US4425570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reversible recording medium and information record
Assignee: RCA Corp
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Filing: 1981-06-12
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Granted: 1984-01-10
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Expires: 2001-06-12
Abstract
Abstract The invention is a recording medium wherein the light absorptive layer is a granular material comprising domains of a light sensitive material embedded in a dielectric matrix. The domains comprise a material which can be reversibly switched from a first state to a second state having different optical properties by the absorption of light. The matrix is composed of a material which is effective for inhibiting the formation of an irreversible change in the optical properties of the absorptive layer. The invention further comprises this optical recording medium having an information track recorded therein as a series of regions in the absorptive layer wherein the domains have been reversibly switched to a second state having different optical properties.
Inventors
- 👤 Alan E. Bell
- 👤 Yehuda Arie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:00
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/705; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24304; G11B2007/24306; G11B2007/2431; G11B2007/24312; G11B2007/24314; G11B2007/24316; G11B2007/24318; G11B2007/2432; G11B2007/24324; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
83 words
In a recording medium comprising a substrate and a light absorptive layer which overlies the substrate and which is absorptive of light at the recording light beam wavelength, the improvement wherein said absorptive layer comprises one or more domains of a light absorbing material, which can be reversibly switched from a first state to a second state having different optical properties, embedded in a matrix of a material effective for inhibiting an irreversible change in the optical properties of the light absorbing material.
Claim 2
Dependent Claim
83 words
In a recording medium comprising a substrate and a light absorptive layer which overlies the substrate and which is absorptive of light at the recording light beam wavelength, the improvement wherein said absorptive layer comprises one or more domains of a light absorbing material, which can be reversibly switched from a first state to a second state having different optical properties, embedded in a matrix of a material effective for inhibiting an irreversible change in the optical properties of the light absorbing material.
Claim 3
Dependent Claim
129 words
In an information record comprising a substrate and a light absorptive layer which overlies the substrate, which is absorptive of light at the recording light beam wavelength and which has an information track therein, the improvement wherein said absorptive layer comprises one or more domains of a light absorbing material, which can be reversibly switched from a first state to a second state having different optical properties, embedded in a matrix of a material effective for inhibiting an irreversible change in the optical properties of the light absorbing material and wherein the information track comprises a series of regions in the absorptive layer wherein the light absorbing material comprising domains has been reversibly switched to a state having different optical properties from the remaining regions of the absorptive layer.
Claim 4
Dependent Claim
129 words
In an information record comprising a substrate and a light absorptive layer which overlies the substrate, which is absorptive of light at the recording light beam wavelength and which has an information track therein, the improvement wherein said absorptive layer comprises one or more domains of a light absorbing material, which can be reversibly switched from a first state to a second state having different optical properties, embedded in a matrix of a material effective for inhibiting an irreversible change in the optical properties of the light absorbing material and wherein the information track comprises a series of regions in the absorptive layer wherein the light absorbing material comprising domains has been reversibly switched to a state having different optical properties from the remaining regions of the absorptive layer.
Claim 5
Dependent Claim
24 words
The article according to claim 1 or 2 wherein the second state has a different degree of crystallinity from that of the original state.
Claim 6
Dependent Claim
22 words
The article according to claim 1 or 2 wherein a light reflective layer is interposed between the absorptive layer and the substrate.
Claim 7
Dependent Claim
36 words
The article according to claim 4 wherein the thickness of the absorptive layer is so related to the optical constants of the reflective and absorptive layers that the reflectivity of the optical recording medium is reduced.
Claim 8
Dependent Claim
20 words
The article according to claim 4 wherein a spacer layer is interposed between the reflective layer and the absorptive layer.
Claim 9
Dependent Claim
44 words
The article according to claim 6 wherein the thickness of the absorptive layer is so related to the thickness of the spacer layer and the optical constants of the reflective, spacer and absorptive layers that the reflectivity of the optical recording medium is reduced.
Claim 10
Dependent Claim
28 words
The article according to claim 6 wherein the spacer layer is comprised of a material selected from the group consisting of oxides of silicon, aluminum, magnesium and titanium.
Claim 11
Dependent Claim
36 words
The article according to claim 1 or 2 wherein the domains are comprised of a material selected from the group consisting of tellurium, selenium, alloys containing tellurium or selenium, chalcogenide alloys, arsenic trisulfide and arsenic triselenide.
Claim 12
Dependent Claim
30 words
The article according to claim 1 or 2 wherein the matrix is composed of a material selected from the group consisting of an oxide of silicon, aluminum, titanium and magnesium.
Claim 13
Dependent Claim
16 words
The article according to claim 1 or 2 wherein an overcoat layer overlies the absorptive layer.
Claim 14
Dependent Claim
20 words
The article according to claim 1 or 2 wherein the dimensions of a domain are less than about 100 nanometers.
Claim 15
Dependent Claim
20 words
The article according to claim 12 wherein the dimensions of a domain are between about 2 and about 30 nanometers.
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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) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |