HK1083271B - Method of overwriting data in write-once medium and data recording and/or reproducing apparatus therefor - Google Patents

Description

Method of overwriting data in write-once medium and data recording and/or reproducing apparatus therefor

Technical Field

The present invention relates to a write-once information storage medium, and more particularly, to a method of overwriting data in a write-once information storage medium and an apparatus suitable for data recording and/or reproducing of the write-once information storage medium.

Background

The rewritable information storage medium may overwrite new data in an area thereof occupied by data. But the write-once information storage medium can only write information once in an area where data can be stored. Therefore, data cannot be overwritten in the write-once information storage medium, and data that has been recorded cannot be deleted or changed.

Typically, a predetermined area of a user data area of an information storage medium is set to store a file system including various information about data recorded in the information storage medium.

In a rewritable information storage medium, an updated file system may be overwritten on a predetermined area occupied by its old file system, so that the area storing the file system is fixed. On the other hand, write-once information storage media cannot be overwritten. Therefore, it is necessary to write the updated file system in an area other than the area in which the old file system has been recorded. Since the conventional data recording and/or reproducing apparatus is designed to read out the file system only from the fixed area of the information storage medium, the conventional system cannot read out the file system from the write-once information storage medium in which the recording location of the file system is changed. In other words, a reproduction compatibility problem may occur. Furthermore, since the conventional data recording and/or reproducing apparatus writes each updated file system in a different area of the write-once information storage medium, the conventional apparatus may take a lot of time to search for a final file system.

Disclosure of Invention

The present invention provides a method of overwriting data in a write-once information storage medium that is not physically rewritable, and a data recording and/or reproducing apparatus therefor.

The present invention also provides a method for logically overwriting data in a write-once information storage medium that is not physically overwritable, thereby easily updating and/or reading the data, and a data recording and/or reproducing apparatus thereof.

According to an aspect of the present invention, a method of overwriting data in a storage medium in which information is written once, includes: receiving a command to overwrite new data in a first area of a write-once information storage medium in which data has been recorded; determining the first area as a defective area and recording new data in the second area; the updated defect management information including the location information on the first and second areas is recorded in the write-once information storage medium.

According to another aspect of the present invention, a method of overwriting data in a write-once information storage medium includes: receiving a logical address from a host to store new data; determining whether a first area having a physical address on the write-once information storage medium corresponding to the logical address is occupied with data, and if the first area is occupied with data, determining that the first area is a defective area and storing new data in a second area having a physical address different from that of the first area; updated defect management information including physical addresses of the first and second areas is recorded in the write-once information storage medium.

According to another aspect of the present invention, there is provided a data recording and/or reproducing apparatus including a writer/reader and a controller. The writer/reader writes data to the write-once information storage medium or reads the written data. When the controller receives a command to overwrite new data in a first area of the write-once information storage medium in which data has been recorded, the controller determines the first area as a defective area and controls the writer/reader to record the new data in a second area. The controller controls the writer/reader to write updated defect management information including information on the locations of the first and second areas in the write-once information storage medium.

According to another aspect of the present invention, there is provided a data recording and/or reproducing apparatus including a writer/reader and a controller. The writer/reader writes data to the write-once information storage medium or reads the written data. The controller receives a logical address in the write-once information storage medium from the host to store new data, and determines whether a first area having a physical address on the write-once information storage medium corresponding to the logical address is occupied with data. If the first area is occupied with data, the controller determines the first area as a defective area and controls the writer/reader to write new data into a second area having a physical address different from that of the first area, and to write updated defect management information including the physical addresses of the first and second areas in the write-once information storage medium.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or other features and advantages of the present invention will become more apparent and more readily appreciated from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

fig. 1 illustrates a data structure of a write-once information storage medium having a single recording layer according to an embodiment of the present invention;

fig. 2 illustrates a data structure of a write-once information storage medium having a single recording layer according to another embodiment of the present invention;

fig. 3A and 3B illustrate a data structure of a write-once information storage medium having two recording layers according to another embodiment of the present invention;

fig. 4A and 4B illustrate the use direction of a spare area according to the present invention;

fig. 5 is a block diagram of a data recording and/or reproducing apparatus according to an embodiment of the present invention;

fig. 6A to 6D illustrate a method of overwriting an updated file system on a write-once information storage medium 100 according to an embodiment of the present invention;

FIG. 7 illustrates a defect list generated by a first logical overwrite according to the embodiment of FIGS. 6A to 6D;

fig. 8 illustrates a defect list generated by the second logic overwriting according to the embodiment of fig. 6A to 6D.

Detailed Description

Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings to explain the present invention.

Fig. 1 illustrates a structure of a write-once disc information storage medium 100 having a single recording layer according to an embodiment of the present invention. Referring to fig. 1, the storage medium 100 includes a lead-in area 120, a data area 130, and a lead-out area 140. An area 121 is formed in the lead-in area 120 for recording a Temporary Disc Defect Structure (TDDS) and a Space Bit Map (SBM). A separate area 122 is also formed in the lead-in area 120 for a temporary defect sequence (TDFL). Spare areas 1 and 2(133 and 134, respectively) are formed at the head and the tail of the data area 130, respectively, and are allocated to manage temporary disc defects, having a predetermined size.

Alternatively, the area 121 for the TDDS and the SBM may be formed in at least one of the lead-out area 140 and the data area 130.

Temporary disc defect management, spare areas allocated for temporary disc defect management, and an SBM will be described in detail below. Disc defect management represents an operation in which, if a defect is generated in user data recorded in the user data area 135, new user data corresponding to the defective user data is recorded to compensate for data loss due to the generated defect.

Disc defect management is roughly classified into disc defect management using a linear replacement technique or disc defect management using a slipping replacement technique. In the linear replacement technique, if a defect is generated in a user data area of a data area, the defective area is replaced with a non-defective spare area allocated in the data area. In the slipping replacement technique, a defective area is skipped, i.e., the area is not used, but is replaced with a non-defective area.

The linear and slipping replacement techniques are widely applied to information storage media, such as DVD-RAM/RW, which can record data multiple times with a random access method.

As illustrated in fig. 1, the write-once information storage medium 100 according to an embodiment of the present invention also allocates spare areas 1 and 2(133 and 134) in the data area 130 for performing defect management using a linear replacement technique. When the write-once information storage medium is initialized to be ready for use, the spare areas 1 and 2(133 and 134) are allocated in the data area 130 according to a command of a data recording and/or reproducing apparatus or a host.

When an information storage medium is loaded on a data recording and/or reproducing apparatus, the data recording and/or reproducing apparatus reads out information stored in a lead-in and/or lead-out area and determines how to manage the medium and how to record or reproduce data in the medium. When the amount of information recorded in the lead-in and/or lead-out area increases, the time required for preparing data recording or reproduction after the information storage medium is loaded also increases. In order to reduce the time required for preparing data recording and/or reproduction, the write-once information storage medium 100 of fig. 1 utilizes temporary management data, which includes a TDDS and a TDFL.

The TDDS may include an identifier of the TDDS, an update counter, data regarding the location of a final TDFL that has been recorded, location data regarding final disc and drive information that has been recorded, data regarding a spare area size for replacing a defective cluster, and the like.

The TDFL may include a TDFL identifier, an update counter, a defect factor, a number of defect factors, and the like. The defect factors include: status data, position data on the defective cluster, and position data on the replacement cluster. The status data may indicate replacement data, the type of defective cluster, and the like. The types of defective clusters may include defective clusters that must be replaced, defective clusters that do not have to be replaced, and possibly defective clusters, etc.

The write-once information storage medium 100 of fig. 1 stores an SBM, i.e., "recording status" data, which indicates whether data is recorded on a cluster unit of the write-once information storage medium. The SBM is formed by allocating a bit value of 0 to occupied clusters and a bit value of 1 to unoccupied clusters.

