CLAIMS

1. A rewritable information recording medium on which a read/write operation is performed on a block-by-block basis,

the information recording medium comprising:

a user data area to store user data written thereon;

a spare area including a replacement block that would replace a defective block in the user data area; and

a defect management information area to store defect management information for use to manage the defective block in the user data area or the spare area,

wherein the spare area is used sequentially in a predetermined direction, and

wherein the defect management information includes:

a spare defect attribute indicating the defective block, if any, in the spare area;

a defect entry specifying the sector address of the defective block; and

next available spare location information for use to manage a location in the spare area from which a next replacement block is available.

2. The information recording medium of claim 1, wherein the information recording medium includes multiple spare areas, and

wherein the defect management information includes the next available spare location information that is defined for each of those multiple spare areas.

3. The information recording medium of claim 1, wherein the spare defect attribute includes at least one of:

a definite spare defect attribute indicating that the defective block in the spare area is definitely unusable; and

a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now.

4. A method for writing information on a rewritable information recording medium on which a read/write operation is performed on a block-by-block basis,

wherein the information recording medium includes:

a user data area to store user data written thereon;

a spare area including a replacement block that would replace a defective block in the user data area; and

a defect management information area to store defect management information for use to manage the defective block in the user data area or the spare area, and

wherein the spare area is used sequentially in a predetermined direction, and wherein the defect management information includes:

a spare defect attribute indicating the defective block, if any, in the spare area;

a defect entry specifying the sector address of the defective block; and

next available spare location information for use to manage a location in the spare area from which a next replacement block is available, and

wherein the method comprises the steps of:

allocating a replacement block to the defective block by reference to the next available spare location information and the defect entry; and

updating the next available spare location information.

5. The information writing method of claim 4, comprising, if the replacement block has been allocated, the steps of:

(a) determining whether or not the location of the next block that follows the replacement block allocated matches to the sector address specified by the defect entry; if the answer to the step (a) is NO, then

(b) updating the next available spare location information so that the information indicates the location of that next block; but if the answer to the step (a) is YES, then

(c) updating the next available spare location information so that the information indicates the location of a block that follows that next one in the predetermined direction with the defective block indicated by the defect entry avoided.

6. The information writing method of claim 5, wherein the spare defect attribute includes at least one of:

a definite spare defect attribute indicating that the defective block in the spare area is definitely unusable; and

a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now, and

wherein the step (a) includes determining whether or not the location of the next block matches to the sector address of the defective block having the definite spare defect attribute, and

wherein if the answer to the step (a) is YES, the step (c) includes updating the next available spare location information so that the information indicates the location of a block that follows that next one in the predetermined direction with the defective block having the definite spare defect attribute avoided.

7. The information writing method of claim 4, wherein the spare defect attribute includes a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now, and

wherein the writing method comprises the steps of:

(a) determining whether or not the location of the next block that follows the replacement block allocated matches to the sector address of the defective block having the provisional spare defect attribute; and if the answer to the step (a) is YES, then

(b) updating the next available spare location information so that the information indicates the location of that next block.

8. The information writing method of claim 4, wherein the spare defect attribute includes a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now, and

wherein if it has turned out, while the replacement block is being allocated, that the location of the block indicated by the next available spare location information

does not match to the sector address specified by the defect entry, the block pointed to by the next available spare location information is allocated as the replacement block, but

if it has turned out, while the replacement block is being allocated, that the location of the block indicated by the next available spare location information matches to the sector address managed by the provisional spare defect attribute, then performed is one of the steps of:

(a) allocating the block managed by the provisional spare defect attribute as the replacement block; and

(b) allocating a next block, which is determined by skipping that block managed by the provisional spare defect attribute in the predetermined direction, as the replacement block.

9. The information writing method of claim 4, comprising, if the replacement block is allocated, the steps of:

(a) determining whether or not the location indicated by

the next available spare location information provided matches to the sector address specified by the defect entry; if the answer to the step (a) is NO, then

(b) determining the block pointed to by the next available spare location information to be the replacement block, but if the answer to the step (a) is YES, then

(c) avoiding the defective block indicated by the defect entry and determining the next block that follows the defective block in the predetermined direction to be the replacement block, and wherein the method further includes the step of

(d) updating, if necessary, the next available spare location information so that the information indicates the location of a block that follows the block that has been determined to be the replacement block in either the step (b) or (c).

10. The information writing method of claim 9, wherein the information recording medium includes multiple spare areas, and

wherein the defect management information includes the next available spare location information that is defined for each of those multiple spare areas, and

wherein the step (a) includes the steps of:

choosing one of the multiple spare areas that needs to be used to allocate the replacement block; and

determining whether or not the next available spare location information provided for that spare area chosen matches to the sector address specified by the defect entry.

11. The information writing method of claim 9, wherein the step (a) includes the steps of:

deciding the defect entry, to which the next available spare location information needs to be compared, to see if the entry matches to the information; and

if the answer is YES, then

updating the defect entry, to which the next available spare location information needs to be compared to see if they match, into a next defect entry.

