Optical disc and optical disc device
First Claim
1. A manufacturing method for manufacturing an optical disc, containing a first recording layer, having a track upon which a first laser beam having a first wavelength is focused to write data on the first recording layer, and a management area on said first recording layer, said manufacturing method comprising:
- recording first information representing if a second recording layer is present in said optical disc on a first position of said management area by using the first laser beam, andrecording second information representing if a third recording layer is present in said optical disc on a second position of said management area by using the first laser beam;
wherein data on the second recording layer is written by using a second laser beam,wherein a second wavelength of the second laser beam which is focused to write data on the second recording layer, is longer than the first wavelength,wherein data on the third recording layer is written by using a third laser beam,wherein a third wavelength of the third laser beam which is focused to write data on the third recording layer is longer than the second wavelength,wherein said first information and said second information comprise two bits respectively,wherein said first information indicating said second recording layer represents absence of said second recording layer by bit values of 00 in the first position,wherein said second information indicating said third recording layer represents absence of said third recording layer by bit values of 00 in the second position.
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Accused Products
Abstract
In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.
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Citations
4 Claims
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1. A manufacturing method for manufacturing an optical disc, containing a first recording layer, having a track upon which a first laser beam having a first wavelength is focused to write data on the first recording layer, and a management area on said first recording layer, said manufacturing method comprising:
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recording first information representing if a second recording layer is present in said optical disc on a first position of said management area by using the first laser beam, and recording second information representing if a third recording layer is present in said optical disc on a second position of said management area by using the first laser beam; wherein data on the second recording layer is written by using a second laser beam, wherein a second wavelength of the second laser beam which is focused to write data on the second recording layer, is longer than the first wavelength, wherein data on the third recording layer is written by using a third laser beam, wherein a third wavelength of the third laser beam which is focused to write data on the third recording layer is longer than the second wavelength, wherein said first information and said second information comprise two bits respectively, wherein said first information indicating said second recording layer represents absence of said second recording layer by bit values of 00 in the first position, wherein said second information indicating said third recording layer represents absence of said third recording layer by bit values of 00 in the second position.
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2. A recording method for recording an optical disc, containing a first recording layer, having a track upon which a first laser beam having a first wavelength is focused to write data on the first recording layer, and a management area on said first recording layer, said recording method comprising:
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recording first information representing if a second recording layer is present in said optical disc on a first position of said management area by using the first laser beam, recording second information representing if a third recording layer is present in said optical disc on a second position of said management area by using the first laser beam; wherein data on the second recording layer is written by using a second laser beam, wherein a second wavelength of the second laser beam which is focused to write data on the second recording layer, is longer than the first wavelength, wherein data on the third recording layer is written by using a third laser beam, wherein a third wavelength of the third laser beam which is focused to write data on the third recording layer is longer than the second wavelength, wherein said first information and said second information comprise two bits respectively, wherein said first information indicating said second recording layer represents absence of said second recording layer by bit values of 00 in the first position, wherein said second information indicating said third recording layer represents absence of said third recording layer by bit values of 00 in the second position.
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3. A reproducing method for reproducing an optical disc, containing a first recording layer, having a track upon which a first laser beam having a first wavelength is focused to read data recorded on the first recording layer, and a management area on said first recording layer, said management area having first recorded information representing if a second recording layer is present in said optical disc and second recorded information representing if a third recording layer is present in said optical disc, said reproducing method comprising:
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reading said first recorded information from a first position of said management area by using the first laser beam and reading said second recorded information from a second position of said management area by using the first laser beam; and reproducing data recorded on said first recording layer, wherein data recorded on the second recording layer is read by using a second laser beam, wherein a second wavelength of the second laser beam which is focused to read data recorded on the second recording layer is longer than the first wavelength, wherein data recorded on the third recording layer is read by using a third laser beam, wherein a third wavelength of the third laser beam which is focused to read data recorded on the third recording layer is longer than the second wavelength, wherein said first recorded information and said second recorded information comprise two bits respectively, wherein said first recorded information indicating said second recording layer represents absence of said second recording layer by bit values of 00 in the first position, wherein said second recorded information indicating said third recording layer represents absence of said third recording layer by bit values of 00 in the second position.
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4. An identifying method for identifying the type of an optical disc, containing a first recording layer, having a track upon which a first laser beam having a first wavelength is focused to read data recorded on the first recording layer, and a management area on said first recording layer, said management area having first recorded information representing if a second recording layer is present in said optical disc and second recorded information representing if a third recording layer is present in said optical disc, said identifying method comprising:
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reading said first recorded information from a first position of said management area bar using the first laser beam and reading said second recorded information from a second position of said management area by using the first laser beam; and identifying the type of said optical disc based on said first recorded information and said second recorded information, wherein data recorded on the second recording layer is read by using a second laser beam, wherein a second wavelength of the second laser beam which is focused to read data recorded on the second recording layer is longer than the first wavelength, wherein data on the third recording layer is read by using a third laser beam, wherein a third wavelength of the third laser beam which is focused to read data recorded on the third recording layer is longer than the second wavelength, wherein said first recorded information and said second recorded information comprise two bits respectively, wherein said first recorded information indicating said second recording layer represents absence of said second recording layer by bit values of 00 in the first position, wherein said second recorded information indicating said third recording layer represents absence of said third recording layer by bit values of 00 in the second position.
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Specification