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1. WO2000039791 - OPTICAL SCANNING DEVICE FOR TWO TYPES OF RECORD CARRIERS

Publication Number WO/2000/039791
Publication Date 06.07.2000
International Application No. PCT/EP1999/010308
International Filing Date 21.12.1999
IPC
G11B 7/09 2006.01
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor
08Disposition or mounting of heads or light sources relatively to record carriers
09with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
G11B 7/135 2012.01
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor
12Heads, e.g. forming of the optical beam spot or modulation of the optical beam
135Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
G11B 7/00 2006.01
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor
G11B 7/13 2012.01
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation, reproducing using an optical beam at lower power; Record carriers therefor
12Heads, e.g. forming of the optical beam spot or modulation of the optical beam
13Optical detectors therefor
CPC
G11B 2007/0006
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation ; by modifying optical properties or the physical structure; , reproducing using an optical beam at lower power ; by sensing optical properties; Record carriers therefor;
0003Recording, reproducing or erasing systems characterised by the structure or type of the carrier
0006adapted for scanning different types of carrier, e.g. CD & DVD
G11B 7/0909
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation ; by modifying optical properties or the physical structure; , reproducing using an optical beam at lower power ; by sensing optical properties; Record carriers therefor;
08Disposition or mounting of heads or light sources relatively to record carriers
09with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
0908for focusing only
0909by astigmatic methods
G11B 7/13
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation ; by modifying optical properties or the physical structure; , reproducing using an optical beam at lower power ; by sensing optical properties; Record carriers therefor;
12Heads, e.g. forming of the optical beam spot or modulation of the optical beam
13Optical detectors therefor
G11B 7/1381
GPHYSICS
11INFORMATION STORAGE
BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
7Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation ; by modifying optical properties or the physical structure; , reproducing using an optical beam at lower power ; by sensing optical properties; Record carriers therefor;
12Heads, e.g. forming of the optical beam spot or modulation of the optical beam
135Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
1381Non-lens elements for altering the properties of the beam, e.g. knife edges, slits, filters or stops
Applicants
  • KONINKLIJKE PHILIPS ELECTRONICS N.V. [NL/NL]; Groenewoudseweg 1 NL-5621 BA Eindhoven, NL
Inventors
  • OPHEY, Willem, G.; NL
Agents
  • COBBEN, Louis, M., H.; Internationaal Octrooibureau B.V. Prof. Holstlaan 6 NL-5656 AA Eindhoven, NL
Priority Data
98204459.629.12.1998EP
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) OPTICAL SCANNING DEVICE FOR TWO TYPES OF RECORD CARRIERS
(FR) DISPOSITIF DE BALAYAGE OPTIQUE POUR DEUX TYPES DE SUPPORT D'ENREGISTREMENT
Abstract
(EN)
In an optical scanning device suited for scanning two types of record carriers (1; 31) having a different thickness of their transparent layers (2; 32) and wherein an astigmatic element (26) is used in combination with a quadrant detector (22) for generating a focus error signal (Sf), this signal, which is generated when one type of record carrier (31) is scanned, can considerably be improved by arranging an aspheric surface profile in only the central part of the beam coming from said one type of record carrier.
(FR)
Selon cette invention, il est possible d'améliorer considérablement un dispositif de balayage optique, approprié pour balayer deux types de supports (1; 31) d'enregistrement dont les couches (2; 32) sont de différente épaisseur et dans lesquels un élément (26) astigmatique est utilisé en combinaison avec un détecteur (22) à quadrants en vue de générer un signal (Sf) d'erreur de focalisation généré lorsqu'un type de support (31) d'enregistrement est balayé, en aménageant un profil de surface asphérique uniquement dans la partie centrale du faisceau provenant d'un type de support d'enregistrement.
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