Patent US4559573A successfully refreshed from Google Patents.
US4559573A
Expired / Lapsed
US
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Magneto-optical recording medium
Assignee: KDDI Corp
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Filing: 1982-11-09
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Granted: 1985-12-17
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Expires: 2002-11-09
Abstract
Abstract A magneto-optical recording medium having an easy axis of magnetization in a direction perpendicular to the film surface, characterized in that a readout medium layer, a reflection layer and a recording medium layer are sequentially disposed in a direction of the incidence of a reading-out light, thereby to increase a reproduced output.
Inventors
- 👤 Shinsuke Tanaka
- 👤 Fujio Tanaka
- 👤 Yasuyuki Nagao
- 👤 Nobutake Imamura
- 👤 Chuichi Ota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:36
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B5/00; G11B5/62; G11B5/72; G11B5/726; G11B5/7262; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12542; Y10T428/12549
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
119 words
A magneto-optical memory medium comprising: a substrate, a magneto-optical readout medium layer having an easy axis of magnetization perpendicular to its surface and provided on said substrate, a reflector medium layer adjacent to and in contact with said readout medium layer, and a magneto-optical recording medium layer having an easy axis of magnetization perpendicular to its surface and provided adjacent to and in contact with the reflector medium layer, the reflector medium layer having good thermal and electrical conduction characteristics so that when light is applied for information reproduction, the light passes through said readout medium layer to said reflector medium layer and is reflected back to said readout medium layer for use in enhancing an optically reproduced output.
Claim 2
Dependent Claim
119 words
A magneto-optical memory medium comprising: a substrate, a magneto-optical readout medium layer having an easy axis of magnetization perpendicular to its surface and provided on said substrate, a reflector medium layer adjacent to and in contact with said readout medium layer, and a magneto-optical recording medium layer having an easy axis of magnetization perpendicular to its surface and provided adjacent to and in contact with the reflector medium layer, the reflector medium layer having good thermal and electrical conduction characteristics so that when light is applied for information reproduction, the light passes through said readout medium layer to said reflector medium layer and is reflected back to said readout medium layer for use in enhancing an optically reproduced output.
Claim 3
Dependent Claim
48 words
A magneto-optical memory medium according to claim 1, in which the reflector medium layer is metallic effective so that the Faraday effect produced by the passage of the light through the readout medium layer is added to the Kerr effect increasing the intensity of the optically reproduced output.
Claim 4
Dependent Claim
45 words
A magneto-optical memory medium according to claim 2, in which the metal of said metallic reflector medium layer is selected to effectively transmit by thermal conduction heat to the recording medium layer generated by application of a recording laser beam to the magneto-optical memory medium.
Claim 5
Dependent Claim
36 words
A magneto-optical memory medium according to claim 2, in which the metal of the metallic reflector medium layer is effective to transfer information recorded on the recording medium layer to the readout layer by magnetic interaction.
Claim 6
Dependent Claim
43 words
A magneto-optical memory according to claim 4, in which the thickness of the reflector medium layer is of a thickness selected to maximize its reflector factor r and the thickness being selected to effectively maintain said magnetic interaction and effective heat conduction thereby.
Claim 7
Dependent Claim
28 words
A magneto-optical memory medium according to claim 1, in which said reflector medium layer is made of a metal selected from the group silver, copper, aluminum or gold.
Claim 8
Dependent Claim
27 words
A magneto-optical memory medium according to claim 1, in which said reflector medium layer is made of an alloy of a magnetic substance and a non-magnetic substance.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |