CA1056950A - Device for detecting focussing error in an optical reader head - Google Patents

Device for detecting focussing error in an optical reader head

Info

Publication number
CA1056950A
CA1056950A CA232,166A CA232166A CA1056950A CA 1056950 A CA1056950 A CA 1056950A CA 232166 A CA232166 A CA 232166A CA 1056950 A CA1056950 A CA 1056950A
Authority
CA
Canada
Prior art keywords
cells
focussing error
read
phase
error detection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA232,166A
Other languages
English (en)
French (fr)
Other versions
CA232166S (en
Inventor
Jean-Claude Lehureau
Claude Bricot
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thomson-Brandt SA
Original Assignee
Thomson-Brandt SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thomson-Brandt SA filed Critical Thomson-Brandt SA
Application granted granted Critical
Publication of CA1056950A publication Critical patent/CA1056950A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording 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
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with 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
    • G11B7/0908—Disposition or mounting of heads or light sources relatively to record carriers with 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 for focusing only
    • G11B7/0917—Focus-error methods other than those covered by G11B7/0909 - G11B7/0916
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/34—Systems for automatic generation of focusing signals using different areas in a pupil plane
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording 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
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with 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
    • G11B7/0908—Disposition or mounting of heads or light sources relatively to record carriers with 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 for focusing only

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Automatic Focus Adjustment (AREA)
CA232,166A 1974-07-26 1975-07-24 Device for detecting focussing error in an optical reader head Expired CA1056950A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7426062A FR2280150B1 (fr) 1974-07-26 1974-07-26 Dispositif de detection d'ecart de mise au point d'une tete de lecture optique par rapport a une surface de lecture

Publications (1)

Publication Number Publication Date
CA1056950A true CA1056950A (en) 1979-06-19

Family

ID=9141771

Family Applications (1)

Application Number Title Priority Date Filing Date
CA232,166A Expired CA1056950A (en) 1974-07-26 1975-07-24 Device for detecting focussing error in an optical reader head

Country Status (5)

Country Link
US (1) US4025784A (enExample)
JP (1) JPS5137538A (enExample)
CA (1) CA1056950A (enExample)
DE (1) DE2533461A1 (enExample)
FR (1) FR2280150B1 (enExample)

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE819399A (fr) * 1973-09-07 1974-12-16 Produit anti-mousse
US4097730A (en) * 1975-07-02 1978-06-27 Zenith Radio Corporation Focus correction system for video disc player
JPS5450492A (en) * 1977-09-30 1979-04-20 Shin Etsu Chem Co Ltd Defoaming agent
JPS54124705A (en) * 1978-03-20 1979-09-27 Teac Corp Optical reproducer
NL8000122A (nl) * 1980-01-09 1981-08-03 Philips Nv Schijfvormige, optisch uitleesbare registratiedrager als opslagmedium voor datainformatie, inrichting voor het vervaardigen van zo'n registratiedrager, inrichting voor het optekenen en/of weergeven van datainformatie in c.q. van zo'n registratiedrager.
FR2481501B1 (fr) * 1980-04-25 1985-09-13 Philips Nv Porteur d'enregistrement comportant une structure d'information lisible par voie optique et dispositif pour la lecture d'un tel porteur d'enregistrement
JPS57181433A (en) * 1981-04-22 1982-11-08 Olympus Optical Co Ltd Tracking system for optical disc reproducer
NL8103505A (nl) * 1981-07-24 1983-02-16 Philips Nv Inrichting voor het puntsgewijs aftasten van een voorwerp.
JPS5877036A (ja) * 1981-10-30 1983-05-10 Olympus Optical Co Ltd ピット中心検出方法
JP2552109B2 (ja) * 1985-11-08 1996-11-06 セイコーエプソン株式会社 光記録再生装置
JPH0721865B2 (ja) * 1986-08-29 1995-03-08 パイオニア株式会社 光学式記録情報読取装置
DE3882918T2 (de) * 1987-11-17 1994-01-20 Matsushita Electric Ind Co Ltd Fokusregelsystem für optische Scheibenvorrichtung mit lichtempfindlichen Elementen in der Fokusebene des Bildes der Informationsstruktur.
JP2735220B2 (ja) * 1987-12-02 1998-04-02 株式会社日立製作所 非点収差を有する光束を用いた焦点ずれ検出方法及び光ディスク装置
EP0343952A3 (en) * 1988-05-26 1991-10-30 Matsushita Electric Industrial Co., Ltd. Focus error detection system for an optical recording/reproducing system
JP2904948B2 (ja) * 1991-03-28 1999-06-14 コニカ株式会社 ハロゲン化銀カラー写真感光材料の処理方法及び安定液
US5424177A (en) * 1991-07-05 1995-06-13 Konica Corporation Stabilizer for silver halide color photographic light-sensitive materials and its concentrated composition, and processing method using said stabilizer
FR2723243B1 (fr) * 1994-07-26 1996-09-06 Thomson Csf Dispositif d'enregistrement et/ou de lecture de tetes magnetiques et son procede de realisation
FR2739965B1 (fr) * 1995-10-17 1997-11-07 Thomson Csf Dispositif emetteur-recepteur de lumiere et systeme de lecture optique
FR2786345B1 (fr) 1998-11-24 2001-02-09 Thomson Csf Dispositif de cryptage quantique
US7149173B2 (en) * 2000-10-17 2006-12-12 Thales Medium for recording optically readable data, method for making same and optical system reproducing said data
FR2824905B1 (fr) * 2001-05-15 2003-08-29 Thomson Csf Gyrometre a fibre optique
US20050047287A1 (en) * 2003-08-29 2005-03-03 Hanks Darwin Mitchel Focus control

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL171516C (nl) * 1972-03-29 1983-04-05 Philips Nv Inrichting voor het langs optische weg uitlezen van een registratiedrager en plaatvormige registratiedrager bestemd om uitgelezen te worden met deze inrichting.
AR205243A1 (es) * 1972-05-11 1976-04-21 Philips Nv Aparato para la lectura de un portador de grabacion reflector plano
AR198680A1 (es) * 1972-09-02 1974-07-15 Philips Nv Aparato lector de un portador de grabacion sobre el cual esta grabada informacion en al menos una pista
FR2266932B1 (enExample) * 1973-03-02 1977-09-02 Thomson Brandt
JPS5016423A (enExample) * 1973-06-11 1975-02-21
US3932700A (en) * 1974-02-04 1976-01-13 Zenith Radio Corporation Focus tracking registration for optical reproducing systems
NL171641C (nl) * 1974-02-13 1983-04-18 Philips Nv Inrichting voor het uitlezen van een registratiedrager waarop informatie is aangebracht in een optisch uitleesbare structuur.

Also Published As

Publication number Publication date
JPS5137538A (enExample) 1976-03-29
FR2280150B1 (fr) 1977-01-07
FR2280150A1 (fr) 1976-02-20
DE2533461A1 (de) 1976-02-05
US4025784A (en) 1977-05-24

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