Accordingly, the data recording and/or reproducing apparatus can check the recording state of the write-once information storage medium of FIG. 1 very quickly by referring to the finally updated SBM. Thus improving the efficiency of use of the medium.

Although the write-once information storage medium 100 of FIG. 1 stores the SBM and the TDDS on one cluster, the present invention is not limited to this embodiment.

Since the SBM indicates whether data has been recorded in a cluster unit of the write-once information storage medium 100, the SBM must be finally updated after all other data including user data is recorded.

Fig. 2 illustrates a structure of a write-once information storage medium 200 having a single recording layer according to another embodiment of the present invention. Referring to fig. 2, the storage medium 200 includes: a lead-in area 220, a data area 230, and a lead-out area 240. A Temporary Disc Management Area (TDMA)221 and an SBM area 222 are separately allocated in the lead-in area 220. Spare areas 1 and 2 (233 and 234, respectively) are allocated at the head and tail of the data area 130, respectively, for managing temporary disc defects, have a certain size, and surround the user data area 235.

The TDMA 221 is defined to store a TDDS and a TDFL, and the SBM area 222 is defined to store space bitmap data in a similar manner as described previously.

Fig. 3A and 3B illustrate a data structure of a write-once information storage medium 300 having first and second recording layers L0 and L1 according to still another embodiment of the present invention. Fig. 3A illustrates a structure of the first recording layer L0, and fig. 3B illustrates a structure of the second recording layer L1. Fig. 3A can be considered as a structure of a write-once recording medium having a single layer.

The data structure of the first recording layer L0 of fig. 3A is similar to that of the write-once information storage medium 200 of fig. 2, except that the SBM and the TDDS and TDFL are stored in a Temporary Defect Management Area (TDMA)321 instead of being stored in separate areas. The structure of the second recording layer L1 of fig. 3B is the same as that of the first recording layer L0 of fig. 3A. The inner area 0(321) includes the TDMA 321 of the first recording layer L0, and the inner area 1(350) includes the TDMA 351 of the second recording layer L1. The data area 0(330) includes a spare area 1(331), a user data area (331), and a spare area 2 (332). The data area 1(360) includes a spare area 3(363), a user data area 365, and a spare area 4 (364).

Fig. 4A and 4B illustrate the use direction of the spare area (133, 134, 233, 234, 331, 332, 363, 364) according to the present invention. Fig. 4A relates to a write-once recording medium (e.g., 100, 200) having a single recording layer, and fig. 4B relates to a write-once recording medium (e.g., 300) having two recording layers (i.e., first and second recording layers). Referring to fig. 4A and 4B, in the first recording layer (or single recording layer), a use direction 401 of the data area excluding the spare area, i.e., the user data area (135, 235, 333), is from an inner boundary 402 to an outer boundary 403 of the recording medium (100, 200, 300). In the second recording layer, the use direction 405 of the user data area 365 is from the outer boundary 403 to the inner boundary 402 of the recording medium 300.

As shown in fig. 4A, the spare area 2(135, 235, 333) is used in a direction 406 opposite to the recording direction 401 of the user data, i.e., in a direction from the outer boundary 403 to the inner boundary 402 of the recording medium (100, 200, 300), thereby being easily expanded. As shown in fig. 4B, the spare area 4(364) is used in a direction 407 from the inner boundary 402 to the outer boundary 403 of the recording medium 300, thereby being easily expanded.

As described below, the write-once information storage medium according to the present invention may require a wider spare area than a conventional information storage medium in order to perform logical overwriting using defect management according to the present invention. Therefore, it is preferable, but not necessary, to extend the spare area during initialization of the information storage medium or during use of the information storage medium. In order to be able to extend the spare area during use of the information storage medium, it is preferable, but not necessary, to record data in the spare area in a direction opposite to the user data recording direction as shown in fig. 4A and 4B.

