Patent EA-002911-B1 (EA)
Title: Recording medium with write protected defect list
Inventor: VAN GESTEL WILHELMUS J
IPC: G11B20/12
Filed: 2000-07-12
Abstract: 1. A recording medium (2) having at least one recording track (3) and having a recording area (40) divided into logic blocks (45) which each have an individual logic address, wherein a defect list (BS) of addresses of defective blocks (45*) is stored in the recording area (40). 2. A recording medium as claimed in Claim 1, wherein said defect list (BS) is protected against overwriting and/or erasing by a user. 3. A recording medium as claimed in Claim 2, wherein for the purpose of said protection said defect list (BS) has a predetermined standard name and/or is recorded at a predetermined location. 4. A method of recording information on a recording medium (2) having at least one recording track (3) and having a recording area (40) divided into logic blocks (45) which each have an individual logic address, wherein, prior to the actual write process, it is examined whether the recording medium (2) has a file having a predetermined name (BS), which file is indicative of the presence of a defect list of addresses of defective blocks (45*) and wherein, if the recording medium (2) does not yet have such file, such file is created first. 5. A method of recording information on a recording medium (2) having at least one recording track (3) and having a recording area (40) divided into logic blocks (45) which each have an individual logic address, wherein, prior to the actual write process, it is examined whether the recording medium (2) has a file having a predetermined name (BS), which file is indicative of the presence of a defect list of addresses of defective blocks (45*) and wherein, if the recording medium (2) actually has such a file, the block addresses specified in said file are read and are skipped in the actual write process. 6. A method of reading information from a recording medium (2) having at least one recording track (3) and having a recording area (40) divided into logic blocks (45) which each have an individual logic address, wherein if problems occur during reading of a block, for example, if reading of a block fails completely or, for example, if a block appears to contain incorrigible errors during reading, and preferably also if the number of corrigible errors occurring in one block is greater than a predetermined acceptance limit, the address of the relevant block is stored in a problem memory (52); and wherein upon termination of the read cycle (200) the addresses of the blocks stored in the problem memory are recorded in a defect list in a predetermined file (BS) on the recording medium (2). 7. A method of reading information from a recording medium (2) having at least one recording track (3) and having a recording area (40) divided into logic blocks (45) which each have an individual logic address, wherein if problems occur during reading of a block, for example, if reading of a block fails completely or, for example, if a block appears to contain incorrigible errors during reading, and preferably also if the number of corrigible errors occurring in one block is greater than a predetermined acceptance limit, the address of the relevant block is stored in a problem memory (52); and wherein upon termination of the read cycle (200) the blocks specified in the problem memory are checked. 8. A method as claimed in Claim 7, wherein during checking of a block specified in the problem memory the information in said block is read and is subjected to an error correction algorithm, and wherein, if the information thus read appears to be restorable, the restored information is written into the relevant block in a restoration step (306), after which preferably a read-after-write check is carried out. 9. A method as claimed in Claim 7, wherein during checking of a block specified in the problem memory the information in said block is read and is subjected to an error correction algorithm; wherein, if the information thus read appears to be nonrestorable, a predetermined code word (skip code) is written into the relevant block, after which a readafter-write check (312) is carried out; and wherein, if during said read-after-write check (312) it appears that said code word has not been written successfully, the address of the relevant block is recorded (314, 400) in a defect list in a predetermined file (BS) on the recording medium (2). 10. A method of recording information, particularly a real-time audio and/or video signal in a recording track (3) of a recording medium (2), which recording track has been divided into blocks (45); wherein the recording medium contains a defect list (BS) of addresses of blocks (45*) which are known to be defective, or is provided with such a list; wherein said defect list is read and wherein during the recording process, which is carried out without a read-after-write check so as to speed up the process, the blocks whose addresses have been read from said defect list are skipped; and wherein said defect list is updated by noting which blocks give rise to read problems during reading of a file and by recording the addresses of these blocks in said defect list on the recording medium after reading. 11. An apparatus (1) for recording information, particularly a real-time audio and/or video signal, in a recording track (3) of a recording medium (2), which recording track has been divided into blocks (45), and for reading information recorded on such a recording medium, which apparatus comprises: - a write/read unit (20) adapted to control the write process and the read process; - an allocation manager (30) coupled to said write/read unit (20); - a first auxiliary memory (51) associated with the allocation manager (30); wherein the allocation manager (30) is adapted to read, after having received a recording command (101) and having defined (102) a part (NW) intended for recording in the recording area (40) of the recording medium (2), a file (BS) recorded on the recording medium (2) and containing a defect list of addresses of defective blocks (45*) and to store (106) the block addresses specified in the defect list in the first auxiliary memory (51); and wherein the allocation manager (30) is adapted to examine (112), each time that a new block (45) is reached during the recording process, whether the block address of said new block appears in the first auxiliary memory (51), and to skip said block if the block address of said new block actually appears in the first auxiliary memory (51). 12. An apparatus as claimed in Claim 11, wherein the allocation manager (30) is adapted not to allow a user to use a predetermined name (BS) reserved for the defect list, and wherein the allocation manager (30) is adapted not to allow a user to erase and/or overwrite the file having said predetermined name (BS) reserved for the defect list. 13. An apparatus as claimed in Claim 11 or 12, further comprising a problem memory (52) associated with the allocation manager (30); wherein the write/read unit (20) is adapted to monitor, using an error correction algorithm, the quality of the data being read during a read cycle (200), each time when the data is read from a given block and, if given problems occur, to transfer (211; 221) the address of the relevant block to the allocation manager (30); and wherein the allocation manager (30) is adapted to store a block address thus received from the write/read unit (20) in the problem memory (52). 14. An apparatus as claimed in Claim 13, wherein the allocation manager (30) is adapted to read, after termination of the read cycle (200), the data of a block stored in the problem memory (52) and to subject said data to an error correction algorithm (302) and, if the data thus read appears to be restorable (305), to write (306) the restored data into the relevant block and after this, to preferably carry out a read-after-write check. 15. An apparatus as claimed in Claim 13 or 14, further comprising an erase memory (53) associated with the allocation manager (30); wherein the allocation manager (30) is adapted to read, after termination of the read cycle (200), the data of a block stored in the problem memory (52) and to subject said data to an error correction algorithm (302) and, if the data thus read appears to be non-restorable (305), to write (311) a predetermined code word (skip code) into the relevant block and, after this, to carry out a read-after-write check (312); wherein the allocation manager (31) is adapted to store (314) the block address of the relevant block in said erase memory (53) if during said read-after-write check (312) it appears that said code word has not been written successfully; and wherein the allocation manager (30) is adapted to record (400) the block addresses stored in the erase memory (53) in a defect list in a predetermined file (BS) on the recording medium (2) after all the blocks stored in the problem memory (52) have thus been checked.