Patent EP0227480A2 successfully refreshed from Google Patents.
EP0227480A2
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EP
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Magneto-optical recording
Assignee: Sony Corp
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Filing: 1986-12-23
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Granted: —
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Expires: 2006-12-23
Abstract
Abstract A magneto-optical recording technique comprises: preparing a magneto-optical recording medium (10) comprising a magneto-optical recording layer (12) and a bias magnetic layer (14) formed on a transparent substrate (11), the recording layer (12) having a Curie temperature higher than room temperature, the bias magnetic layer (14) having a compensation temperature lower than a Curie temperature, and the recording layer (12) and the bias magnetic layer (14) being superposed with a non-magnetic layer (13) therebetween; and applying heating (for example by means of a laser beam L.B) to the magneto-optical recording medium (10) at first and second heating power levels, the first level being sufficient to heat the recording layer (12) to a temperature higher than the Curie temperature of the recording layer (12) and to heat the bias magnetic layer (14) to a temperature higher than the compensation temperature of the bias magnetic layer (14), and the second level being sufficient to heat the recording layer (12) to a temperature higher than the Curie temperature of the recording layer (12) while keeping the bias magnetic layer (14) below the compensation temperature of the bias magnetic layer (14).
Inventors
- 👤 Hideyoshi Horimai
- 👤 Osamu Kawakubo
- 👤 Yoshio Aoki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 12:20
CPC Classifications
G; G11; G11B; G11B7/00; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10517; G11B11/10519; G11B11/10521; G11B11/10504; G11B11/10506
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
188 words
A magneto-optical recording method comprising: preparing a magneto-optical recording medium (10) comprising a magneto-optical recording layer (12) and a bias magnetic layer (14) formed on a transparent substrate (11), the magneto-optical recording layer (12) having a Curie temperature higher than room temperature, the bias magnetic layer (14) having a compensation temperature lower than a Curie temperature, and the magneto-optical recording layer (12) and the bias magnetic layer (14) being superposed with a non-magnetic layer (13) therebetween; and applying heating to the magneto-optical recording medium (10) at first and second heating power levels, the first heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) and to heat the bias magnetic layer (14) to a temperature higher than the compensation temperature of the bias magnetic layer (14), and the second heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) while keeping the bias magnetic layer (14) below the compensation temperature of the bias magnetic layer (14).
Claim 2
Dependent Claim
188 words
A magneto-optical recording method comprising: preparing a magneto-optical recording medium (10) comprising a magneto-optical recording layer (12) and a bias magnetic layer (14) formed on a transparent substrate (11), the magneto-optical recording layer (12) having a Curie temperature higher than room temperature, the bias magnetic layer (14) having a compensation temperature lower than a Curie temperature, and the magneto-optical recording layer (12) and the bias magnetic layer (14) being superposed with a non-magnetic layer (13) therebetween; and applying heating to the magneto-optical recording medium (10) at first and second heating power levels, the first heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) and to heat the bias magnetic layer (14) to a temperature higher than the compensation temperature of the bias magnetic layer (14), and the second heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) while keeping the bias magnetic layer (14) below the compensation temperature of the bias magnetic layer (14).
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein the heating is applied by a laser beam (L.B) having the first and second heating power levels.
Claim 4
Dependent Claim
20 words
A method according to claim 1 or claim 2, wherein the bias magnetic layer (14) is formed of ferrimagnetic material.
Claim 5
Dependent Claim
189 words
A magneto-optical recording arrangement comprising: a magneto-optical recording medium (10) comprising a magneto-optical recording layer (12) and a bias magnetic layer (14) formed on a transparent substrate (11), the magneto-optical recording layer (12) having a Curie temperature higher than room temperature, the bias magnetic layer (14) having a compensation temperature lower than a Curie temperature, and the magneto-optical recording layer (12) and the bias magnetic layer (14) being superposed with a non-magnetic layer (13) therebetween; and heating means capable of applying first and second heating power levels to the magneto-optical recording medium (10), the first heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) and to heat the bias magnetic layer (14) to a temperature higher than the compensation temperature of the bias magnetic layer (14), and the second heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) while keeping the bias magnetic layer (14) below the compensation temperature of the bias magnetic layer (14).
Claim 6
Dependent Claim
189 words
A magneto-optical recording arrangement comprising: a magneto-optical recording medium (10) comprising a magneto-optical recording layer (12) and a bias magnetic layer (14) formed on a transparent substrate (11), the magneto-optical recording layer (12) having a Curie temperature higher than room temperature, the bias magnetic layer (14) having a compensation temperature lower than a Curie temperature, and the magneto-optical recording layer (12) and the bias magnetic layer (14) being superposed with a non-magnetic layer (13) therebetween; and heating means capable of applying first and second heating power levels to the magneto-optical recording medium (10), the first heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) and to heat the bias magnetic layer (14) to a temperature higher than the compensation temperature of the bias magnetic layer (14), and the second heating power level being sufficient to heat the magneto-optical recording layer (12) to a temperature higher than the Curie temperature of the magneto-optical recording layer (12) while keeping the bias magnetic layer (14) below the compensation temperature of the bias magnetic layer (14).
Claim 7
Dependent Claim
25 words
An arrangement according to claim 4, wherein the heating means comprises means for generating a laser beam (L.B) having the first and second power levels.
Claim 8
Dependent Claim
20 words
An arrangement according to claim 4 or claim 5, wherein the bias magnetic layer (14) is formed of ferrimagnetic material.
References Cited (Backward Citations)
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