12. The information writing method of claim 9, wherein the spare defect attribute includes:

a definite spare defect attribute indicating that the defective block in the spare area is definitely unusable; and

a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now,

wherein the step (a) includes the steps of:
deleting the defect entry having the provisional spare defect attribute if the defect entry specifies the same sector address as the one indicated by the next available spare location information; and

determining whether or not the location indicated by the next available spare location information matches to the sector address specified by the defect entry having the definite spare defect attribute.

13. An information writing apparatus for writing information on a rewritable information recording medium on

which a read/write operation is performed on a block-by-block basis,

wherein the information recording medium includes:

a user data area to store user data written thereon;

a spare area including a replacement block that would replace a defective block in the user data area; and

a defect management information area to store defect management information for use to manage the defective block in the user data area or the spare area, and

wherein the spare area is used sequentially in a predetermined direction, and

wherein the defect management information includes:

a spare defect attribute indicating the defective block, if any, in the spare area;

a defect entry specifying the sector address of the defective block; and

next available spare location information for use to manage a location in the spare area from which a next replacement block is available, and

wherein the information writing apparatus allocates a replacement block to the defective block by reference to the next available spare location information and the defect entry and updates the next available spare location information.

14. The information writing apparatus of claim 13, wherein if the replacement block has been allocated, the apparatus determines whether or not the location of the next block that follows the replacement block allocated matches to the sector address specified by the defect entry,

wherein if the apparatus has decided that the location does not match to the sector address, the apparatus updates the next available spare location information so that the information indicates the location of that next block; but

if the apparatus has decided that the location does match to the sector address, then the apparatus updates the next available spare location information so that the information indicates the location of a block that follows that next one in the predetermined direction with the defective block indicated by the defect entry avoided.

15. The information writing apparatus of claim 14,

wherein the spare defect attribute includes at least one of:

a definite spare defect attribute indicating that the defective block in the spare area is definitely unusable; and

a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now, and
wherein the writing apparatus determines whether or not the location of the next block that follows .the block allocated as the replacement block matches to the sector address of the defective block having the definite spare defect attribute, and

wherein if the apparatus has decided that the location matches to the sector address, the apparatus updates the next available spare location information so that the information indicates the location of a block that follows that next one in the predetermined direction with the defective block having the definite spare defect attribute avoided.

16. The information writing apparatus of claim 13,

wherein the spare defect attribute includes a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now, and

wherein the writing apparatus determines whether or not the location of the next block that follows the replacement block allocated matches to the sector address of the defective block having the provisional spare defect attribute, and

wherein if the apparatus has decided that the location does match to the sector address, then the apparatus updates the next available spare location information so that the information indicates the location of that next block that follows the block allocated as the replacement block.

17. The information writing apparatus of claim 13, wherein the spare defect attribute includes a provisional spare defect attribute indicating that the defective .block in the spare area used to be a defective one but may have had its defect repaired by now, and

wherein if the writing apparatus has found, while allocating the replacement block, that the location of the block indicated by the next available spare location information does not match to the sector address specified by the defect entry, the apparatus allocates the block pointed to by the next available spare location information as the replacement block, but

if the apparatus has found, while allocating the replacement block, that the location of the block indicated by the next available spare location information matches to the sector address managed by the provisional spare defect attribute, then the apparatus allocates the replacement block by either

(a) allocating the block managed by the provisional spare defect attribute as the replacement block, or

(b) allocating a next block, which is determined by skipping that block managed by the provisional spare defect attribute in the predetermined direction, as the replacement block.

18. The information writing apparatus of claim 13, wherein the apparatus comprises:
a decision section for deciding, to allocate the replacement block, whether or not the location indicated by the next available spare location information provided matches to the sector address specified by the defect entry; and

a determining section that determines, if the decision section has found the location and the sector address not matching to each other, the block pointed to by the next available spare location information to be the replacement block,

wherein if the decision section has found the location and the sector address matching to each other, the determining section determines the next block that follows, in the predetermined direction, the defective block indicated by the defect entry to be the replacement block, and

wherein the writing apparatus further comprises an updating section for updating the next available spare location information so that the information indicates the location of the next block that follows the one determined to be the replacement block by the determining section.

19. The information writing apparatus of claim 18,

wherein the information recording medium includes multiple spare areas, and

wherein the defect management information includes the next available spare location information that is defined for each of those multiple spare areas, and

wherein the decision section chooses one of the multiple spare areas that needs to be used to allocate the replacement block and determines whether or not the next available spare location information provided for that spare area chosen matches to the sector address specified by the defect entry.

20. The information writing apparatus of claim 18, wherein the decision section decides the defect entry, to which the next available spare location information needs to be compared, to see if the entry matches to the information, And

wherein if the decision section has found the entry and the information matching, then the decision section updates the defect entry, to which the next available spare location information needs to be compared to see if they match, into a next defect entry.