Now, methods of overwriting data according to two embodiments of the present invention will be described in detail with reference to the information storage medium 300 shown in fig. 3A and 3B.

In the method of overwriting data according to an embodiment of the present invention, data may be overwritten in a write-once information storage medium that cannot be physically overwritten using a logical overwrite technique.

Fig. 5 is a block diagram of an apparatus 500 for data recording and/or reproducing according to an embodiment of the present invention. As shown in fig. 5, the apparatus 500 includes a writer/reader 510, a controller 520, and a memory 530. The write-once information storage medium 300 is the same as the write-once information storage medium of fig. 3A.

The writer/reader 510 writes data to the write-once information storage medium 300 under the control of the controller 520, and reads the written data from the write-once information storage medium to verify the data.

The controller 520 performs defect management using the TDMA included in the write-once information storage medium 300 when recording and/or reproducing data on the write-once information storage medium 300.

The controller 520 follows a verify-after-write process, i.e., after recording data in a predetermined unit of the write-once information storage medium 300, verifies the recorded data for defective data. Accordingly, the controller 520 records user data in predetermined units and verifies the recorded user data to identify defective data. The controller 520 generates a TDFL and a TDDS indicating an area storing defective data found in the verification process. The controller 520 stores the TDFL and the TDDS in the memory 530, collects a predetermined number of TDFLs and TDDSs, and writes the collected TDFLs and TDDSs to the TDMA 321 allocated in the write-once information storage medium 300.

The above-described overwriting of data in the write-once information storage medium 300 by the data recording and/or reproducing apparatus 500 of fig. 5 will now be described in more detail by taking an updated file system as an example of data to be overwritten.

If the data recording and/or reproducing apparatus performs defect management to record and/or reproduce data in the write-once information storage medium, a file system recorded in the write-once information storage medium may be updated through the defect management. In other words, the data recording and/or reproducing apparatus 500 receives data regarding the updated file system and a logical address of the write-once information storage medium from the host to store the updated file system, and thereafter checks from the SBM whether a physical address corresponding to the logical address is occupied with the data. The SBM is read out in advance from the write-once information storage medium by the writer/reader 510 and stored in the memory 530. If it is determined that the physical address is occupied by data, the area having the physical address is determined as a defective area. Then, the updated file system is recorded in the spare area allocated to replace the defective area.

If the data recording and/or reproducing apparatus 500 does not use such an SBM, the recording and/or reproducing apparatus 500 may determine the occupied data area as a defective area through a verify-after-write method and then record an updated file system in the spare area. Thereafter, the updated TDDS and the updated TDFL are recorded in the TDMA 321.

Fig. 6A to 6D illustrate a method of overwriting an updated file system in the write-once information storage medium 300. In the method described with reference to fig. 6A to 6D, the first and second spare areas 331 and 332 are determined as SA1 and SA2 and are allocated at the head and tail of a data area (e.g., data area 330). Also, an area storing a file system is allocated at the head of the user data area 335.

In fig. 6A, an initial file system FS #0 is recorded in an arrangement area from the head of the user data area 335 to a predetermined position. In fig. 6B, first user data 601 is recorded next to the initial file system FS #0 in the user data area 335, and then a first updated file system FS #1 is generated after defect management is recorded in the second spare area SA2 according to the overwriting method of the above-described embodiment of the present invention. In fig. 6C, in the user data area, second user data 602 is recorded next to the first user data 601, and then a second updated file system FS #2 is recorded next to the first updated file system FS # 1. In fig. 6D, updated second user data 603 is recorded next to the second user data 602 in the user data area 335, and then a third updated file system FS #3 is recorded next to the second updated file system FS # 2.

The second spare area SA2 in fig. 6D is expanded from the second spare area SA2 shown in fig. 6A through 6C. In other words, when the second spare area SA2 of FIG. 6A is used up, the second spare area SA2 of FIG. 6A can be extended by reinitializing the write-once information storage medium 300. In order to easily extend the spare area such as SA2, the use direction of the spare area, i.e., the direction in which data is recorded in the spare area, is set to be opposite to the direction in which data is recorded in the user data area, i.e., 335.

Even if the above logical overwriting continues on the same Logical Sector Number (LSN), the amount of data included in the defect list does not increase. For example, assume that LSNs corresponding to Physical Sector Numbers (PSNs) 100h to 1FFh in the user data area are 00h to FFh, and an initial file system is recorded in the PSNs 100h to 1 FFh. LSN denotes an address of a logical sector, and PSN denotes an address of a physical sector.

Thus, since additional user data is recorded in the write-once information storage medium, the host issues a command to the data recording and/or reproducing apparatus 500 of FIG. 5 to write the first updated file system over the LSNs 00h through FFh in which the initial file system was recorded. If it is determined that the LSNs 00h through FFh are occupied with data using the SBM or through the verify-after-write process, the data recording and/or reproducing apparatus determines sectors corresponding to the PSNs 100h through 1FFh as defective areas. Then, the data recording and/or reproducing apparatus records the first updated file system (FS #1) in the spare area (e.g., SA 2). Fig. 7 illustrates a defect list generated by a first logical overwrite in the method of fig. 6A to 6D. Referring to FIG. 7, sectors corresponding to the PSNs 100h through 1FFh in which the initial file system is recorded are determined as defective sectors, and replacement sectors of the defective sectors are PSNs 11FFFh through 11F00h in a spare area (e.g., SA 2).

When a first update file system is recorded in sectors LSN00h through FFh by a first logical overwrite and then additional user data is recorded in the write-once information storage medium, the host commands the data recording and/or reproducing apparatus to overwrite a second update file system in sectors LSN00h through FFh. When it is determined that the sectors corresponding to the LSNs 00h through FFh are occupied with data using an SBM or through a verify-after-write process, the data recording and/or reproducing apparatus determines the sectors corresponding to the PSNs 100h through 1FFh as defective sectors. Then, the data recording and/or reproducing apparatus 500 records the second updated file system (e.g., FS #2) in the spare area (e.g., SA 2).

Fig. 8 illustrates a defect list generated by a second logical overwrite in the method of fig. 6A to 6D. Referring to FIG. 8, sectors corresponding to the PSNs 100h through 1FFh in which the initial file system is recorded are determined as defective sectors, and replacement sectors of the defective sectors are PSNs 11EFFh through 11E00h in a spare area (e.g., SA 2).

Comparing the defect lists of fig. 7 and 8, although the defect list is generated each time overwriting is performed on the same LSN, only the PSN of the replacement sector included in each defect list is changed without an increase in the amount of data contained in each defect list.

Now, a method of overwriting data in a write-once information storage medium according to another embodiment of the present invention will be described in detail. In this embodiment, the data overwriting is performed using a file system.

To perform the overwriting, the data recording and/or reproducing apparatus 500 of fig. 5 receives a command from the host to reproduce data recorded in sectors LSN00h through FFh, accesses PSNs corresponding to the LSNs, e.g., 100h through 1FFh, to read out the data, and transfers the read-out data to the host.

When the host attempts to correct data received from the data recording and/or reproducing apparatus and then record the corrected data in the write-once information storage medium, or attempts to additionally record data received from the data recording and/or reproducing apparatus in the write-once information storage medium 300, the data recording and/or reproducing apparatus 500 transmits an SBM, defect information, and the like to the host. The host distinguishes the data recordable area and the data unrecordable area by referring to the SBM, the defect information, etc., in consideration of the state of the user data area (i.e., 333) to which data is logically allocated and the physical recording status of the user data area, thereby selecting the overwritable area. In other words, the overwriting method according to the embodiment of the present invention is characterized in that the host selects the overwritable area.

