JPS57195389A - Optical recording medium - Google Patents

Optical recording medium

Info

Publication number
JPS57195389A
JPS57195389A JP7970281A JP7970281A JPS57195389A JP S57195389 A JPS57195389 A JP S57195389A JP 7970281 A JP7970281 A JP 7970281A JP 7970281 A JP7970281 A JP 7970281A JP S57195389 A JPS57195389 A JP S57195389A
Authority
JP
Japan
Prior art keywords
film
recording
reproduction
reversible recording
unreversible
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
JP7970281A
Other languages
Japanese (ja)
Inventor
Motoharu Tanaka
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 JP7970281A priority Critical patent/JPS57195389A/en
Publication of JPS57195389A publication Critical patent/JPS57195389A/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
    • G11B13/00—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for
    • G11B13/04—Recording simultaneously or selectively by methods covered by different main groups among G11B3/00, G11B5/00, G11B7/00 and G11B9/00; Record carriers therefor not otherwise provided for; Reproducing therefrom not otherwise provided for magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties

Abstract

PURPOSE:To obtain both unreversible and reversible recording functions according to the purpose of use of a memory, by providing a transparent protective film on a magnetized film having large coercive force, and then forming a metallic thin film having a low melting point and high reflectivity on the protective film. CONSTITUTION:For reversible recording, a laser beam, etc., from a light source 5 is modulated by a modulator and made into a fine spot through a half-mirror 8 and a convergent lens 9 to heat a magnetized film approximately up to its Curie point, and an external magnetic field (coil 10) is applied to invert magnetic moment. For reproduction, a beam passed through a polarizer 7 is caused to strike the film surface, and its reflected light whose plane of polarization is rotated by magnetooptic effect is detected by an analyzer 11 and a photodetector. For unreversible recording and reproduction, laser power is only increased and the principle is the same with the reversible recording and reproduction except the perforating of the metallic thin film during the recording.
JP7970281A 1981-05-26 1981-05-26 Optical recording medium Pending JPS57195389A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7970281A JPS57195389A (en) 1981-05-26 1981-05-26 Optical recording medium

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7970281A JPS57195389A (en) 1981-05-26 1981-05-26 Optical recording medium

Publications (1)

Publication Number Publication Date
JPS57195389A true JPS57195389A (en) 1982-12-01

Family

ID=13697535

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7970281A Pending JPS57195389A (en) 1981-05-26 1981-05-26 Optical recording medium

Country Status (1)

Country Link
JP (1) JPS57195389A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2578083A1 (en) * 1985-02-27 1986-08-29 Xerox Corp Optical disk unit utilising erasable and non-erasable forms of storage
US4944037A (en) * 1985-01-18 1990-07-24 Kabushiki Kaisha Toshiba Optical system for recording information in erasable and non-erasable modes
JPH04103047A (en) * 1990-08-23 1992-04-06 Nec Corp Optical disk

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4944037A (en) * 1985-01-18 1990-07-24 Kabushiki Kaisha Toshiba Optical system for recording information in erasable and non-erasable modes
FR2578083A1 (en) * 1985-02-27 1986-08-29 Xerox Corp Optical disk unit utilising erasable and non-erasable forms of storage
JPH04103047A (en) * 1990-08-23 1992-04-06 Nec Corp Optical disk

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