EP0190774A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Record carrier body provided with preformed optically detectable servo-track portions and sector addresses
Assignee: Koninklijke Philips NV
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Filing: 1986-01-09
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Granted: —
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Expires: 2006-01-09
Abstract
Abstract A record-carrier body is described, in which a user can record information by means of optical radiation, which record-carrier body has a relief structure of optically detectable servo-track portions (7) and sector addresses.(6) If the maximum width of the servo-track portions and the areas in the sector addresses is at least of the order of half the track period (P) the servo-track portions can be tracked in an optimum manner and the sector-address areas and the information areas recorded by the user provided a read signal of high amplitude.
Inventors
- 👤 Johannes Hermanus Theodorus Pasman
- 👤 Nicolaas Cornelis Josephus Antonius Van Hijningen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 10:53
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B23/00; G11B23/0057; G11B7/007; G11B7/00745; G11B7/08; G11B7/09; G11B7/0938; G11B7/12; G11B7/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
122 words
A record-carrier body in which a user can record information by means of optical radiation, which record-carrier body comprises a substrate and a recording layer on said substrate, said body being provided with a preformed optically detectable relief structure of servo- track portions and sector addresses in which address information about associated recordable portions of the record-carrier body is contained in the form of optically detectable areas which alternate with intermediate areas, which areas in the sector addresses have another phase depth than the servo track portions, characterized in that the maximum width of the servo-track portions and the sector-address areas is at least of the order of half the period of the tracks in a direction transverse to the track direction.
Claim 2
Dependent Claim
122 words
A record-carrier body in which a user can record information by means of optical radiation, which record-carrier body comprises a substrate and a recording layer on said substrate, said body being provided with a preformed optically detectable relief structure of servo- track portions and sector addresses in which address information about associated recordable portions of the record-carrier body is contained in the form of optically detectable areas which alternate with intermediate areas, which areas in the sector addresses have another phase depth than the servo track portions, characterized in that the maximum width of the servo-track portions and the sector-address areas is at least of the order of half the period of the tracks in a direction transverse to the track direction.
Claim 3
Dependent Claim
113 words
An apparatus for recording a structure similar to the relief structure of the servo-track portions and sector addresses on a record-carrier body as claimed in Claim 1, which apparatus comprises a radiation source, a modulator for switching the intensity of the radiation beam produced by the source, and an objective system for focusing the radiation beam to form a radiation spot of the record carrier, characterized in that between the radiation source and the objective system optical means are arranged to limit the beam which enters the objective system in one of two mutually perpendicular directions, so that its width is smaller than the width of the entrance pupil of the objective system.
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