US4551828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quadrilayer optical draw medium
Assignee: 3M Co
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Filing: 1983-03-18
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Granted: 1985-11-05
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Expires: 2003-03-18
Abstract
Abstract Quadrilayer optical DRAW medium which differs from prior trilayer optical DRAW media by having a thin triggering layer adjacent each of the optical spacer and light-absorbing layers. The triggering layer is a material, preferably organic, which when heated by a modulated laser-diode beam to a temperature less than the melting point of the optical spacer layer develops substantial vapor pressure or otherwise rapidly expands to implement or enhance the formation of pits or bubbles in the light-absorbing layer without disturbing the optical spacer layer or its function of protecting the substrate of the medium.
Inventors
- 👤 Chi H. Chung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:14
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/244; G11B7/004; G11B7/0045; G11B7/00451; G11B7/00452; G11B7/2403; G11B7/24067; G11B7/252; G11B7/257; G11B7/2572; G11B7/2575; G11B7/243; G11B2007/24302; G11B2007/24312; G11B2007/24318; G11B2007/2432; G11B7/253; G11B7/2533; G11B7/258; G11B7/2585; G11B7/26
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
113 words
An optical DRAW medium comprising an optically-smooth reflective substrate, an optical spacer layer overlying the reflective substrate, and a light-absorbing layer overlying the optical spacer layer, information being recordable in the form of discrete features in the light-absorbing layer creatable by a focused, modulated laser beam, wherein the improvement comprises: adjacent to each of the light-absorbing and optical spacer layers is a triggering layer formed of an organic material which has a thickness less than that of the optical spacer layer and when heated to a temperature below the melting point of the optical spacer layer rapidly expands to implement or enhance the formation of a bubble or pit in the light-absorbing layer.
Claim 2
Dependent Claim
113 words
An optical DRAW medium comprising an optically-smooth reflective substrate, an optical spacer layer overlying the reflective substrate, and a light-absorbing layer overlying the optical spacer layer, information being recordable in the form of discrete features in the light-absorbing layer creatable by a focused, modulated laser beam, wherein the improvement comprises: adjacent to each of the light-absorbing and optical spacer layers is a triggering layer formed of an organic material which has a thickness less than that of the optical spacer layer and when heated to a temperature below the melting point of the optical spacer layer rapidly expands to implement or enhance the formation of a bubble or pit in the light-absorbing layer.
Claim 3
Dependent Claim
25 words
An optical DRAW medium as defined in claim 1 wherein the organic material has an activation temperature within the range of 200° to 500° C.
Claim 4
Dependent Claim
23 words
An optical DRAW medium as defined in claim 2 wherein the organic material is selected from hydrocarbon polymers, fluorocarbon polymers, and chlorocarbon polymers.
Claim 5
Dependent Claim
19 words
An optical DRAW medium as defined in claim 1 wherein the triggering layer is a polymeric silane or titanate.
Claim 6
Dependent Claim
16 words
An optical DRAW medium as defined in claim 1 wherein the triggering layer is a dye.
Claim 7
Dependent Claim
74 words
An optical DRAW medium as defined in claim 1 which is especially adapted to be recorded using a laser diode having a wavelength within the range of 700-900 nm, wherein the light-absorbing layer has a thickness within the range of 3 to 20 nm, the optical spacer layer has a thickness within the range of 50 to 225 nm, and the triggering layer has a thickness within the range of 5 to 50 nm.
Claim 8
Dependent Claim
25 words
An optical DRAW medium as defined in claim 6 wherein the thickness of the triggering layer is within the range of 10 to 30 nm.
Claim 9
Dependent Claim
24 words
An optical DRAW medium as defined in claim 1 which is reflective by virtue of a reflective layer immediately underlying the optical spacer layer.
Claim 10
Dependent Claim
112 words
Quadrilayer optical DRAW medium comprising an optically-smooth, reflective, disk-shaped substrate, an environmentally stable optical spacer layer overlying and in contact with the reflective layer substrate, a triggering layer overlying and in contact with the optical spacer layer, and a light-absorbing layer overlying and in contact with the triggering layer, which triggering layer is formed of an organic material and has a thickness less than that of the optical spacer layer and when heated to a temperature below the melting point of the optical spacer layer rapidly expands to implement or enhance the formation of a bubble or pit in the light-absorbing layer without disturbing the optical spacer layer and its protective function.
Claim 11
Dependent Claim
112 words
Quadrilayer optical DRAW medium comprising an optically-smooth, reflective, disk-shaped substrate, an environmentally stable optical spacer layer overlying and in contact with the reflective layer substrate, a triggering layer overlying and in contact with the optical spacer layer, and a light-absorbing layer overlying and in contact with the triggering layer, which triggering layer is formed of an organic material and has a thickness less than that of the optical spacer layer and when heated to a temperature below the melting point of the optical spacer layer rapidly expands to implement or enhance the formation of a bubble or pit in the light-absorbing layer without disturbing the optical spacer layer and its protective function.
Claim 12
Dependent Claim
19 words
Quadrilayer optical recording medium as defined in claim 9 having formed in the light-absorbing layer discrete features representing information.
Claim 13
Dependent Claim
15 words
Quadrilayer optical recording medium as defined in claim 10 wherein the discrete features are bubbles.
Claim 14
Dependent Claim
15 words
Quadrilayer optical recording medium as defined in claim 10 wherein the discrete features are pits.
Claim 15
Dependent Claim
31 words
Quadrilayer optical recording medium as defined in claim 9 wherein the triggering layer experiences rapidly increasing vapor pressure when heated to a temperature within the range of 200° to 500° C.
Claim 16
Dependent Claim
84 words
Method of making an optical DRAW medium comprising the steps of sequentially depositing onto an optically-smooth reflective substrate an optical spacer layer, a triggering layer, the thickness of which is less than that of the optical spacer layer, and a light-absorbing layer, the triggering layer being formed of an organic material which when heated to a temperature less than the melting point of the optical spacer layer rapidly expands to implement or enhance the formation of a bubble or pit in the light-absorbing layer.
Claim 17
Dependent Claim
84 words
Method of making an optical DRAW medium comprising the steps of sequentially depositing onto an optically-smooth reflective substrate an optical spacer layer, a triggering layer, the thickness of which is less than that of the optical spacer layer, and a light-absorbing layer, the triggering layer being formed of an organic material which when heated to a temperature less than the melting point of the optical spacer layer rapidly expands to implement or enhance the formation of a bubble or pit in the light-absorbing layer.
Claim 18
Dependent Claim
40 words
Method as defined in claim 14 wherein the substrate is disk-shaped and including the further step of focusing a modulated laser-diode beam on the light-absorbing layer while the substrate is rotated upon its axis, thus creating discrete features representing information.
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) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |