US4675767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Opto-magnetic recording medium
Assignee: Canon Inc
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Filing: 1984-12-07
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Granted: 1987-06-23
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Expires: 2004-12-07
Abstract
Abstract There is disclosed a magnetooptical recording medium, which is provided with a recording layer composed of a magnetic layer having an easy axis of magnetization perpendicular to the surface of recording layer, and a reflective layer positioned adjacent to the recording layer and composed of a mixture of a substance of a low absorbance to the light of a determined wavelength and a substance of a high reflectivity to the above-mentioned light.
Inventors
- 👤 Yoichi Osato
- 👤 Ichiro Saito
- 👤 Kozo Arao
- 👤 Eiichi Fujii
- 👤 Yoshio Takasu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:21
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
59 words
An opto-magnetic recording medium comprising: a recording layer composed of a magnetic layer having a characteristic in which the magnetic layer is easily magnetized in a direction perpendicular to the surface of the layer; and a reflective layer positioned on said recording layer and composed of a mixture of a reflective metal and a low light absorbing dielectric material.
Claim 2
Dependent Claim
59 words
An opto-magnetic recording medium comprising: a recording layer composed of a magnetic layer having a characteristic in which the magnetic layer is easily magnetized in a direction perpendicular to the surface of the layer; and a reflective layer positioned on said recording layer and composed of a mixture of a reflective metal and a low light absorbing dielectric material.
Claim 3
Dependent Claim
34 words
An opto-magnetic recording medium according to claim 1 wherein said low light absorbing dielectric material is selected from the group consisting of metallic or semi-metallic oxides, fluorides, sulfides or iodides and organic macromolecular materials.
Claim 4
Dependent Claim
32 words
An opto-magnetic recording medium according to claim 1, wherein, in said reflective layer, said reflective metal represents a content in a range of 80 to 95 atomic % in the entire mixture.
Claim 5
Dependent Claim
23 words
An opto-magnetic recording medium according to claim 1, wherein said reflective layer has a thickness in a range from 700 to 3,000 Å.
Claim 6
Dependent Claim
27 words
An opto-magnetic recording medium according to claim 1, wherein said reflective layer is a co-evaporated layer of the reflective metal and the low light absorbing dielectric material.
Claim 7
Dependent Claim
22 words
An opto-magnetic recording medium according to claim 1, wherein said recording layer is composed of an amorphous rare earth-transition metal alloy layer.
Claim 8
Dependent Claim
23 words
An opto-magnetic recording medium according to claim 1, wherein said recording layer has a thickness in a range from 100 to 1,000 Å.
Claim 9
Dependent Claim
21 words
An opto-magnetic recording medium according to claim 1, comprising, in sequence, a translucent substrate, said recording layer and said reflective layer.
Claim 10
Dependent Claim
26 words
An opto-magnetic recording medium according to claim 8, further comprising a protective layer on said translucent substrate on a face thereof opposite to said reflective layer.
Claim 11
Dependent Claim
22 words
An opto-magnetic recording medium according to claim 8, further comprising a heat insulating layer between said translucent substrate and said recording layer.
Claim 12
Dependent Claim
21 words
An opto-magnetic recording medium according to claim 8, further comprising an anti-reflection layer between said translucent substrate and said recording layer.
References Cited (Backward Citations)
US4467383A
Cited
US4569881A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |