JPS56137538A - Magneto-optical playback device - Google Patents

Magneto-optical playback device

Info

Publication number
JPS56137538A
JPS56137538A JP4077980A JP4077980A JPS56137538A JP S56137538 A JPS56137538 A JP S56137538A JP 4077980 A JP4077980 A JP 4077980A JP 4077980 A JP4077980 A JP 4077980A JP S56137538 A JPS56137538 A JP S56137538A
Authority
JP
Japan
Prior art keywords
light
circular polarization
polarizer
lambda
irradiated
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
JP4077980A
Other languages
Japanese (ja)
Inventor
Kenji Oota
Toshihisa Deguchi
Shozo Kobayashi
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.)
Sharp Corp
Original Assignee
Sharp 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 Sharp Corp filed Critical Sharp Corp
Priority to JP4077980A priority Critical patent/JPS56137538A/en
Publication of JPS56137538A publication Critical patent/JPS56137538A/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 make the device low-cost and to increase the SN ratio, by projecting the light of circular polarization with polarizer and lambda/4 plate to the magnetic thin film recording information, and playing back through the detection of transmitted or reflected light. CONSTITUTION:After the light of circular polarization made from the laser beam 29 with polarizer and lambda/4 plate 14 is irradiated on the amorphous vertical magnetized film 25 via the galvano-mirror 21 and condenser lens 22, the transmitted light is irradiated to the photodetector 27 via the mirror 27. In this case, since the transmissivity of light of circular polarization is changed with the direction of magnetization of the vertical magnetized film 25, the information recorded on the magnetic film 25 is reproduced. Thus, the low cost device can be made and the SN ratio can be increased.
JP4077980A 1980-03-28 1980-03-28 Magneto-optical playback device Pending JPS56137538A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4077980A JPS56137538A (en) 1980-03-28 1980-03-28 Magneto-optical playback device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4077980A JPS56137538A (en) 1980-03-28 1980-03-28 Magneto-optical playback device

Publications (1)

Publication Number Publication Date
JPS56137538A true JPS56137538A (en) 1981-10-27

Family

ID=12590106

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4077980A Pending JPS56137538A (en) 1980-03-28 1980-03-28 Magneto-optical playback device

Country Status (1)

Country Link
JP (1) JPS56137538A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4539662A (en) * 1981-06-04 1985-09-03 Pioneer Electronic Corporation Method and system for optically recording and playing back information on a recording medium having magnetization film thereon
EP0156058A2 (en) * 1983-08-06 1985-10-02 Brother Kogyo Kabushiki Kaisha Magneto-optical reading apparatus
US4549287A (en) * 1981-08-06 1985-10-22 Pioneer Electronic Corporation System for recording and playing back information with magneto-optical disk memory using record and readout light beams of different wavelengths
US4550346A (en) * 1982-04-15 1985-10-29 Pioneer Electronic Corporation Magneto-optic information recording system
US4670865A (en) * 1982-04-15 1987-06-02 Pioneer Electronic Corporation Method of recording information on magneto-optic information storage medium

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5456807A (en) * 1977-10-14 1979-05-08 Mitsubishi Electric Corp Photo-magnetic information reader

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5456807A (en) * 1977-10-14 1979-05-08 Mitsubishi Electric Corp Photo-magnetic information reader

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4539662A (en) * 1981-06-04 1985-09-03 Pioneer Electronic Corporation Method and system for optically recording and playing back information on a recording medium having magnetization film thereon
US4549287A (en) * 1981-08-06 1985-10-22 Pioneer Electronic Corporation System for recording and playing back information with magneto-optical disk memory using record and readout light beams of different wavelengths
US4550346A (en) * 1982-04-15 1985-10-29 Pioneer Electronic Corporation Magneto-optic information recording system
US4670865A (en) * 1982-04-15 1987-06-02 Pioneer Electronic Corporation Method of recording information on magneto-optic information storage medium
EP0156058A2 (en) * 1983-08-06 1985-10-02 Brother Kogyo Kabushiki Kaisha Magneto-optical reading apparatus
US5007021A (en) * 1983-08-06 1991-04-09 Brother Kogyo Kabushiki Kaisha Magneto-optical data reading apparatus

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