摘要:
A disk drive apparatus is provided that can reproduce data at low bit error rate even if a crosstalk is large. This apparatus comprises means (104,106,109) for writing three or more different states of record marks in a read track and adjacent tracks thereof on a disk storage medium (101), means (104,110) for detecting read levels of the record marks in the read track, means (115) for calculating every possible read level regarding every possible combination of the record marks in the read track and adjacent tracks thereof according to the detected read levels, and means (116) for performing most-liklihood decoding of written data in accordance with the possible read levels as reference levels.
摘要:
An optical disk storing write-once information usable for protecting the copyright of the software by preventing the duplication, unauthorized use, etc., of the software. In the optical disk, a recording layer (213) is formed on a disk substrate (211) with a dielectric layer (212) inbetween. Then, an intermediate dielectric layer (214) and a reflecting layer (215) are successively laminated upon the recording layer (213), and an overcoat layer (216) is formed on the surface of the reflecting layer (215). A plurality of BCA (one of write-once identification information systems) sections (220a and 220b) are recorded by lowering the vertical magnetic anisotropy of the recording layer (213). At the time of reproduction, the write-once information is detected from differential signals.
摘要:
An optical disk comprises a first recording area for recording contents data and data for recording and reproducing the contents data, and a second recording area for recording secondary data on the contents recorded in the first recording area, the secondary data being recorded as stripe marks longer in radial direction. Further, the second recording area comprises a first section for recording control data on the second recording area, a second section for recording data not to be inhibited to be outputted from a recording and reproducing apparatus for the optical disk, and a third section for recording data to be inhibited to be outputted from a recording and reproducing apparatus. The control data recorded in the first section includes an identifier which shows whether said second recording area includes said third section or not. By using the data to be inhibited to be outputted in the second recording area, a copyright of contents is protected and illegal use of software is prevented.
摘要:
An optical disk storing write-once information usable for protecting the copyright of the software by preventing the duplication, unauthorized use, etc., of the software. In the optical disk, a recording layer (213) is formed on a disk substrate (211) with a dielectric layer (212) inbetween. Then, an intermediate dielectric layer (214) and a reflecting layer (215) are successively laminated upon the recording layer (213), and an overcoat layer (216) is formed on the surface of the reflecting layer (215). A plurality of BCA (one of write-once identification information systems) sections (220a and 220b) are recorded by lowering the vertical magnetic anisotropy of the recording layer (213). At the time of reproduction, the write-once information is detected from differential signals.
摘要:
An optical disk comprising a magnetic recording layer may be used to protect software copyright by preventing the duplication, unauthorised use, etc., of the software. Write-once information is formed on the optical disk by first recording areas and second recording areas in a predetermined portion of the recording layer. The recording layers have different magnetic anisotropies in a direction perpendicular to a surface of the magnetic layer. In a method and apparatus for reproducing write-once information from an optical disk, linearly polarised laser light is irradiated onto the predetermined portion of an optical disk and a change in polarisation orientation of light transmitted or reflected from the optical disk is detected in accordance with the recording signal on the optical disk, allowing write-once information to be reproduced from the optical disk.
摘要:
An optical disk comprises a first recording area for recording contents data and data for recording and reproducing the contents data, and a second recording area for recording secondary data on the contents recorded in the first recording area, the secondary data being recorded as stripe marks longer in radial direction. Further, the second recording area comprises a first section for recording control data on the second recording area, a second section for recording data not to be inhibited to be outputted from a recording and reproducing apparatus for the optical disk, and a third section for recording data to be inhibited to be outputted from a recording and reproducing apparatus. The control data recorded in the first section includes an identifier which shows whether said second recording area includes said third section or not. By using the data to be inhibited to be outputted in the second recording area, a copyright of contents is protected and illegal use of software is prevented.
摘要:
An optical disk comprises a first recording area for recording contents data and data for recording and reproducing the contents data, and a second recording area for recording secondary data on the contents recorded in the first recording area, the secondary data being recorded as stripe marks longer in radial direction. Further, the second recording area comprises a first section for recording control data on the second recording area, a second section for recording data not to be inhibited to be outputted from a recording and reproducing apparatus for the optical disk, and a third section for recording data to be inhibited to be outputted from a recording and reproducing apparatus. The control data recorded in the first section includes an identifier which shows whether said second recording area includes said third section or not. By using the data to be inhibited to be outputted in the second recording area, a copyright of contents is protected and illegal use of software is prevented.