Industrial applicability

The overwriting method according to the latter embodiment of the present invention is suitable for write-once information storage media having a user data area with a large storage capacity. The overwriting method according to the previous embodiment of the present invention can prevent the consumption of the user data area by overwriting new data in the spare area applied in defect management.

As described above, in the present invention, overwriting can be performed in a write-once information storage medium in which physical overwriting is impossible, by applying a logical overwriting technique. Accordingly, data recorded in the write-once information storage medium may be changed or updated. Also, when data recorded in a fixed area of the write-once information storage medium is required, for example, when a file system is updated, the updated file system is recorded at a physical address different from the physical address at which the original file system was recorded, but the logical address at which the updated file system was recorded is the same as the logical address at which the original file system was recorded. Therefore, the host recognizes that the file system is always recorded in a fixed area, thereby easily accessing and reproducing the file system.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims (16)

1. A method of overwriting data in a write-once information storage medium, the method comprising:

receiving a command to overwrite new data in a first area of a write-once information storage medium in which data has been recorded;

determining the first area as a defective area and recording new data in a second area where no data is recorded;

updated defect management information including information on locations of the first and second areas is recorded in the write-once information storage medium.

2. The method of claim 1, wherein the recording of new data comprises: whether the first area is occupied with data is determined using recording status information representing a recording status of the write-once information storage medium by distinguishing occupied data areas from unoccupied areas.

3. The method of claim 2, wherein the recording-status information is a bitmap generated by allocating different bit values to occupied and unoccupied clusters of the write-once information storage medium.

4. The method of claim 1, wherein the recording of new data comprises: writing new data to the first area and thereafter verifying the written new data, and determining the first area as a defective area according to a result of the verification of the new data.

5. The method of claim 1, wherein the data previously recorded in the first area is a previous file system, and the new data to be recorded in the second area is an updated file system.

6. The method of claim 5, wherein the second area is included in a spare area allocated in a data area of the write-once information storage medium.

7. The method of claim 6, wherein the information on the updated file system is recorded in the spare area in a direction opposite to a direction in which the user data is recorded.

8. A data recording and/or reproducing apparatus comprising:

a writer/reader for writing data to the write-once information storage medium or reading the written data; and

and a controller for determining a first area of the write-once information storage medium occupied by the data as a defective area when a command is received to overwrite new data in the first area, and controlling the writer/reader to write the new data to a second area and to write updated defect management information including information on locations of the first and second areas in the write-once information storage medium.

9. The apparatus of claim 8, further comprising a memory for storing recording status information representing a recording status of the write-once information storage medium by distinguishing occupied data areas from unoccupied areas,

wherein the controller determines whether the first area is occupied with data using the recording status information.

10. The apparatus of claim 9, wherein the recording-status information is a bitmap generated by allocating different bit values to occupied and unoccupied clusters of the write-once information storage medium.

11. The apparatus of claim 8, wherein the controller controls the writer/reader to write new data into the first area, reads the new data from the first area to verify the new data, and determines the first area as a defective area according to a result of the verification of the new data.

12. The apparatus of claim 8, wherein the data previously recorded in the first area is a previous file system, and the new data to be recorded in the second area is an updated file system.

13. The apparatus of claim 12, wherein the second area is included in a spare area allocated in a data area of the write-once information storage medium.

14. The apparatus of claim 13, wherein the controller controls the writer/reader to write information on the updated file system into the spare area in a direction opposite to a direction in which the user data is recorded.

15. A method of managing data in a write-once information storage medium, the method comprising:

designating a data area and storing first data in a first portion of the data area;

storing an initial file structure for identifying a location of the stored first data in a second portion of the data area;

storing second data in a first portion of the data area;

an updated file structure identifying the location of the first and second data in the first data area is stored in a third portion of the data area.

16. The method of claim 15, wherein the direction of storing the first and second data in the storage medium is opposite to the direction of storing the initial file structure and the updated file structure in the storage medium.