Optical disk and optical disk apparatus
First Claim
1. An optical disk having a plurality of sectors constituting tracks arranged spirally or concentrically, each of the plurality of sectors including:
- a recording region for recording user data; and
a header region for recording address information including at least one address information start mark for synchronizing with a beginning of address information regarding the position of the sector, the address information start mark being represented by a sequence of pulses having a first logic level and pulses having a second logic level which is an inverse of the first logic level;
wherein the address information is recorded in the header region primarily based on variable-length codes such that, between each pair of nearest bits having a first logic value, at least two and at most seven bits having a second logic value are disposed, the address information start mark being recorded based on either a code permitted for the rest of the address information or a code not permitted for the rest of the address information, and the address information start mark is detected based on a first detection criterion that a combination of pulse widths each defined in association with a nearest pair of bits having the first logic value is present in a pulse sequence, and also based on a second detection criterion that, when the logic level of the pulse sequence alternates between the first logic level and the second logic level in association with occurrence of each of a plurality of bits having the first logic value intermittently disposed among a plurality of bits having the second logic value, the logic levels of a number of pulses in the pulse sequence respectively coincide with the logic levels of the corresponding pulses constituting the combination of pulse widths.
1 Assignment
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Accused Products
Abstract
In an optical disk, address information, including an address information start mark, is recorded in a header region primarily based on variable-length codes such that, between each pair of nearest bits having a first logic value, at least two and at most seven bits having a second logic value are disposed. The address information start mark is detected based on a first criterion that a combination of pulse widths each defined in association with a nearest pair of bits having the first logic value is present in a pulse sequence, and also based on a second criterion that, when the logic level of the pulse sequence alternates between a first logic level and a second logic level in association with occurrence of bits having the first logic value intermittently disposed among bits having the second logic value, the logic levels of pulses in the pulse sequence coincide with their respective counterparts in the combination of pulse widths.
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Citations
8 Claims
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1. An optical disk having a plurality of sectors constituting tracks arranged spirally or concentrically, each of the plurality of sectors including:
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a recording region for recording user data; and
a header region for recording address information including at least one address information start mark for synchronizing with a beginning of address information regarding the position of the sector, the address information start mark being represented by a sequence of pulses having a first logic level and pulses having a second logic level which is an inverse of the first logic level;
wherein the address information is recorded in the header region primarily based on variable-length codes such that, between each pair of nearest bits having a first logic value, at least two and at most seven bits having a second logic value are disposed, the address information start mark being recorded based on either a code permitted for the rest of the address information or a code not permitted for the rest of the address information, and the address information start mark is detected based on a first detection criterion that a combination of pulse widths each defined in association with a nearest pair of bits having the first logic value is present in a pulse sequence, and also based on a second detection criterion that, when the logic level of the pulse sequence alternates between the first logic level and the second logic level in association with occurrence of each of a plurality of bits having the first logic value intermittently disposed among a plurality of bits having the second logic value, the logic levels of a number of pulses in the pulse sequence respectively coincide with the logic levels of the corresponding pulses constituting the combination of pulse widths. - View Dependent Claims (2, 3, 4)
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5. An optical disk apparatus for playing back data from an optical disk having a plurality of sectors constituting tracks formed spirally or concentrically, each of the plurality of sectors including:
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a recording region for recording user data; and
a header region for recording address information including at least one address information start mark for synchronizing with a beginning of address information regarding the position of the sector, the address information start mark being represented by a sequence of pulses having a first logic level and pulses having a second logic level which is an inverse of the first logic level;
the optical disk detecting the address information start mark from the header region of the optical disk, and playing back the user data recorded in the recording region based on the address information obtained by synchronizing with the detected address information start mark, wherein the address information start mark is detected based on a first detection criterion that a combination of pulse widths each defined in association with a nearest pair of bits having the first logic value is present in a pulse sequence, and also based on a second detection criterion that, when the logic level of the pulse sequence alternates between the first logic level and the second logic level in association with occurrence of each of a plurality of bits having the first logic value intermittently disposed among a plurality of bits having the second logic value, the logic levels of a number of pulses in the pulse sequence respectively coincide with the logic levels of the corresponding pulses constituting the combination of pulse widths. - View Dependent Claims (6, 7, 8)
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Specification