudo-overwrite recording. 
       FIG. 31  shows a data structure after directories and files are recorded in the information recording medium  1  which is a write-once optical disc. In the state shown in  FIG. 31 , it is assumed that the pseudo-overwrite recording has not been performed. 
     In the write-once optical disc, the user data area on the disc is managed as a unit of track or session. 
     In  FIG. 31 , the user data recorded in the user data area is managed by a file system. A space managed by the file system is referred to as a volume space  2 . 
     In the description below, it is assumed that information recorded in the information recording medium  1  as the volume/file structure of the file system (e.g. descriptor, pointer, metadata partition and metadata file) has a data structure defined in the ISO/IEC 13346 standard or the UDF (Universal Disc Format) specification, unless it is explicitly described on the contrary. 
     In  FIG. 31 , a volume structure area  3  and a physical partition  4  are recorded in the volume space  2 . 
     In the physical partition  4 , metadata partitions  5   a ,  5   b  defined by version 2.5 of the UDF specification are included. 
     In the physical partition  4 , metadata file  6   a  and metadata mirror file  6   b  which is the duplication of the metadata file  6   a  are recorded. 
     FE (metadata file)  7   a  and FE (metadata mirror file)  7   b , each being a file entry (FE) indicating the recording location in the physical partition  4 , are recorded. Further, data file (File-a)  8  and data file (File-b)  9  are also recorded. 
     All information on the file structure such as a file entry and directory file is allocated in the metadata partition, i.e. the metadata file. 
     In the data structure defined in the UDF specification, the respective recording locations of the metadata partition  5   a  and the file set descriptor (FSD)  12  are recorded in the volume structure area  3 . 
     By retrieving the file structure from the ROOT directory using the FSD  12  as a start point, it is possible to access data file (File-a)  8 , for example. 
     Next, in the state shown in  FIG. 31 , it is assumed that the pseudo-overwrite recording for data file (File-c) is performed. 
       FIG. 32  shows a data structure after the pseudo-overwrite recording for data file (File-c) is completed. 
     Herein, it is assumed that the data file (File-c) is recorded immediately under the ROOT directory on the information recording medium  1 . 
     During recording the data file (File-c), the required information on the file structure is updated or generated in order to add the data file (File-c). Specifically, FE (ROOT)  13  is updated and FE (File-c)  14  is generated, for example. 
     The data file (File-c)  15  is recorded in an unrecorded area shown in  FIG. 31 .  FIG. 32  shows a state at this time. 
     When the FE (File-c)  14  is recorded, the FE (File-c)  14  is recorded in the unrecorded area  11   a  in the metadata partition  5   a  (i.e. the metadata file  6   a ). 
     Next, the pseudo-overwrite recording is performed as if the FE (ROOT)  16  would be overwritten on the FE (ROOT)  13 . 
     In this case, as shown in  FIG. 32 , the data for the FE (ROOT)  16  is recorded in the spare area  17 . 
     Further, the replacement information included in the disc management information  2  is updated such that the FE (ROOT)  13  is mapped to the FE (ROOT)  16 . 
     After performing the recording process for files, a reproduction operation for reproducing the data file (File-c)  15  will be described. 
     The location information of FE (metadata file)  7   a  and the location information of FSD  12  are obtained from the volume structure area  3  of the information recording medium  1 . 
     Next, the file structure is reproduced. In order to reproduce the file structure, the FSD  12  is reproduced based on the location information of FE (metadata file)  7   a  and the location information of FSD  12 . 
     The location information of the FE (ROOT)  13  is obtained as a logical address from the reproduced FSD  12 . 
     The FE (ROOT)  13  is reproduced based on the location information of the FE (ROOT)  13 . 
     By referring to the replacement information, the FE (ROOT)  16 , to which the FE (ROOT)  13  is mapped, is reproduced. 
     The FE (ROOT)  16  includes the latest ROOT directory file. Accordingly, the FE (ROOT)  16  includes the location information of the FE (File-c)  14 . 
     The data file (File-c)  15  is reproduced using the location information of the data file (File-c)  15  which is obtained from the FE (File-c)  14 . 
     Thus, in the write-once optical disc, it is possible to perform a pseudo-overwrite recording using the defective management mechanism. 
     However, according to the pseudo-overwrite recording for the write-once optical disc described above, there is a problem that if there is no unrecorded area in the spare area, it is not possible to further perform the data recording even if there is an unrecorded area in the user data area. This is because it is not possible to update file system information. 
     In particular, in the write-once optical disc, the size of the spare area is fixed at the time when the disc is formatted (initialized), unlike the rewritable optical disc in which the size of the spare area can be extended if required. 
     It is difficult to determine the size of the spare area appropriately in view of the pseudo-overwrite recording which may be performed in the future. 
     If the size of the spare area is determined as a relatively large size, the size of the user data area must be reduced. If the size of the spare area is determined as a relatively small size, a problem may be caused. The problem is that it is not possible to further perform the data recording even if there is an unrecorded area in the user data area. In either case, it is not possible to effectively utilize the user data area of the write-once optical disc. 
     The present invention is intended to solve the problem described above. One of the purposes of the present invention is to provide a drive apparatus capable of utilizing the user data area without any loss in the pseudo-overwrite recording for the write-once optical disc. 
     According to the present invention, it is possible to provide a drive apparatus capable of utilizing the user data area without any loss in the pseudo-overwrite recording for the write-once optical disc. 
     DISCLOSURE OF THE INVENTION 
     According to one aspect of the invention, a drive apparatus is provided for performing a sequential recording for a write-once recording medium. The drive apparatus includes: a recording/reproduction section for performing a recording operation or a reproduction operation for the write-once recording medium; a drive control section for controlling the recording/reproduction section; and a memory circuit for storing data to be recorded, wherein the drive control section performs a process including: receiving a recording instruction specifying at least data to be recorded; storing the data to be recorded in the memory circuit; defining data from a start location of the data stored in the memory circuit to a location corresponding to a next writable address as a first data portion; defining data from the location corresponding to the next writable address to an end location of the data stored in the memory circuit as a second data portion; and controlling the recording/reproduction section to record the second data portion before recording the first data portion. 
     According to another aspect of the invention, a drive apparatus is provided for performing a sequential recording for a write-once recording medium, wherein the write-once recording medium includes a spare area and a user data area. The drive apparatus includes: a recording/reproduction section for performing a recording operation or a reproduction operation for the write-once recording medium; and a drive control section for controlling the recording/reproduction section, wherein the drive control section performs a process including: receiving a recording instruction specifying at least a location at which data is to be recorded; determining whether or not an ECC cluster including the location specified by the recording instruction is replaced by a replacement cluster; determining whether or not a read-modify-write process is required; when it is determined that the ECC cluster including the location specified by the recording instruction is replaced by a replacement cluster and the read-modify-write process is required, determining a specific location in the user data area which is close to the recording location of the replacement cluster as a recording location at which the data is to be recorded; controlling the recording/reproduction section to record the data at the determined recording location. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is an illustrative diagram showing an appearance of information recording medium  100  according to an embodiment of the present invention. 
         FIG. 1B  is an illustrative diagram showing an exemplary data structure of the information recording medium  100  according to an embodiment of the present invention. 
         FIG. 1C  is an illustrative diagram showing an exemplary data structure of the user data area  108  shown in  FIG. 1B . 
         FIG. 2A  is an illustrative diagram showing an exemplary data structure of the session management information  200  according to an embodiment of the present invention. 
         FIG. 2B  is an illustrative diagram showing an exemplary data structure of the track management information  210  according to an embodiment of the present invention. 
         FIG. 2C  is an illustrative diagram showing an exemplary data structure of the space bitmap management information  220  according to an embodiment of the present invention. 
         FIG. 3  is an illustrative diagram showing an exemplary data structure of the disc structure information  1110  according to an embodiment of the present invention. 
         FIG. 4  is an illustrative diagram showing an exemplary data structure of the information recording medium  100   b  according to an embodiment of the present invention. 
         FIG. 5A  is an illustrative diagram showing an exemplary data structure of the replacement management information list  1000  according to an embodiment of the present invention. 
         FIG. 5B  is an illustrative diagram showing an exemplary data structure of the replacement management information  1010  according to an embodiment of the present invention. 
         FIG. 6  is a block diagram showing an exemplary configuration of the information recording/reproduction apparatus  300  according to an embodiment of the present invention. 
         FIG. 7  is an illustrative diagram showing an exemplary data structure of the information recording medium after the formatting process according to an embodiment of the present invention. 
         FIG. 8A  is a flowchart showing a recording process according to an embodiment of the present invention. 
         FIG. 8B  is a flowchart showing a RMW process according to an embodiment of the present invention. 
         FIG. 9  is an illustrative diagram showing an exemplary data structure of the information recording medium after the recording process according to an embodiment of the present invention. 
         FIG. 10  is a flowchart showing a reproduction process according to an embodiment of the present invention. 
         FIG. 11  is an illustrative diagram showing an exemplary data structure of the replacement management information  1010 B according to an embodiment of the present invention. 
         FIG. 12  is an illustrative diagram showing an exemplary data structure of the physical address space and the logical address space according to an embodiment of the present invention. 
         FIG. 13A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 13B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 14A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 14B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 15A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 15B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 16A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 16B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 17A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 17B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 18  is an illustrative diagram showing an exemplary data structure of the DFL entry  2010  which is an example of the replacement management information according to an embodiment of the present invention. 
         FIG. 19A  is a flowchart showing a recording process according to an embodiment of the present invention. 
         FIG. 19B  is a flowchart showing a recording process according to an embodiment of the present invention. 
         FIG. 20A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 20B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 21A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 21B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 22A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 22B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 23A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 23B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 24A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 24B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 25  is an illustrative diagram showing an exemplary data structure of the track management information according to an embodiment of the present invention. 
         FIG. 26A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 26B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 27  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 28  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 29  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 30  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 31  is an illustrative diagram showing an exemplary data structure of the information recording medium according to the conventional technique. 
         FIG. 32  is an illustrative diagram showing an exemplary data structure of the information recording medium after the file recording process according to the conventional technique. 
         FIG. 33A  is an illustrative diagram showing an exemplary data structure of the TDFL according to the conventional technique. 
         FIG. 33B  is an illustrative diagram showing an exemplary data structure of the TDFL according to the conventional technique. 
         FIG. 34  is a flow chart showing a recording process according to an embodiment of the present invention. 
         FIG. 35  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 36  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 37  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 38  is a flow chart showing a recording process according to an embodiment of the present invention. 
         FIG. 39  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 40  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 41  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 42  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 43  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 44A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 44B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 45A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 45B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 46A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 46B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 47A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 47B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 48  is a flowchart showing a recording process according to an embodiment of the present invention. 
         FIG. 49A  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 49B  is an illustrative diagram showing a RMW process according to an embodiment of the present invention. 
         FIG. 49C  is an illustrative diagram showing a replacement recording according to an embodiment of the present invention. 
         FIG. 50  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 51  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 52A  is an illustrative diagram of a data structure on an information recording medium according to an embodiment of the present invention. 
         FIG. 52B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
         FIG. 53B  is an illustrative diagram showing replacement management information according to an embodiment of the present invention. 
     
    
    
     
         
         
           
               100 ,  100   b  information recording medium 
               101  lead-in area 
               102 ,  102   a  data area 
               103  lead-out area 
               103   b ,  103   c  outer area 
               104 ,  105  disc management information area 
               104   a ,  105   a  disc management information area 
               106   a  inner spare area 
               107   a  outer spare area 
               108   a  user data area 
               109  volume space 
               122  unrecorded area 
               120 ,  121  LRA 
               210  track management information 
               211  session start information 
               212  track start location information 
               213  last recorded address information within track (LRA) 
               300  information recording/reproduction apparatus 
               301  system control section 
               302  memory circuit 
               303  I/O bus 
               304  magnetic disc apparatus 
               310  drive apparatus 
               311  drive control section 
           
         
       
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Embodiment 1 
     1-1. Write-Once Recording Medium 
       FIG. 1A  shows an appearance of information recording medium  100  according to an embodiment of the present invention. 
     A lead-in area  101  is located in an inner-most periphery of the information recording medium  100 . A lead-out area  103  is located in an outer-most periphery of the information recording medium  100 . A data area  102  is located between the lead-in area  101  and the lead-out area  103  of the information recording medium  100 . 
     In the lead-in area  101 , reference information necessary for an optical pickup included in the recording/reproduction section  314  which will be described below to access the information recording medium  100 , information for identifying from other recording media, and the like are recorded. In the lead-out area  103 , similar information as those in the lead-in area  101  is recorded. 
     A plurality of physical sectors are assigned to the lead-in area  101 , the data area  102  and the lead-out area  103 . Each physical sector is a minimum access unit. Each physical sector is identified by an address information such as a physical sector number (hereinafter, “PSN”). 
     The data recording/reproduction is performed for each ECC cluster (or each ECC block) including a plurality of physical sectors. An ECC cluster (or an ECC block) is a minimum unit for the data recording/reproduction. 
       FIG. 1B  shows a data structure of the information recording medium  100 . In  FIG. 1B , the lead-in area  101 , the data area  102  and the lead-out area  103  are shown in a lateral arrangement, although they are actually arranged in a concentric circular manner as shown in  FIG. 1A . 
     The lead-in area  101  includes a disc management information area  104 . The lead-out area  103  includes a disc management information area  105 . Disc management information is recorded in each of the disc management information areas  104  and  105 . The disc management information includes replacement management information, session management information, and space bitmap management information. This information will be described below. The disc management information areas  104  and  105  are used as an area for updating the disc management information. The area for updating the disc management information is also referred to as a temporal disc management information area. 
     In a case where the present invention is applied to the BD-R specification, the term “disc management information area” in the present specification should be read as a “Disc Management Area (DMA)”, the term “temporal disc management information area” in the present specification should be read as a “Temporal Disc Management Area (TDMA)”, the term “disc management information” in the present specification should be read as a “Disc Management Structure (DMS)” and the term “temporal disc management information” in the present specification should be read as a “Temporal Disc Management Structure (TDMS)”. 
     The data area  102  includes an inner spare area  106 , a user data area  108  and an outer spare area  107 . 
     The user data area  108  is an area used for recording a user data. 
       FIG. 1C  shows a data structure of the user data area  108 . 
     The user data area  108  includes a plurality of sessions. Each session includes a plurality of tracks. 
     Each track is a contiguous area on the information recording medium  100 . Each track is managed by track management information which will be described below. 
     In a case where the present invention is applied to the BD-R specification, the term “track” in the present specification should be read as a “Sequential Recording Range” (hereinafter, “SRR”). 
     Each session includes a plurality of tracks which are contiguously allocated on the information recording medium  100 . Each session is managed by session management information which will be described below. 
       FIG. 2A  shows a data structure of the session management information  200  for managing the session. The session management information  200  is included in the disc management information. 
     The session management information  200  includes header information  201  and a plurality of track management information. 
     The header information  201  includes general information such as an identifier of the session management information  200  and the number of the track management information  210  shown in  FIG. 2B . 
     The track management information #N contains information corresponding to the track #N shown in  FIG. 1C , where N denotes an integer greater than or equal to 1. 
       FIG. 2B  shows a data structure of the track management information  210  for managing the track. The track management information  210  is included in the disc management information. 
     The track management information  210  includes session start information  211  which indicates whether or not the track is a leading track of the session, track start location information  212  which indicates a start location of the track, and last recorded address information within track  213  which indicates a location at which data has been lastly recorded within the track. Hereinafter, the last recorded address information within track  213  is referred to as LRA  213 . 
     If the track managed by the track management information is  210  located at a leading position of the session, a value (e.g. “1”) indicating that the track is located at a leading position of the session is set to session start information  211 . Otherwise, a different value (e.g. “0”) is set to session start information  211 . 
     The track start location information  212  includes a physical address indicating a start location of the track. 
     The LRA  213  includes a physical address indicating a location at which valid data has been lastly recorded within the track. Valid data may be, for example, user data supplied from the host apparatus  305 . The LRA  120  and the LRA  121  shown in  FIG. 1C  are an example of the LRA  213 . 
     In the case where the present invention is applied to the BD-R specification, the term “track management information” in the present specification should be read as a “Sequential Recording Range Entry (SRR Entry)” and the term “session management information” in the present specification should be read as a “Sequential Recording Range Information”. 
     In the case where the data recording is performed for each ECC cluster as a minimum unit on the information recording medium  100 , the location indicated by the LRA  213  does not always match the boundary of ECC clusters. 
     In general, the size of data specified by the recording instruction does not match multiple integral of the size of one ECC cluster. In this case, the LRA  213  indicates an address of the last physical sector among the physical sectors in which the data specified by the recording instruction is recorded. 
     If the location indicated by the LRA  213  does not match the boundary of ECC clusters, padding data is recorded after the valid data so that the end of the recorded data can match the boundary of ECC clusters. 
     In the present embodiment, the data recording can be performed for each track. In this case, the recording of new data is started from a leading position of each track, and the new data is contiguously recorded within the track (a sequential recording). When the data recording is performed for a track, the location at which the data has been lastly recorded within the track is reflected to the LRA  213 . 
     When the data recording is restarted within the track, a value of the LRA  213  is checked. By checking the value of the LRA  213 , it is possible to determine a next writable address within the track. 
     In the case where no data is recorded within the track (e.g. immediately after the track is allocated), a predetermined value (e.g. “0”) indicating such a status can be set to the LRA  213 . 
     In general, a next writable address (hereinafter, “NWA”) indicates a location of a physical sector which is next to the physical sector indicated by the LRA  213 . Alternatively, in the case where the data recording is performed for each ECC cluster as a minimum unit on the information recording medium  100 , the NWA indicates a location of a leading position of an ECC cluster which is next to the ECC cluster including the physical sector indicated by the LRA  213 . 
     The location of the NWA is calculated according to Expression (1) below. 
     (a) When LRA≠0
 
NWA= N ×(Floor(LRA/ N )+1)
 
     N: the number of the physical sectors included in each ECC cluster (for example, N=32). 
     (b) When LRA=0
 
NWA=(start location of the corresponding track)
 
     where Floor(x) represents the largest integer number=x 
     Hereinafter, it is assumed that the NWA indicates a leading position of the ECC cluster. 
     A track where it is possible to record data is referred to as an open track. 
     The track number of the open track is included in the header information  201  of the session management information  200  shown in  FIG. 2A  (for example, a first open track number  203 , a second open track number  204 , etc.). 
     Any track other than the open track is referred to as a closed track. 
     For example, a track which does not include any unrecorded area or a track designated by a user can be a closed track. 
     Unlike the open track, the track number of the closed track is not stored in the header information  201  of the session management information  200 . 
     The data recording to any closed track is prohibited. 
     In the case where the present invention is applied to the BD-R specification, the term “open track” in the present specification should be read as an “Open SRR” and the term “closed track” should be read as a “Closed SRR”. 
     By checking the open track number and the LRA  213  in the track management information  210 , it is possible to determine an unrecorded area on the information recording medium  100 . 
     By managing the recorded clusters for the write-once type of the information recording medium  100 , it is possible to perform a kind of random recording (i.e. recording data at an arbitrary location (physical address) on the information recording medium  100 ). 
     In order to realize such a random recording, it is necessary to manage unrecorded areas on the information recording medium  100  and to manage the last recorded address. 
     In the present embodiment, these managements are realized by utilizing the space bitmap management information  220  shown in  FIG. 2C  and the disc management information recorded in the disc management information area  104  and  105 . 
     When the random recording is performed, the space bitmap management information  220  shown in  FIG. 2C  is recorded in the disc management information area  104 . 
       FIG. 2C  shows a data structure of space bitmap management information  220 . The space bitmap management information  220  includes header information  221 , managed area information  222  and space bitmap information  223 . 
     The header information  221  includes general information such as an identifier of the space bitmap management information  220 . 
     The managed area information  222  includes information which specifies an area in the user data area  108 , wherein the recorded/unrecorded status of a sector included in the area is managed by the space bitmap management information  220 . For example, the managed area information  222  includes a start location of the area and a length of the area. 
     The space bitmap information  223  includes information indicating whether each ECC cluster included in the area to be managed is a recorded ECC cluster or an unrecorded ECC cluster. For example, a single bit data is assigned to each ECC cluster, a predetermined value (e.g. “0”) is set to the single bit data when the ECC cluster is an unrecorded ECC cluster, and a predetermined value (e.g. “1”) is set to the single bit data when the ECC cluster is a recorded ECC cluster. This makes it possible to manage unrecorded areas for all ECC clusters in the area to be managed. 
     The disc management information recorded in the disc management information area  104  includes disc structure information  1100  shown in  FIG. 3 . The disc structure information  1100  includes last recorded address information  1107 . The last recorded address information  1107  includes a physical address indicating a location at which data has been lastly recorded within the user data area  108 . 
     The disc structure information  1100  further includes general information  1101  concerning an entire disc structure information  1100 , replacement management information list location information  1102  which indicates location information of the latest replacement management information list  1000  within the disc management information area  104 ,  105 , user area start location information  1103  which indicates a start location of the user data area  108 , user area end location information  1104  which indicates an end location of the user data area  108 , disc management information area size  1107   b , and spare area information  1105  and spare area management information  1108  which indicates the size of the inner spare area  106  and the outer spare area  107  and an area available for replacement. 
     By using the disc management information area size  1107   b , it is possible to change the size of the disc management information area for each information recording medium. Further, by using the disc management information area size  1107   b , it is possible to change the temporal disc management information area described above in the inner spare area  106  and the outer spare area  107 . 
     By using the spare area information  1105 , it is possible to change the size of the spare area for each information recording medium. For example, it is possible to set the size of the inner spare area  106  or the size of the outer spare area  107  to zero. 
     The spare area management information  1108  includes next available location information indicating a next available location in the inner spare area  106  and the outer spare area  107 . 
     In each spare area, a sequential recording is performed in the same way in each track. The next available location in each spare area performs the similar function as the NWA in each track. The recording of new data to each spare area is performed sequentially from the location indicated by the next available location information. 
     The disc structure information  1100  further includes session management information location information  1109  which indicates location information of the latest session management information  200  in the disc management information areas  104  and  105 , and space bitmap management information location information  1110  which indicates location information of the latest space bitmap management information  220  in the disc management information areas  104  and  105 . 
     As described above, by using the session management information  200  or the space bitmap management information  220 , it is possible to manage the status of unrecorded physical sectors on the information recording medium  100 . Accordingly, it is possible to selectively use one of the session management information  200  and the space bitmap management information  220  for its purposes. Alternatively, it is possible to use both information. The information concerning a method for managing unrecorded areas is included in the recording mode information  1106  of the disc structure information  1100 . 
     The disc management information area  105  is an extended area which is used to record duplication of the disc management information recorded in the disc management information area  104  or is used to record the information which cannot be recorded in the disc management information area  104  in updating the disc management information. Hereinafter, the detailed description of the disc management information area  105  will be omitted. This is similar to the temporal disc management information recorded in the spare area. 
     In the example shown in  FIG. 1C , the user data recorded in the user data area  108  is managed by a file system. A space managed by the file system is referred to as a volume space  109 . 
     A plurality of logical sectors are assigned to the volume space  109 . Each logical sector is identified by address information such as a logical sector number (hereinafter, “LSN”). 
     In the description below, it is assumed that information recorded in the information recording medium  100  as the volume/file structure of the file system (e.g. descriptor, pointer, metadata partition and metadata file) has a data structure defined in the ISO/IEC 13346 standard or the UDF (Universal Disc Format) specification, unless it is explicitly described on the contrary. Of course, it is possible to use a file system other than those described above. 
     The information recording medium  100  shown in  FIGS. 1A to 1C  is described as an information recording medium having a single recording layer. However, the information recording medium  100  may have two or more recording layers. 
       FIG. 4  shows a data structure of an information recording medium  100   b  having two recording layers. 
     In  FIG. 4 , L 0  denotes a first layer and L 1  denotes a second layer. Each of the first and second layers has almost the same structure as the information recording medium  100 . Specifically, the lead-in area  101  is located in an inner-most periphery of the first layer and the lead-out area  103   a  is located in an inner-most periphery of the second layer. Further, the outer area  103   b  is located in an outer-most periphery of the first layer and the outer area  103   c  is located in an outer-most periphery of the second layer. The lead-in area  101 , the outer area  103   b , the lead-out area  103   a  and the outer area  103   c  includes a disc management information area  104 ,  105 ,  104   a  and  105   a , respectively. 
     Further, as shown in  FIG. 4 , the spare areas  106 ,  106   a ,  107  and  107   a  are provided. As described above, it is possible to change the size of each spare area for each information recording medium. It is also possible to provide an additional temporal disc management information area in each spare area. The user data areas  108  and  108   a  are logically treated as a single volume space having contiguous logical addresses. 
     Thus, it is possible to logically treat an information recording medium having a plurality of recording layers as an information recording medium having a single recording layer. Hereinafter, an information recording medium having a single recording layer is described. It is possible to apply the description of the information recording medium having a single recording layer to an information recording medium having a plurality of recording layers. Therefore, an information recording medium having a plurality of recording layers is referred to only when a special description is required. 
     1-2. Pseudo-Overwrite Recording 
     The replacement information is described with reference to  FIGS. 5A and 5B . 
     The replacement information is defined as a replacement management information list (or a defect list) including replacement management information (or a defect list entry). The replacement management information (or the defect list entry) includes original location information indicating a location of a cluster in which a defect occurs on the information recording medium (i.e. a defective cluster) and replacement location information indicating a location of a replacement cluster which is used instead of the defective cluster. 
     The present invention enables recording a replacement cluster in the user data area. 
     Further, the present invention realizes a pseudo-overwrite recording on a write-once information recording medium using the replacement information. 
     As shown in  FIG. 1B , the data area  102  includes the inner spare area  106 , the user data area  108  and the outer spare area  107 . 
     At least a part of the inner spare area  106  and the outer spare area  107  is used as an area for replacement recording of the data to be recorded in the user data area  108 . 
     For example, when there exists a defective cluster in the user data area  108 , at least a part of the inner spare area  106  and the outer spare area  107  is used as an area for recording a replacement cluster with which the defective cluster is replaced. 
     Alternatively, at least a part of the inner spare area  106  and the outer spare area  107  can be used as an area for recording the updated data in the pseudo-overwrite recording described below. 
     The replacement recording, which is the combination of the replacement information with the spare area, is performed as well as a verify process. 
     The verify process is a process including the steps of reproducing data immediately after the data is recorded, comparing the reproduced data with the recorded data and determining whether or not the data is recorded correctly based on the comparison result. Such a process including these steps is called a verify-after-write process. 
     When an error occurs during the verify process (i.e. it is determined that the data is not recorded correctly), a replacement recording is performed. Specifically, the defective cluster is replaced by a replacement cluster and the data is recorded in the replacement cluster. 
     The replacement cluster is recorded in the inner spare area  106  (or the outer spare area  107 ) or the user data area  108 . 
     The pseudo-overwrite recording is defined as a method for mapping a physical address at which the data is actually recorded to another physical address, such that it can be seen as if the logical address at which the data is recorded is not changed. 
     When the overwrite of new data is instructed to a logical address at which data is recorded, a physical address corresponding to the logical address is replaced by a separate physical address and the new data is written into an ECC cluster on the separate physical address. Then, the ECC cluster before overwrite is mapped to the ECC cluster (replacement cluster) in which the new data is recorded. 
     The replacement cluster used in the pseudo-overwrite recording is recorded in the spare area or the user data area. 
     As the replacement information for performing such a mapping process, the replacement management information list  1000  shown in  FIG. 5A  is used. 
     By performing such a mapping process, it is possible to realize that it can be seen as if the data is overwritten, although the data is not actually overwritten. Hereinafter, this recording method is referred to as a pseudo-overwrite recording. 
       FIG. 5A  shows a data structure of a replacement management information list  1000  which is replacement information according to the present invention. The replacement management information list  1000  is used to map the location of the defective cluster to the location of the replacement cluster. The replacement management information list  1000  includes header information  1001  and a plurality of replacement management information  1010  (e.g. replacement management information # 1 , # 2 , # 3  . . . ). 
     The header information  1001  includes the number of the replacement management information included in the replacement management information list  1000 . The replacement management information includes information indicating the mapping described above. 
       FIG. 5B  shows a data structure of the replacement management information  1010 . The replacement management information  1010  includes status information  1011 , original location information  1012  and replacement location information  1013 . 
     The status information  1011  includes status information concerning the mapping described above. For example, the status information indicates a type or an attribute of the replacement management information  1010 , the valid/invalid status of the original location information  1012  and the replacement location information  1013  and like. 
     The original location information  1012  indicates a location of original information (e.g. a defective cluster). 
     The replacement location information  1013  indicates a location of replacement information (e.g. a replacement cluster). 
     In the pseudo-overwrite recording, the location of the ECC cluster before overwrite is indicated by the original location information  1012 , and the location of the ECC cluster after overwrite is indicated by the replacement location information  1013 . Thus, the location of the ECC cluster before overwrite is mapped to the location of the ECC cluster after overwrite. 
     Herein, the original location  1012  and the replacement location information  1013  registered in the replacement management information  1010  may be represented by a physical address (e.g. PSN) of the first sector in the corresponding ECC cluster. This is because a mapping is performed as a unit of ECC cluster in the defective management and the pseudo-overwrite recording. 
     In the conventional linear replacement method, the replacement cluster is recorded in the spare area. Accordingly, in every case, the information indicating a location of the ECC cluster in the spare area is set to the replacement location information  1013 . 
     On the other hand, in the present invention, the location at which the replacement cluster can be recorded is not limited to the location in the spare area. It is possible to record the replacement cluster in the user data area. Accordingly, the information indicating a location of the ECC cluster in the spare area or the information indicating a location of the ECC cluster in the user data area may be set to the replacement location information  1013 . 
     Thus, the replacement location information  1013  may indicate a location of the ECC cluster recorded in one of two areas (i.e. the spare area and the user data area). In order to determine whether the replacement location information  1013  indicates a location of the ECC cluster in the spare area or a location of the ECC cluster in the user data area, information indicating one of the two cases may be defined. Such information may be incorporated into the status information  1011 . 
     1-3. Recording/Reproduction Apparatus 
       FIG. 6  shows a configuration of an information recording/reproduction apparatus  300  according to an embodiment of the present invention. 
     The information recording/reproduction apparatus  300  includes a host apparatus  305  and a drive apparatus  310 . 
     The host apparatus  305  can be, for example, a computer system or a personal computer. 
     The drive apparatus  310  can be, for example, any one of a recording apparatus, a reproduction apparatus and a recording/reproduction apparatus. The information recording/reproduction apparatus  300  as a whole also can be called any one of a recording apparatus, a reproduction apparatus and a recording/reproduction apparatus. 
     The host apparatus  305  includes a system control section  301  and a memory circuit  302 . The host apparatus  305  may further include magnetic disc apparatus  304  such as a hard disc drive. The components in the host apparatus  305  are connected to each other via an I/O bus  303 . 
     The system control section  301  can be implemented, for example, by a microprocessor including a system control program and a memory for operation. The system control section  301  controls various processes and performs various operations such as recording/reproduction of a volume structure/file structure of a file system, recording/reproduction of a metadata partition/file structure described below, recording/reproduction of files and recording/reproduction of the lead-in/lead-out areas. 
     The memory circuit  302  is used to operate information such as a volume structure, a file structure, a metadata partition/file structure and files, and is used to temporarily store them. 
     The drive apparatus  310  includes a drive control section  311 , a memory circuit  312 , and a recording/reproduction section  314 . The components in the drive apparatus  310  are connected to each other via an internal bus  313 . 
     The drive control section  310  can be implemented, for example, by a microprocessor including a drive control program and a memory for operation. The drive control section  310  controls various processes and performs various operations such as recording/reproduction of the disc management information area and the spare area and the pseudo-overwrite recording/reproduction. 
     The system control section  301  and drive control section  310  shown in  FIG. 6  can be implemented by a semiconductor integrated circuit such as an LSI. Alternatively, they can be implemented by a general processor and a memory (e.g. a ROM). 
     A program is stored in the memory (e.g. a ROM). The program is executable by a computer (e.g. a general processor). This program may represent a reproduction process and/or a recording process according to the present invention described above or described below. A computer (e.g. a general processor) performs the reproduction process and/or the recording process according to the present invention in accordance with the program. 
     The memory circuit  312  is used to operate data concerning the disc management information area and the spare area and data transferred to the drive apparatus  310 , and is used to temporarily store them. 
     1-4. Procedure of Recording Process (1) 
     With reference to  FIG. 7 , the data structure of the information recording medium  100  after performing a format process according to the present embodiment of the invention will be described below. 
     Track # 1   401 , track # 2   402  and track # 3   403  are allocated in the user data area  108 . 
     A volume space  109  is allocated in the user data area  108 . A volume structure area  410 , a physical partition  420  and a volume structure area  411  are allocated in the volume space  109 . 
     In the physical partition  420 , a metadata partition  430  is included. The metadata partition  430  is defined in a pseudo-overwrite method in version 2.5 or higher version of the UDF specification. 
     In the metadata partition  430 , a metadata file  440  is recorded. In order to simplify the description, the description of a metadata mirror file is omitted below. The metadata mirror file is a duplication of metadata file  440 . The metadata mirror file can be also recorded. 
     A FE (Metadata file)  441  is recorded. The FE (Metadata file)  441  is a file entry (FE) indicating a recording location of the metadata file  440  in the physical partition  420 . 
     The information on the file structure such as a file entry (FE) indicating a recording location of a user data file or a directory, is located in the metadata partition  430  (i.e. the metadata file  440 ). 
     In  FIG. 7 , only the ROOT directory is recorded. In the metadata file  440 , only a file set descriptor  433  FE and an FE (ROOT)  442  are recorded. In order to simplify the description, it is assumed that a directory file is included in each FE. 
     It is assumed that the state shown in  FIG. 7  is a state in which any replacement recording has not been performed yet. The management of unrecorded areas in the metadata partition  430  may be performed using a metadata bitmap (not shown) as defined in version 2.5 of the UDF specification. 
     Alternatively, it is possible to perform the management of unrecorded areas in the metadata partition  430  by the LRA  405  in the track # 1  while maintaining unrecorded areas in the metadata partition  430  unrecorded. 
     The method for allocating tracks is not limited to the method shown in  FIG. 7 . For example, more tracks can be allocated. It is possible to add a new track when it is required, while maintaining the state of the last track in the user data area such that the new track can be added to the last track. 
     Next, with reference to a flowchart shown in  FIG. 8A , the procedure of the data recording process will be described below. 
     Herein, a case where a data file (File-a) is to be recorded in the information recording medium  100  is described as an example. 
     A plurality of physical addresses are assigned to the data area  102  of the information recording medium  100 . A plurality of logical addresses are assigned to the user data area  108  of the information recording medium  100 . It is assumed that a corresponding relationship between the plurality of logical addresses and the plurality of physical addresses is predetermined. 
     Each of the plurality of logical addresses is represented by a logical sector number (LSN) or a logical block address (LBA). Each of the plurality of physical addresses is represented by a physical sector number (PSN) or physical block address (PEA). Further, it is assumed that at least one track is allocated in user data area  108 . 
     (Step S 101 ) Prior to recording the data file (File-a), the drive control section  311  performs a preparation process for the data recording. Such a preparation process for the data recording is performed, for example, when the information recording medium  100  is loaded into the drive apparatus  310 . 
     For example, the drive control section  311  reads the latest disc management information from the disc management information area  104  (or the disc management information area  105 ) of the information recording medium  100 . 
     The drive control section  311  obtains the user area start location information  1103 , the user area end location information  1104 , the spare area information  1105  and like from the disc management information in order to determine a primary logical address-physical address mapping indicating the corresponding relationship between the plurality of logical addresses and the plurality of physical addresses assigned to the user data area  108 . 
     Hereinafter, the drive control section  311  performs translation between the logical address and primary physical address in accordance with the primary logical address-physical address mapping. 
     The drive control section  311  obtains track management information included in the disc management information area  104 . 
     (Step S 102 ) The drive control section  311  receives a recording instruction from the host apparatus  305 . The recording instruction includes a logical address indicating a location at which data is to be recorded. This logical address is represented, for example, by a logical sector number (LSN) or a logical block address (LBA). The recording instruction may include a single logical address indicating a location at which single data is to be recorded, or it may include a plurality of logical addresses indicating a plurality of locations at which a plurality of data are to be recorded respectively. 
     The logical address included in the recording instruction is determined, for example, by the host apparatus  305  based on a logical address indicating a location at which data is to be recorded the next time (i.e. a logical next writable address (a logical NWA)). 
     The logical NWA is output from the drive apparatus  310  to the host apparatus  305  in response to a request from the host apparatus  305  to the drive apparatus  310 , for example. 
     The logical NWA is obtained by translating the NWA determined by Expression (1) described above in accordance with the primary logical address-physical address mapping. This translation is performed by the drive control section  311 . The procedure for determining the NWA and the logical NWA will be described later in detail in embodiment 2 of the invention. 
     The system control section  301  of the host apparatus  305  generates and updates file system information as necessary in order to record data file (File-a). For example, the system control section  301  generates an FE (File-a) for the data file (File-a) and updates the ROOT directory which is a parent directory of the data file (File-a) using the memory circuit  302 . 
     The generated FE (File-a) for the data file (File-a) and the updated ROOT directory are recorded in the information recording medium  100  by outputting the recording instruction from the host apparatus  305  to the drive apparatus  310 . Thus, the latest file system information is reflected on the information recording medium  100 . 
     If necessary, the host apparatus  305  inquires the drive apparatus  310  using a predetermined command as to whether or not there is any remaining unrecorded area for performing a replacement recording. 
     The instructions from the host apparatus  305  to the drive apparatus  310  may be a standardized command such as a SCSI multi-media command. 
     For example, a request for the logical NWA may be a READ TRACK INFORMATION command, and a recording instruction may be a WRITE command. 
     (Step S 103 ) The drive control section  311  translates the logical address included in the recording instruction received in step S 102  into a physical address in accordance with the primary logical address-physical address mapping. 
     (Step S 104 ) The drive control section  311  determines a track (an open track) of the at least one track allocated in the user data area  108  based on the physical address corresponding to the logical address included in the recording instruction and the track management information  210  ( FIG. 2B ) included in the disc management information. 
     The drive control section  311  determines a physical address indicating a location at which data is to be recorded the next time (i.e. NWA) within the determined track, based on LRA  213  within the determined track. This NWA is a next writable address determined in accordance with Expression (1) described above. 
     The NWA may be determined in step S 104 . Alternatively, the NWA may be determined in other steps other than step S 104  (e.g. in the preparation process for the data recording described above). 
     By calculating the NWA using the LRA, it is not necessary to hold the information on the NWA in the track management information. As a result, it is possible to simplify the data structure of the track management information. 
     (Step S 105 ) The drive control section  311  determines Whether or not the physical address corresponding to the logical address included in the recording instruction is less than the NWA. 
     When it is determined that the physical address corresponding to the logical address included in the recording instruction is less than the NWA, the recording instruction is determined as a recording instruction for the recorded area in the user data area  108 . In this case, the process proceeds to Step S 106 . Otherwise, the process proceeds to step S 108 . 
