Patent US4725502A successfully refreshed from Google Patents.
US4725502A
Expired / Lapsed
US
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Information recording medium having Al-Ti alloy reflective layer
Assignee: Sony Corp
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Filing: 1986-12-05
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Granted: 1988-02-16
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Expires: 2006-12-05
Abstract
Abstract An optical information record medium comprising a transparent substrate, an optical information recording layer, and a reflective metal layer. The reflective metal layer is formed of an aluminum-titanium alloy in which the titanium content is between 0.1 and 10 weight %. The medium has improved stability against corrosion due to the improved reflective metal layer.
Inventors
- 👤 Tadashi Kiyomiya
- 👤 Mitsuo Naito
- 👤 Tatsuya Sasaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:39
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B7/2585; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24314; G11B2007/24316; G11B7/253; G11B7/2533; G11B7/2534; G11B7/254; G11B7/2542; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S430/00; Y10S430/146; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
48 words
An optical information record medium comprising: a transparent substrate, an optical information record layer carried by said substrate, and a reflective metal laayer associated with said optical information record layer, said reflective metal layer being composed of an Al-Ti alloy containing from 0.3 to 3.0% by weight Ti.
Claim 2
Dependent Claim
48 words
An optical information record medium comprising: a transparent substrate, an optical information record layer carried by said substrate, and a reflective metal laayer associated with said optical information record layer, said reflective metal layer being composed of an Al-Ti alloy containing from 0.3 to 3.0% by weight Ti.
Claim 3
Dependent Claim
34 words
An optical information record medium according to claim 1 in which said optical information record layer is formed of a magnetic material which changes its direction of magnetization upon irradiation by a laser beam.
Claim 4
Dependent Claim
64 words
An optical information record medium according to claim 1 wherein said reflective metal layer contains at least one of the following additives per 100 parts by weight of the Al-Ti alloy: Pd in 0.01 to 0.3 parts by weight Mn is 0.1 to 1.0 parts by weight Mg in 0.1 to 1.0 parts by weight, or Si in 0.1 to 1.0 parts by weight.
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) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |