Optical disk containing information about usability of recording layers and optical disk apparatus for reproducing the optical disk
AssigneeSanyo Electric Co., Ltd.
InventorMorio Nakatani
Life of this patent
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Abstract
A disk has a plurality of recording layers in a laminated direction. When a defect occurs in any one of recording layers during disk manufacture, information about the defect is recorded in a read-only region in the recording layer. An optical disk apparatus determines which of the recording layers is usable based on the information about the defect read from the disk, and executes a recording/reproducing operation according to a determination result. Therefore, even when a disk with a defect in the recording layer is used, that disk may be offered to a user as an appropriately usable disk.
Claims4
A recordable optical disk having a plurality of recording layers in a laminated direction, the optical disk comprising:
- a recordable region;
- and
- a read-only region, wherein
- in the read-only region, usability information by which usability of each of the recording layers is individually indicated is recorded, wherein
- when all the recording layers are determined as not being a defective recording layer, the usability information sets all the recording layers as being in a usable state, and
- when at least one of the recording layers is determined as being a defective recording layer,
- the usability information sets at least one of the recording layers not being determined as a defective recording layer, as being in a non-usable state.
Dependencies are inferred from the claim text.