Patent US4897829A successfully refreshed from Google Patents.
US4897829A
Expired / Lapsed
US
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Cardlike optical recording medium
Assignee: Canon Inc
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Filing: 1987-11-16
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Granted: 1990-01-30
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Expires: 2007-11-16
Abstract
Abstract A cardlike optical recording medium comprises a substrate, a recording layer and a protective layer, wherein an ultra-hard film containing a carbon atom is provided at least on the side of said optical recording medium on which a laser beam for writing-reproducing is irradiated.
Inventors
- 👤 Keiko Ikoma
- 👤 Noriko Kurihara
- 👤 Keiji Hirabayashi
- 👤 Susumu Itoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:35
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/254; G11B2007/25408; G11B2007/25417; G11B7/242; G11B7/244; G11B7/246; G11B7/247; G11B7/2472; G11B7/253; G11B7/2533; G11B7/2534; G11B7/256; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12625; Y10T428/12986; Y10T428/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
82 words
In a cardlike optical recording medium comprising a transparent substrate having on one side, in sequence, a recording layer adapted to have information written thereupon and reproduced by a laser beam, and a protective layer subject to scratching or contamination, the improvement comprising providing on a second side of said transparent substrate an ultra-hard outer layer comprising a laser beam transmittable carbon matrix having at least one of an amorphous carbon phase to impart flexibility or a diamond phase to enhance hardness.
Claim 2
Dependent Claim
82 words
In a cardlike optical recording medium comprising a transparent substrate having on one side, in sequence, a recording layer adapted to have information written thereupon and reproduced by a laser beam, and a protective layer subject to scratching or contamination, the improvement comprising providing on a second side of said transparent substrate an ultra-hard outer layer comprising a laser beam transmittable carbon matrix having at least one of an amorphous carbon phase to impart flexibility or a diamond phase to enhance hardness.
Claim 3
Dependent Claim
17 words
The cardlike optical recording medium of claim 1, wherein said ultra-hard outer layer contacts said transparent substrate.
Claim 4
Dependent Claim
21 words
The cardlike optical recording medium of claim 1, including an adhesive layer interposed between said ultra-hard outer layer and said substrate.
Claim 5
Dependent Claim
32 words
The cardlike optical recording medium of claim 1, wherein said ultra-hard outer layer contacts a support layer, said recording medium including an adhesive layer interposed between said substrate and said support layer.
Claim 6
Dependent Claim
23 words
The cardlike optical recording medium of claim 1, wherein said ultra-hard outer layer has a hydrogen content of 0.1 to 40 atom %.
Claim 7
Dependent Claim
21 words
The cardlike optical recording medium of claim 1, wherein said ultra-hard outer layer has a thickness of 0.01 to 20 μm.
Claim 8
Dependent Claim
25 words
A cardlike optical recording medium according to claim 1, wherein the ultra-hard outer layer has a transmittance of 780 nm light of at least 90%.
References Cited (Backward Citations)
US4335173A
Cited
US4590493A
Cited
US4673626A
Cited
US4658388A
Cited
US4774130A
Cited
US4717622A
Cited
US4833031A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |