US4787077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for optically storing information using materials having a single phase in both the crystalline state and the amorphous state
Assignee: International Business Machines Corp
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Filing: 1987-08-28
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Granted: 1988-11-22
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Expires: 2007-08-28
Abstract
Abstract An optical storage system has an information containing film of a material which has a crystallization temperature between 100° C. and 400° C. and can be switched between the amorphous and the crystalline states. Both the amorphous and crystalline states are substantially a single phase where the stoichiometric ratio of the material remains unchanged. Spots on the film is heated with a circular laser beam with a controlled pulse duration and intensity to melt the material in the spots. The spots are quenched at one rate to produce the amorphous state, and in a second revolution of the disk, at a different rate to produce the crystalline state.
Inventors
- 👤 Roger W. Barton
- 👤 Martin Y. Chen
- 👤 Charles R. Davis
- 👤 Grace L. Gorman
- 👤 Vincent Marrello
- 👤 Kurt A. Rubin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:37
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/004; G11B7/0045; G11B7/00454; G11B7/24; G11B7/241; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24312; G11B2007/24316; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
A process for optically storing information comprising the steps of: (1) depositing a film of a material which is selected from the group consisting of GeTe, and GeTe with small amounts of an additional element, and (2) heating spots in said film using a controlled laser beam with controlled duration and intensity to melt the material in said spots, and (3) quenching the spots at one rate to produce the amorphous state, and in a second revolution of the disk at a different rate to produce the crystalline state.
Claim 2
Dependent Claim
89 words
A process for optically storing information comprising the steps of: (1) depositing a film of a material which is selected from the group consisting of GeTe, and GeTe with small amounts of an additional element, and (2) heating spots in said film using a controlled laser beam with controlled duration and intensity to melt the material in said spots, and (3) quenching the spots at one rate to produce the amorphous state, and in a second revolution of the disk at a different rate to produce the crystalline state.
Claim 3
Dependent Claim
16 words
A process as claimed in claim 1 wherein the material is (GeTe) 85 Sn 15 .
Claim 4
Dependent Claim
22 words
A process as claimed in claim 1 wherein the material is (GeTe) 100-x Sn x where x is between 0 and 30.
Claim 5
Dependent Claim
17 words
A process as claimed in claim 1 wherein the film is about 200 to 1,000 Angstroms thick.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |