JPS6455762A - Magneto-optical disk inspection device - Google Patents

Magneto-optical disk inspection device

Info

Publication number
JPS6455762A
JPS6455762A JP21220687A JP21220687A JPS6455762A JP S6455762 A JPS6455762 A JP S6455762A JP 21220687 A JP21220687 A JP 21220687A JP 21220687 A JP21220687 A JP 21220687A JP S6455762 A JPS6455762 A JP S6455762A
Authority
JP
Japan
Prior art keywords
signal
magnetic field
added
proportion
accordance
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
JP21220687A
Other languages
Japanese (ja)
Inventor
Akira Oya
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.)
Yokogawa Electric Corp
Original Assignee
Yokogawa Electric Corp
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 Yokogawa Electric Corp filed Critical Yokogawa Electric Corp
Priority to JP21220687A priority Critical patent/JPS6455762A/en
Publication of JPS6455762A publication Critical patent/JPS6455762A/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
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing

Abstract

PURPOSE:To constantly keep the magnetic field strength added to the recording surface of a disk, by extracting the signal in proportion to an objective lens shifting quantity out of a focus servo mechanism, correcting a magnetic setting signal in accordance with the size and changing an electromagnetic current. CONSTITUTION:A signal Ea extracted from a focus servo mechanism 8 and added to an LPF 11 is in proportion to a driving current of a lens driving device 6. A signal E'a through the LPF 11 is in proportion to the shifting quantity of an objective lens 5, and this is added to an electromagnetic driving circuit 10. By the driving circuit 10, a magnetic field setting signal Sm is corrected in accordance with the signal E'a and a corresponding driving current im is supplied to an electromagnet 9. When a magneto-optical disk 1 raises from a reference condition x=0, the signal E'a is increased. When the electromagnet 9 is driven with a corrected signal Sm, a generating magnetic field strength is changed in accordance with the distance of the magnet 9 and the recording surface of the disk 1, a magnetic field intensity H added to the recording surface is constantly kept and the quality of the signal recorded is improved.
JP21220687A 1987-08-26 1987-08-26 Magneto-optical disk inspection device Pending JPS6455762A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP21220687A JPS6455762A (en) 1987-08-26 1987-08-26 Magneto-optical disk inspection device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP21220687A JPS6455762A (en) 1987-08-26 1987-08-26 Magneto-optical disk inspection device

Publications (1)

Publication Number Publication Date
JPS6455762A true JPS6455762A (en) 1989-03-02

Family

ID=16618680

Family Applications (1)

Application Number Title Priority Date Filing Date
JP21220687A Pending JPS6455762A (en) 1987-08-26 1987-08-26 Magneto-optical disk inspection device

Country Status (1)

Country Link
JP (1) JPS6455762A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5148415A (en) * 1990-09-20 1992-09-15 Mitsubishi Denki Kabushiki Kaisha Magneto-optical disc apparatus having head-disc distance control
JPH0590620U (en) * 1991-10-24 1993-12-10 日本電気ホームエレクトロニクス株式会社 Magneto-optical recording device
US5329408A (en) * 1991-07-10 1994-07-12 Sharp Kabushiki Kaisha Magnetic field modulation magnet-optical recording apparatus in which an FM modulator and a magnetic head driving circuit are used in common

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57133503A (en) * 1981-02-10 1982-08-18 Sharp Corp Optical and magnetic recorder and reproducer
JPS62189655A (en) * 1986-02-17 1987-08-19 Fujitsu Ltd Driving method for bias magnetic field of photomagnetic recording head
JPS63100642A (en) * 1986-10-17 1988-05-02 Hitachi Ltd Magneto-optical recording and reproducing device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57133503A (en) * 1981-02-10 1982-08-18 Sharp Corp Optical and magnetic recorder and reproducer
JPS62189655A (en) * 1986-02-17 1987-08-19 Fujitsu Ltd Driving method for bias magnetic field of photomagnetic recording head
JPS63100642A (en) * 1986-10-17 1988-05-02 Hitachi Ltd Magneto-optical recording and reproducing device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5148415A (en) * 1990-09-20 1992-09-15 Mitsubishi Denki Kabushiki Kaisha Magneto-optical disc apparatus having head-disc distance control
US5329408A (en) * 1991-07-10 1994-07-12 Sharp Kabushiki Kaisha Magnetic field modulation magnet-optical recording apparatus in which an FM modulator and a magnetic head driving circuit are used in common
JPH0590620U (en) * 1991-10-24 1993-12-10 日本電気ホームエレクトロニクス株式会社 Magneto-optical recording device

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