21. The information writing apparatus of claim 18, wherein the spare defect attribute includes:

a definite spare defect attribute indicating that the defective block in the spare area is definitely unusable; and

a provisional spare defect attribute indicating that the defective block in the spare area used to be a defective one but may have had its defect repaired by now,

wherein the decision section deletes the defect entry having the provisional spare defect attribute if the defect entry specifies the same sector address as the one indicated by the next available spare location information, and determines whether or not the location indicated by the next available spare location information matches to the sector address specified by the defect entry having the definite spare defect attribute.

22. A method for reading information from an information recording medium on which the information has been written by the method of claim 4,

wherein the information is retrieved by scanning the replacement block allocated.

23. An apparatus for reading information from an information recording medium on which the information has been written by the apparatus of claim 13,

wherein the information is retrieved by scanning the replacement block allocated.

24. A method for writing information on a rewritable information recording medium on which a read/write operation is performed on a block-by-block basis,

wherein the information recording medium includes: a user data area to store user data written thereon; a spare area including a replacement block that would replace a defective block in the user data area; and

a defect management information area to store defect management information for use to manage the defective block in the user data area or the spare area, and

wherein the spare area is used sequentially in a predetermined direction, and

wherein the defect management information includes:

a defect entry specifying the sector address of the defective block; and next available spare location information for use to manage a location in the spare area from which a next replacement block is available, and

wherein the information writing method comprises the steps of:

(a) detecting a defective block in the user data area;

(b) detecting a defective block in the spare area;

(c) allocating a replacement block to the defective block that has been detected in the step (a) so that the defective block detected in the step (b) is avoided and that blocks of the spare area are sequentially used in a predetermined direction on a first come, first use basis;

(d) adding a defect entry, including the sector address of the defective block that has been detected in the step (a), to the defect management information;

(e) updating the next available spare location information so that the information indicates the location of the next block that follows the replacement block allocated in the step (c); and

(f) writing the defect management information that has been updated in the steps (d) and (e) on the defect management information area.

25. The information writing method of claim 24, wherein the information recording medium includes multiple spare areas, and

wherein the defect management information includes the next available spare location information that is defined for each said spare area, and

wherein the step (c) includes choosing one of the spare areas that is going to be used to allocate the replacement block, and

wherein the step (e) includes updating the next available spare location information for the spare area chosen so that the information indicates the location of the next block that follows the replacement block allocated in the step (c).

26. An information writing apparatus for writing information on a rewritable information recording medium on which a read/write operation is performed on a block-by-block basis,

wherein the information recording medium includes:

a user data area to store user data written thereon;

a spare area including a replacement block that would replace a defective block in the user data area; and

a defect management information area to store defect management information for use to manage the defective block in the user data area or the spare area, and

wherein the spare area is used sequentially in a predetermined direction, and

wherein the defect management information includes:

a defect entry specifying the sector address of the defective block; and

next available spare location information for use to manage a location in the spare area from which a next replacement block is available, and

wherein the information writing apparatus comprises:

a user data area defective block detecting section for detecting a defective block in the user data area;

a spare area defective block detecting section for detecting a defective block in the spare area;

a replacement block calculating section for allocating a replacement block to the defective block that has been detected in the user data area so that the defective block detected in the spare area is avoided and that blocks of the spare area are seguentially used in a predetermined direction on a first come, first use basis and for adding a defect entry, specifying the sector address of the defective block that has been detected in the user data area, to the defect management information;

a next available spare location information updating

section for updating the next available spare location information so that the information indicates the location of the next block that follows the replacement block allocated; and

a management information writing section for writing the defect management information that has been updated by the replacement block calculating section and the next available spare location information updating section on the defect management information area.

27. The information writing apparatus of claim 26, wherein the information recording medium includes multiple spare areas, and

wherein the defect management information includes the next available spare location information that is defined for each said spare area, and

wherein the replacement block calculating section chooses one of the spare areas that is going to be used to allocate the replacement block, and

wherein the next available spare location information updating section updates the next available spare location information for the spare area chosen so that the information indicates the location of the next block that follows the replacement block allocated.

28. An information recording medium on which information is written by the information writing method of claim 24, the recording medium comprising:

a user data area to store user data written thereon;

a spare area including a replacement block that would replace a defective block in the user data area; and

a defect management information area to store defect management information for use to manage the defective block in the user data area or the spare area, and

wherein the spare area is used sequentially in a predetermined direction, and

wherein the defect management information includes:

a defect entry specifying the sector address of the defective block; and next available spare location information for use to manage a location in the spare area from which a next replacement block is available, and

wherein the defect management information updated is written on the defect management information area.

29. A method for reading information from an information recording medium on which the information has been written by the information writing method of claim 24,

wherein the information is retrieved by scanning the replacement block allocated.

30. An information reading apparatus for reading information from an information recording medium on which the information has been written by the information writing apparatus of claim 2 6,

wherein the information is retrieved by scanning the replacement block allocated.