Information recording media, a method for recording/reproducing information, an apparatus for recording/reproducing information
AssigneeHitachi, Ltd.
InventorsAkemi Hirotsune, Harukazu Miyamoto, Takeshi Maeda
Life of this patent
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Abstract
An information recording medium comprising a plurality of layers for recording or reproduction of information by optical irradiation. Each of the layers of the recording medium includes asperities made up of a groove, wherein the groove in each of the layers has wobbles of a first frequency and wobbles of a second frequency that is different from the first frequency within a single track. The first frequency is constant in each of the layers, and a different signal is obtained from the wobbles of the first and second frequencies in each of the plurality of layers.
Claims5
An information recording medium comprising:
- a plurality of layers for recording or reproduction of information by optical irradiation;
- wherein each of said layers includes asperities made up of a groove, the groove in each of the layers having wobbles of a first frequency and wobbles of a second frequency that is different from the first frequency within a single track;
- wherein the first frequency is constant in each of the layers;
- and
- wherein a different signal is obtained from the wobbles of the first and second frequencies in each of the plurality of layers.
Dependencies are inferred from the claim text.