Patent EP0318337A2 successfully refreshed from Google Patents.
EP0318337A2
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Magneto-optic memory medium
Assignee: Sharp Corp
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Filing: 1988-11-28
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Granted: —
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Expires: 2008-11-28
Abstract
Abstract A magneto-optic memory medium comprising a dielectric film, a magneto-optic memory film, a dielectric film and a reflective film superposed in layers on a light trnasmitting substrate, the magneto-optic memory film being a rare earth-transition metal alloy film having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y wherein x is 0.58 to 0.62, and y is 0.27 to 0.33, which is useful as a magneto-optic disc or magneto-optic card.
Inventors
- 👤 Kenji Ohta
- 👤 Akira Takahashi
- 👤 Yoshiteru Murakami
- 👤 Junichiro Nakayama
- 👤 Tomoyuki Miyake
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 21:39
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24306; G11B7/2433; G11B7/2585; G11B7/2595
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
63 words
A magneto-optic memory medium comprising a dielectric film a magneto-optic memory film, a dielectric film and a reflective film superposed in layers on a light transmitting substrate, the magneto-optic memory film being a rare earth-transition metal alloy film having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y wherein x is 0.58 to 0.62, and y is 0.27 to 0.33.
Claim 2
Dependent Claim
63 words
A magneto-optic memory medium comprising a dielectric film a magneto-optic memory film, a dielectric film and a reflective film superposed in layers on a light transmitting substrate, the magneto-optic memory film being a rare earth-transition metal alloy film having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y wherein x is 0.58 to 0.62, and y is 0.27 to 0.33.
Claim 3
Dependent Claim
23 words
The magneto-optic memory medium of claim 1 in which the rare earth-transition metal alloy film has a thickness of 5 - 100 nm.
Claim 4
Dependent Claim
23 words
The magneto-optic memory medium of claim 1 in which the rare earth-transition metal alloy film has a thickness of 20 - 50 nm.
Claim 5
Dependent Claim
32 words
The magneto-optic memory medium of claim 1 in which the rare earth-transition metal alloy film of the formula wherein x is 0.60 to 0.62 and y is 0.27 to 0.29 is used.
Claim 6
Dependent Claim
20 words
The magneto-optic memory medium of claim 1 in which each of the dielectric films is made of a metal nitride.
Claim 7
Dependent Claim
20 words
The magneto-optic memory medium of claim 5 in which the metal nitride is silicon nitride, aluminium nitride or silicon-aluminium nitride.
Claim 8
Dependent Claim
24 words
The magneto-optic memory medium of claim 1 in which the reflective film is made of aluminium, nickel, titanium, gold, silicon, tellurium or stainless steel.
Claim 9
Dependent Claim
19 words
The magneto-optic memory medium of claim 1 in which the light transmitting substrate is made of glass or plastics.
Claim 10
Dependent Claim
18 words
The magneto-optic memory medium of claim 1 in the form of 9 magneto-optic disc or a magneto-optic card.
Claim 11
Dependent Claim
114 words
A magneto-optic memory medium comprising: a transparent substrate (1); a magneto-optic memory film (3) mounted on said substrate; a first dielectric layer (2) disposed between said transparent substrate and said magneto-optic memory film; a second dielectric layer (4) disposed to the side of said magneto-optic memory film remote from the transparent substrate; and a reflective film (5) disposed to the side of said second dielectric layer which is remote from the magneto- optic memory film; the magneto-optic memory film comprising a rare earth-transition metal alloy having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y characterised in that x is from 0.58 to 0.62, and y is from 0.27 to 0.33.
Claim 12
Dependent Claim
114 words
A magneto-optic memory medium comprising: a transparent substrate (1); a magneto-optic memory film (3) mounted on said substrate; a first dielectric layer (2) disposed between said transparent substrate and said magneto-optic memory film; a second dielectric layer (4) disposed to the side of said magneto-optic memory film remote from the transparent substrate; and a reflective film (5) disposed to the side of said second dielectric layer which is remote from the magneto- optic memory film; the magneto-optic memory film comprising a rare earth-transition metal alloy having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y characterised in that x is from 0.58 to 0.62, and y is from 0.27 to 0.33.
Claim 13
Dependent Claim
45 words
A magneto-optic memory medium which includes a magneto-optic memory film comprising a rare earth-transition metal alloy having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y characterised in that x is from 0.58 to 0.62, and y is from 0.27 to 0.33.
Claim 14
Dependent Claim
45 words
A magneto-optic memory medium which includes a magneto-optic memory film comprising a rare earth-transition metal alloy having the composition formula of: (Gd x Tb 1-x ) y Fe 1-y characterised in that x is from 0.58 to 0.62, and y is from 0.27 to 0.33.
References Cited (Backward Citations)
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