EP0189948A1 — Record-carrier body provided with a relief struct…

Claim 1

Independent Claim 127 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 and which has been provided with a preformed and 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 is at least 60% of the track period, transverse to the track direction, and is at least of the order of twice the maximum width of the sector-address areas.

Claim 2

Dependent Claim 127 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 and which has been provided with a preformed and 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 is at least 60% of the track period, transverse to the track direction, and is at least of the order of twice the maximum width of the sector-address areas.

Claim 3

Dependent Claim 120 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 and which has been provided with a preformed and optically detectable relief structure of servo-track portions and sector addresses in which addresss 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 servo-track portions constitute continuous tracks and the sector addresses are situated between servo tracks which are situated adjacent each other in a direction transverse to the track direction.

Claim 4

Dependent Claim 120 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 and which has been provided with a preformed and optically detectable relief structure of servo-track portions and sector addresses in which addresss 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 servo-track portions constitute continuous tracks and the sector addresses are situated between servo tracks which are situated adjacent each other in a direction transverse to the track direction.

Claim 5

Dependent Claim 85 words

An apparatus for forming a structure similar to the structure of servo-track portions and sector addresses of the record-carrier body as claimed in Claim 1 or 2, comprising a radiationsource system for producing two radiation beams, a separate intensity modulator for each of the beams, and an objective system for focussing the beams to form two radiation spots of different dimensions, characterized in that the smaller radiation spot is employed for recording the sector addresses and the larger radiation spot for recording the servo-track portions.

Claim 6

Dependent Claim 34 words

An apparatus as claimed in Claim 3, characterized in that the two radiation spots have the same position viewed in a direction transverse to the longitudinal direction of the servo-track portions to be recorded.

Claim 7

Dependent Claim 36 words

An apparatus as claimed in Claim 3, characterized in that the two radiation spots are shifted relative to each other viewed in a direction transverse to the longitudinal direction of the servo-track portions to be recorded.

Claim 8

Dependent Claim 126 words

An apparatus for recording and reading information in a record-carrier body as claimed in Claim 2, which apparatus comprises a radiation-source system for producing a single or double write/read beam, an intensity modulator arranged in the path of the beam, and an objective system for focussing the beam to form a single or double write/read spot, characterized in that there is provided an auxiliary beam for theplrpose of tracking, which auxiliary beam is focussed by means of the objective system to form an auxiliary radiation spot which, viewed in a direction transverse to the direction of a servo track, is shifted relative to the single or double write/read spot over a distance equal to half the track period in a direction transverse to the track direction.

Claim 9

Dependent Claim 41 words

A record carrier comprising a record-carrier body as claimed in Claim 2, in which information has been recorded, characterized by continuous servo tracks between which sector addresses are situated, information areasbeing recorded between successive sector addresses, viewed in the track direction.

Record-carrier body provided with a relief structure of optically detectable servo-track portions and sector addresses and apparatus for forming said structure

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