JPS6421736A - Magneto-optical pickup device - Google Patents

Magneto-optical pickup device

Info

Publication number
JPS6421736A
JPS6421736A JP62177986A JP17798687A JPS6421736A JP S6421736 A JPS6421736 A JP S6421736A JP 62177986 A JP62177986 A JP 62177986A JP 17798687 A JP17798687 A JP 17798687A JP S6421736 A JPS6421736 A JP S6421736A
Authority
JP
Japan
Prior art keywords
output
semiconductor lasers
comparators
plural
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
JP62177986A
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 JP62177986A priority Critical patent/JPS6421736A/en
Publication of JPS6421736A publication Critical patent/JPS6421736A/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 a prescribed reference value, by lightening the plural semiconductor lasers in order when no pickup is located in an information recording area, and controlling the current of the semiconductor laser so that the output signal of a comparator can be set at 0. CONSTITUTION:The titled device is provided with a detection circuit which detects the output of the plural semiconductor lasers 12-14, the comparators 21-23 which compare the output signal of the detection circuit with a reference signal, a counter 36 controlled by the output signals of the comparators 21-23, digital/analog converters 28-30 which convert the output signal of the counter 36, and a semiconductor laser driving circuit which permits a current proportional to the output signals of the converters 28-30 to flow on the semiconductor lasers 12-14. And when no pickup is located in the information recording area, the plural semiconductor lasers 12-14 are lit in order, and the currents on the semiconductor lasers 12-14 are controlled so as to always set the output signals of the comparators 21-23 at 0s. In such a way, it is possible to perform erasure, recording, and reproduction at high speed without applying complicated output control on the semiconductor laser.
JP62177986A 1987-07-16 1987-07-16 Magneto-optical pickup device Pending JPS6421736A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62177986A JPS6421736A (en) 1987-07-16 1987-07-16 Magneto-optical pickup device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62177986A JPS6421736A (en) 1987-07-16 1987-07-16 Magneto-optical pickup device

Publications (1)

Publication Number Publication Date
JPS6421736A true JPS6421736A (en) 1989-01-25

Family

ID=16040533

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62177986A Pending JPS6421736A (en) 1987-07-16 1987-07-16 Magneto-optical pickup device

Country Status (1)

Country Link
JP (1) JPS6421736A (en)

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