HK51086A - Focus detector - Google Patents

Focus detector Download PDF

Info

Publication number
HK51086A
HK51086A HK510/86A HK51086A HK51086A HK 51086 A HK51086 A HK 51086A HK 510/86 A HK510/86 A HK 510/86A HK 51086 A HK51086 A HK 51086A HK 51086 A HK51086 A HK 51086A
Authority
HK
Hong Kong
Prior art keywords
reflected
aperture
beams
reflected beams
focus
Prior art date
Application number
HK510/86A
Other languages
English (en)
French (fr)
Inventor
John S. Winslow
Original Assignee
Discovision Associates
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 Discovision Associates filed Critical Discovision Associates
Publication of HK51086A publication Critical patent/HK51086A/en

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
    • G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • 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
    • G11B7/0912—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 by push-pull method
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/40—Optical focusing aids

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Automatic Focus Adjustment (AREA)
  • Eye Examination Apparatus (AREA)
  • Optical Head (AREA)
  • Electron Beam Exposure (AREA)

Claims (4)

1. Einrichtung zur Feststellung des Fokusfehlers eines Bündels aus Strahlungsenergie bezüglich einer Oberfläche (16), auf die das Bündel durch eine Objektivlinse (18) gerichtet wird, mit folgenden Bestandteilen: Vorrichtungen (20, 22) zur Strahlteilung, die in dem Weg eines von der Oberfläche (16) durch die Objektivlinse (18) zurückreflektierten Strahlenbündels angeordnet sind und erste und zweite reflektierte Strahlenbündel mit ungefähr gleicher Leistung erzeugen; Blendenvorrichtungen (26), die im Weg des ersten und des zweiten Strahlenbündels so angeordnet sind, daß bei auf der Oberfläche fokussiertem ursprünglichen Strahlenbündel das erste reflektierte Strahlenbündel zu einem ersten Brennpunkt konvergiert, bevor es auf die Blende trifft, und das zweite reflektierte Strahlenbündel zu einem zweiten Brennpunkt konvergiert, nachdem es die Blende getroffen hat; Detektorvorrichtungen (28a, 28b), die in den Wegen der ersten und der zweiten reflektierten Strahlenbündel nach dem Durchgang durch die Blende (26) angeordnet sind, um elektrische Signale proportional zur Leistung in jedem der ersten und zweiten reflektierten Strahlenbündel zu erzeugen; und Subtraktionsvorrichtungen, um ein Signal zu erzeugen, das proportional zur Differenz zwischen den Leistungen des ersten und des zweiten reflektierten Strahlenbündels ist, dadurch gekennzeichnet, daß die Blendenvorrichtungen (26) eine einzelne Blende darstellen, daß die Vorrichtungen (20, 22) zur Strahlteilung so angeordnet sind, daß sich die beiden Strahlenbündel bei der Blendenvorrichtung (26) kreuzen und daß die Detektorvorrichtungen zwei Wandlerelemente (28a, 28b) aufweisen, die so angeordnet sind, daß sie jeweils eines der Strahlenbündel empfangen.
2. Einrichtung nach Anspruch 1, dadurch gekennzeichnet, daß Summiervorrichtungen (38a, 38b, 40a, 40b) vorgesehen sind, um ein Signal zu erzeugen, das proportional zur Summe der Leistungen des ersten und des zweiten reflektierten Strahlenbündels ist und daher proportional zur Intensität der von der Oberfläche (16) reflektierten Strahlungsenergie.
3. Einrichtung nach Anspruch 2, dadurch gekennzeichnet, daß das zur Summe der Leistungen des ersten und des zweiten Strahlenbündels proportionale Signal zur Wiedergabe der auf der Oberfläche (16) aufgezeichneten Information verwendet wird.
4. Einrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Detektorvorrichtungen eine geteilte Photodiode (28a, 28b) und einen Differentialverstärker (34) enthalten.
HK510/86A 1980-07-14 1986-07-03 Focus detector HK51086A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US06/168,812 US4357533A (en) 1980-07-14 1980-07-14 Focus detector for an optical disc playback system

Publications (1)

Publication Number Publication Date
HK51086A true HK51086A (en) 1986-07-11

Family

ID=22613031

Family Applications (1)

Application Number Title Priority Date Filing Date
HK510/86A HK51086A (en) 1980-07-14 1986-07-03 Focus detector

Country Status (11)

Country Link
US (1) US4357533A (de)
EP (1) EP0044074B1 (de)
JP (1) JPS5732410A (de)
KR (1) KR850001003B1 (de)
AT (1) ATE9741T1 (de)
AU (1) AU538975B2 (de)
BR (1) BR8103377A (de)
CA (1) CA1147860A (de)
DE (1) DE3166473D1 (de)
HK (1) HK51086A (de)
MY (1) MY8600741A (de)

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS567246A (en) * 1979-06-25 1981-01-24 Olympus Optical Co Ltd Method and unit for focus detection
JPS5752006A (en) * 1980-08-19 1982-03-27 Olympus Optical Co Ltd Method and device for detecting focus
EP0068390B1 (de) * 1981-06-22 1990-08-22 Kabushiki Kaisha Toshiba Optischer Kopf
US4412743A (en) * 1981-09-08 1983-11-01 Discovision Associates Off-axis light beam defect detector
US4538062A (en) * 1981-11-19 1985-08-27 Olympus Optical Co., Ltd. Focusing detecting device with coaxial source and detector
EP0095852A1 (de) * 1982-05-19 1983-12-07 BURROUGHS CORPORATION (a Michigan corporation) Einrichtung zur Fokussierregelung für ein optisches Speichersystem
US4621353A (en) * 1982-09-09 1986-11-04 Burroughs Corporation Optical memory system providing improved focusing control and improved beam combining and separating apparatus
US4622659A (en) * 1982-09-09 1986-11-11 Burroughs Corporation Focus detection and control apparatus for maintaining accurate focusing in an optical memory system by detecting reflected beam diameter variations at spaced predetermined locations
US4559622A (en) * 1982-09-09 1985-12-17 Burroughs Corporation Optical memory system providing improved focus detection and control by detecting reflected beam diameter variations at spaced predetermined locations in the system
JPS59125727U (ja) * 1983-02-15 1984-08-24 パイオニア株式会社 光学式情報ピツクアツプ装置
JPS59162514A (ja) * 1983-03-08 1984-09-13 Dainippon Screen Mfg Co Ltd 画像走査記録装置における焦点調整方法
US4705941A (en) * 1983-06-30 1987-11-10 Kabushiki Kaisha Toshiba Apparatus for detecting a focusing state of an optical system
DE3429382A1 (de) * 1983-08-10 1985-02-28 Canon K.K., Tokio/Tokyo Optischer kopf
NL8403034A (nl) * 1984-10-05 1986-05-01 Philips Nv Opto-elektronisch fokusfout-detektiestelsel.
JPS6282525A (ja) * 1985-10-08 1987-04-16 Toshiba Corp 光学ヘツド
EP0241537A1 (de) * 1985-10-10 1987-10-21 Opticon Technology Incorporated Vorrichtung zum speichern und ablesen von optischen datenzeichen auf einem optischen medium
US4843603A (en) * 1988-03-11 1989-06-27 Optotech, Inc. Concentric photodetector arrangement for focusing and tracking
US5072437A (en) * 1988-09-19 1991-12-10 Pioneer Electronic Corporation Optical information reproducing apparatus
TW218427B (de) * 1991-06-04 1994-01-01 Ibm
US5978329A (en) * 1995-06-07 1999-11-02 Discovision Associates Technique for closed loop servo operation in optical disc tracking control
KR100316135B1 (ko) * 1995-12-06 2002-04-24 데니스 피셸 빔 포커스 제어 장치 및 방법
US5689485A (en) * 1996-04-01 1997-11-18 Discovision Associates Tracking control apparatus and method
FR2759208B1 (fr) * 1997-01-31 1999-05-07 Thomson Csf Dispositif de controle du pointage et de la focalisation des chaines laser sur une cible
US9234854B2 (en) * 2013-03-15 2016-01-12 International Business Machines Corporation Single fiber noncritical-alignment wafer-scale optical testing

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3454772A (en) * 1966-12-20 1969-07-08 Hughes Aircraft Co Photoelectric monitoring system for holding the object plane in proper focus
FR2222666B1 (de) * 1973-03-19 1976-11-05 Thomson Brandt
JPS5016423A (de) * 1973-06-11 1975-02-21
US3967110A (en) * 1973-09-21 1976-06-29 Corning Glass Works Automatic focusing system
JPS5091317A (de) * 1973-12-12 1975-07-22
US3932700A (en) * 1974-02-04 1976-01-13 Zenith Radio Corporation Focus tracking registration for optical reproducing systems
JPS5250130B2 (de) * 1974-02-20 1977-12-22
JPS5154432A (en) * 1974-11-07 1976-05-13 Asahi Optical Co Ltd Shotenkenshutsusochi
JPS51120725A (en) * 1975-04-16 1976-10-22 Sankyo Kogaku Kogyo Kk Automatic forcusing camera
JPS5238944A (en) * 1975-09-23 1977-03-25 Canon Inc Optical system for scanning
JPS53116852A (en) * 1977-03-23 1978-10-12 Olympus Optical Co Ltd Automatic focus adjusting system
US4220850A (en) * 1978-09-29 1980-09-02 Abbott Laboratories Bimodal autofocusing apparatus

Also Published As

Publication number Publication date
MY8600741A (en) 1986-12-31
AU538975B2 (en) 1984-09-06
KR850001003B1 (ko) 1985-07-15
EP0044074B1 (de) 1984-10-03
ATE9741T1 (de) 1984-10-15
BR8103377A (pt) 1982-08-24
JPS5732410A (en) 1982-02-22
EP0044074A1 (de) 1982-01-20
US4357533A (en) 1982-11-02
CA1147860A (en) 1983-06-07
AU7057481A (en) 1982-01-21
DE3166473D1 (en) 1984-11-08

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