JPS6419548A - Method for controlling semiconductor laser output of multi-beam magneto-optical pickup - Google Patents

Method for controlling semiconductor laser output of multi-beam magneto-optical pickup

Info

Publication number
JPS6419548A
JPS6419548A JP62174136A JP17413687A JPS6419548A JP S6419548 A JPS6419548 A JP S6419548A JP 62174136 A JP62174136 A JP 62174136A JP 17413687 A JP17413687 A JP 17413687A JP S6419548 A JPS6419548 A JP S6419548A
Authority
JP
Japan
Prior art keywords
output
semiconductor lasers
sample
semiconductor laser
optical pickup
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
JP62174136A
Other languages
Japanese (ja)
Inventor
Isamu Shibata
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.)
Ricoh Co Ltd
Original Assignee
Ricoh Co 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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP62174136A priority Critical patent/JPS6419548A/en
Publication of JPS6419548A publication Critical patent/JPS6419548A/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
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing

Landscapes

  • Optical Head (AREA)

Abstract

PURPOSE:To control the output of plural semiconductor lasers at prescribed reference values respectively, by detecting laser beams emitted to the rear sides of three semiconductor lasers for erasure, recording, and reproduction by one optical detector, amplifying them, and comparing them with reference voltages. CONSTITUTION:The laser beams emitted to the rear sides of the semiconductor lasers 17, 18, and 19 for erasure, recording, and reproduction are detected by the optical detector 20 consisting of one photodiode, and are amplified by an amplifier 21. The output of the amplifier 21 are compared with the reference voltages Vref1, Vref2, and Vref3, respectively, and their error output are sample- held at sample/hold circuits 28, 29 and 30 by timing signals T1, T2, and T3 via low-pass filters 25, 26, and 27, respectively. Semiconductor laser driving circuits 32, 33, and 34 control optical output by controlling the driving currents of the semiconductor lasers 17, 18, and 19 by the output signals of the sample/ hold circuits 28, 29, and 30.
JP62174136A 1987-07-13 1987-07-13 Method for controlling semiconductor laser output of multi-beam magneto-optical pickup Pending JPS6419548A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62174136A JPS6419548A (en) 1987-07-13 1987-07-13 Method for controlling semiconductor laser output of multi-beam magneto-optical pickup

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62174136A JPS6419548A (en) 1987-07-13 1987-07-13 Method for controlling semiconductor laser output of multi-beam magneto-optical pickup

Publications (1)

Publication Number Publication Date
JPS6419548A true JPS6419548A (en) 1989-01-23

Family

ID=15973290

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62174136A Pending JPS6419548A (en) 1987-07-13 1987-07-13 Method for controlling semiconductor laser output of multi-beam magneto-optical pickup

Country Status (1)

Country Link
JP (1) JPS6419548A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03183034A (en) * 1989-12-11 1991-08-09 Fujitsu Ltd Semiconductor laser control circuit for optical disk device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03183034A (en) * 1989-12-11 1991-08-09 Fujitsu Ltd Semiconductor laser control circuit for optical disk device

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