EP0119740A2
Expired / Lapsed
EP
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Optical recording medium of high sensitivity
Assignee: 3M Co
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Filing: 1984-02-15
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Granted: —
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Expires: 2004-02-15
Abstract
Abstract An optical recording medium having a laserrecordable light-absorbing layer which is a carbide of iron or chromium. The medium exhibits surprisingly high sensitivity, and high carrier-to-, noise ratios using a laser-diode recording system at power levels below 10 mW.
Inventors
- 👤 Thomas A. Minnesota Mining And Rinehart
- 👤 Richard F. Minnesota Mining And Willson
- 👤 Vaughn W. Minnesota Mining And Halling
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 11:16
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/004; G11B7/0045; G11B7/00452; G11B7/00451; G11B7/24; G11B7/2403; G11B7/24067; G11B7/241; G11B7/242; G11B7/243; G11B7/26; G11B2007/24302; G11B2007/24306; G11B2007/24318; G11B2007/24328; G11B7/252; G11B7/253; G11B7/2531; G11B7/2533; G11B7/258; G11B7/2585; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
72 words
An optical recording medium (10, 20 or 30) comprising an optically-flat, disk-shaped, polymeric or glass substrate (12, 22 or 32) and a continuous, light-absorbing layer (18, 28 or 38) having a thickness of 1-60 nm and in which information is recordable in the form of discrete features creatable by a focused, modulated laser beam, characterized by: said light-absorbing layer comprising a carbide of a metal selected from iron, chromium, and alloys therebetween.
Claim 2
Dependent Claim
72 words
An optical recording medium (10, 20 or 30) comprising an optically-flat, disk-shaped, polymeric or glass substrate (12, 22 or 32) and a continuous, light-absorbing layer (18, 28 or 38) having a thickness of 1-60 nm and in which information is recordable in the form of discrete features creatable by a focused, modulated laser beam, characterized by: said light-absorbing layer comprising a carbide of a metal selected from iron, chromium, and alloys therebetween.
Claim 3
Dependent Claim
29 words
An optical recording medium as defined in Claim 1 further characterized by the inclusion of an optical spacer layer (16 or 26) beneath the light-absorbing layer (18 or 28).
Claim 4
Dependent Claim
25 words
An optical recording medium as defined in Claim 2 further characterized by the inclusion of a reflecting layer (14) beneath the optical spacer layer (16).
Claim 5
Dependent Claim
25 words
An optical recording-medium as defined in Claims 2 or 3 characterized by the thicknesses of said layers being selected to provide an interferometrically antireflective condition.
Claim 6
Dependent Claim
25 words
An optical recording medium as defined in any of claims 1-4 further characterized by the inclusion of an adhesion-promoting layer (11) adjacent to said substrate.
Claim 7
Dependent Claim
23 words
An optical recording medium as defined in any of claims 1-5 characterized by discrete features representing information being formed in the light-absorbing layer.
Claim 8
Dependent Claim
17 words
An optical recording medium as defined in claim 6 characterized by said discrete features being pits (40).
Claim 9
Dependent Claim
17 words
An optical recording medium as defined in claim 6 characterized by said discrete features being bubbles (42).
Claim 10
Independent Claim
49 words
The method of making an optical recording medium comprising the step of depositing onto an optically-flat, disk-shaped, polymeric or glass substrate a continuous, light-absorbing layer having a thickness of 1-60 nm, characterized by: said light-absorbing layer comprising a carbide of a metal selected from iron, chromium, and alloys therebetween.
Claim 11
Independent Claim
49 words
The method of making an optical recording medium comprising the step of depositing onto an optically-flat, disk-shaped, polymeric or glass substrate a continuous, light-absorbing layer having a thickness of 1-60 nm, characterized by: said light-absorbing layer comprising a carbide of a metal selected from iron, chromium, and alloys therebetween.
Claim 12
Dependent Claim
37 words
The method of making an optical recording medium as defined in claim 9 characterized by the step of applying an optical spacer layer to the substrate and by applying said light-absorbing layer onto the optical spacer layer.
Claim 13
Dependent Claim
33 words
The method of making an. optical recording medium as defined in claim 10 characterized by applying a reflecting layer to the substrate and by applying said optical spacer layer onto the reflecting layer.
Claim 14
Dependent Claim
27 words
The method of making an optical recording medium as defined in claim 11, characterized by applying an adhesion-promoting layer to the substrate before applying the reflecting layer.
Claim 15
Independent Claim
39 words
The method as defined in any of claims 9-12, further characterized by focusing a modulated laser-diode beam on the light-absorbing layer while the substrate is rotated upon its axis, thus creating in the light-absorbing layer discrete features representing information.
References Cited (Backward Citations)
No citation records indexed.
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