EP0570235A2
Expired / Lapsed
EP
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Optical disk
Assignee: Sharp Corp
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Filing: 1993-05-14
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Granted: —
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Expires: 2013-05-14
Abstract
Abstract An optical disk including concentric or spiral grooves, a first series of pits formed in the interrupted portions, and a second series of pits formed in portions of lands. Both of the first and second series of pits represent address information. The portions of the lands and the interrupted portions of the grooves are located in different radial directions. With this arrangement, even when the optical disk has a reduced track pitch, accurate address information is obtained, achieving a high-density recording optical disk.
Inventors
- 👤 Tetsuya Inui
- 👤 Akira Takahashi
- 👤 Kenji Ohta
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 20:26
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10556; G11B11/10563; G11B11/10565; G11B7/00; G11B7/004; G11B7/0045; G11B7/007; G11B7/00718; G11B7/08; G11B7/09; G11B7/0938; G11B7/24; G11B7/2407; G11B7/24073; G11B7/24079; G11B7/26; G11B7/261; G11B11/10576; G11B11/10578; G11B11/10582; G11B7/00745; G11B7/24085
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
63 words
An optical disk comprising: concentric or spiral grooves, said grooves having an interrupted portion in each rotation; a first series of pits recorded in an interrupted portion as address information; and a second series of pits recorded in a portion of land as address information, the portion of said land and the interrupted portion of said groove being located in different radial directions.
Claim 2
Dependent Claim
24 words
The optical disk according to claim 1, wherein a width of said land between said grooves is equal to a width of said groove.
Claim 3
Dependent Claim
30 words
The optical disk according to claim 1, wherein said second series of pits is formed in a portion of said land located far from the interrupted portion of said groove.
Claim 4
Dependent Claim
46 words
The optical disk according to claim 1, wherein the width of said groove becomes smaller near the interrupted portion of said groove, and said second series of pits are formed in a portion of said land located between portions of said grooves with a smaller width.
Claim 5
Dependent Claim
31 words
The optical disk according to claim 1, wherein said optical disk is a magneto-optical disk, and information is recorded and reproduced on/from tracks in the form of said grooves and lands.
Claim 6
Dependent Claim
120 words
An optical disk comprising: concentric or spiral grooves having interrupted portions; a first series of pits recorded as address information in said interrupted portion of said grooves; and a second series of pits recorded as address information in a portion of land, the portion of said land and the interrupted portion of said groove being located in different radial directions, wherein a width of said land between said grooves or a width of said groove is not less than 30 percent of a diameter of a light spot projected to reproduce said address information from said first and second series of pits but not greater than 45 percent of a sum of the widths of said land and said groove.
Claim 7
Dependent Claim
129 words
An optical disk comprising: concentric or spiral grooves having interrupted portions; a magneto-optical recording medium layer, formed on a side of a substrate having said grooves, for enabling information to be recorded thereon by magnetic super resolution effects, a first series of pits recorded as address information on a line extending from the interrupted portion of said groove; and a second series of pits recorded as address information in a portion of land located between said grooves, the portion of said land and the interrupted portion of said groove being located in different radial directions; wherein information is recorded on said magneto-optical recording medium layer on said grooves and lands with magnetic super resolution effects, and said address information is reproduced from said first and second series of pits.
Claim 8
Dependent Claim
95 words
An optical data storage disc having a substrate formed with a spiral groove or with a set of concentric grooves, said groove or set of grooves having a plurality of groove interruptions, wherein said substrate is also formed with a first series of address data pits in a said interruption and a second series of address data pits in a land lying adjacent to the interrupted groove, said second series of address data pits being displaced in a direction along the groove (ie. in a circumferential direction) from said first series of address data pits.
References Cited (Backward Citations)
No citation records indexed.
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