     (Step S 106 ) The drive control section  311  determines data to be recorded. When the data recording is performed as a unit of ECC cluster in the information recording medium  100 , the drive control section  311  determines the data specified by the recording instruction as the data to be recorded. For example, if the recording location and the size of the data specified by the recording instruction match a boundary of the ECC clusters, then an entire ECC cluster is rewritten. In this case, the drive control section  311  determines the data itself specified by the recording instruction as the data to be recorded. 
     If it does not match any boundary of the ECC clusters, then the drive control section  311  performs a read-modify-write process described below. In this case, the drive control section  311  determines the data as a unit of ECC cluster which is obtained during the read-modify-write process as the data to be recorded. 
     (Step S 107 ) The drive control section  311  determines the recording location of the data determined in step S 106 . Specifically, the drive control section  311  determines a specific location in the user data area  108 , which is other than the location indicated by the physical address corresponding to the logical address included in the recording instruction, as the recording location of the data determined in step S 106 . 
     The specific location may be the NWA within the track determined in Step S 104 . 
     Alternatively, the specific location may be a location indicated by an NWA within an open track which is different from the track determined in step S 104 . In this case, it is preferable that the NWA within the open track is an NWA which indicates a location which is closest to the location indicated by the physical address corresponding to the logical address included in the recording instruction. 
     (Step S 108 ) The drive control section  311  determines whether or not the physical address corresponding to the logical address included in the recording instruction is equal to the NWA. 
     When it is determined that the physical address corresponding to the logical address included in the recording instruction is equal to the NWA, the recording instruction is determined as a recording instruction to the location indicated by the NWA. That is, the data recording instructed by the recording instruction is determined as an appending recording (a new recording). In this case, the process proceeds to Step S 109 . Otherwise, the process proceeds to Step S 111 . 
     (Step S 109 ) The drive control section  311  determines data to be recorded. Specifically, the drive control section  311  determines the data specified by the recording instruction as the data to be recorded. 
     Then, the drive control section  311  determines whether or not the end of the data specified by the recording instruction matches a boundary of the ECC clusters. If it does not match the boundary of the ECC clusters, padding data (e.g. data consisting of one or more “00” h) is inserted such that the end of the data after insertion matches the boundary of the ECC clusters. In this case, the drive control section  311  determines the data after insertion as the data to be recorded. 
     (Step S 110 ) The drive control section  311  determines the recording location of the data determined in Step S 106 . Specifically, the drive control section  311  determines the location indicated by the physical address corresponding to the logical address included in the recording instruction (i.e. the location indicated by the NWA), as the recording location of the data determined in step S 106 . 
     (Step S 11 ) The drive control section  311  performs an error process. 
     (Step S 112 ) The drive control section  311  performs a recording process for the determined recording location. 
     When the determination result in step S 105  is “Yes”, the drive control section  311  controls the recording/reproduction section  314  to record the data determined in step S 106  at the recording location determined in step S 107 . 
     When the determination result in step S 108  is “Yes”, the drive control section  311  controls the recording/reproduction section  314  to record the data determined in step S 109  at the recording location determined in step S 110 . 
     Further, the drive control section  311  performs a verify process for the recorded data to determine whether or not the data recording has succeeded. If the data recording has succeeded, then the process proceeds to step S 113 . 
     If the data recording has failed, then an unrecorded area in the spare area (e.g. the inner spare area  106 ) or the user data area  108  is allocated as a replacement cluster and the data is recorded in the replacement cluster. 
     After the data recording has finally succeeded, the process proceeds to step S 113 . 
     For example, the processes of step S 106  and step S 112  described above is performed as a read-modify-write process (hereinafter RMW process). 
     According to the RMW process, firstly, the drive control section  311  controls the recording/reproduction section  314  to reproduce the data recorded in the ECC cluster including a physical sector at a location indicated by the physical address corresponding to the logical address included in the recording instruction, and it stores the data reproduced from the ECC cluster in the memory circuit  312  (i.e. “read” process). 
     There is a possibility that the ECC cluster to be reproduced is replaced with a replacement cluster at the time when the reproduction process is performed. The drive control section  311  refers to the replacement management information list  1000 , and, if necessary, it controls the recording/reproduction section  314  to reproduce the data recorded in the replacement cluster. The procedure of the data reproduction referring to the replacement management information list  1000  will be described later. 
     Secondly, the drive control section  311  replaces the data recorded in the physical sector at the location indicated by the physical address corresponding to the logical address included in the recording instruction among the data reproduced from the ECC cluster with the data included in the recording instruction (i.e. “modify” process). As a result, the data to be recorded in the replacement cluster is obtained. 
     The drive control section  311  performs a read process and a modify process in step S 106 . 
       FIG. 8B  shows the steps performed when the read process and the modify process are performed in step S 106  shown in  FIG. 8A . Each step shown in  FIG. 8B  is performed by the drive control section  311  of the drive apparatus  310 . 
     (Step S 151 ) The drive control section  311  determines whether or not the ECC cluster including the location specified by the recording instruction has been already replaced by an replacement cluster. Such a determination is made, for example, by retrieving the replacement management information list  1000 . 
     If the replacement management information  1010  which indicates the location specified by the recording instruction as original location is found, it is determined that the ECC cluster has been already replaced by the replacement cluster and the process proceeds to step S 152 A. Otherwise, the process proceeds to step S 152 B. 
     By holding the determination result of step S 151  as a value of the internal variable, it is possible to refer to the value of the internal variable. By referring to the value of the internal variable, if necessary, in the steps other than step S 151 , it is possible to determine whether or not the ECC cluster including the location specified by the recording instruction has been already replaced by a replacement cluster. This makes it possible to avoid repeatedly performing the same process. For example, if the determination result of step S 151  is “Yes”, then the value of “1” may held as the value of the internal variable, and if the determination result of step S 151  is “No”, then the value of “0” may held as the value of the internal variable. 
     (Step S 152 A) The drive control section  311  determines whether or not the RMW process is required. For example, if the location and the size specified by the recording instruction matches a boundary of the ECC clusters, then drive control section  311  determines that the RMW process is not required. If the location and the size specified by the recording instruction do not match any boundary of the ECC clusters, then drive control section  311  determines that the RMW process is required. 
     If it is determined that the RMW process is required, then the process proceeds to Step S 153 . Otherwise, the process proceeds to Step S 157 . 
     Similar to step S 151 , by holding the determination result of step S 152 A as a value of the internal variable, it is possible to refer to the value of the internal variable. By referring to the value of the internal variable, if necessary, in the steps other than step S 152 A, it is possible to determine whether or not the RMW process is required. 
     (Step S 152 B) The drive control section  311  determines whether or not the RMW process is required. The process of step S 152 B is the same as the process of step S 152 A. 
     (Step S 153 ) The drive control section  311  controls the recording/reproduction section  314  to reproduce the data recorded in the replacement cluster indicated by the replacement management information  1010  found in Step S 151 , instead of the ECC cluster including the location specified by the recording instruction, and stores the reproduced data in the memory circuit  312 . 
     (Step S 154 ) The drive control section  311  controls the recording/reproduction section  314  to reproduce the data recorded in the ECC cluster including the location specified by the recording instruction, and stores the reproduced data in the memory circuit  312 . 
     (Step S 155 ) The drive control section  311  replaces the reproduced data by the data specified by the recording instruction so as to generate a modified data. 
     (Step S 156 ) The drive control section  311  determines the modified data as the data to be recorded in the information recording medium  100 . 
     (Step S 157 ) The drive control section  311  determines the data specified by the recording instruction as the data to be recorded in the information recording medium  100 . 
     Thus, the read process and the modify process are completed. 
     Thirdly, the drive control section  311  controls the recording/reproduction section  314  to record the data obtained as a result of the modify process (i.e. the data to be recorded in the replacement cluster) in a location of the original ECC cluster (i.e. “write” process). The drive control section  311  performs write process in step S 112 . 
     However, in the present invention, since the information recording medium is a write-once recording medium, it is not possible to actually record the data in a location of the original ECC cluster. 
     Accordingly, in the present invention, an unrecorded area in the spare area such as the inner spare area  106  or the user data area  108  is allocated as a replacement cluster, and the updated data is recorded in the replacement cluster. 
     Further, the drive control section  311  performs a verify process to determine whether or not the data recording has succeeded. When it is determined that the data recording has succeeded, the process proceeds to step S 113 . 
     When it is determined that the data recording has failed, an unrecorded area in the spare area such as the inner spare area  106  or the user data area  108  is allocated as a further replacement cluster, and the data is recorded in the further replacement cluster. 
     After the data recording has finally succeeded, the process proceeds to step S 113 . 
     When the area specified by the recording instruction corresponds to an entire ECC cluster, the entire ECC block is rewritten. In this case, the read process described above is not required. 
     (Step S 113 ) The drive control section  311  generates replacement management information  1010  in accordance with the process in step S 112 , and stores the replacement management information  1010  in memory circuit  312 . For example, in step S 112 , when the drive control section  311  controls the recording/reproduction section  314  to record data at a specific location in the user data area  108  wherein the specific location is any location other than the location indicated by the physical address corresponding to the logical address included in the recording instruction, the drive control section  311  generates replacement management information  1010  which maps the physical address corresponding to the logical address included in the recording instruction to a physical address indicating the specific location. 
     It is possible to determine whether or not the replacement management information  1010  having the original location information  1012 , which indicates the same location as the physical address corresponding to the logical address included in the recording instruction, is found in the existing replacement management information list  1000  by retrieving the existing replacement management information list  1000 . 
     If it is found, the drive control section  311  updates the replacement management information  1010  so as to set the physical address indication of the specific address as a new replacement location information  1013 . 
     If it is not found, the drive control section  311  generates new replacement management information  1010  and adds the new replacement management information  1010  to the replacement management information list  1000 . 
     Next, the drive control section  311  sorts the replacement management information list  1000 . For example, the drive control section  311  sorts the replacement management information list  1000  by the status information  1011 , and then sorts it by the physical address indicated by the original location information  1012 . 
     Thus, a new replacement management information list  1000  including the replacement management information  1010  which maps the physical address corresponding to the logical address included in the recording instruction to the physical address indicating the specific location is generated. 
     (Step S 114 ) The drive control section  311  updates the disc management information to reflect the recording process described above. For example, the drive control section  311  updates the last recorded address information  1107 . In addition, the drive control section  311  updates the LRA  213  in each track management information  210  corresponding to the tracks in which data have been recorded to reflect the latest recording status. 
     Further, the drive control section  311  generates the new disc management information including the updated information such as the new replacement management information list  1000  and track management information  210 . In addition, the drive control section  311  sets the replacement management information list location information  1102  and the session management information location information  1109  included in the new disc management information to indicate the latest recording location of the new replacement management information list  1000  and track management information  210  on the information recording medium  100 . 
     The drive control section  311  controls the recording/reproduction section  314  to record the new disc management information in a predetermined area (e.g. a temporal disc management information area) on the information recording medium  100 . Thus, the disc management information is updated to reflect the latest status. 
     When the data recording is completed, the drive apparatus  310  can notify the host apparatus  305  of the result of the recording process. The result of the recording process is, for example, information indicating that the data recording has succeeded or failed. 
     Such a notification can be sent to the host apparatus  305  at a predetermined timing. For example, it is possible to send this notification to the host apparatus  305  at the timing of the end of step S 108  or at the timing when an error occurs in step S 112 . Alternatively, it is possible to send this notification before the data recording is actually completed. For example, it is possible to send a notification indicating that the data recording is completed to the host apparatus  305  at the timing when the interpretation of the received record instruction is completed correctly. 
     In the replacement recording process, it is possible to retrieve an unrecorded area in a direction along which the PSNs are increased from the location of the original ECC cluster. If the unrecorded area is found during the retrieval, the unrecorded area is allocated as a replacement cluster. 
     Alternatively, it is possible to first retrieve an unrecorded area in a track including the original ECC cluster, and then retrieve an unrecorded area for each track in a direction along which the PSNs are increased from the track. 
     When the retrieval for the unrecorded area reaches the end of the user data area  108  without finding any unrecorded area, it is possible to retrieve an unrecorded area in the outer spare area  107  following the user data area  108 . 
     Further, the retrieval for the unrecorded area reaches the end of the outer spare area  107  without finding any unrecorded area, it is possible to retrieve an unrecorded area in a direction along which the PSNs are increased from a predetermined location at the inner side of the information recording medium  100  (e.g. a leading position of the inner spare area  106  or a leading position of the user data area  108  or a location apart from its leading position by a predetermined distance). 
     In steps S 105  and S 108  of the procedure of the recording process, it is determined whether the data recording is a pseudo-overwrite recording or an appending recording by comparing the physical address corresponding to the logical address included in the recording instruction with the NWA. 
     The reason why it is determined whether the data recording is a pseudo-overwrite recording or an appending recording based on such a comparison is that the information recording medium  100  is a write-once recording medium and that a sequential recording is performed for the write-once recording medium. 
     The replacement recording method using the user data area described above according to the present invention is applicable to any rewritable optical disc. However, in order to determine whether the data recording is an overwrite recording or an appending recording (or a new recording) for the rewritable optical disc, a more complex process is required. This is because, in the case of the rewritable optical disc, it is possible to randomly rewrite data at an arbitrary location on the optical disc. 
     When the drive apparatus manages an unrecorded area on the rewritable optical disc as described in the embodiment above, it is necessary to manage replacement management information corresponding to all ECC clusters on the rewritable optical disc using the SDL, as described in the background art of the present specification, for example. Further, in order to determine whether the data recording for recording data at a certain location in the user data area is an overwrite recording or a new recording, it is necessary to retrieve an entire replacement management information list  1000 , for example. Similarly, in order to determine whether or not an ECC cluster is used as a replacement cluster, it is necessary to retrieve an entire replacement management information list  1000 . The amount of such a retrieving process is increased as the size of the replacement management information list  1000  is increased. This should be a problem since the capacity of the optical disc is being increased more and more. 
     On the other hand, in the present invention, since the information recording medium  100  is a write-once recording medium, it is ensured that every area in a track which has an address less than the NWA is an unrecorded area. 
     Accordingly, by performing the comparison described in steps S 105  and S 108 , it is possible to easily determine whether the data recording is a pseudo-overwrite recording or an appending recording, regardless of the size of the replacement management information list  1000 . Further, it is possible to easily select a replacement cluster since the replacement cluster can be selected from any location after the NWA. 
     The pseudo-overwrite recording in a random recording method for a write-once optical disc is performed in a similar way as the rewritable optical disc. 
     Further, in order to perform the random recording method for the write-once optical disc, a special structure such as the space bitmap management information  220  is required. The management of the unrecorded area for the random recording method using the space bitmap management information  220  requires significantly greater processing load to the drive control section  311 , compared to the management of the unrecorded area for the sequential recording method. 
     In particular, in the sequential recording method, it is possible to limit the number of open tracks to a predetermined number (for example, four at maximum) so that the utilization of a file system is not reduced. 
     In this case, the number of open tracks depends on the structure of the file system, and it is independent from the capacity of the optical disc. On the other hand, the size of the space bitmap management information  220  is increased as the capacity of the optical disc is increased. As a result, the processing load is also increased. 
     Thus, the effect of the present invention for performing a pseudo-overwrite in the sequential recording method is very significant for the optical disc, since the capacity of the optical disc is being increased more and more. 
     One feature of the present invention is to determine an NWA in accordance with LRA  213  included in the latest track management information  210  and expression (1) in order to determine whether the data recording is a pseudo-overwrite recording or an appending recording. 
     By recording the LRA  213 , which has been updated as a result of the data recording, on the disc, it is possible to reduce the time required to find the latest LRA  213  when the information recording medium  100  is loaded into the drive apparatus  310 . 
     By calculating the NWA using the LRA  213 , it is not necessary to hold information on the NWA in the track information. As a result, it is possible to simplify the data structure of the track management information. 
     In order to determine whether the data recording is a pseudo-overwrite recording or an appending recording without using a method according to the present invention, the following procedure is required, for example. 
     Specifically, the procedure includes the steps of determining a track including a physical address corresponding to the logical address included in the recording instruction, sequentially checking ECC clusters from a leading position of the determined track, and determining whether or not each of the ECC clusters is recorded. 
     If the ECC cluster is in a recorded state at a location indicated by the recording instruction, then it is determined that the data recording is a pseudo-overwrite recording. 
     However, it is not preferable to perform such a procedure since the amount of the required processing is increased as the size of the track is increased. 
     On the other hand, according to the present invention, it is possible to easily determine whether the data recording is a pseudo-overwrite recording or an appending recording, regardless of the size of the track. 
     Further, since LRA  213  is included in the track management information  210 , it is possible to easily determine an NWA as well as the determination of a track in which the data is to be recorded when the drive apparatus  310  receives the recording instruction. 
       FIG. 9  shows a data structure on the information recording medium  100  after the data file has been recorded in accordance with the procedure of the data recording. 
     Referring to  FIG. 9 , data file (File-a)  460  is described as an example of the data file. It is assumed that a defective cluster # 1  and a defective cluster # 2  are detected in the data file (File-a)  460  in the procedure of the data recording. 
     The disc management information including replacement management information indicating a replacement of the defective cluster # 1  with a replacement cluster # 1  and a replacement management information indicating a replacement of the defective cluster # 2  with a replacement cluster # 2  is recorded in the disc management information area  104 . 
     As shown in  FIG. 9 , the replacement cluster # 1  is recorded in the inner spare area  106  and the replacement cluster # 2  is recorded in the user data area  108 . 
     The content of the data file (File-a)  460  is updated by the pseudo-overwrite recording. Specifically, an overwritten cluster # 3  and an overwritten cluster # 4  correspond to the updated portions of the data file (File-a)  460  according to the pseudo-overwrite recording. 
     The new data updated by the pseudo-overwrite recording is recorded in a replacement cluster # 3  assigned as the substitute for the overwritten cluster # 3  and is recorded in a replacement cluster # 4  assigned as the substitute for the overwritten cluster # 4 . The corresponding replacement information is recorded in the disc management information area  104 . 
     As shown in  FIG. 9 , the replacement cluster # 3  is assigned in the inner spare area  106  and the replacement cluster # 4  is assigned in the user data area  108 . 
     1-5. Procedure of Reproduction Process (1) 
     With reference to a flowchart shown in  FIG. 10 , a reproduction process for a file is described. Herein, a reproduction process for the data file (File-a)  460  shown in  FIG. 9  is described as an example. 
     (Step S 201 ) Prior to performing a reproduction process, the drive control section  311  performs a preparation process for the data reproduction. Such a preparation process for the data reproduction is performed, for example, when the information recording medium  100  is loaded into the drive apparatus  310 . 
     For example, the drive control section  311  reads disc management information from the disc management information area  104  (or the disc management information area  105 ) of the information recording medium  100 . 
     The drive control section  311  obtains user area start location information  1103 , user area end location information  1104 , spare area information  1105  and like from the disc management information to generate a primary logical address-physical address mapping indicating the corresponding relationship between the plurality of logical addresses and the plurality of physical addresses assigned to the user data area  108 . 
     Hereinafter, the drive apparatus  310  performs translation between the logical address and the primary physical address in accordance with primary logical address-physical address mapping. 
     (Step S 202 ) The system control section  301  outputs a reproduction instruction to the drive apparatus  310  to reproduce an AVDP recorded at a predetermined location (e.g. LSN=256) of the information recording medium  100 . 
     The AVDP is a data structure defined by the UDF specification as an anchor point of the file system information. The AVDP is recorded in the volume structure area  410  and the volume structure area  411 . 
     (Step S 203 ) The system control section  301  obtains location information of a main volume descriptor sequence  410 A recorded in the volume structure area  410  from the AVDP. The system control section  301  outputs an instruction to the drive apparatus  310  to reproduce the main volume structure  410 A. 
     Further, the system control section  301  obtains location information (LSN) of an FE (metadata file)  441  by retrieving the data structure from the reproduced main volume descriptor sequence  410 A in steps. 
     (Step S 204 ) The system control section  301  reproduces a file structure. In order to reproduce the file structure, the system control section  301  outputs a reproduction instruction to the drive apparatus  310  based on the obtained location information (LSN) of the FE (metadata file)  441  to reproduce the FE (metadata file)  441 . 
     The system control section  301  obtains location information of a metadata file  440  from the reproduced FE (metadata file)  441 . As a result, it is possible to access the metadata file  440 . 
     (Step S 205 ) In accordance with the procedure of the data reproduction based on the UDF specification, the FDS  433 , the FE (ROOT)  442 , the FE (File-a)  443  and the data file (File-a)  460  are reproduced in this order. The description of the reproduction of the directory file is omitted. 
     In each step in the reproduction process described above, a reproduction instruction is output from the host apparatus  305  to the drive apparatus  310 . The drive control section  311  of the drive apparatus  310  receives the reproduction instruction from the host apparatus  305 , and performs a reproduction process in accordance with the reproduction instruction. 
     The reproduction instruction includes a logical address indicating a location from which data is to be reproduced. The logical address is, for example, represented by a logical sector number (LSN). Alternatively, the logical address may be represented by a logical block address (LBA). The reproduction instruction is, for example, a READ command. 
     The drive control section  311  translates the logical address included in the reproduction instruction into a physical address in accordance with the primary logical address-physical address mapping (for example, see  FIG. 12 ). 
     The drive control section  311  determines whether or not the replacement management information  1010  having the original location information  1012 , which indicates the same location as the physical address corresponding to the logical address included in the reproduction instruction, is found in the replacement management information list  1000  by retrieving the replacement management information list  1000 . 
     If it is found, the drive control section  311  refers to the replacement location information  1013  of the replacement management information  1010  and controls the recording/reproduction section  314  to reproduce data from the location indicated by the replacement location information  1013 . 
     If it is not found, the drive control section  311  controls the recording/reproduction section  314  to reproduce data from the location indicated by the physical address corresponding to the logical address included in the reproduction instruction. The reproduced data is sent back to the host apparatus  305 . 
     1-6. Procedure of Recording Process (2) 
       FIG. 11  shows a data structure of the replacement management information  1010 B. The replacement management information  1010 B is a different embodiment of the replacement management information  1010  shown in  FIG. 5B . 
     As shown in  FIG. 11 , the status information  1011  of the replacement management information  1010 B includes three information, i.e. Flag 1 , Flag 2  and Flag 3 . 
     Flag 1  is information for classifying the replacement management information  1010 B. Flag 1  includes information indicating whether the replacement information is for the purpose of the replacement recording or for the purpose of the designation of the defective cluster. 
     Flag 2  is information on the recording location of the replacement cluster managed by the replacement management information  1010 B. Flag 2  includes information indicating whether the recording location of the replacement cluster is in the spare area (or there is no replacement cluster) or the recording location of the replacement cluster is in the user data area. 
     Flag 3  is information on the number of the clusters managed by the replacement management information  1010 B. Flag 3  includes information indicating whether the replacement information corresponds to a single cluster or a plurality of contiguous clusters. When the replacement information corresponds to a plurality of contiguous clusters, Flag 3  further includes information indicating whether the replacement information corresponds to a start location of the contiguous range or an end location of the contiguous range. 
     Hereinafter, with reference to  FIG. 11 , the procedure of the data recording according to the present invention will be described in detail. 
     The symbols at the right side of  FIG. 11  represent the respective types of the replacement management information. These symbols are referred to in the description below, if necessary. For example, the replacement management information (type (1)) includes the status information  1011  such that Flag 1 =1 (for the purpose of the replacement recording), Flag 2 =0 (for the replacement in the spare area) and Flag 3 =00 (for a single cluster). This replacement management information (type (1)) may be denoted by the replacement management information ( 1 ). 
       FIG. 12  shows an example of the data structure of the physical address space and the logical address space on the information recording medium  100  according to the present invention. 
       FIG. 12  also shows a corresponding relationship between the logical sector number (LSN) and the physical sector number (PSN) in a primary state. The logical sector number (LSN) is a logical address indicating a location which is seen from the host apparatus  305  on the information recording medium  100 . The physical sector number (PSN) is a physical address indicating an actual location on the information recording medium  100 . This corresponding relationship is referred to as a primary logical address-physical address mapping. This mapping is represented by broken line arrows in  FIG. 12  (or other figures). 
     Each row shown in  FIG. 12  corresponds to one ECC cluster. In  FIG. 12 , a physical address (PSN) and a logical address (LSN) corresponding to the physical address (PSN) are shown in the same row. 
     In  FIG. 12 , the values of the PSNs and the LSNs are shown as the values of the PSNs and the LSNs from the first sector to the last sector in the corresponding ECC cluster. 
     Herein, it is assumed that one ECC cluster consists of 32 sectors. However, one ECC cluster may be any other configuration. 
     The PSNs are assigned to the inner spare area  106 , the outer spare area  107  and the user data area  108 . 
     The tracks are allocated from a leading position of the user data area  108 . In the state shown in  FIG. 12 , since no data is recorded, the LRA  500  designates a leading position of the user data area  108 . 
     The LSNs are assigned to only the user data area  108  (or the volume space  109 ). 
     The host apparatus  305  instructs a recording process or a reproduction process. These instructions specify a specific logical sector on the information recording medium  100  using the LSN. 
     The drive apparatus  310  translates the LSN received from the host apparatus  305  into a PSN using the primary logical address-physical address mapping, and accesses a physical sector or ECC cluster in accordance with the PSN. 
     In the replacement recording described hereinafter, the primary logical address-physical address mapping is basically used. When the logical address-physical address mapping other than the primary logical address-physical address mapping is required, the replacement management information  1010  is used. 
     The values of the PSNs and the LSNs are only examples for explanation. These values can be varied depending on the structure and the capacity of the information recording medium  100 . 
     As described above, the size of the disc management information and the spare area can be changed. The size of these is determined at the time when the format process is performed in response to an instruction from the host apparatus  305 . After the format process, the start location and the end location of the user data area  108  is not changed. 
     In this case, it is possible to determine a relationship of the primary logical address-physical address mapping uniquely (e.g. by a predetermined calculation) from information of the disc structure information  1100  (e.g. in more detail, user area start location information  1103 , user area end location information  1104 , spare area information  1105  and like) included in the disc management information. 
     With reference to  FIGS. 12 to 17B , an exemplary use of the replacement management information  1010 B shown in  FIG. 11  will be described. 
     Firstly, the transition from the state shown in  FIG. 12  to the state shown in  FIG. 13A  is described. 
     The host apparatus  305  instructs to record data “A” at a location of LSN=0. 
     Upon the receipt of the recording instruction, the drive apparatus  310  translates LSN=0 into PSN=1100 in accordance with the primary logical address-physical address mapping and records data “A” at a location of PSN=1100. 
     Next, the drive apparatus  310  performs a verify process for the recorded data. Herein, it is assumed that the recording of data “A” has succeeded. 
     The host apparatus  305  instructs to record data “A 1 ” at a location of LSN=0. 
     Upon the receipt of the recording instruction, the drive apparatus  310  translates LSN=0 into PSN=1100 in accordance with the primary logical address-physical address mapping and performs a RMW process at a location of PSN=1100. Then, the drive apparatus  310  records data “A 1 ” at a location of PSN=100 in the inner spare area  106 . 
     The drive apparatus  310  generates replacement management information  511 . The location of PSN=1100 at which data “A” is recorded is set to the original location of the replacement management information  511 . The location of PSN=100 at which data “A 1 ” is recorded is set to the replacement location of the replacement management information  511 . The status information  1011  of the replacement management information  511  is set in accordance with  FIG. 11 . 
     The replacement management information  511  corresponds to solid line arrows shown in  FIG. 13A . The tail of each arrow represents the original location of the replacement management information  511  and the head of each arrow represents the replacement location of the replacement management information  511 . Hereinafter, a similar notation will be used. 
     In the state shown in  FIG. 13A , the host apparatus  305  instructs to record data “B” at a location of LSN=2. Herein, it is assumed that the recording of data “B” has failed. Then, the data “B” is recorded at a location of PSN=132 in the inner spare area  106 . 
     The replacement management information  512  is generated in response to this replacement recording. The location of PSN=1032 is set to the original location of the replacement management information  512 . The location of PSN=132 is set to the replacement location of the replacement management information  512 . The status information  1011  of the replacement management information  512  is set in accordance with  FIG. 11 . 
     The data allocation and the replacement management information list after the data recording described above is completed are shown in  FIG. 13A  and  FIG. 13B , respectively. In the replacement management information list  1000 A shown in  FIG. 13B , the replacement management information ( 1 ) is used. 
     With reference to  FIGS. 14A and 14B , the cases where the replacement management information ( 4 ) and ( 7 ) are used will be described. 
     The host apparatus  305  instructs to record data “C” at a location of LSN=64. In accordance with the recording instruction, the drive apparatus  310  records data “C” at a location of PSN=1164. Herein, it is assumed that the recording of data “C” has failed. Then, a recorded area in the user data area  108  (PSN=1196) is allocated and the data “C” is recorded at a location of PSN=1196 instead of the location of PSN=1164. 
     The replacement management information  513  is generated in response to this replacement recording. 
     The host apparatus  305  instructs to record data “D” at a location of LSN=128. Then, the host apparatus  305  instructs to record data “D 1 ”. Herein, it is assumed that the recording of data “D 1 ” has failed. Then, the data “D 1 ” is recorded at a location of PSN=1292. 
     The replacement management information  514  is generated in response to this replacement recording. 
     PSN=1260 indicates a location of a defective cluster, wherein there is no replacement cluster corresponding to the defective cluster. Then, the replacement management information  515  is generated. 
     The host apparatus  305  instructs to record data “D 2 ” at a location of LSN=128. Then, the data “D 2 ” is recorded at a location of PSN=1324. 
     The replacement management information  514 A is generated in response to this replacement recording. The replacement management information  514  becomes unnecessary. Accordingly, the replacement management information  514  is deleted from the replacement management information list  1000 . 
     After the recording process described above is completed, the location of the LRA is updated to a location indicated by  500 B. 
     The replacement management information list  1000 B ( FIG. 14B ) is sorted by Flag 1  of the status information  1011 , and then it is sorted by the value of PSN indicated by the original location information  1012 . 
     With reference to  FIGS. 15A and 15B , the cases where the replacement management information ( 5 ) and ( 6 ) are used will be described. 
     The host apparatus  305  instructs to record data “E” at a location of LSN=256˜X1. Herein, it is assumed that the recording of data “E” has failed. Then, the data “E” is recorded at a location of PSN=x2˜x3. The replacement management information  516  and the replacement management information  517  are generated. Each of the replacement management information  516  and  517  indicates the first PSN of the ECC cluster corresponding to a start location of the replacement recording and the first PSN of the ECC cluster corresponding to an end location of the replacement recording. 
     In the state shown in  FIGS. 16A and 16B , the host apparatus  305  instructs to record data “E 1 ” at a location of LSN=256˜X1. Then, the data “E 1 ” is recorded at a location of PSN=x4˜x5, which are an recorded area in the state shown in  FIG. 15A . 
     The replacement management information  516 A is generated as information indicating a start point of the replacement recording. The replacement management information  517 A is generated as information indicating an end point of the replacement recording. 
     At this time, the replacement management information  516  and  517  become unnecessary. Accordingly, the replacement management information  516  and  517  are deleted from the replacement management information list  1000 . 
     In the examples shown in  FIGS. 15A and 16A , all of data are recorded in the user data area  108  as a result of the replacement recording. However, it is possible to record these data in the inner spare area  106 . In this case, the replacement management information ( 2 ) and ( 3 ) are used. 
     As described in reference with  FIG. 8A , the updated replacement management information list is recorded in the disc management information area. 
     1-7. Procedure of Reproduction Process (2) 
     In order to reproduce the recorded data, the following reproduction process is performed. 
     Prior to performing a reproduction process, the drive control section  311  performs a preparation process for the data reproduction. Such a preparation process for the data reproduction is performed, for example, in a manner similar to step S 201  described above. 
     For example, in the state shown in  FIG. 13A , the host apparatus  305  outputs a reproduction instruction to the drive apparatus  310  to reproduce data “B” at a location of LSN=32. The drive apparatus  310  translates the location of LSN=32 into a location of PSN=1132 in accordance with the primary logical address-physical address mapping. 
     The drive apparatus  310  retrieves the replacement management information having a location of PSN=1132 as an original location in the latest replacement management information list  1000 . 
     In this case, the replacement management information  512  is found, the drive apparatus  310  obtains a location of PSN=132 as a replacement location. 
     The drive apparatus  310  reproduces data “B” from the location of PSN=132 and sends the reproduced data back to the host apparatus  305 . 
     Even if the LSN specified by the host apparatus  305  is changed, the drive apparatus  310  performs the same reproduction process. Specifically, the drive apparatus  310  translates the received LSN into a PSN in accordance with the primary logical address-physical address mapping, and determines whether or not the replacement management information corresponding to the PSN is found in the replacement management information list  1000 . If it is found, then the data is reproduced from the replacement cluster. If it is not found, then the data is reproduced from the PSN. 
     As described above, it is possible to use the user data area  108  as an area for a replacement location without any loss in the pseudo-overwrite recording for the information recording medium  100 . 
     1-8. Procedure of Recording Process (3) 
       FIG. 18  shows a data structure of a DFL entry  2010 . The DFL entry  2010  is a different embodiment of the replacement management information  1010  and the replacement management information  1010 B described above. 
     The DFL entry  2010  includes status  1   2011 A, status  2   2011 B, a defective cluster first PSN  2012  and a replacement cluster leading PSN  2013 . The status  1   2011 A and the status  2   2011 B correspond to the status information  1011  described above. The defective cluster first PSN  2012  corresponds to the original location information  1012  described above. The replacement cluster first PSN  2013  corresponds to the replacement location information  1013  described above. 
     Herein, similar to the explanation with reference to  FIG. 5B , the defective cluster first PNS  2012  and the replacement cluster first PSN  2013  may be represented by a physical address (e.g. PSN) of the first sector in the corresponding ECC cluster. This is because a mapping is performed as a unit of ECC cluster in the defective management and the pseudo-overwrite recording. 
     The status  1   2011 A includes at least information corresponding to Flag 1  and Flag 2  in the replacement management information  1010 B. For example, when the status  1   2011 A has a value of “1000”, it is determined that there is no replacement cluster for the replacement information. This corresponds to a case where Flag 2 =0 and there is no replacement cluster. In this case, a value of “0” is set to the replacement cluster first PSN  2013 . 
     On the other hand, when there exists a replacement cluster, a value of “0000” is set to the status  1   2011 A. This corresponds to a case where Flag 2 =0 and there is a replacement cluster. 
     The status  2   2011 B includes at least information corresponding to Flag 3  in the replacement management information  1010 B. For example, when the status  2   2011 E has a value of “0000”, it is determined that the replacement information corresponds to a single cluster. This corresponds to a case where Flag 3 =00. 
     When the status  2   2011 B has a value of “0001”, it is determined that the replacement information corresponds to a location of the first sector of a start cluster of a contiguous range including a plurality of clusters. This corresponds to a case where Flag 3 =01. When the status  2   2011 B has a value of “0010”, it is determined that the replacement information corresponds to a location of the last sector of an end cluster of a contiguous range including a plurality of clusters. This corresponds to a case where Flag 3 =10. 
     The DFL entry  2010  can be applied to all embodiments. 
     With reference to the data structure of the DFL entry  2010  shown in  FIG. 18  and the flowchart shown in  FIG. 19A , an exemplary process for the replacement management information in step S 113  of  FIG. 8A  will be described in detail. 
     Herein, it is assumed that the replacement recording for the pseudo-overwrite recording is performed in step S 112  shown in  FIG. 8A  and then the process proceeds to Step S 113 . 
     (Step S 301 ) It is determined whether the pseudo-overwrite recording is a first time replacement recording or a second time or more replacement recording. 
     This determination is performed, for example, by retrieving a DFL entry  2010  having a value of the first PSN of the ECC cluster including the physical address corresponding to the logical address included in the recording instruction as a value of the defective cluster first PSN  2012  in the latest replacement management information list. The physical address corresponding to the logical address included in the recording instruction is obtained in step S 103  shown in  FIG. 8A . 
     This latest replacement management information list is reproduced from the disc management information area and is stored in the memory circuit  312  in step S 101  ( FIG. 8A ), for example. 
     When the corresponding replacement management information (e.g. the DFL entry  2010 ) is not found in the replacement management information list, it is determined that the pseudo-overwrite recording is a first time replacement recording. As a result, the process proceeds to step S 302 . 
     When the corresponding replacement management information is found in the replacement management information list, it is determined that the pseudo-overwrite recording is a second time or more replacement recording. As a result, the process proceeds to step S 304 . 
     Whether the pseudo-overwrite recording is a first time replacement recording or a second time or more replacement recording may be predetermined in another step. For example, it may be predetermined in step S 106 . The determination result in step S 106  may be held and may be used in step S 301 . 
     (Step S 302 ) The first time replacement recording is performed as follows. 
     The drive control section  311  creates a new DFL entry  2010  and stores it in the memory circuit  312 . 
     (Step S 303 ) The drive control section  311  sets values to the DFL entry  2010 . 
     An appropriate value is set to the status  1   2011 A of the DFL entry  2010 . For example, when the replacement recording is performed with the replacement cluster, the value of “0000” is set to the status  1   2011 A of the DFL entry  2010 . 
     A value of a first PSN of the ECC cluster located at the physical address corresponding to the logical address included in the recording instruction is set to the defective cluster first PSN  2012  of the DFL entry  2010 . 
     A value of a first PSN of the replacement cluster in which the data is actually recorded in the replacement recording is set to the replacement cluster first PSN  2013  of the DFL entry  2010 . 
     An appropriate value is set to the status  2   2011 B of the DFL entry  2010 . For example, when the replacement recording is performed for the single cluster, the value of “0000” is set to the status  2   2011 B of the DFL entry  2010 . 
     (Step S 304 ) The second time or more replacement recording is performed as follows. 
     The process proceeds to step S 305  in order to update the DFL entry  2010  which has been found in step S 301 . 
     (Step S 305 ) The status  1   2011 A of the DFL entry  2010  is updated to an appropriate value. For example, when the replacement recording is performed and there exists a replacement cluster, the value of “0000” is set to the status  1   2011 A of the DFL entry  2010 . 
     The replacement cluster first PSN  2013  of the DFL entry  2010  is updated to a value of a first PSN of the replacement cluster in which the data is actually recorded in the replacement recording. That is, the location of a new replacement cluster is set. 
     It is not necessary to update the defective cluster first PSN  2012  of the DFL entry  2010 , since the second time or more replacement recording is performed for the same ECC cluster. The defective cluster first PSN  2012  of the DFL entry  2010  maintains the same value. 
     The status  2   2011 B of the DFL entry  2010  is updated to an appropriate value. For example, when the replacement recording is performed for the single cluster, the value of “0000” is set to the status  2   2011 B of the DFL entry  2010 . 
     (Step S 306 ) According to the process mentioned above, the replacement management information list is updated. That is, a new DFL entry  2010  is added to the replacement management information list or the existing DFL entry  2010  in the replacement management information list is updated. 
