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Patent US4710431A successfully refreshed from Google Patents.
US4710431A
Expired / Lapsed
US
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Magnetooptical recording element and a magnetooptical recording device
Assignee: US Philips Corp
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Filing: 1986-11-10
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Granted: 1987-12-01
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Expires: 2006-11-10
Abstract
Abstract A magnetooptical recording element has a substrate bearing a magnetooptical recording layer. The recording layer is crystalline and comprises a compound of the formula R 2 T 14 B, wherein R is a rare earth metal or a combination of two or more rare earth metals, and T is a transition metal or a combination of two or more transition metals, in particular Fe or Co or a mixture thereof. A magnetooptical recording device comprises such a magnetooptical recording element.
Inventors
- 👤 Petrus P. J. Van Engelen
- 👤 Kurt H. J. Buschow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:53
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
A magnetooptical recording element comprising: a substrate; a thin recording layer on the substrate; and a heading means on the substrate for providing information for controlling the recording of information onto the recording element. characterized in that the recording layer consists essentially of a crystalline alloy having the composition R 2 T 14 B, where R is one or more rare-earth metals, T is one or more transition metals, and B is boron.
Claim 2
Dependent Claim
73 words
A magnetooptical recording element comprising: a substrate; a thin recording layer on the substrate; and a heading means on the substrate for providing information for controlling the recording of information onto the recording element. characterized in that the recording layer consists essentially of a crystalline alloy having the composition R 2 T 14 B, where R is one or more rare-earth metals, T is one or more transition metals, and B is boron.
Claim 3
Dependent Claim
21 words
A magnetooptical recording element as claimed in claim 1, characterized in that T is one or more of iron and cobalt.
Claim 4
Dependent Claim
22 words
A magnetooptical recording element as claimed in claim 2, characterized in that R is one or more of neodymium, gadolinium, and lanthanum.
Claim 5
Dependent Claim
23 words
A magnetooptical recording element as claimed in claim 3, characterized in that the crystalline alloy has the composition Nd 2 Fe 14 B.
Claim 6
Dependent Claim
98 words
A magnetooptical recording device comprising: a substrate; a thin magnetized recording layer on the substrate; means for writing information on the recording layer by optically changing the magnetization state of an area of the recording layer; and means for reading information written on the recording layer by optically sensing the magnetization state of an area of the recording layer; characterized in that the recording layer consists essentially of a crystalline alloy having the composition R 2 T 14 B, where R is one or more rare-earth metals, T is one or more transition metals, and B is boron.
Claim 7
Dependent Claim
98 words
A magnetooptical recording device comprising: a substrate; a thin magnetized recording layer on the substrate; means for writing information on the recording layer by optically changing the magnetization state of an area of the recording layer; and means for reading information written on the recording layer by optically sensing the magnetization state of an area of the recording layer; characterized in that the recording layer consists essentially of a crystalline alloy having the composition R 2 T 14 B, where R is one or more rare-earth metals, T is one or more transition metals, and B is boron.
Claim 8
Dependent Claim
21 words
A magnetooptical recording device as claimed in claim 5, characterized in that T is one or more of iron and cobalt.
Claim 9
Dependent Claim
22 words
A magnetooptical recording device as claimed in claim 6, characterized in that R is one or more of neodymium, gadolinium, and lanthanum.
Claim 10
Dependent Claim
23 words
A magnetooptical recording device as claimed in claim 7, characterized in that the crystalline alloy has the composition Nd 2 Fe 14 B.
References Cited (Backward Citations)
US4310899A
Cited
US4612587A
Cited
JPS60128606A
Cited
US4663066A
Cited
JPS6148148A
Cited
JPS6196706A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-30 | 1991-06-01 | 1991-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-30 | 1995-06-01 | 1995-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-30 | 1999-06-01 | 1999-12-01 | $7700.00 | Window Closed / Lapsed |