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Magneto-optical recording medium

Assignee: KDDI Corp
•
Filing: 1984-07-17
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Granted: 1986-12-09
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Expires: 2004-07-17
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Abstract

Abstract A magneto-optical recording medium comprising: a recording layer of a magnetic thin film low in the Curie temperature or magnetic compensation temperature and high in coersive force and having an easy axis of magnetization in a direction perpendicular to the film surface; a reproducing layer disposed adjacent the recording layer and large in the magnetic Kerr rotation angle and having an easy axis of magnetization in a direction perpendicular to the film surface; and a transparent substrate disposed on the side of incidence of light. In accordance with the present invention, a reflecting metal layer is provided for reflecting light having entered from the side of the transparent substrate and passed through the recording layer and the reproducing layer. A dielectric layer may be further disposed at least on one side of the transparent substrate or the reflecting metal layer with respect to the recording layer and the reproducing layer. The order of the recording layer and the reproducing layer may be replaced by each other.

Inventors

  • 👤 Fujio Tanaka
  • 👤 Yasuyuki Nagao
  • 👤 Nobutake Imamura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 20:31
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/672; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10589; G11B11/10593

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 158 words
A magneto-optical recording medium comprising: a recording layer of a magnetic thin film low in the Curie temperature or magnetic compensation temperature and high in coercive force and having an easy axis of magnetization in a direction perpendicular to the film surface; a reproducing layer disposed adjacent the recording layer and large in the magnetic Kerr rotation angle and having an easy axis of magnetization in a direction perpendicular to the film surface; a transparent substrate disposed on the side of incidence of light; a reflecting metal layer for reflecting incident light having entered from the side of the transparent substrate passed through the recording layer and the reproducing layer; and a dielectric layer disposed at least on the side of the transparent substrate with respect to the recording layer and the reproducing layer and effective to cause multiple light reflections by the reproducing layer or the recording layer so that Kerr rotation and Faraday rotation are increased.
Claim 2
Dependent Claim 158 words
A magneto-optical recording medium comprising: a recording layer of a magnetic thin film low in the Curie temperature or magnetic compensation temperature and high in coercive force and having an easy axis of magnetization in a direction perpendicular to the film surface; a reproducing layer disposed adjacent the recording layer and large in the magnetic Kerr rotation angle and having an easy axis of magnetization in a direction perpendicular to the film surface; a transparent substrate disposed on the side of incidence of light; a reflecting metal layer for reflecting incident light having entered from the side of the transparent substrate passed through the recording layer and the reproducing layer; and a dielectric layer disposed at least on the side of the transparent substrate with respect to the recording layer and the reproducing layer and effective to cause multiple light reflections by the reproducing layer or the recording layer so that Kerr rotation and Faraday rotation are increased.
Claim 3
Dependent Claim 30 words
A magneto-optical recording medium according to claim 1, characterized in that, of the recording layer and the reproducing layer, the latter is disposed on the side of the transparent substrate.
Claim 4
Dependent Claim 30 words
A magneto-optical recording medium according to claim 1, characterized in that, of the recording layer and the reproducing layer, the former is disposed on the side of the transparent substrate.

References Cited (Backward Citations)

EP0051296A1 Cited
US4497006A Cited
US4559573A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-12-08 1990-06-09 1990-12-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-12-08 1994-06-09 1994-12-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-12-08 1998-06-09 1998-12-09 $7700.00 Window Closed / Lapsed

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