     Then, the replacement management information list is sorted. For example, the replacement management information list is sorted by the status  1   2011 A. Further, the replacement management information list is sorted by the defective cluster first PSN  2012 , the status  2   2011 B and the replacement cluster first PSN  2013 , in this order. 
     The process of step S 113  shown in  FIG. 8A  is terminated. The latest replacement management information list obtained in the process is additionally recorded in the (temporary) disc management information area. 
     In the exemplary process, a case is described where the replacement recording for the pseudo-overwrite recording is performed. However, the process can be also applied to the replacement recording due to the occurrence of the defective cluster. 
     As described in the background art with reference to  FIGS. 33A and 33B , in the conventional defective management for the write-once optical discs, new replacement management information is added to the replacement management information list each time the replacement recording is performed, while maintaining the existing replacement management information in the replacement management information list. 
     When such a method is applied to a recording method in which the user data area is used as an area for recording a replacement cluster as described in the present embodiment, the number of the replacement management information is increased each time the replacement recording is performed, and the size of the replacement management information list is increased each time the replacement recording is performed. This is not preferable in implementing the drive apparatus and the like. 
     In particular, in the conventional defective management for the write-once optical discs, the cluster which has been replaced with another cluster is not further replaced. However, in the pseudo-overwrite recording as described in the present embodiment, it is possible to further replace the cluster which has been replaced with another cluster. Accordingly, there is a possibility that the size of the replacement management information list is much increased. 
     Further, it is possible that there exists a plurality of replacement management information in the replacement management information list, wherein each of the plurality of replacement management information has the same value as the defective cluster first PSN  2012 . Accordingly, an additional process and/or structure are required to obtain the latest replacement management information. 
     In the defective management for the rewritable optical discs, the replacement management information is provided for every replacement cluster, regardless of whether or not the replacement cluster is actually used. 
     When such a method is applied to a recording method in which the user data area is used as an area for recording a replacement cluster as described in the present embodiment, a large amount of replacement management information is required from an initial state. This is not preferable in implementing the drive apparatus and the like. 
     According to the method shown in  FIG. 19A , it is sufficient to generate and manage the minimum number of replacement management information. It is possible to easily find the latest replacement management information. 
     1-9. Procedure of Recording Process (4) 
     With reference to  FIG. 19B , an exemplary process of the replacement management information in the procedure of the recording process will be described in more detail. 
     The respective steps shown in  FIG. 19B  are included in step S 113  shown in  FIG. 8A . The following description refers to a data structure of the DFL entry  2010  which is an example of the replacement management information shown in  FIG. 18 . 
     Herein, it is assumed that the replacement recording for the pseudo-overwrite recording is performed in step S 112  shown in  FIG. 8A  and then the process proceeds to Step S 113 . 
     (Step S 601 ) The drive control section  311  determines whether or not the area specified by the recording instruction is a contiguous range in the physical address space. 
     For example, the drive control section  311  determines the size of the area on the physical address space based on the recording location specified by the recording instruction and the size of the data to be recorded specified by the recording instruction. When the size of the area on the physical address space which is thus determined is greater than the size of one ECC cluster, the drive control section  311  determines that the area specified by the recording instruction is a contiguous range in the physical address space. 
     If the determination result in Step S 601  is “Yes”, then the process proceeds to step S 602 . If the determination result in step S 601  is “No”, then the process proceeds to Step S 603 . 
     (Step S 602 ) The drive control section  311  determines whether or not the area in which the data is actually recorded in step S 112  is a contiguous range in the physical address space. 
     For example, the size of the area in which the data is actually recorded in Step S 112  is equal to the size of the area specified by the recording instruction, the drive control section  311  determines that the area in which the data is actually recorded in step S 112  is a contiguous range in the physical address space. 
     If the determination result in Step S 602  is “Yes”, then the process proceeds to step S 604 . If the determination result in step S 602  is “No”, then the process proceeds to Step S 603 . 
     (Step S 603 ) The drive control section  311  performs the process described with reference to  FIG. 19A , for example. 
     (Step S 604 ) The drive control section  311  determines whether the pseudo-overwrite recording is a first time replacement recording or a second time or replacement recording. 
     Such a determination is performed, for example, by retrieving the latest replacement management information list to determine whether or not a first DFL entry  2010  (status  2   2011 B=“0001”) and a second DFL entry  2010  (status  2   2011 B=“0010”), each of which having original location information indicating the same area as the contiguous range determined in step S 601 , are found in the replacement management information list. 
     When the first DFL entry  2010  and the second DFL entry  2010  are not found in the replacement management information list, it is determined that the pseudo-overwrite recording is a first time replacement recording. As a result, the process proceeds to step S 605 . 
     When the first DFL entry  2010  and the second DFL entry  2010  are found in the replacement management information list, it is determined that the pseudo-overwrite recording is a second time or more replacement recording. As a result, the process proceeds to step S 607 . 
     (Step S 605 ) The drive control section  311  creates new first DFL entry  2010  and a new second DFL entry  2010  and stores them in the memory circuit  312 . 
     (Step S 606 ) The drive control section  311  sets values to the first DFL entry  2010  and the second DFL entry  2010 . 
     A value of “0000” indicating that the replacement recording is performed and there exists a replacement cluster is set to the status  1   2011 A of the first DFL entry  2010 . 
     A value of a first PSN of the ECC cluster including a start location of the area specified by the recording instruction is set to the defective cluster first PSN  2012  of the first DFL entry  2010 . 
     A value of a first PSN of the ECC cluster including a start location of the contiguous range in which the data is actually recorded is set to the replacement cluster first PSN  2013  of the first DFL entry  2010 . 
     A value of “0001” indicating a start location of the contiguous range is set to the status  2   2011 B of the first DFL entry  2010 . 
     A value of “0000” indicating that the replacement recording is performed and there exists a replacement cluster is set to the status  1   2011 A of the second DFL entry  2010 . 
     A value of a first PSN of the ECC cluster including an end location of the area specified by the recording instruction is set to the defective cluster first PSN  2012  of the second DFL entry  2010 . The end location of the area specified by the recording instruction is calculated, for example, by the physical address corresponding to the logical address and the length of the data to be recorded, which are specified by the recording instruction. 
     A value of a first PSN of the ECC cluster including an end location of the contiguous range in which the data is actually recorded is set to the replacement cluster first PSN  2013  of the second DFL entry  2010 . 
     A value of “0010” indicating an end location of the contiguous range is set to the status  2   2011 B of the second DFL entry  2010 . 
     (Step S 607 ) The drive control section  311  performs an update process for the first DFL entry  2010  and the second DFL entry  2010  found in step S 604 . Specifically, the update process is performed by setting values to the first DFL entry  2010  and the second DFL entry  2010  in step S 608 . 
     (Step S 608 ) The drive control section  311  sets values to the first DFL entry  2010  and the second DFL entry  2010 . 
     A value of a first PSN of the ECC cluster including a start location of the contiguous range in which the data is actually recorded is set to the replacement cluster first PSN  2013  of the first DFL entry  2010 . That is, the start location of a new replacement range is set. 
     It is not necessary to update the defective cluster first PSN  2012  of the first DFL entry  2010 , since the second time or more replacement recording is performed for the same ECC cluster. The defective cluster first PSN  2012  of the first DFL entry  2010  maintains the same value. 
     A value of a first PSN of the ECC cluster including an end location of the contiguous range in which the data is actually recorded is set to the replacement cluster first PSN  2013  of the second DFL entry  2010 . That is, the end location of a new replacement range is set. 
     It is not necessary to update the defective cluster first PSN  2012  of the second DFL entry  2010 , since the second time or more replacement recording is performed for the same ECC cluster. The defective cluster first PSN  2012  of the second DFL entry  2010  maintains the same value. 
     (Step S 609 ) According to the process mentioned above, the replacement management information list is updated. That is, a new first DFL entry  2010  and a new second DFL entry  2010  are added to the replacement management information list or the existing first DFL entry  2010  and the existing second DFL entry  2010  in the replacement management information list are updated. 
     Then, the replacement management information list is sorted. For example, the replacement management information list is sorted by the status  1   2011 A. Further, the replacement management information list may be sorted by the defective cluster first PSN  2012 , the status  2   2011 B and the replacement cluster first PSN  2013 , in this order. 
     The process of step S 113  shown in  FIG. 8A  is terminated. The latest replacement management information list obtained in the process is additionally recorded in the (temporary) disc management information area. 
     In the exemplary process, a case is described where the replacement recording for the pseudo-overwrite recording is performed. However, the process can be also applied to the replacement recording due to the occurrence of the defective cluster. 
     With reference to  FIGS. 20A to 24B , the procedure of the data recording will be further described. 
       FIG. 20A  shows a physical address space and a logical address space on the information recording medium  100 , which is similar to  FIG. 13A  and the like.  FIG. 20A  shows a state in which data “A 0 ” is recorded at the location of LSN=0 immediately after the formatting process. In the physical space, data “AO” is recorded in the location of PSN=1000. 
     The location of LSN=0 and the location of PSN=1000 maintain the relationship of the primary logical address-physical address mapping. 
       FIG. 20B  shows a replacement management information list corresponding to  FIG. 20A . The replacement management information list includes header information  1001  only and does not include any replacement management information. 
     In the state shown in  FIG. 20A , it is assumed that the drive apparatus  310  is instructed by the host apparatus  305  to record data “A 1 ” at the location of LSN=0. 
       FIG. 21A  shows a state in which the recording of data “A 1 ” is completed. 
     As shown in  FIG. 21A , data “A 1 ” is recorded at the location of PSN=1132 in the user data area  108  instead of the location of PSN=1000 in the user data area  108 , for example. This is because the data has been already recorded at the location of PSN=1000. 
     This replacement recording is a first time replacement recording. Accordingly, in accordance with step S 302  and the subsequent steps shown in  FIG. 19A , the process for the first time replacement recording is performed. As a result, the DFL entry  2100 A shown in  FIG. 21B  is added to the replacement management information list. 
     Next, in the state shown in  FIG. 21A , it is assumed that the drive apparatus  310  is instructed by the host apparatus  305  to record data “A 2 ” at the location of LSN=0. 
       FIG. 22A  shows a state in which the recording of data “A 2 ” is completed. 
     As shown in  FIG. 22A , data “A 2 ” is recorded at the location of PSN=1164 in the user data area  108  instead of the location of PSN=1000 In the user data area  108 , for example. This is because the data has been already recorded at the location of PSN=1000. 
     This replacement recording is a second time or more replacement recording. Accordingly, in accordance with step S 304  and the subsequent steps shown in  FIG. 19A , the process for the second time or more replacement recording is performed. As a result, the DFL entry  2100 A is updated to the DFL entry  2100 B shown in  FIG. 22B . That is, any DFL entry is not added to the replacement management information list. 
     Next, in the state shown in  FIG. 22A , it is assumed that the drive apparatus  310  is instructed by the host apparatus  305  to record data “B 0 ” at the location of LSN=96 and to record data “C 0 ” at the location of LSNs=128 to 192. 
       FIG. 23A  shows a state in which the recording of data “B 0 ” and data “C 0 ” is completed. 
     As shown in  FIG. 23A , it is assumed that an error occurs during the verify process for verifying the recording of data “B 0 ” at the location of PSN=1192. 
     In this case, data “B 0 ” is recorded at the location of PSN=x10 in the outer spare area  107  instead of the location of PSN=1193 in the user data area  108 , for example. 
     This replacement recording is a first time replacement recording. Accordingly, in accordance with step S 302  and the subsequent steps shown in  FIG. 19A , the process for the first time replacement recording is performed. As a result, the DFL entry  2101 A shown in  FIG. 23B  is added to the replacement management information list. 
     It is assumed that the verify process for verifying the recording of data “C 0 ” has been successfully completed. In this case, the replacement management information list is maintained without any change. 
     Next, in the state shown in  FIG. 23A , it is assumed that the drive apparatus  310  is instructed by the host apparatus  305  to record data “C 1 ” at the location of LSNs=128 to 192. 
       FIG. 24A  shows a state in which the recording of data “C 1 ” is completed. 
     As shown in  FIG. 24A , data “C 1 ” is recorded at the location of PSNs=1324 to 1388 in the user data area  108  instead of the location of PSNs=1288 to 1292 in the user data area  108 , for example. This is because the data has been already recorded at the location of PSNs=1288 to 1292. 
     This replacement recording is a first time replacement recording. Accordingly, in accordance with step S 302  and the subsequent steps shown in  FIG. 19A , the process for the first time replacement recording is performed. As a result, the DFL entry  2102 A and the DFL entry  2103 A shown in  FIG. 24B  are added to the replacement management information list. 
     This replacement recording is based on a replacement of the contiguous range  2200  (PSNs=1228 to 1292) with the contiguous range  2201  (PSNs=1324 to 1388). The replacement is represented using the DFL entry  2012 A indicating start location of the replacement range and the DFL entry  2103 A indicating end location of the replacement range. 
     Thus, in the pseudo-overwrite recording which replaces the contiguous range  2200  with the contiguous range  2201  in the user data area  108 , the drive apparatus  310  generates a first replacement management information (DFL entry  2102 A) for mapping the start location of the contiguous range  2200  to the start location of the contiguous range  2201  and a second replacement management information (DFL entry  2103 A) for mapping the end location of the contiguous range  2200  to the end location of the contiguous range  2201   
     Although the replacement recording is performed for the contiguous range including three ECC clusters, only two DFL entries are added to the replacement management information list. This is an effect obtained by using the DFL entry  2102 A and the DFL entry  2103 A which map the contiguous range  2200  to the contiguous range  2201  in the user data area  108 . 
     Regarding the replacement of the contiguous range, when the pseudo-overwrite recording is a second time or more replacement recording, it is needless to say that the existing DFL entries are updated. 
     Embodiment 2 
     2-1. Procedure of NWA Determining Process 
     Hereinafter, a method for determining a next writable address represented by a logical address (hereinafter, “logical NWA”) will be described. The drive device  310  returns the logical NWA back to the host apparatus  305  in response to a request from the host apparatus  305 . 
     The logical NWA is determined in accordance with the following procedure in the present invention. 
     An ECC cluster which is next to the ECC cluster including the physical sector indicated by the LRA is determined. This ECC cluster is a next writable ECC cluster. The first physical sector of the next writable ECC cluster is a next writable address. The next writable address represented by a physical address is the NWA described above. 
     The logical NWA has a value which is obtained by translating the value of the PSN indicated by the NWA into a value of the LSN in accordance with the primary logical address-physical address mapping. 
     Several specific examples will be described below. 
     In the state shown in  FIG. 12 , the LRA  500  indicates a leading position of the user data area  108 . In this state, the NWA in the physical address space is PSN=1100. The LSN corresponding to PSN=1000 is LSN=0. Therefore, the logical NWA=0. 
     In  FIG. 13A , the host apparatus  305  obtains the logical NWA from the drive apparatus  310  and instructs the drive apparatus  310  to record data “A” at the location of LSN=0. 
     In the state immediately after the recording of data “A” is completed, the LRA of the track # 1  indicates an ECC cluster including the location of PSN=1132. In this state, the NWA Is PSN=1132. Accordingly, the logical NWA is LSN=32. The host apparatus  305  can instruct the drive apparatus  310  to record data “B” at the logical NWA (i.e. LSN=32). 
     In the state immediately after the recording of data “B” is completed, the LRA of the track # 1  indicates a physical sector within an ECC cluster including the location of PSN=1132. In this state, the NWA is PSN=1164. Accordingly, the logical NWA is LSN=64. 
     The feature of the method for determining a logical NWA described above is to determine the logical NWA to maintain the relationship of the primary logical address-physical address mapping. Specifically, the NWA is determined from the LRA within a track and then the logical NWA is obtained in accordance with the primary logical address-physical address mapping. As a result, the replacement management information  1010 B is not required for the new data recording. 
     In  FIG. 14A , it is possible that the host apparatus  305  erroneously holds a value corresponding to the LRA  501 B as the logical NWA, even through the actual latest logical NWA should correspond to the LRA  500 B. 
     For example, such a state may be caused when the drive apparatus  310  performs a recording operation for recording data at the location after PSN=1292 as an operation independent of the host apparatus  305  and the host apparatus  305  does not obtain the latest logical NWA from the drive apparatus  310 . 
     In this state, when the host apparatus  305  instructs the drive apparatus  310  to record new data, the host apparatus  305  outputs a recording instruction for recording data at the logical NWA corresponding to the LRA  501 B. However, the drive apparatus  310  records the data at the location of PSN=1336. 
     This recording causes a replacement recording. Accordingly, new replacement management information is required. 
     On the other hand, when the host apparatus  305  instructs the drive apparatus  310  to record new data, after it obtains the logical NWA corresponding to the latest LRA  500 B from the drive apparatus  310 , the recording does not cause any replacement recording. Accordingly, any new replacement management information is not required. 
     In  FIGS. 15A and 16A , a similar state may be caused. In  FIGS. 15A and 16A , it is possible that the host apparatus  305  erroneously holds a value corresponding to the LRA  501 C as the logical NWA, even through the actual latest logical NWA should correspond to the LRA  500 C and the LRA  500 D. 
     Therefore, it is desirable that the host apparatus  305  obtains the latest logical NWA before recording a new data. 
     In summary, when the host apparatus  305  instructs the drive apparatus  310  to record new data, the host apparatus  305  outputs a request to the drive apparatus  310  immediately before step S 102  shown in  FIG. 8A , for example, in order to obtain the latest logical NWA from the drive apparatus  310 . Upon receipt of the request, the drive apparatus  310  determines the logical NWA from the LRA and the NWA in accordance with the process described above and returns the logical NWA back to the host apparatus  305 . 
     Upon receipt of the logical NWA, the host apparatus  305  generates a next recording instruction based on the logical NWA and outputs the next recording instruction to the drive apparatus  310 . 
     By performing the operations described above, the replacement management information  1010 B is not required for recording new data. The replacement management information  1010 B is required for performing the replacement recording only. 
     As a result, it is possible to restrict increasing the data amount of the replacement management information list  1000 . This provides an effect such as the reduction of the amount of processing in the data recording/reproduction, the reduction of the size of the memory, the reduction of the data size on the information recording medium  100  and the like. 
     Embodiment 3 
     3-1. Procedure of Recording Process (1) 
     A method for determining NWA described in the Embodiment 2 causes a state in which a particular LSN is not used. 
     For example, in  FIG. 14A , the logical sector at the location of LSN=96 is a logical sector in which any data has not been recorded when it is seen from the host apparatus  305  or the file system. 
     Such a logical sector is referred to as an unrecorded logical sector or a unused logical sector, an orphan logical sector and the like. 
     A logical cluster consisting of the unrecorded logical sectors is referred to as an unrecorded logical cluster. For example, in  FIG. 14A , the logical cluster corresponding to the location of LSNs=96 to 127 is an unrecorded logical cluster. 
     Similarly, in  FIG. 15A , the logical sector corresponding to the location of LSN=X2 is an unrecorded logical sector. 
     As shown in  FIG. 14A  and the like, the LSNs are assigned to the unrecorded logical sectors in the same manner as other normal logical sectors. Further, it is the feature of the method for determining logical NWA according to the present embodiment that the LSNs of the logical sectors subsequent to the unrecorded logical sector are not changed. 
     When it is instructed to record data at the unrecorded logical sector, the pseudo-overwrite recording is performed in a similar manner as the embodiments described above. For example, the following process is performed. 
     Herein, in the state shown in  FIG. 14A , it is assumed that it is instructed to record data “F” at the location of LSN=96. 
     In this case, the drive apparatus  310  translates LSN=96 into PSN=1196 in accordance with the primary logical address-physical address mapping. 
