Optical disk medium and method and apparatus for reading information
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiromichi Ishibashi, Shigeru Furumiya, Atsushi Nakamura, Junichi Minamino, Takashi Ishida
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Abstract
An optical disk medium includes a track groove thereon. On the optical disk medium, information is recorded along the track groove on a block unit basis. The block unit has a predetermined length. The block unit having the predetermined length includes a number of sub-blocks that are arranged along the groove. A sub-block mark is provided within each of the sub-blocks and used to identify the sub-block.
Claims2
An optical disk medium which comprises a track groove thereon and on which information is recorded along the track groove on a block unit basis, the block unit having a predetermined length,
- wherein the block unit includes a number of sub-blocks that are arranged along the groove,
- wherein a sub-block mark is provided wobbling in a sine wave curve within each said sub-block and used to identify the sub-block, and
- wherein a part of the track groove has a sawtooth-like wobble shape that is defined by a combination of a steep displacement pattern and a gentle displacement pattern to represent address information of the block unit,
- wherein the sub-block mark is formed by locally changing the phase of the sine wave and wobble.
Dependencies are inferred from the claim text.