EP0153676A1
Expired / Lapsed
EP
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Magneto-optical recording system
Assignee: Hitachi Ltd
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Filing: 1985-02-15
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Granted: —
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Expires: 2005-02-15
Abstract
Abstract in a magneto-optical file memory a storage medium (17) including a magnetic film (17b) is irradiated with a laser beam to reverse the magnetization direction of the magnetic fiim, thereby to write and/or erase information. The laser beam is focused by an optical system (15) on the storage medium (17), which optical system (15) is controlled by an actuator (16), wherein the sense of the leakage magnetic field (Ha) of the actuator (16) is set to agree with the sense of the initial magnetization of the magnetic film (17b) of the storage medium (17). T6 reproduce the information recorded on the storage medium the rotation of the polarization plane of light reflected from the storage medium is detected.
Inventors
- 👤 Tsuyoshi Kato
- 👤 Masahiro Ojima
- 👤 Toshio Niihara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 20:20
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/06; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10532; G11B11/10534; G11B11/10536
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
164 words
A magneto-optical file memory, characterized by a laser source (11), a storage medium (17) which includes a magnetic film (17b) that is magnetized in a first direction beforehand and that is magnetized in a second direction opposite to the first direction thereby to have information written therein, an optical system (15) which condenses on said storage medium (17) a laser beam (1) emitted from said laser source (11), an actuator (16) which controls said optical system (15) so that the condensed beam (1) may form a predetermined spot on said storage medium (17) while tracking a motion of said storage medium, and magnetization reversal means (18) to reverse the magnetization direction of said magnetic film (17b) of said storage medium irradiated with the light spot when information is written and erased, a sense of a leakage magnetic field (Ha) of said actuator (16) on said storage medium (17) being set to be the same as the first magnetization direction of said magnetic film (17b).
Claim 2
Dependent Claim
164 words
A magneto-optical file memory, characterized by a laser source (11), a storage medium (17) which includes a magnetic film (17b) that is magnetized in a first direction beforehand and that is magnetized in a second direction opposite to the first direction thereby to have information written therein, an optical system (15) which condenses on said storage medium (17) a laser beam (1) emitted from said laser source (11), an actuator (16) which controls said optical system (15) so that the condensed beam (1) may form a predetermined spot on said storage medium (17) while tracking a motion of said storage medium, and magnetization reversal means (18) to reverse the magnetization direction of said magnetic film (17b) of said storage medium irradiated with the light spot when information is written and erased, a sense of a leakage magnetic field (Ha) of said actuator (16) on said storage medium (17) being set to be the same as the first magnetization direction of said magnetic film (17b).
Claim 3
Dependent Claim
41 words
A magneto-optical file memory according to claim 1, wherein a magnetization direction (Hb) of said magnetization reversal means (18) and the sense of the leakage magnetic field (Ha) of said actuator (16) are opposite to each other in the writing mode.
Claim 4
Dependent Claim
39 words
A magneto-optical file memory according to claim 1 or 2, wherein a magnetization direction (Hb1) of said magnetization reversal means (18) and the sense of the leakage magnetic field (Ha) of said actuator (16) agree in the erasing mode.
Claim 5
Dependent Claim
36 words
A magneto-optical file memory according to any of claims 1 to 3, wherein the magnetization direction (MS) of said magnetic film (17b) of said storage medium (17) is perpendicular to a surface of said storage medium.
Claim 6
Dependent Claim
39 words
A magneto-optical file memory according to any of claims 1 to 4, wherein a direction of an optical axis of said optical system (15) and a magnetization direction of said magnetization reversal means (18) are parallel to each other.
Claim 7
Dependent Claim
39 words
A magneto-optical file memory according to any of claims 1 to 5, wherein said actuator (16) includes a magnet having polar directions which agree with the magnetization direction (MS) of said magnetic film (17b) of said storage medium (17).
References Cited (Backward Citations)
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