     By comparing the location of PSN=1196 with the location indicated by the NWA, it is recognized that the data is recorded at the location of PSN=1196. 
     Then, the pseudo-overwrite recording is performed in a similar manner as the other embodiments described above. 
     In this case, the drive apparatus  310  records data “F” at the location indicated by the NWA (e.g. the location of PSN=1336) and generates replacement management information  518 . 
     Thus, the data recording is performed for the location of LSN=96. As a result, a logical cluster corresponding to the location of LSN=96 changes from the unrecorded logical cluster to the normal logical cluster. 
     A logical cluster corresponding to the location of LSNs=256 to 287 associated with the location of PSN=1336 in accordance with the primary logical address-physical address mapping newly becomes an unrecorded cluster. 
       FIGS. 17A and 17B  show a state after the recording of data “G” is completed. 
     3-2. Procedure of Reproduction Process (1) 
     In  FIG. 14A , the logical cluster at the location of LSN=224 is an unrecorded logical cluster. 
     The physical cluster corresponding to the unrecorded logical cluster at the location of LSN=223 is a physical cluster at the location of PSN=1324. The relationship between the LSNs and the PSNs are predetermined in accordance with the primary logical address-physical address mapping. 
     The physical cluster at the location of PSN=1324 is related to the physical cluster at the location of PSN=1228 by the replacement management information  514 . 
     The physical cluster at the location of PSN=1228 is mapped to the logical cluster at the location of LSN=128 in accordance with the primary logical address-physical address mapping. 
     Thus, the physical cluster at the location of PSN=1228 is assigned to the logical cluster at the location of LSN=128 and the unrecorded logical cluster at the location of LSN=224. 
     The procedure of the reproduction process will be described in a case where two logical clusters are assigned to one physical cluster. 
     The host apparatus  305  outputs a reproduction instruction for the location of LSN=128 to the drive apparatus  310 . Upon the receipt of the reproduction instruction, the drive apparatus  310  translates the LSN into the PSN in accordance with the primary logical address-physical address mapping. The PSN is referred to as a reproduction PSN. 
     In this case, the reproduction PSN is PSN=1228. Replacement management information having the location of PSN=1228 as the replacement location is retrieved in the replacement management information list. As a result, the replacement management information  514 A is found. 
     The replacement cluster indicated by the replacement management information  514 A is a physical cluster at the location of PSN=1324. The data recorded in the physical cluster at the location of PSN=1324 is reproduced. 
     The host apparatus  305  outputs a reproduction instruction for the location of LSN=224 to the drive apparatus  310 . Upon the receipt of the reproduction instruction, the drive apparatus  310  translates the LSN into the reproduction PSN in accordance with the primary logical address-physical address mapping. 
     In this case, the reproduction PSN is PSN=1324. Replacement management information having the location of PSN=1324 as the replacement location is retrieved in the replacement management information list. However, such replacement management information is not found. 
     The drive apparatus  310  reproduces data recorded in the physical cluster at the location of PSN=1324. 
     According to the reproduction process described above, when the host apparatus  305  outputs a reproduction instruction for the location of an unrecorded logical sector in which any data has not been logically recorded, it is possible to reproduce data recorded in the physical sector corresponding to the unrecorded logical sector. 
     As a result, it is seen from the file system and the like at the side of the host apparatus  305  that there is no exceptional area on the information recording medium  100 . Further, it is not necessary to implement a complex error process in the system structure. It is possible to configure the system with a simplified implementation. 
     Upon the receipt of a reproduction instruction for an unrecorded logical sector, if the drive apparatus  310  reproduces data recorded in the physical cluster corresponding to the unrecorded logical sector, then the data which should not be essentially reproduced is reproduced. If such a reproduction is inconvenient for the system configuration, it is possible to adopt the following procedure for the reproduction process. 
     The drive apparatus  310  translates the LSN specified by the reproduction instruction into a PSN in accordance with the primary logical address-physical address mapping, and retrieves the replacement management information  1010 B having the original location information  1012  corresponding to the translated PSN in the replacement management information list  1000 . 
     If the replacement management information  1010 B having the original location information  1012  corresponding to the translated PSN is found, the data is reproduced from the ECC cluster at the replacement location indicated by the replacement location information  1013  of the replacement management information  10   10 B in a similar manner as the other embodiments described above. 
     If it is not found, the drive apparatus  310  retrieves the replacement management information  1010 B having the replacement location information  1013  corresponding to the translated PSN in the replacement management information list  1000 . 
     If the replacement management information  1010 B having the replacement location information  1013  corresponding to the translated PSN is found, the ECC cluster indicated by the replacement location information  1013  is determined as the replacement cluster in which the data has been already recorded. 
     Then, the drive apparatus  310  does not reproduce the data from the replacement cluster. Instead, the drive apparatus  310  returns a predetermined data (e.g. data having a value of “00 . . . 0”) as the reproduced data back to the host apparatus  305 . 
     According to the reproduction process described above, when it is instructed to reproduce data from the unrecorded logical sector, the data can be reproduced appropriately from the physical sector corresponding to the unrecorded logical sector. 
     Such a reproduction process can be performed when the drive apparatus  310  receives the reproduction instruction from the host apparatus  305  in each step of the reproduction process described with reference to  FIG. 10 . 
     3-3. Comparison Between Procedures of NWA Determining Process 
     Unlike the embodiment described above, a method for determining a logical NWA will be described. In this method, any unrecorded logical sector does not occur. 
     In this method, the logical LRA is managed, and a new data is recorded at the logical NWA which is adjacent to the logical LRA. 
     The LSN indicating the logical NWA is translated into a PSN in accordance with the primary logical address-physical address mapping. The translated PSN is referred to as “PSN- 1 ”. 
     The data is actually recorded at the NWA within an ECC cluster which is next to the ECC cluster including the PSN indicated by the LRA  213 . The PSN indicated by the NWA is referred to as “PSN- 2 ”. 
     The replacement recording is performed with the original location of PSN- 1  and the replacement location of PSN- 2 . 
       FIG. 25  shows a data structure of the track management information  3210  according to the present embodiment. The track management information  3210  is used to manage the logical NWA. 
     In the track management information  3210  shown in  FIG. 25 , last recorded logical address information within track  3214  is newly defined. 
     The last recorded logical address information within track  3214  is used to manage the last recorded address represented by LSN in the logical address space, whereas the last recorded address information within track (LRA)  213  is used to manage the last recorded address represented by PSN in the physical address space. 
     The drive apparatus  310  can determine the logical NWA for each track by referring to the last recorded logical address information within track  3214 . 
     The last recorded logical address information within track  3214  is updated in the following manner. 
     The value of “0” is set to the last recorded logical address information within track  3214  as an initial value. The drive apparatus  310  receives a recording instruction including a LSN. When the LSN in the recording instruction is greater than the last recorded logical address information within track  3214 , the drive apparatus  310  updates the last recorded logical address information within track  3214  to the LSN. 
     According to the update process described above, it is possible to maintain the last recorded logical address information within track  3214  as being a maximum value. 
       FIG. 26A  shows a data structure after the recording of data “A”, “B”, “C”, “D”, “F” and “G” are completed in the same order as in  FIGS. 13A ,  14 A and  17 A in accordance with the procedure of NWA determining process described above. 
     In  FIG. 26B , all of defective clusters are registered as the replacement management information ( 7 ). However, it is possible to delete these replacement management information ( 7 ) from the replacement management information list  1000 F. By deleting these, the size of the replacement management information list  1000 F can be reduced. 
     By comparing the replacement management information list  1000 E shown in  FIG. 17B  with the replacement management information list  1000 F shown in  FIG. 26B , it is understood that the number of the replacement management information in the replacement management information list  1000 E is smaller than the number of the replacement management information in the replacement management information list  1000 F. 
     By comparing these lists after deleting replacement management information ( 7 ), it is also understood that the number of the replacement management information in the replacement management information list  1000 E is much smaller than the number of the replacement management information in the replacement management information list  1000 F. 
     Accordingly, the method for determining NWA while allowing the occurrence of the unrecorded logical sector as described in Embodiment 1 and Embodiment 2 is more desirable rather than the method which refers to  FIG. 26A  while not allowing the occurrence of the unrecorded logical sector in that the size of replacement management information list can be reduced. 
     By maintaining the replacement management information ( 7 ) in the replacement management information list  1000 F, it is possible to recognize the distribution of the defective clusters on the information recording medium  100 . The distribution of the defective clusters can be used to optimize the reproduction process. Such an optimization is made, for example, by reading data in advance without reading data from the defective sectors. 
     Embodiment 4 
     The procedure of the data recording according to the present embodiment will be described. 
       FIG. 27  shows an exemplary data structure of the information recording medium  100  before performing the data recording according to the present embodiment. In  FIG. 27 , each symbol of triangle indicates a boarder between the ECC clusters. Hereinafter, even in other figures, each symbol of triangle has the same meaning. 
     In the state shown in  FIG. 27 , it is assumed that the host apparatus  305  outputs a recording instruction for data “D 1 ”  4622  and data “E 1 ”  4623  to the drive apparatus  310 . In this case, the procedure of the recording process will be described. 
     The data recording for data “D 1 ”  4622  is determined as the pseudo-overwrite recording at the location of PSN=a 0  in the recorded area  4600 , for example. 
     Prior to outputting the recording instruction, the host apparatus  305  outputs a request for the logical NWA to the drive apparatus  310 . 
     Upon the receipt of the request for the logical NWA, the drive apparatus  310  determines NWA  4611 A from LRA  4610 A and returns the logical NWA corresponding to the NWA  4611 A back to the host apparatus  305 . 
     The host apparatus  305  outputs a recording instruction for recording data “D 1 ”  4622  at the location of LSN=A 0  corresponding to PSN=a 0  to the drive apparatus  310 , and then outputs a recording instruction for recording data “E 1 ”  4623  at the location of LSN=A 2  corresponding to NWA  4611 A (PSN=a 2 ) to the drive apparatus  310 . 
       FIG. 28  shows a recording result after the drive apparatus  310  performs a recording process for data “D 1 ”  4622  and a recording process for data “E 1 ”  4623  in accordance with the order of the recording instructions as instructed by the host apparatus  305 . 
     In this case, the data recording for data “D 1 ”  4622  is determined as the pseudo-overwrite recording for the recorded area  4600 . As a result, data “D 1 ”  4622  is recorded at the location of NWA  4611 A (PSN=a 2 ) instead of the location of PSN=a 0 . Then, the NWA  4611 A is updated to the NWA  4611 B (PSN=a 3 ). 
     As a result of this replacement recording, data “D 1 ”  4622  is recorded at the location of PSN=a 2 . As a result, data “E 1 ”  4623  is recorded at the location of NWA  4611 B (PSN=a 3 ) instead of the location of PSN=a 2 . 
     Thus, although the host apparatus  305  outputs a recording instruction for recording data “E 1 ”  4623  at the location of LSN=A 2  corresponding to NWA  4611 A (PSN=a 2 ) as described above, data “E 1 ”  4623  is recorded at the location of PSN=a 3  which is deferent from the location as instructed. 
     In this case, the replacement management information  1010  for data “D 1 ”  4622  is generated, and the replacement management information  1010  for data “E 1 ”  4623  is also generated. This causes a problem that the size of the replacement management information list  1000  is increased. 
     This problem is caused by the drive apparatus  310  performing the replacement recording which is not expected by the host apparatus  305 . 
     After performing the replacement recording by the drive apparatus  310 , it is necessary to perform further replacement recording as the host apparatus  305  outputs a recording instruction. This results in increasing the size of the replacement management information list  1000 . 
     Hereinafter, a method according to the present embodiment will be described. In this method, the replacement management information  1010  for data “E 1 ”  4623  is not generated during the recording process. 
     In the present embodiment, in the state shown in  FIG. 27 , the host apparatus  305  first outputs a recording instruction for the appending recording. Then, the host apparatus  305  outputs a recording instruction for the pseudo-overwrite recording after outputting the recording instruction for the appending recording. 
       FIG. 29  shows a recording result after the drive apparatus  310  performs recording processes in accordance with the order of the recording instructions as instructed by the host apparatus  305 . 
     The file system operating on the host apparatus  305  can determine the order of the recording instructions, since it manages updating all existing files and creating new files. 
     In  FIG. 29 , data “E 1 ”  4623 B is recorded at the location of NWA  4611 A (PSN=a 2 ), and data “D 1 ”  4622 B is recorded at the location of PSN=a 4 . 
     The host apparatus  305  outputs a recording instruction for recording data “E 1 ”  4623 B at the location of NWA  4611 A (PSN=a 2 ) as described above. In the present embodiment, data “E 1 ”  4623 B is recorded at the location of PSN=a 2  which is the same as the location as instructed. This data recording is not a replacement recording. 
     Thus, the replacement management information  1010  for data “E 1 ”  4623 B is not generated. As a result, it is possible to avoid increasing the size of the replacement management information list  1000 . 
     In either case shown in  FIG. 28  or the case shown in  FIG. 29 , the same number of the replacement management information  1010  is required in order to record data “D 1 ”  4622 . Although the recording location (i.e. replacement location) of data “D 1 ”  4622  are different from each other in  FIGS. 28 and 29 , the required number of the replacement management information  1010  is maintained. 
     As described above, when the host apparatus  305  instructs the drive apparatus  310  to perform both of the pseudo-overwrite recording and the appending recording, the host apparatus  305  outputs a recording instruction for the appending recording to the drive apparatus  310  prior to outputting a recording instruction for the pseudo-overwrite recording to the drive apparatus  310 . This makes it possible to avoid generating the replacement management information  1010 , thereby reducing the size of the replacement management information list  1000 . 
     Embodiment 5 
     Herein, it is assumed the host apparatus  305  divides data having a size into a plurality of portions, such that each of the plurality of portions has a size of one ECC cluster. It is also assumed that the host apparatus  305  sequentially outputs a recording instruction for each portion of the data as a recording unit to the drive apparatus  310 . 
     The drive apparatus  310  records the respective portions of the data contiguously. It is assumed that a defective cluster including the recording location is detected, and a cluster which is adjacent to the defective cluster is used as a replacement cluster in order to replace the defective cluster with the replacement cluster. 
     In this case, the replacement recording is required for each recording unit after the recording location. In the replacement recording, each cluster is replaced by an adjacent cluster which is located in a direction along which the PSNs increase. 
     In this case, the replacement management information is required for each recording unit. Accordingly, when the size of data to be recorded is very large, the large number of replacement management information is required, thereby increasing the size of the replacement management information list  1000 . 
     Hereinafter, a method according to the present embodiment will be described with reference to  FIG. 30 . This method is effective to reduce the size of the replacement management information list  1000 . 
     In  FIG. 30 , a replacement recording is performed in accordance with the recording instruction from the host apparatus  305 . In the replacement recording, it is assumed that the original location is original cluster  5700 . 
     The replacement location of the replacement recording is determined in the following manner. 
     In  FIG. 30 , the replacement cluster may be allocated in one of the unrecorded area  5601 A (in track #N  5602 ), the unrecorded area  5612  (in track #N+1  5610 ), the unrecorded area  5622  (in track #N+2  5620 ) and the unrecorded area  5632  (in track #N+3  5630 ). Each of these unrecorded areas is a candidate area for the replacement cluster. 
     Herein, a distance between the location of the original cluster  5700  (e.g. the location of the first physical sector in the original cluster  5700 ) and the location of the candidate area for the replacement cluster (e.g. the location of the NWA in the open track) is evaluated. The respective distances with respect to the respective candidate areas for the replacement cluster are D 13 , D 12 , D 10  and D 11 , as shown in  FIG. 30 . 
     It is assumed that the respective distances satisfy the relationship of D 13 &gt;D 12 &gt;D 11 &gt;D 10 . 
     By selecting the unrecorded area  5622  which has a minimum distance D 10  as an area for the replacement cluster, it is possible to minimize a distance between the original cluster and the replacement cluster. As a result, it is possible to minimize an access time in the data reproduction. 
     However, the unrecorded area  5622  is included in the same track #N+2  5620  as the original cluster  5700 . Accordingly, when the unrecorded area  5622  is selected as an area for the replacement cluster, it may cause a problem that the size of the replacement management information list  1000  is increased in the case where the drive apparatus  310  sequentially receives a plurality of recording instructions from the host apparatus  305  as described above. 
     According to the present embodiment, an unrecorded area which has a minimum distance from the original cluster is selected as an area for the replacement cluster. However, during the selection process, an unrecorded area included in the same track as the original cluster is excluded from the selection. 
     In  FIG. 30 , the unrecorded area  5622  which has a minimum distance D 10  is excluded from the selection. The unrecorded area  5632  which has the next minimum distance D 11  is selected as an area for the replacement cluster. 
     Thus, upon receipt of the recording instruction for the original cluster  5700  from the host apparatus  305 , the drive apparatus  310  allocates the replacement cluster  5710  at the location of NWA in the unrecorded area  5632  and records data in the replacement cluster  5710 . 
     The drive apparatus  310  generates the replacement management information which maps the original cluster  5700  to the replacement cluster  5710  and records the replacement management information. 
     As described in steps S 107  and S 112  ( FIG. 8A ), when the drive control section  311  according to the present invention performs the pseudo-overwrite recording, it controls the recording/reproduction section  314  to record data at a specific location in the user data area  108 , which is other than the location indicated by the physical address corresponding to the logical address included in the received recording instruction. 
     In the present embodiment, the specific location is the NWA within an open track which is different from the track determined in step S 104  ( FIG. 8A ). 
     Further, the NWA within the open track indicates a location which is the closest to the location indicated by the physical address corresponding to the logical address included in the recording instruction. 
     According to the procedure of the recording process, even if the host apparatus  305  further outputs a recording instruction to the drive apparatus  310 , the data recording for the unrecorded area  5622  does not cause any replacement recording. The addition of the replacement management information is not required. 
     A distance between the original location and the replacement location becomes minimum, except for a case where the original location and the replacement location are included in the same track. As a result, it is possible to reduce an access time in the data reproduction. 
     The drive apparatus  310  may determine the location of the replacement cluster by evaluating a distance between the original cluster and an unrecorded area which has PSNs greater than the PSNs of the original cluster. In the write-once recording mediums, a sequential recording is performed in a direction along which the PSNs increase. Accordingly, it is possible to efficiently access data by replacing the original cluster with the replacement cluster which has PSNs greater than the PSNs of the original cluster. 
     In this case, if there is no remaining unrecorded area which has PSNs greater than the PSNs of the original cluster, then the drive apparatus  310  may determine the location of the replacement cluster by evaluating a distance between the original cluster and an unrecorded area which has PSNs smaller than the PSNs of the original cluster. 
     When there are a plurality of unrecorded areas which have the same distance from the original cluster, it is desirable to select one of the plurality of unrecorded areas, which has PSNs greater than the PSNs of the original cluster. In the write-once recording mediums, a sequential recording is performed in a direction along which the PSNs increase. 
     Accordingly, it is possible to efficiently access data by replacing the original cluster with the replacement cluster which has PSNs greater than the PSNs of the original cluster. 
     The distance between the original location and the replacement location may be determined from a difference between a PSN indicating the original location and a PSN indicating the replacement location. Alternatively, the distance may be determined from a physical distance between the original location and the replacement location. This is because the difference between the PSNs does not necessarily correspond to the physical distance, since the PSNs increase from the inner side to the outer side in a spiral manner in the information recording medium  100 . For example, with respect to ECC clusters which are adjacent to each other in a radius direction, even if the physical distance is close to zero, the difference between the PSNs does not become minimum. 
     Embodiment 6 
     With reference to  FIG. 34 , a procedure of data recording according to the present embodiment will be described. In this embodiment, the information recording/reproduction apparatus  300  shown in  FIG. 6  is used for recording data in the information recording medium  100 . Each step shown in  FIG. 34  is performed by the drive control section  311  of the drive apparatus  310 . 
     (Step S 601 ) The drive control section  311  receives a logical NWA request instruction from the host apparatus  305 . 
     The logical NWA request instruction includes information which specifies one of at least one tracks allocated in the user data area  108 . The logical NWA request instruction is defined as an instruction output from the host apparatus  305  to the drive apparatus  310  in order for the host apparatus  305  to obtain the logical NWA in the specified track from the drive apparatus  310 . 
     The logical NWA request instruction corresponds to, for example, a READ TRACK INFORMATION command. 
     (Step S 602 ) In response to the logical NWA request instruction, the drive control section  311  refers to the memory circuit  312 , and determines the size of each of at least one data to be recorded, which are stored in the memory circuit  312 . Herein, the data to be recorded is defined as data which is instructed to be recorded in the information recording medium  100  by the recording instruction from the host apparatus  305 . Specifically, the data to be recorded is data temporally stored in the memory circuit  312 , before being recorded in the information recording medium  100 . 
     The size of each of the at least one data to be recorded may be determined by, for example, referring to the size of the data to be recorded which is specified by the recording instruction. 
     (Step S 603 ) The drive control section  311  determines an NWA within the track specified by the logical NWA request instruction, based on the LRA  213  (physical address) in the track specified by the logical NWA request instruction, and the size of each of the at least one data to be recorded, which is stored in the memory circuit  312  which is determined in step S 602 . 
     (Step S 604 ) The drive control section  311  translates the NWA within the track into a logical NWA within the track in accordance with the primary logical address-physical address mapping. 
     (Step S 605 ) The drive control section  311  outputs the logical NWA within the track to the host apparatus  305 . 
     Hereinafter, an example of the data recording as shown in  FIG. 34  will be described. 
       FIG. 35  shows a data structure of the information recording medium  100  before the data recording according to the present embodiment is performed, and an exemplarily state of the memory circuit  312  in the drive apparatus  310 . Any memory (for example, a cache memory) may be used instead of the memory circuit  312 . 
     In  FIG. 35 , track #N  6000  includes a recorded area  6600  and an unrecorded area  6601 . It is assumed that user data is recorded to the location denoted by LRA  6610 A (PSN=a 1 ). 
     The drive apparatus  310  performs a buffering process for improving responsibility toward the recording instruction from the host apparatus  305 . 
     For example, the host apparatus  305  instructs the drive apparatus  310  to record data “A”  6602  and data “B”  6603 . 
     In response to this recording instruction, the drive control section  311  of the drive apparatus  310  does not operate to immediately record the data “A”  6602  and data “B”  6603  in the information recording medium  100 , but temporarily stores the data into the memory circuit  312 . 
     Then, the drive control section  311  controls the recording/reproduction section  314  to record the data “A”  6602  and data “B”  6603  in the information recording medium  100  at a predetermined timing. 
     In the state shown in  FIG. 35 , it is assumed that the host apparatus  305  instructs the drive apparatus  310  to record data “C”  6604  at the location of NWA  6611 A. Herein, data to be recorded is stored in the memory circuit  312  and the host apparatus  305  does not consider the stored data. 
     In this case, the host apparatus  305  requests the drive apparatus  310  to obtain a logical NWA within a track in which data “C”  6604  is to be recorded before the host apparatus  305  instructs the drive apparatus  310  to record the data “C”  6604 . 
     The track in which data “C”  6604  is to be recorded is determined by, for example, a file system which operates in the host apparatus  305 . In the example shown in  FIG. 35 , the track in which data “C”  6604  is to be recorded is the track #N  6000 . 
     It is assumed that the drive apparatus  310  determines the NWA  6611 A (PSN=a 2 ) from the LRA  6610 A (PSN=a 1 ) in accordance with (Expression 1) in response to a request for the logical NWA. 
     In this case, the drive apparatus  310  translates PSN=a 2  into LSN=A 2  in accordance with the primary logical address-physical address mapping, and returns the logical address (LSN=A 2 ) as the logical NWA to the host apparatus  305 . 
     The host apparatus  305  receives the logical NWA and outputs a recording instruction to the drive apparatus  310  so as to record data “C”  6604  at the location of LSN=A 2 . 
     The drive apparatus  310  receives the recording instruction and records data “A”  6602  and data “B”  6603  which are stored in the memory circuit  312  in the information recording medium  100 . 
     As shown in  FIG. 36 , data “A”  6602  is recorded at the location of PSN=a 2 , and then, data “B”  6603  is recorded. 
     Then, the drive apparatus  310  tries to record data “C”  6604  at the location of PSN=a 2  in accordance with the recording instruction from the host apparatus  305 . However, data “A”  6602  is recorded at the location of PSN=a 2 . 
     The drive apparatus  310  records data “C”  6604  at the location of PSN=a 4 , instead of the location of PSN=a 2 . 
     As a result, the data structure on the information recording medium  100  becomes as the one shown in  FIG. 36 . 
     As described above, although the host apparatus  305  outputs the recording instruction for recording data “C”  6604  at the location of LSN=A 2 , i.e., PSN=a 2 , the data “C”  6604  is actually recorded at the location of PNS=a 4 , which is different from the location of PSN=a 2 . This means that replacement recording which replaces the location of PSN=a 2  with the location of PSN=a 4  is performed. 
     As a result, the replacement management information  1010  for data “C”  6604  is generated. This causes a problem that the size of the replacement management information list  1000  increases. 
     On the other hand, according to the procedure of data recording of the present embodiment as shown in  FIG. 34 , the replacement management information  1010  for the data “C”  6604  is not generated. Thus, according to the procedure of data recording of the present embodiment as shown in  FIG. 34 , the above-described problem that the size of the replacement management information list  1000  increases can be solved. 
     Hereinafter, a process in the drive apparatus  310  when the logical NWA is requested will be described in detail. 
     The drive control section  311  determines the size of data “A”  6602  and the size of data “B”  6603  which are stored in the memory circuit  312 . The size of data “A”  6602  may be determined by referring to, for example, the data size specified by the recording instruction for data “A”  6602 . The size of data “B”  6603  maybe determined by referring to, for example, the data size specified by the recording instruction for data “B”  6603 . 
     The drive control section  311  determines the NWA based on the current LRA  6610 A, the size of data “A”  6602  and the size of data “B”  6603  which are stored in the memory circuit  312 . 
     Specifically, the NWA is determined in accordance with the following procedure. 
     1) By putting the current LRA  6610 A (PSN=a 1 ) into Expression (1), the NWA  6611 A (PSN=a 2 ) is calculated. 
     2) By adding the size of data “A”  6602  to the NWA  6611 A (PSN=a 2 ), a first intermediate LRA is calculated. 
     3) By putting the first intermediate LRA into Expression (1), a first intermediate NWA is calculated. 
     4) By adding the size of data “B”  6603  to the first intermediate NWA, a second intermediate LRA is calculated. 
     5) By putting the second intermediate LRA into Expression (1), the NWA is calculated. 
     In the example shown in  FIG. 35 , the NWA calculated above is equals to the NWA  6611 B (PSN=a 4 ). 
     The drive control section  311  translates PSN=a 4  into LSN=A 4  in accordance with the primary logical address-physical address mapping, and returns the logical address (LSN=A 4 ) as the logical NWA to the host apparatus  305 . 
     Calculating the location of the NWA  6611 B in this manner is equivalent to calculating a new location of the NWA after recording data “A”  6602  and data “B”  6603  under the assumption that data “A”  6602  and data “B”  6603  are actually recorded from the location of NWA  6611 A. 
     The data stored in the memory circuit  312  may include a plurality of data which the host apparatus  305  instructs the drive apparatus  310  to record in the respective different tracks. In this case, the location of the NWA may be calculated in view of the size of the data to be recorded in the track per each track. 
     The data stored in the memory circuit  312  is not limited to data which the host apparatus  305  instructs the drive apparatus  310  to record at an unrecorded area. The data stored in the memory circuit  312  may be data the host apparatus  305  instructs the drive apparatus  310  to record at a recorded area. 
     When the drive apparatus  310  is instructed by the host apparatus  305  to record data at a recorded area, the drive apparatus  310  may determine a track in which the data stored in the memory circuit  312  is to be recorded and a recording location within the track, after the drive apparatus  310  receives a request for the logical NWA from the host apparatus  305 . In this case, the drive apparatus  310  may calculate a new location of the NWA after recording the under the assumption that the data is actually recorded in the determined track. 
     The host apparatus  305  receives the logical NWA corresponding to the NWA  6611 B outputs a recording instruction to the drive apparatus  310  so as to record data “C”  6604  at the location of LSN=A 4 . 
     The drive apparatus  310  receives the recording instruction and records data “A”  6602  and data “B”  6603  which are stored in the memory circuit  312 , and then, records data “C”  6604 . 
     As a result, the drive apparatus  310  does not perform the pseudo-overwrite recording for data “C”  6604 . Accordingly, the replacement management information is not generated. 
       FIG. 37  shows another example of locations of data recorded in the information recording medium  100 . For example, the drive apparatus  310  contiguously records data stored in the memory circuit  312  without recording padding data. 
     In the example shown in  FIG. 37 , the NWA is determined in accordance with the following procedure. 
     1) By putting the current LRA  6610 A (PSN=a 1 ) into Expression (1), the NWA  6611 A (PSN=a 2 ) is calculated. 
     2) By adding the size of data “A”  6602  and the size of data “B”  6603  to the NWA  6611 A (PSN=a 2 ), the NWA is calculated. 
     In the example shown in  FIG. 37 , the NWA equals to PSN=a 3 . 
     The drive control section  311  translates PSN=a 3  into a logical address in accordance with the primary logical address-physical address mapping, and returns the logical address as the logical NWA to the host apparatus  305 . 
     When the host apparatus  305  receives the logical NWA and outputs a recording instruction to the drive apparatus  310  to record data “C”  6604  at the location indicated by the received logical NWA. 
     The drive apparatus  310  receives the recording instruction and contiguously records data “A”  6602 , data “B”  6603  and data “C”  6604  which are stored in the memory circuit  312 . 
     Thus, in the example shown in  FIG. 37 , the recording location of data “C”  6604  is equal to the recording location specified by the host apparatus  305 , like the example shown in  FIG. 36 . 
     As a result, the recording of the data “C”  6604  does not cause any replacement recording. Accordingly, the replacement management information  1010  is not generated. 
     As described above, according to the present embodiment, the drive apparatus  310  determines the logical NWA based on not only LRA  213  but also the size of the data to be recorded, which are stored in the memory circuit  312  (e.g. a cache memory), and outputs the logical NWA to the host apparatus  305 . This makes it possible to avoid the generation of the replacement management information  1010 . As a result, the data size of the replacement management information list  1000  can be reduced. 
     Embodiment 7 
     With reference to  FIG. 38 , a procedure of data recording according to the present embodiment will be described. In this embodiment, the information recording/reproduction apparatus  300  shown in  FIG. 6  is used for recording data in the information recording medium  100 . Each step shown in  FIG. 38  is performed by the drive control section  311  of the drive apparatus  310 . 
     (Step S 701 ) The drive control section  311  receives a recording instruction from the host apparatus  305 . The recording instruction specifies data to be recorded, and a logical address indicating the location at which the data is to be recorded. 
     (Step S 702 ) The drive control section  311  translates the logical address included in the recording instruction into a physical address. Such a translation is performed, for example, in accordance with the primary logical address-physical address mapping. 
     (Step S 703 ) The drive control section  311  determines a track among at least one track allocated in the user data area  108 . Such a determination is made, for example, based on the physical address corresponding to the logical address included in the recording instruction and the track management information  210  ( FIG. 2B ) included in the disc management information. The track management information  210  indicates a range of the track on the data area  102 . Thus, if a physical address is determined, a track corresponding to the physical address can be determined. 
     (Step S 704 ) The drive control section  311  refers to the data to be recorded which is stored in the memory circuit  312  (hereinafter, referred to as a recording data in the memory), defines data from a start location of the recording data in the memory to a location corresponding to the NWA as a first data portion, and defines data from the location corresponding to the NWA to an end location of the recording data in the memory as a second data portion. Herein, the NWA is the NWA in the track determined at step S 703 . 
     When the location corresponding to the NWA is located between the start location and the end location of the recording data in the memory, the recording data in the memory is divided into the first data portion and the second data portion as a boundary of the location corresponding to the NWA. 
     (Step S 705 ) The drive control section  311  controls the recording/reproduction section  314  to record the second data portion before recording the first data portion. As a result, the recording of the second data portion becomes an appending recording for the location of the NWA, and the recording of the first data portion becomes a pseudo-overwrite recording. 
     Hereinafter, an example of a specific process in accordance with data recording procedure shown in  FIG. 38  will be described. 
       FIG. 39  shows an exemplary data structure of the information recording medium  100  before the data recording according to the present embodiment is performed. 
     As shown in  FIG. 39 , track #N  7000  includes a recorded area  7600 , and an unrecorded area  7601 . A user data is recorded to the location of the LRA  7610 A. 
     In the state shown in  FIG. 39 , it is assumed that the host apparatus  305  outputs a recording instruction to the drive apparatus  310  to record data “F”  7626  at the location of LSN=a 0 . 
     The drive control section  311  receives the recording instruction and stores data “F”  7626  in the memory circuit  312 . 
     The drive control section  311  translates the logical address (LSN=A 0 ) specified by the recording instruction into a physical address (PSN=a 0 ), and determines track #N  7000  including PSN=a 0 . Then, it determines the NWA  7611 A (PSN=a 1 ) based on the LRA  7610 A of track #N  7000 . 
     The drive control section  311  compares the start location and the end location of data “F”  7626  stored in the memory circuit  312  with the location corresponding to the NWA  7611 A, defines data “D 2 ”  7624  as a first data portion of data “F”  7626  and defines data “E 2 ”  7625  as a second data portion of data “F”  7626 . 
     In this example, data “D 2 ”  7624  is data from the start location of data “F”  7626  corresponding to the location of PSN=a 0  to the location corresponding to the NWA  7611 A, and data “E 2 ”  7625  is data from the location corresponding to the NWA  7611 A to the end location of data “F”  7626 . 
     The drive control section  311  controls the recording/reproduction section  314  to record data “E 2 ”  7625  at the location of NWA  7611 A (PSN=a 1 ), and then, controls the recording/reproduction section  314  to record the data “D 2 ”  7624  at the location of PSN=a 0  corresponding to LSN=a 0  which is specified by the recording instruction. As a result, the recording of data “E 2 ” becomes an appending recording for the location of PSN=a 1 , and the recording of data “D 2 ” becomes a pseudo-overwrite recording for the location of PSN=a 0 . 
     In the example shown in  FIG. 39 , data “D 2 ” is recorded at a location of the NWA  7611 C (PSN=a 3 ) instead of PSN=a 0 . 
       FIG. 40  shows a data structure of the information recording medium  100  after the data recording according to the present embodiment is performed. Data “E 2 ” is recorded at a location of PSN=a 1 , and data “D 2 ” is recorded at a location of PSN=a 3 . 
     In the drive apparatus  310  which performs a sequential recording and a pseudo-overwrite recording for the information recording medium  100  of the present invention, which is a write-once recording medium, it is important to record data “E 2 ” before recording data “D 2 ”. By controlling the order of recording data in this manner, a range of the replacement recording can be minimized, and an unnecessary replacement recording is not caused. As a result, the data size of the replacement management information list  1000  can be reduced. 
       FIG. 41  shows another example of the data structure of the information recording medium  100  before the data recording according to the present embodiment is performed. 
     In the state shown in  FIG. 41 , it is assumed that the host apparatus  305  outputs a first recording instruction to the drive apparatus  310  to record data “D 1 ”  7622  at a location of LSN=a 0 , and outputs a second recording instruction to the drive apparatus  310  to record data “E 1 ”  7623  at a location of LSN=A 1  in this order. 
     In this case, if the drive control section  311  performs the data recording processes in the same order as it receives the two recording instructions (i.e., in the order of the first recording instruction, and the second recording instruction), the recording result is as shown in  FIG. 42 . The replacement recording for data “E 1 ”  7623  is performed. This is as described above with reference to the above embodiment. 
     As a result, the replacement management information  1010  for data “E 1 ”  7623  is generated. Accordingly, a problem is caused that the size of the replacement management information list  1000  increases. 
     On the other hand, according to the data recording procedure of the present embodiment as shown in  FIG. 38 , the replacement management information  1010  is not generated. Thus, according to the data recording procedure of the present embodiment as shown in  FIG. 38 , the above-described problem that the size of the replacement management information list  1000  increases can be solved. 
     Hereinafter, a process in the drive apparatus  310  when it receives a plurality of recording instructions from the host apparatus  305  will be described. 
     The drive control section  311  stores data “D 1 ”  7622  corresponding to a first recording instruction and data “E 1 ” corresponding to a second recording instruction in the memory circuit  312 . 
     The drive control section  311  analyzes contents of the first and second recording instructions, and detects a data portion of the data to be recorded, which is available for an appending recording. When such a data portion is detected, the drive control section  311  records the data portion before recording the remaining data portion of the data to be recorded. 
     The determination whether or not the appending recording can be performed for the data portion is made, for example, by using a method similar to the method described in steps S 105  and S 108  in  FIG. 8A . 
     The drive control section  311  performs the appending recording for the detected data portion, and then, performs the pseudo-overwrite recording for the remaining data portion of the data to be recorded. 
     In the case where data “D 1 ”  7622  and data “E 1 ”  7623  can be regarded as a single data (for example, in the case where the start address of data “E 1 ”  7623  is an address next to the end address of data “D 1 ”  7622 ), it is possible to perform a process similar to the process in the example shown in  FIG. 39 . 
     In the example shown in  FIG. 41 , the recording of data “E 1 ”  7623  is detected as an appending recording. As a result, data “E 1 ”  7623  is recorded at a location of PSN=a 1 . Then, the NWA  7611 A (PSN=a 1 ) is updated to the NWA  7611 C (PSN=a 3 ). Then, the pseudo-overwrite recording of data “D 1 ”  7622  is performed at a location of PSN=a 0 . As a result, data “D 1 ”  7622  is recorded at a location of PSN=a 3 , instead of PSN=a 0 . 
       FIG. 43  shows a recording result of such a data recording procedure. As shown in  FIG. 43 , the appending recording of data “E 1 ”  7623  is performed at a location of PSN=a 1 . Thus, the replacement management information  1010  for data “E 1 ”  7623  is not generated. As a result, it is possible to avoid increasing the size of the replacement management information list  1000 . 
     As described above, according to the present embodiment, the drive apparatus  310  analyzes the recording instructions from the host apparatus  305 , and preferentially performs the appending recording rather than the pseudo-overwrite recording. This makes it possible to reduce the size to data recorded by the pseudo-overwrite recording. As a result, the generation of the replacement management information  1010  can be avoided. This is effective in reducing the data size of the replacement management information list  1000 . 
     Embodiment 8 
     With reference to the present embodiment, a different recording procedure for pseudo-overwrite recording will be described. 
       FIG. 44A  shows a state before data is recorded according to a recording procedure of the present embodiment. 
     In this example, data “H” is recorded at locations of LSN=P 1  to P 3  in the logical address space. Physical addresses corresponding to the logical addresses are locations of PSN=p 1  to p 3  in the physical address space. The location of PSN=p 3  is replaced with the location of PSN=s 1  in the replacement cluster in the inner spare area  106 . 
     In order to reflect this replacement recording, the replacement management information list  1000  shown in  FIG. 44B  includes replacement management information  8620 . 
