Abstract:
PROBLEM TO BE SOLVED: To provide a recording medium which stably performs data recording and reproduction even at the start and end of data recording. SOLUTION: The recording medium 101 includes a recording area 102. The recording area 102 includes a first area and a second area 201. The first area includes a frame area 202. The frame area 202 includes an area to which a second synchronous code system SY pattern and at least part of data are recorded. The second area includes an area to which a third synchronous code system PA pattern and a fourth synchronous code system 2101 are recorded. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide an optical storage medium which effectively prevents the illegal use of the optical storage medium itself, which causes the infringement of a copyright, without deteriorating a function which reproduces physical format information and optical storage medium manufacture information. SOLUTION: The optical storage medium is provided with: a main information area 41b to which encrypted data information is recorded as a pit sequence which can be read out through light; and a control data area 41a. In addition, key information for decoding the encryption of the data information, physical format information and optical storage medium manufacture information are recorded in the control data area 41a by wobbling grooves. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To solve such problems in a conventional data recording method which records two error correcting codes and synchronization signals by a predetermined interleave regulation, that what is inserted between constitution symbols of second error correcting codes having lower error detection capabilities on both sides is worse in reliability due to the difference in an error detection capability as compared with one inserted between the synchronization signal and the second error correction code, and that reliability is limited as a whole by one having the lowest reliability. SOLUTION: The data recording method comprises steps of encoding user data into first error correcting codes having a first correction capability, encoding control information into second error correcting codes having a second correction capability higher than the first correction capability, generating a data stream containing the first error correcting code, the second error correcting code and the synchronization signals, wherein the second error correcting codes and the synchronization signals alternately interleave the first error correcting codes. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for managing a buffer memory that prevents increase in memory allocation size used for defect management required in a disk device and for holding management data required for control of recording/reproduction. SOLUTION: An area for reading a defect management list for managing defects on the disk medium from the disk medium and storing it in a buffer memory, is variably allocated according to the number of entries in the defect management list. It is controlled such that a remaining space is allocated to a data buffer for storing recording/reproduction data. As the number of entries in the defect management list is smaller, the size of the data buffer can be increased. This enhances speed performance of recording/reproduction with small capacity of the buffer memory. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To prevent an information recording medium from falling into a non-reproducible state even when an area in which latest management information of a write-once information recording medium is recorded becomes unreadable due to contamination or damage.SOLUTION: A system, such as a disk array (RAID) used associated with a plurality of information recording media, records management information in a certain information recording medium in TDMA (Temporary Disk Management Area) in another information recording medium besides TDMA in the certain information recording medium so as to improve redundancy.
Abstract:
PROBLEM TO BE SOLVED: To solve such a problem that in conventional data recording method in which two error correction codes and a synchronous signal are recorded by the prescribed interleave rule, reliability of a signal in which both sides are held between constitution symbols of a second error correction code of which the error detection capability is low is more inferior than a signal held between the synchronous signal and the second error correction code caused by difference of error detection performance, then, a whole reliability is limited by a signal of the lowest reliability.SOLUTION: Such data stream is constituted that it includes a first error correction code having first correction capability in which user data is encoded, a second error correction code having second correction capability which is higher than the first correction capability in which control information is encoded, and the synchronous signal, wherein the second error correction code and the synchronous signal are interleaved alternately for the first error correction code.