Patent EP0517490A2 successfully refreshed from Google Patents.
EP0517490A2
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Multiple data surface optical medium and data storage system
Assignee: International Business Machines Corp
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Filing: 1992-06-02
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Granted: —
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Expires: 2012-06-02
Abstract
Abstract Described is an optical data storage system which comprises a multiple data surface medium (12) and optical head. The medium comprises a plurality of substrates (50, 56, 62, 68) separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. <IMAGE>
Inventors
- 👤 Margaret Evans Best
- 👤 Hal Jervis Rosen
- 👤 Kurt Allan Ruben
- 👤 Timothy Carl Strand
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:36
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1381; G11B7/007; G11B7/00745; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10576; G11B11/10578; G11B11/10582; G11B11/10584; G11B19/00; G11B19/02; G11B19/12; G11B7/004; G11B7/005; G11B7/0053; G11B7/0055; G11B7/00557; G11B7/013; G11B7/08; G11B7/085; G11B7/08505; G11B7/08511; G11B7/08517; G11B7/09; G11B7/0901; G11B7/0908; G11B7/0938; G11B7/1353; G11B7/1365; G11B7/1372; G11B7/1376; G11B7/1392; G11B7/13925; G11B7/14; G11B7/24; G11B7/2403; G11B7/24035; G11B7/24038; G11B7/241; G11B7/242; G11B7/243; G11B7/2433; G11B7/252; G11B7/253; G11B7/257; G11B7/2578; G11B11/10595; G11B2007/0003; G11B2007/0009; G11B2007/0013; G11B2007/24302; G11B2007/24312; G11B2007/24314; G11B2007/24316; G11B2007/25705; G11B2007/25706; G11B2007/2571; G11B2007/25713; G11B2007/25715; G11B2007/25716; G11B2007/25718; G11B7/002; G11B7/0037; G11B7/00718; G11B7/00736; G11B7/0945; G11B7/2531; G11B7/2533; G11B7/2534; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
124 words
An optical data storage medium comprising: a first radiation transmissive member (56) having a first data surface (90) for storing recorded data, the first data surface having a land portion (134) and nondata tracking marks (132) at an elevation different from the land portion; a second member, spaced from the first member, having a second data surface (92) for storing recorded data, the second data surface having a land portion (138) and nondata tracking marks (136) at an elevation different from the land portion; and a radiation transmissive medium (78;122) located between the first and second data surfaces through which a beam of radiation can pass from a first side of the medium to a focus on either the first or second data surface.
Claim 2
Dependent Claim
15 words
A medium as claimed in claim 1, wherein the radiation medium transmissive medium is air.
Claim 3
Dependent Claim
29 words
A medium as claimed in claim 1, wherein the radiation transmissive medium is a solid transparent material which supports the first and second data surfaces in spaced apart relationship.
Claim 4
Dependent Claim
27 words
A medium as claimed in any preceding claim 1, wherein the marks on the first and second data surfaces take the form of grooves or inverse grooves.
Claim 5
Independent Claim
24 words
A medium as claimed in any of claims 1 to 3 on the first and the second data surfaces are pits or inverse pits.
Claim 6
Independent Claim
37 words
A medium as claimed in any preceding claim, wherein the first data surface is either an uncoated ROM surface or has one of : a WORM material coating; a phase change material coating; a magneto-optic material coating.
Claim 7
Dependent Claim
35 words
A medium as claimed in claim 6 wherein the second data surface is either a ROM surface, or has one of : a WORM material coating; a phase change material coating; a magneto-optic material coating.
Claim 8
Independent Claim
63 words
A medium as claimed in any preceding claim, wherein the ratio of the perpendicular distance of the marks of the second data surface to the perpendicular distance of the marks of the first data surface is approximately equal to n1/n2, where n1 is the index of refraction of the first member and n2 equals the index of refraction of the radiation transmissive medium.
Claim 9
Independent Claim
32 words
A medium as claimed in any preceding claim, wherein the first data surfare has a dielectric coating having an index of refraction greater than the index of refraction of the first member.
Claim 10
Independent Claim
35 words
A medium as claimed in any of claims 1 to 8, wherein the first data surface has a dielectric coating having an index of refration less than the index of refraction of the first member.
Claim 11
Dependent Claim
99 words
An optical data storage medium comprising: a first substrate (50) having a first data surface (90) for storing recorded data, the first data surface having a land portion and having marks at elevations different from the land portions; a second substrate (56) having a second data surface (92) for storing recorded data, the second data surface having a land portion and having marks at elevations different from the land portions; and a spacer member (52, 54) attached between the first and second substrates for defining a space between the first and second data surfaces, the space containing a gas.
Claim 12
Independent Claim
24 words
A medium claim as claimed in 11, wherein the spacer member has a passage (82) connecting the space with the atmosphere outside the medium.
Claim 13
Dependent Claim
17 words
A medium as claimed in of claim 12 further including a filter (84) positioned across the passage.
Claim 14
Dependent Claim
63 words
An optical data storage system comprising: a radiation source; an optical medium as claimed in any preceding claim an optical transmission means for directing a radiation beam from the radiation source to one of the data surfaces of the optical medium; and an optical reception means for receiving a reflected radiation beam from the optical medium and providing a data signal responsive thereto.
Claim 15
Dependent Claim
75 words
An optical data storage medium comprising: a first radiation transmissive member having a first data surface, the first data surface consisting essentially of means in which data and tracking marks may be recorded; a second member having a second data surface spaced apart from the first surface, the second data surface having means in which data and tracking marks may be recorded; and a radiation transmissive medium located between the first and second data surfaces.
References Cited (Backward Citations)
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