     In this state, it is assumed that the host apparatus  305  outputs a recording instruction to record data “H 1 ”. The state after recording data “H 1 ” is shown in  FIG. 45A . 
     In the present embodiment, the recording is performed such that overwrite data are located as contiguously as possible in the physical address space on the information recording medium  100 . 
     Specifically, in  FIG. 44A , although the locations of PSN=s 2  and p 4  to p 6  are unrecorded areas, the locations of PSN=p 4  to p 6  are selected as recording locations so that data “H 1 ” which is overwrite data is contiguously located. 
     Although the location of PSN=s 2 , which is the location of an ECC cluster next to the location of PSN=s 1 , which corresponds to the location of LSN=P 3  at which data “H” before update is recorded, is an unrecorded area, the location of PSN=s 2  is not used to record data “H 1 ” after update. 
     In order to reflect this replacement recording, the replacement management information list  1000  shown in  FIG. 45B  includes replacement management information  8621  and  8622 . 
     Similarly,  FIG. 46A  shows a state before data is recorded according to a recording procedure of the present embodiment. 
     In this example, data “H” is recorded in logical sectors located at LSN=P 1  and P 3  in the logical address space. Further, data “H 2 ” is recorded in a logical sector located at LSN=P 2 . 
     At the location of LSN=P 2  in the logical address space, data “H” is overwritten by data “H 2 ”. In order to correspond to this, in the physical address space, the recording location of data “H 2  is replaced from the location of PSN=p 2  to the location of PSN=p 4  in the user data area. 
     In order to reflect this replacement recording, the replacement management information list  1000  shown in  FIG. 46B  includes replacement management information  8302 . 
     In this state, it is assumed that the host apparatus  305  outputs a recording instruction to record data “H 3 ”. The state after recording data “H 3 ” is shown in  FIG. 47A . 
     In the present embodiment, the recording is performed such that overwrite data are located as contiguously as possible in the physical address space on the information recording medium  100 . 
     Specifically, in  FIG. 47A , although the locations of PSN=p 5  to p 6  and p 7  to p 9  are unrecorded areas, the locations of PSN=p 7  to p 9  are selected as recording locations such that data “H 3 ” which is overwrite data is contiguously located. 
     Although the locations of PSN=p 5  to P 6 , which are the locations of ECC clusters next to the location of PSN=p 4 , which corresponds to the location of LSN=P 2  at which data “H 2 ” before update is recorded, are unrecorded areas, the locations of PSN=p 5  to p 6  are not used as replacement locations, since all of data “H 3 ” after update cannot be recorded at the locations. 
     In order to reflect this replacement recording, the replacement management information list  1000  shown in  FIG. 47B  includes replacement management information  8400  and  8401 . 
     The replacement management information  8400  and  8401  have status  2   2011 B set to “0001” and “0010”, respectively, for replacing contiguous areas consisting of a plurality of clusters. 
     For performing such recording, when the drive apparatus  310  receives recording instructions from the host apparatus  305 , the drive apparatus  310  analyzes the contents of the recording instructions. 
     When the values of LSN to be recorded are contiguous, the drive apparatus  310  selects a replacement cluster such that the PSN of the recording areas after replacement to be also contiguous, and performs the data recording. 
     As a result of rearrangement of the recording locations, it is possible to contiguously access data after replacement, thereby improving a reproduction performance. 
     Further, since the replacement management information list  1000  can be handled as replacement recording of contiguous areas as shown in  FIGS. 45B and 47B , the number of replacement management information can be reduced. 
     If the recording method of the present embodiment is not used, in the case of similar recording, the same number of replacement management information as the ECC clusters for which pseudo-overwrite recording are performed (for example, three in the example shown in  FIG. 45A ) are required. 
     Therefore, an effect of reducing replacement management information by the present embodiment is significant. 
     Further, when the original locations of a plurality of replacement management information ( 1 ) or ( 4 ) are contiguous in the physical address space, but the replacement locations are not contiguous, the replacement management information can be reduced by performing a rearrangement process of data at the replacement location. 
     More specifically, data recorded in ECC clusters of replacement locations are reproduced, and the reproduced data is recorded such that they are contiguously located in unrecorded areas. 
     By performing such a re-recording, it is possible to contiguously locate the replacement locations for the above-mentioned plurality of replacement management information ( 1 ) or ( 4 ). It is possible to translate the replacement management information ( 2 ) and ( 5 ), or, ( 5 ) and ( 6 ) using a process similar to the above process, thereby reducing the size of the replacement management information list  1000 . 
     As a result of rearrangement of the recording locations, it is possible to contiguously record data, thereby improving a performance of a contiguous data reproduction. 
     The translation process of the replacement management information in the present embodiment and the above embodiments may be performed when effects of the translation are detected. Specifically, the translation is performed in the case where the number of replacement management information decreased when the plurality of replacement management information ( 1 ) or ( 4 ) are translated into the replacement management information ( 2 ) and ( 5 ) or ( 5 ) and ( 6 ). 
     Further, it is also possible to determine whether or not the translation is performed immediately before recording the replacement management information list  1000  in the information recording medium  100 . Alternatively, such a determination can be made at a predetermined timing or a predetermined period defined by the drive apparatus  310 . In this case, the drive apparatus  310  performs the translation process if required. Alternatively, the translation process may be performed in accordance with an instruction from the host apparatus  305 . For example, when the host apparatus  305  outputs an instruction for a disc close to the drive apparatus  310 , the drive apparatus  310  records the replacement management information list  1000 . At this time, the translation process of the replacement management information may be performed. 
     Alternatively, the translation process may be performed when the size of the replacement management information list  1000  reaches a predetermined value. 
     Further, even when the drive apparatus  310  does not update the replacement management information  1000 , if it is detected that the replacement management information list  1000  read from the information recording medium  100  is in a state where it can be translated, the drive apparatus  310  may perform the above-described translation process, and then, rewrite the replacement management information list  1000  in the information recording medium  100 . This makes it possible to reduce the amount of data to be processed in the reading and/or update process of the replacement management information  1000  in the subsequent steps. 
     Embodiment 9 
     With reference to  FIGS. 48 ,  49 A,  49 B and  49 C, a procedure of data recording according to the present embodiment will be described. In this embodiment, the information recording/reproduction apparatus  300  shown in  FIG. 6  is used for recording data in the information recording medium  100 . 
       FIG. 48  shows steps included in Step S 107  shown in  FIG. 8A . Each step shown in  FIG. 48  is performed by the drive control section  311  of the drive apparatus  310 . 
     (Step S 9101 ) In order to determine the recording location at which data to be recorded, the drive control section  311  determines whether or not a predetermined condition is satisfied. 
     Herein, the predetermined condition includes a condition that the ECC cluster including the location specified by the recording instruction is replaced by a replacement cluster and the RMW process is required. 
     The predetermined condition may further include a condition that the replacement cluster is allocated in the user data area. This makes it possible to avoid using the spare area and to use the user data area efficiently. 
     A process for determining whether or not the ECC cluster including the location specified by the recording instruction is replaced by a replacement cluster is the same as the process in step S 151  shown in  FIG. 8B . It is possible to hold the determination result in step S 151  shown in  FIG. 8B  as a value of an internal variable and to refer to the value of the internal variable in step S 9101 . 
     Whether or not the replacement cluster is allocated in the user data area can be determined, for example, by determining whether or not a value of the original location information  1012  of the replacement management information  1010  found in step S 151  shown in  FIG. 8B  is within the range of the user data area. 
     A process for determining whether or not the RMW process is required is the same as the process in step S 152 A or step S 152 B shown in  FIG. 8B . It is possible to hold the determination result in step S 152 A or step S 152 B shown in  FIG. 8B  as a value of an internal variable and to refer to the value of the internal variable in step S 9101 . 
     When it is determined that the ECC cluster including the location specified by the recording instruction is replaced by a replacement cluster and the RMW process is required, the process proceeds to step S 9102 . Otherwise, the process proceeds to step S 9103 . 
     (Step S 9102 ) The drive control section  311  determines a location which is close to the recording location of the replacement cluster as the location at which data is to be recorded. 
     Herein, the location which is “close” to the recording location of the replacement cluster is defined as a location where access time from the recording location of the replacement cluster obtained in step S 151  ( FIG. 8B ) is less than or equal to a predetermined time. For example, a location which is physically adjacent to the recording location of the replacement cluster is an example of the location which is “close” to the recording location of the replacement cluster. However, the location which is “close” to the recording location of the replacement cluster is not limited to this example. 
     (Step S 9103 ) The drive control section  311  determines a specific location in the user data area  108 , which is other than the location specified by the recording instruction as the location at which data is to be recorded. 
     Herein, the meaning of the “specific location” is the same as the meaning described in step S 107  shown in  FIG. 8A . 
     In the pseudo-overwrite recording, when it is determined that the RMW process is required and the ECC cluster including the location specified by the recording instruction is replaced by a replacement cluster, the drive control section  311  controls the recording/reproduction section  314  to record the modified data which is obtained by modifying a part of the reproduced data from the replacement cluster at a location which is close to the recording location of the replacement cluster. 
     Thus, by arranging the recording location of the modified data which is obtained by modifying a part of the reproduced data from the replacement cluster close to the recording location of the replacement cluster, it is possible to realize performing the replacement recording at higher speed. Further, it is possible to improve access performance for the information recording medium  100 . 
       FIGS. 49A ,  49 B and  49 C show an exemplary process performed in accordance with the steps shown in  FIG. 48 . 
     In  FIG. 49A , it is assumed that the ECC cluster  9301  in the track #N is replaced by the replacement cluster  9302  in the track #N+1. The ECC cluster  9301  includes a sector at which data “A 1 ” is recorded, a sector at which data “A 2 ” is recorded and a sector at which data “A 3 ” is recorded. The replacement cluster (ECC cluster)  9302  includes a sector at which data “B 1 ” is recorded, a sector at which data “B 2 ” is recorded and a sector at which data “B 3 ” is recorded. 
     Further, it is assumed that the drive apparatus  310  receives a recording instruction for recording data “C 1 ” at the location of the sector at which data “A 1 ” is recorded. 
     In this case, the drive control section  311  determines that the ECC cluster  9301  including the location specified by the recording instruction is replaced by the replacement cluster  9302  and the RMW process is required (steps S 151  and S 152 A). As a result, the drive control section  311  controls the recording/reproduction section  314  to reproduce data “B 1 ”, data “B 2 ” and data “B 3 ” recorded in the replacement cluster  9302  (Step S 153 ). 
     As shown in  FIG. 49B , the drive control section  311  generates modified data including data “C 1 ”, data “B 2 ” and data “B 3 ” by replacing data “B 1 ” with data “C 1 ” (Step S 155 ). 
     As shown in  FIG. 49C , the drive control section  311  determines a location which is close to the recording location of the replacement cluster  9302  as a recording location of a new replacement cluster  9303  (Step S 9102 ) and controls the recording/reproduction section  314  to record the modified data at the new replacement cluster  9303 . 
     In the example shown in  FIG. 49C , the location which is close to the recording location of the replacement cluster  9302  is a location which is physically adjacent to the replacement cluster  9302  within the same track as the replacement cluster  9302 . However, this location is an example and it is not limited to this example. 
     In the state shown in  FIG. 49A , there is an unrecorded area in track #N−1 and this unrecorded area can be determined as a recording location of a new replacement cluster. However, if the unrecorded area in track #N−1 is determined as a recording location of a new replacement cluster, it is necessary to access to track #N−1 after data is reproduced from the replacement cluster  9302 . 
     On the other hand, according to the present embodiment, since a recording location of a new replacement cluster is determined as a location which is close to the replacement cluster  9302 , it is possible to reduce access time required. 
     Accordingly, it is possible to realize performing the replacement recording at higher speed. 
     Embodiment 10 
       FIG. 50  shows an exemplary data structure of the replacement management information list  1000  before the replacement recording is performed. 
     In the example shown in  FIG. 50 , the replacement management information list  1000  includes replacement management information  9800  and replacement management information  9801 . 
     The replacement management information  9800  indicates that the ECC cluster having a start location of PSN=1132 is replaced by the replacement cluster having a start location of PSN=132. Herein, the location of PSN=132 is a location in the spare area. 
     The replacement management information  9801  indicates that the ECC cluster having a start location of PSN=1164 is replaced by the replacement cluster having a start location of PSN=1196. Herein, the location of PSN=1196 is a location in the user data area. 
     In the state shown in  FIG. 50 , it is assumed that a new data recording is performed for the location of PSN=1228, and a verify error occurs. 
     In this case, the drive control section  311  operates in the following manner. 
     The drive control section  311  retrieves replacement management information having a value of PSN which is closest to a defective cluster including the location of PSN=1228 as the original location information  1012  in the replacement management information list  1000  shown in  FIG. 50 . 
     In the example shown in  FIG. 50 , the replacement management information  9801  is retrieved as the replacement management information which satisfies the retrieval condition. 
     The drive control section  311  checks the value of Flag  2  of status information  1011  of the replacement management information  9801  so as to determine whether the replacement location of the replacement management information  9801  is in the spare area or in the user data area. 
     In the example shown in  FIG. 50 , it is determined that the replacement location of the replacement management information  9801  is in the user data area. The drive control section  311  determines the recording location of the replacement cluster corresponding to the defective cluster including the location of PSN=1228 as a location in the user data area. 
     It is possible to determine whether the replacement location of the replacement management information  9801  is in the spare area or in the user data area, by checking the value of the replacement location information  1013  of the replacement management information  9801  rather than checking the value of Flag  2  of status information  1011  of the replacement management information  9801 . 
     The drive control section  311  determines a specific location in the user data area (in this example, the location of PSN=1260) as the recording location at which the modified data is to be recorded and controls the recording/reproduction section  314  to record the modified data at the recording location. 
     The drive control section  311  newly generates replacement management information  9810  for replacing the defective cluster including the location of PSN=1228 by the replacement cluster having a start location of PSN=1260, and adds the replacement management information  9810  to the replacement management information list  1000 . Thus, the replacement management information list  1000  shown in  FIG. 50  is updated to the replacement management information list  1000  shown in  FIG. 51 . 
     As described above, according to the present embodiment, when the ECC cluster is required to be replaced by a replacement cluster, it is determined whether or not there exists an ECC cluster which is replaced by a replacement cluster, among a plurality of neighborhood clusters which are located in the neighborhood of the ECC cluster. If such a neighborhood cluster exists, the same area as the area for recording the replacement location of the neighborhood cluster is selected as an area for recording the replacement location of the ECC cluster. This is a feature of the replacement recording according to the present embodiment. Such a process is performed, for example, in step S 107  shown in  FIG. 8A . 
     When the replacement location is in the spare area, it is preferable to select the same spare area among a plurality of spare areas as an area for recording the replacement location of the ECC cluster. Further, when the replacement location is in the user data area, it is preferable to select the same track among a plurality of tracks allocated in the user data area as an area for recording the replacement location of the ECC cluster. 
     In general, data having close PSN values often form a file, or are data closely related to each other. It is more likely in the information recording medium of write-once type, since sequential recording is performed for such medium. 
     Thus, if replacement recording is performed in the same area as the near data, it is possible to contiguously read data during reproduction, thereby improving a reproduction performance. 
     In the above description, the replacement management information  1010 B having the PSN value close to original location cluster as original location information  1012  is retrieved. However, it is also possible to add following conditions to the retrieving process. 
     Specifically, a certain range of PSN values with respect to the PSN value of the original location cluster maybe defined as a retrieving range for the retrieving process. This is because, when information regarding replacement recording at the location too far is checked, it is likely to be another file or data which is not related so much, thereby causing degradation of a reproduction performance. 
     Alternatively, only replacement management information  1010 B having PSN values in the same track as the original cluster as the replacement location information  1013  may be defined as a retrieving range for the retrieving process. Again, data recorded in different tracks is likely to be another file, or data which is not related so much. 
     In this embodiment, the replacement recording for the defective cluster has been described. However, the present embodiment is also applicable to the replacement recording for the pseudo-overwrite recording. 
     A procedure for selecting recording location of the replacement cluster according to the present embodiment of the invention will be further described. 
       FIG. 52A  shows an exemplary data structure on the information recording medium  100  before the replacement recording is performed. 
       FIG. 52B  shows an exemplary data structure of the replacement management information list  1000  before the replacement recording is performed. 
       FIG. 53B  shows an exemplary data structure of replacement management information list  1000  after the replacement recording is performed. 
     In  FIG. 52A , track #N  10000 , track #N+1  10001 , track #N+2  10002  are allocated in the user data area. 
     It is assumed that the ECC cluster located at PSN=a 1  in track #N  10000  is replaced by the replacement cluster located at PSN=c 1 . Replacement management information  10800  indicating this replacement recording is included in the replacement management information list  1000  shown in  FIG. 52B . 
     In this state, it is assumed that a new data recording is performed for an unrecorded ECC cluster located at PSN=a 2  and a verify error occurs. 
     In this case, the recording location of the replacement cluster is determined in the following manner in the replacement recording performed by the drive apparatus  310 . 
     The session management information  200  is checked so as to determine which track includes the ECC cluster located at PSN=a 2 . In  FIG. 52A , it is determined that track #N  10000  includes the ECC cluster located at PSN=a 2 . 
     Next, in the replacement management information list  1000  shown  FIG. 52B , replacement management information having PSN included in track #N  10000  as original location information  1012  is retrieved. In  FIG. 52B , the replacement management information  10800  is found. 
     Next, the replacement location information  1013  of the replacement management information  10800  is obtained. Then, a track including PSN value of the obtained replacement location information  1013  is obtained from the session management information  200 . In the example shown in  FIG. 52A , the value of the replacement location information  1013  is PSN=c 1 . Thus, track #N+2  10002  is determined as a track corresponding to PSN=c 1 . 
     The drive apparatus  310  selects an unrecorded ECC cluster in track #N+2  10002  as a replacement location of the ECC cluster located at PSN=a 2 . 
     Further, the drive apparatus  310  obtains the LAR  10103  (PSN=c 2 ) of track #N+2  10002 , and performs the replacement recording for the subsequent unrecorded areas. 
     As a result of such a process, the data which is instructed to be recorded at the location of PSN=a 2  is actually recorded at a location other than the location of PSN=a 2  (for example, PSN=c 2 ). In this case, as shown in  FIG. 53B , the replacement management information  10801  indicating the replacement recording from PSN=a 2  to PSN=c 2  is generated. 
     As described above, according to the present embodiment, when the replacement recording is required, the replacement management information list  1000  and the session management information  200  are checked so as to determine whether or not a cluster included in the same original track as the original cluster is replaced by a replacement cluster in a replacement track which is different from the original track. If yes, the replacement track is selected as a replacement location. This is a feature of the replacement recording according to the present embodiment. 
     In general, data having close PSN values often form a file, or are data closely related to each other. It is more likely in the information recording medium of write-once type, since sequential recording is performed for such medium. 
     Thus, if replacement recording is performed from a track to another track, it is possible to contiguously read data during reproduction by locating the same track as the replacement location, thereby improving a reproduction performance. 
     When replacement clusters are present in a plurality of tracks, as described with reference to  FIG. 50 , a replacement location which has a closer original location may be prioritized. 
     In this embodiment, the replacement recording for the defective cluster has been described. However, the present embodiment is also applicable to the replacement recording for the pseudo-overwrite recording. 
     There may be a case where a replacement area is selected as the replacement location. In this case, the replacement area can be considered as one track. 
     INDUSTRIAL APPLICABILITY 
     The present invention is useful, since it provides a drive apparatus and the like capable of utilizing the user data area without any loss in the pseudo-overwrite recording for the write-once optical disc.