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EP0437308A2
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Recording method for magneto-optical memory medium
Assignee: Sharp Corp
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Filing: 1991-01-02
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Granted: —
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Expires: 2011-01-02
Abstract
Abstract A recording method for a magneto-optic memory medium of exchange-coupled type having a recording layer of a low Curie point and high coercive force and a reading layer of a high Curie point and low coercive force, which comprises the steps of: applying a magnetic field to the magneto-optic memory medium to develop a predetermined data in the reading layer, and then applying both an optical beam and a magnetic field to the magneto-optic memory medium for writing the predetermined data in the recording layer, and simultaneously verifying the data upon said writing on the basis of a Kerr effect of the optical beam caused by the reading layer.
Inventors
- 👤 Tomoyuki Miyake
- 👤 Mitsuo Ishii
- 👤 Hiroyuki Katayama
- 👤 Kenji Ohta
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 10:55
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10515; G11B11/10517; G11B11/10519; G11B11/1055; G11B11/1058; G11B11/10582; G11B11/10586
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A recording method for a magneto-optic memory medium of exchange-coupled type having a recording layer of a low Curie point and high coercive force and a reading layer of a high Curie point and low coercive force, which comprises the steps of: applying a magnetic field to the magneto-optic memory medium to develop a predetermined data in the reading layer, and then applying both an optical beam and a magnetic field to the magneto-optic memory medium for writing the predetermined data in the recording layer, and simultaneously verifying the data upon said writing on the basis of a Kerr effect of the optical beam caused by the reading layer.
Claim 2
Dependent Claim
29 words
The recording method of claim 1 in which the recording layer is a GdTbFe amorphous alloy thin film and the reading layer is a GdNdFe amorphous alloy thin film.
Claim 3
Dependent Claim
23 words
The recording method of claim 2 in which each of the recording and reading layers has a thickness of 100 to 1000 Å.
Claim 4
Dependent Claim
31 words
The recording method of claim 2 in which the recording layer has a thickness of 200 to 600 Å and the reading layer has a thickness of 150 to 600 Å.
Claim 5
Dependent Claim
89 words
The recording method of claim 2 in which the GdTbFe amorphous alloy is represented by the following formula: (Gd p Tb 1-p ) q Fe 1-q (wherein p and q satisfy the inequalities 0.1 < q < 0.35, 0 < p x q < 0.25, 0 < (1 - p) x q < 0.25), and the GdNdFe amorphous alloy is represented by the following formula: Gd x Nd y Fe 1-x-y (wherein x and y satisfy the inequalities 0.1 < x < 0.3 and 0 < y < 0.25).
Claim 6
Dependent Claim
15 words
The recording method of claim 1 in which the optical beam is a laser beam.
Claim 7
Dependent Claim
111 words
Apparatus for recording data on a magneto-optic memory medium of exchange-coupled type having a recording layer of a low Curie point and high coercive force and a reading layer of a high Curie point and low coercive force, said apparatus comprising: means for applying a magnetic field to the magneto-optic memory medium to develop a predetermined data in the reading layer, and for then applying both an optical beam and a magnetic field to the magneto-optic memory medium for writing the predetermined data in the recording layer, and simultaneously verifying the data upon said writing on the basis of a Kerr effect of the optical beam caused by the reading layer.
References Cited (Backward Citations)
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