Patent US4731755A successfully refreshed from Google Patents.
US4731755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal design for reversible phase change optical storage media
Assignee: International Business Machines Corp
•
Filing: 1986-04-10
•
Granted: 1988-03-15
•
Expires: 2006-04-10
Abstract
Abstract Reversible phase change storage material is thermally isolated in a storage medium by means of grooves in the substrate and at least one layer of a thermally conductive dielectric material.
Inventors
- 👤 Gary C. Bjorklund
- 👤 Martin Y. Chen
- 👤 Victor B. Jipson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:00
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/257; G11B7/2578; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24312; G11B2007/24314; G11B2007/24316; G11B2007/25705; G11B2007/25706; G11B2007/25708; G11B2007/2571; G11B2007/25713; G11B2007/25715; G11B7/253; G11B7/2533; G11B7/2534
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
76 words
An optical storage medium comprising a substrate having lands and grooves, a reversible phase change active layer approximately 1,000 Angstroms thick above said substrate, and at least one thermally conductive dielectric layer, between 1,000 and 2,000 Angstroms thick either between said substrate and said active layer or on top of said active layer, with the grooves in the substrate being of at least 5,000 Angstroms in depth to provide thermal isolation between adjacent lands and grooves.
Claim 2
Dependent Claim
76 words
An optical storage medium comprising a substrate having lands and grooves, a reversible phase change active layer approximately 1,000 Angstroms thick above said substrate, and at least one thermally conductive dielectric layer, between 1,000 and 2,000 Angstroms thick either between said substrate and said active layer or on top of said active layer, with the grooves in the substrate being of at least 5,000 Angstroms in depth to provide thermal isolation between adjacent lands and grooves.
Claim 3
Dependent Claim
29 words
An optical storage medium as claimed in claim 1 wherein there are two layers of thermally conductive dielectric material, one layer above and one layer below the active layer.
Claim 4
Dependent Claim
29 words
An optical storage medium as claimed in claim 1 wherein the thermally conductive dielectric layer on top of the active layer is covered by a layer of crystalline material.
References Cited (Backward Citations)
US3530441A
Cited
US3778785A
Cited
US4298975A
Cited
US4363844A
Cited
US4422159A
Cited
US4408213A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |