US4969141A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical memory for storing and retrieving information by light exposure
Assignee: Toshiba Corp
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Filing: 1989-04-18
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Granted: 1990-11-06
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Expires: 2009-04-18
Abstract
Abstract An optical disc memory for optically storing and retrieving information formed of a substrate and a recording layer supported on the substrate. The recording layer has a chemically stable dielectric material and a semiconductor which has an optical property that changes reversibly as a function of the intensity of a laser beam applied through the substrate. A multilayered optical disc memory having a substrate, a recording layer formed on the substrate and a metallic layer formed on the recording layer, and a method of optically storing and retrieving information by using the above-described optical disc memory, are also disclosed.
Inventors
- 👤 Takashi Takaoka
- 👤 Kiyoshi Tsuboi, deceased
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:24
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/257; G11B7/242; G11B7/243; G11B7/2433; G11B7/004; G11B7/0055; G11B7/00557; G11B7/26; G11B2007/24302; G11B2007/2431; G11B2007/24312; G11B2007/24314; G11B2007/24316; G11B2007/25705; G11B2007/25706; G11B2007/25708; G11B2007/2571; G11B2007/25715; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
156 words
An optical memory comprising: (a) a transparent substrate (b) a semitransparent metallic layer supported on said transparent substrate, said semitransparent metallic layer comprising at least one material selected from the group consisting of Au, Ag, Cu and Al and having a layer thickness of between 0.01 μm and less than about 0.03 μm; (c) a recording layer supported on said semitransparent metallic layer, said recording layer comprising a chemically stable dielectric material and a semiconductor material capable of undergoing a reversible phase transition between amorphous structure and crystalline structure when exposed to light; and (d) a reflective metallic layer supported on said recording layer, such that light passing through said transparent substrate, said semitransparent metallic layer and said recording layer is reflected by said reflective metallic layer, said reflective metallic layer comprising at least one material selected from the group consisting Au, Ag, Cu and Al and having a thickness of about 0.05 μm or more.
Claim 2
Dependent Claim
156 words
An optical memory comprising: (a) a transparent substrate (b) a semitransparent metallic layer supported on said transparent substrate, said semitransparent metallic layer comprising at least one material selected from the group consisting of Au, Ag, Cu and Al and having a layer thickness of between 0.01 μm and less than about 0.03 μm; (c) a recording layer supported on said semitransparent metallic layer, said recording layer comprising a chemically stable dielectric material and a semiconductor material capable of undergoing a reversible phase transition between amorphous structure and crystalline structure when exposed to light; and (d) a reflective metallic layer supported on said recording layer, such that light passing through said transparent substrate, said semitransparent metallic layer and said recording layer is reflected by said reflective metallic layer, said reflective metallic layer comprising at least one material selected from the group consisting Au, Ag, Cu and Al and having a thickness of about 0.05 μm or more.
Claim 3
Dependent Claim
19 words
An optical memory as claimed in claim 1, further comprising a protective layer provided on said reflective metallic layer.
Claim 4
Dependent Claim
15 words
An optical memory as claimed in claim 1, wherein said light is a laser beam.
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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) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |