EP0092707A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical storage system employing a novel multi-layer optical medium
Assignee: Unisys Corp
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Filing: 1983-04-07
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Granted: —
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Expires: 2003-04-07
Abstract
Abstract An optical data storage system employing a data-modulated writing laser beam and a non-erasing reading laser beam of predetermined wavelength along with an improved optical medium comprised of multiple layers whose optical characteristics and thicknesses are chosen in conjunction with the writing and reading laser beams to provide an anti-reflection condition for unrecorded portions of the medium and a relatively high reflectivity for recorded portions of the optical medium. A preferred optical medium includes a highly reflective aluminum layer, a fluorinated hydrocarbon polymer spacer layer overlaying the reflective layer, and a gold absorber layer overlaying the spacer layer.
Inventors
- 👤 Edward V. Labudde
- 👤 Miguel A. Capote
- 👤 Shiuh Chao
- 👤 Neville K. Lee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 11:14
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/08; G11B7/2407; G11B7/24085; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24308; G11B2007/24316; G11B7/007; G11B7/00745; G11B7/252; G11B7/253; G11B7/2531; G11B7/257; G11B7/2572; G11B7/2575; G11B7/258; G11B7/2585
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
177 words
In an optical storage system, the combination comprising: an optical recording medium; means for providing a recording laser beam having a predetermined wavelength; means for modulating said recording beam in accordance with applied data; means for focusing the modulated beam upon said recording medium; and means providing for relative movement between the focused recording laser beam and said recording medium; said recording medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers being chosen in conjunction with the intensity and wavelength of said recording laser beam such that during relative movement between the focused laser beam and said medium optically detectable changes representative of said applied data are produced at predetermined regions of said medium, said fluorinated hydrocarbon polymer spacer layer further being chosen so as to reduce heat loss from the absorber layer during the production of an optically detectable change by the incident recording laser beam.
Claim 2
Dependent Claim
177 words
In an optical storage system, the combination comprising: an optical recording medium; means for providing a recording laser beam having a predetermined wavelength; means for modulating said recording beam in accordance with applied data; means for focusing the modulated beam upon said recording medium; and means providing for relative movement between the focused recording laser beam and said recording medium; said recording medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers being chosen in conjunction with the intensity and wavelength of said recording laser beam such that during relative movement between the focused laser beam and said medium optically detectable changes representative of said applied data are produced at predetermined regions of said medium, said fluorinated hydrocarbon polymer spacer layer further being chosen so as to reduce heat loss from the absorber layer during the production of an optically detectable change by the incident recording laser beam.
Claim 3
Dependent Claim
132 words
The invention in accordance with claim 1, including means for providing a reading laser beam having a predetermined wavelength and wherein said means for focusing and said means providing for relative movement are also employed for focusing said reading laser beam upon said medium and for providing relative movement therebetween, said optically detectable changes formed in said medium being chosen in conjunction with the intensity and wavelength of said reading laser beam such that during relative movement between the focused reading laser beam and said medium the reflected reading laser beam from said medium varies in accordance with the optically detectable changes traversed by said reading means, the intensity of said reading laser beam additionally being chosen so that it does not significantly affect the subsequent readability of said optically detectable changes.
Claim 4
Dependent Claim
176 words
In an optical storage system, the combination comprising: an optical medium having data recorded as a series of optically detectable changes in said medium; means for providing a reading laser beam having a predetermined wavelength; means for focusing said reading laser beam on said medium; and means providing for relative movement between the focused reading laser beam and said medium; said medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers and said optically detectable changes being chosen in conjunction with the intensity and wavelength of said reading laser beam such that during relative movement between the focused reading laser beam and said medium the reflected reading laser beam from said medium varies in accordance with the optically detectable changes traversed thereby, the intensity of said reading laser beam additionally being chosen so that it does not significantly affect the subsequent readability of said optically detectable changes.
Claim 5
Dependent Claim
176 words
In an optical storage system, the combination comprising: an optical medium having data recorded as a series of optically detectable changes in said medium; means for providing a reading laser beam having a predetermined wavelength; means for focusing said reading laser beam on said medium; and means providing for relative movement between the focused reading laser beam and said medium; said medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers and said optically detectable changes being chosen in conjunction with the intensity and wavelength of said reading laser beam such that during relative movement between the focused reading laser beam and said medium the reflected reading laser beam from said medium varies in accordance with the optically detectable changes traversed thereby, the intensity of said reading laser beam additionally being chosen so that it does not significantly affect the subsequent readability of said optically detectable changes.
Claim 6
Dependent Claim
141 words
An optical medium for use in an optical storage system capable of providing a data-modulated focused recording laser beam on said medium while providing relative movement therebetween, said medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers being chosen in conjunction with the intensity and wavelength of said recording laser beam such that during relative movement between said beam and said medium optically detectable changes can be produced at predetermined regions of said medium corresponding to said data, said fluorinated hydrocarbon polymer spacer layer being further chosen so as to reduce heat loss from the absorber layer during the production of an optically detectable change by the incident recording laser beam.
Claim 7
Dependent Claim
141 words
An optical medium for use in an optical storage system capable of providing a data-modulated focused recording laser beam on said medium while providing relative movement therebetween, said medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers being chosen in conjunction with the intensity and wavelength of said recording laser beam such that during relative movement between said beam and said medium optically detectable changes can be produced at predetermined regions of said medium corresponding to said data, said fluorinated hydrocarbon polymer spacer layer being further chosen so as to reduce heat loss from the absorber layer during the production of an optically detectable change by the incident recording laser beam.
Claim 8
Dependent Claim
144 words
An optical medium for use in an optical storage system capable of providing a focused reading laser beam on said medium while providing relative movement therebetween, said medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers and said optically detectable changes being chosen in conjunction with the intensity and wavelength of said reading laser beam such that during relative movement between the focused reading laser beam and said medium the reflected reading laser beam from said medium varies in accordance with the optically detectable changes traversed by said reading means, the intensity of said reading laser beam additionally being chosen so as to not significantly affect the subsequent readability of said optically detectable changes.
Claim 9
Dependent Claim
144 words
An optical medium for use in an optical storage system capable of providing a focused reading laser beam on said medium while providing relative movement therebetween, said medium comprising a plurality of layers including a reflective layer, a fluorinated hydrocarbon polymer spacer layer overlaying said reflective layer, and an absorber layer overlaying said fluorinated hydrocarbon polymer spacer layer, the thicknesses and optical characteristics of said layers and said optically detectable changes being chosen in conjunction with the intensity and wavelength of said reading laser beam such that during relative movement between the focused reading laser beam and said medium the reflected reading laser beam from said medium varies in accordance with the optically detectable changes traversed by said reading means, the intensity of said reading laser beam additionally being chosen so as to not significantly affect the subsequent readability of said optically detectable changes.
Claim 10
Independent Claim
169 words
A method of making an optical storage medium for use in an optical storage system providing a data-modulated laser beam of predetermined wavelength which is capable of being focused upon said medium while relative movement is provided therebetween, said method including the steps of: providing a reflective layer; depositing a fluorinated hydrocarbon polymer spacer layer over said reflective layer; and depositing an absorber layer over said spacer layer; the thicknesses and optical characteristics of said layers being chosen so that at the wavelength of said laser beam an anti-reflection condition is produced for unrecorded portions of said medium; the thicknesses and optical characteristics of said layers also being chosen so that an intensity-modulated laser beam is able to form optically detectable changes at selected regions of said absorber layer by heating each such region so as to disturb the anti-reflection condition thereat; said fluorinated hydrocarbon polymer spacer layer also being chosen so as to reduce heat loss from the absorber layer during the formation of an optically detectable change.
Claim 11
Independent Claim
169 words
A method of making an optical storage medium for use in an optical storage system providing a data-modulated laser beam of predetermined wavelength which is capable of being focused upon said medium while relative movement is provided therebetween, said method including the steps of: providing a reflective layer; depositing a fluorinated hydrocarbon polymer spacer layer over said reflective layer; and depositing an absorber layer over said spacer layer; the thicknesses and optical characteristics of said layers being chosen so that at the wavelength of said laser beam an anti-reflection condition is produced for unrecorded portions of said medium; the thicknesses and optical characteristics of said layers also being chosen so that an intensity-modulated laser beam is able to form optically detectable changes at selected regions of said absorber layer by heating each such region so as to disturb the anti-reflection condition thereat; said fluorinated hydrocarbon polymer spacer layer also being chosen so as to reduce heat loss from the absorber layer during the formation of an optically detectable change.
Claim 12
Dependent Claim
23 words
The invention in accordance with claim 6, wherein said fluorinated hydrocarbon polymer spacer layer is deposited by plasma polymerization of the monomer vapor.
Claim 13
Dependent Claim
24 words
The invention in accordance with claim 6, wherein said fluorinated hydrocarbon polymer spacer layer is deposited by evaporation from a melt in a vacuum.
Claim 14
Dependent Claim
22 words
The invention in accordance with claim 6, wherein said fluorinated hydrocarbon polymer spacer layer is deposited by glow discharge on the solid.
Claim 15
Dependent Claim
22 words
The invention in accordance with claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein said absorber layer is gold.
Claim 16
Dependent Claim
18 words
ll. The invention in accordance with claim 10, wherein the gold absorber layer is 150 Angstroms or less.
Claim 17
Dependent Claim
19 words
The invention in accordance with claim 10, wherein the gold absorber layer is in the range of 20-80 Angstroms.
Claim 18
Dependent Claim
24 words
The invention in accordance with claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein said fluorinated hydrocarbon polymer layer is polytetrafluoroethylene.
Claim 19
Dependent Claim
41 words
The invention in accordance with claim 1, 2, 3, 4 or 5, wherein the thicknesses and optical characteristics of said layers are chosen to substantially provide an anti-reflection condition for said laser beam when incident on unrecorded portions of said medium.
References Cited (Backward Citations)
No citation records indexed.
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