JPS56117339A - Optical information processor - Google Patents

Optical information processor

Info

Publication number
JPS56117339A
JPS56117339A JP1781380A JP1781380A JPS56117339A JP S56117339 A JPS56117339 A JP S56117339A JP 1781380 A JP1781380 A JP 1781380A JP 1781380 A JP1781380 A JP 1781380A JP S56117339 A JPS56117339 A JP S56117339A
Authority
JP
Japan
Prior art keywords
laser
photodetector
detected
disk
semiconductor laser
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.)
Pending
Application number
JP1781380A
Other languages
Japanese (ja)
Inventor
Masahiro Oshima
Seiji Yonezawa
Toshio Sugiyama
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP1781380A priority Critical patent/JPS56117339A/en
Priority to US06/152,297 priority patent/US4333173A/en
Priority to NL8003411A priority patent/NL8003411A/en
Priority to FR8013059A priority patent/FR2459513B1/en
Priority to CA000353936A priority patent/CA1136273A/en
Priority to DE19803022299 priority patent/DE3022299A1/en
Priority to GB8019469A priority patent/GB2053553B/en
Publication of JPS56117339A publication Critical patent/JPS56117339A/en
Pending 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
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1359—Single prisms
    • 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
    • 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
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/13—Optical detectors therefor

Abstract

PURPOSE:To expand the leading-in range of automatic of focusing control by coating the disk flank surface of a semiconductor laser with a reflection preventing film. CONSTITUTION:Optical pickup 12 consists of semiconductor laser 1, lenses 31 and 32, and photodetector 4, and laser beam is reflected out of optical disk 2 and fed back to emission end face 11 of semiconductor laser 1. Since the laser output varies with the reflectance of disk 2, the variation is detected by photodetector 4 to reproduce information. The laser output detected by photodetector 4 is synchronously detected by phase detecting circuit 8 by referring to an AC source signal and its output is fed back to electromagnetic coil 5 to reduce defocusing. Laser emission end face 11 is coated with a reflection preventing film, so that the leading-in range of automatic focusing control can be expanded.
JP1781380A 1979-06-15 1980-02-18 Optical information processor Pending JPS56117339A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
JP1781380A JPS56117339A (en) 1980-02-18 1980-02-18 Optical information processor
US06/152,297 US4333173A (en) 1979-06-15 1980-05-22 Optical information processor with prismatic correction of laser beam shape
NL8003411A NL8003411A (en) 1979-06-15 1980-06-12 DEVICE FOR PROCESSING OPTICAL INFORMATION.
FR8013059A FR2459513B1 (en) 1979-06-15 1980-06-12 OPTICAL INFORMATION PROCESSING UNIT
CA000353936A CA1136273A (en) 1979-06-15 1980-06-13 Optical information processor
DE19803022299 DE3022299A1 (en) 1979-06-15 1980-06-13 OPTICAL INFORMATION PROCESSING DEVICE
GB8019469A GB2053553B (en) 1979-06-15 1980-06-13 Optical information processor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1781380A JPS56117339A (en) 1980-02-18 1980-02-18 Optical information processor

Publications (1)

Publication Number Publication Date
JPS56117339A true JPS56117339A (en) 1981-09-14

Family

ID=11954169

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1781380A Pending JPS56117339A (en) 1979-06-15 1980-02-18 Optical information processor

Country Status (1)

Country Link
JP (1) JPS56117339A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50112056A (en) * 1974-02-12 1975-09-03
JPS5317706A (en) * 1976-08-02 1978-02-18 Philips Nv Optical recording carrier reader

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50112056A (en) * 1974-02-12 1975-09-03
JPS5317706A (en) * 1976-08-02 1978-02-18 Philips Nv Optical recording carrier reader

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