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1. WO2007138548 - OPTIMIZING FOCUS CROSSTALK CANCELLING

Publication Number WO/2007/138548
Publication Date 06.12.2007
International Application No. PCT/IB2007/052007
International Filing Date 29.05.2007
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
CPC
G11B 7/0903
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
0901for track following only
0903Multi-beam tracking systems
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 7/0917
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
0917Focus-error methods other than those covered by G11B7/0909 - G11B7/0916
G11B 7/0941
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
0941Methods and circuits for servo gain or phase compensation during operation
Applicants
  • KONINKLIJKE PHILIPS ELECTRONICS N.V. [NL]/[NL] (AllExceptUS)
  • BAKX, Johannes, L. [NL]/[NL] (UsOnly)
Inventors
  • BAKX, Johannes, L.
Agents
  • UITTENBOGAARD, Frank
Priority Data
06114854.001.06.2006EP
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) OPTIMIZING FOCUS CROSSTALK CANCELLING
(FR) OPTIMISATION D'ANNULATION DE DIAPHONIE DE FOCALISATION
Abstract
(EN)
A device is arranged for scanning an optical record carrier (11), which has a data layer with parallel data tracks. The device has an optical head (22) comprising a detector having sub-detectors (44) for generating a main focus signal and sub-detectors (43,45) for generating satellite signals. A focus control unit (32) provides a focus actuator signal (38) to a focus actuator (34) in dependence of a focus error signal. A combining unit (41) generates the focus error signal based on the main focus signal and satellite signals in dependence on weight factors (Ga,Gb) for adjusting a correction of the main focus signal by the satellite signals. A servo filter (42) generates the focus actuator signal based on the focus error signal. A setting unit (40) sets the weight factors in dependence of an adjustment signal, which is based on the focus actuator signal (38). Advantageously the dissipation in the actuator is reduced, instead of minimizing residual focus error signals at the cost of large focus actuator dissipation.
(FR)
La présente invention concerne un dispositif pour balayer un support d'enregistrement optique (11), qui comprend une couche de données avec des pistes de données parallèles. Le dispositif comporte une tête optique (22) comprenant un détecteur incluant des sous-détecteurs (44) pour générer un signal de focalisation principal et des sous détecteurs (43, 45) pour générer des signaux satellites. Une unité de commande de focalisation (32) fournit un signal d'actionneur de focalisation (38) à un actionneur de focalisation (34) dépendant d'un signal d'erreur de focalisation. Une unité de combinaison (41) génère le signal d'erreur de focalisation en fonction du signal de focalisation principal et des signaux satellites selon des facteurs de pondération (Ga, Gb) pour ajuster une correction du signal de focalisation principal en fonction du signal d'erreur de focalisation. Un filtre d'asservissement (42) génère le signal d'actionneur de focalisation en fonction du signal d'erreur de focalisation. Une unité de réglage (40) règle les facteurs de pondération selon un signal d'ajustement, qui est basé sur le signal d'actionneur de focalisation (38). De manière avantageuse, la dissipation dans l'actionneur est réduite, au lieu de minimiser les signaux d'erreur de focalisation résiduels au prix d'une grande dissipation d'actionneur de focalisation.
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