EP0521619A2
Expired / Lapsed
EP
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Multiple data surface optical data storage system and method
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 An optical data storage system is descried which comprises a multiple data surface medium (12) and optical head (22). The medium comprises a plurality of substrates 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. The system includes a filter which rejects unwanted reflected light, and allows transmission of light reflected from the desired data surface.
Inventors
- 👤 Hal Jervis Rosen
- 👤 Kurt Allan Rubin
- 👤 Timothy Carl Strand
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:34
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10502; G11B11/10515; G11B11/10532; G11B11/10541; G11B11/10543; G11B11/10545; G11B7/00; G11B7/08; G11B7/085; G11B7/08505; G11B7/08511; G11B7/09; G11B7/0943; G11B7/12; G11B7/125; G11B7/126; G11B7/135; G11B7/1353; G11B7/1356; G11B7/1365; G11B7/1369; G11B7/1381; G11B7/1392; G11B7/13925; G11B2007/0003; G11B2007/0009; G11B2007/0013; G11B7/1372; G11B2007/13727; G11B7/24; G11B7/2403; G11B7/24035; G11B7/24038
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
93 words
An optical data storage system comprising: a light source (200); an optical medium (12) having a plurality of data surfaces (90,92,94,96); an optical transmission means (203,204,205,208,210,212) for selectively directing a light beam from the source to one of the data surfaces of the medium; and an optical reception means (212,210,208,205,222,224) for receiving a reflected light beam from the optical medium and providing a data signal responsive thereto, the optical reception means having a filter (222) for passing light reflected from a selected data surface and rejecting other light reflected from the optical medium.
Claim 2
Dependent Claim
37 words
A system as claimed in claim 1, the optical reception means having a collimation means for collimating the light reflected from said selected data surface and the filter passing said collimated reflected light and rejecting uncollimated light.
Claim 3
Dependent Claim
59 words
A system as claimed in claim 2, wherein the filter comprises a focus lens (752) for focusing said collimated ted light to a focal spot, radiation blocking member means (754,764) located in a plane of said focal spot defining an aperture (760) at said focal spot, and a collimating lens (756) for collimating the light passing through said aperture.
Claim 4
Dependent Claim
39 words
A system as claimed in claim 3, wherein the aperture is circular and has a diameter approximately equal to lambda /(2*(NA)) where lambda is the wavelength of the light and NA is the numerical aperture of the focus lens.
Claim 5
Dependent Claim
13 words
A system as claimed in claim 3, wherein the aperture comprises a slit.
Claim 6
Dependent Claim
36 words
A system as claimed in claim 5, wherein the slit has a width approximately equal to lambda /(2*(NA)), where lambda is the wavelength of the light and NA is the numerical aperture of the focus lens.
Claim 7
Dependent Claim
50 words
A system as claimed in claim 2, wherein the filter comprises afocus lens for focusing said collimated. light to a focal spot, first and second radiation blocking members located in a plane of said focal spot, the first and second blocking members located a distance apart to form an aperture.
Claim 8
Dependent Claim
96 words
A system as claimed in claim 2, wherein the filter comprises a focus lens (802) for focusing said collimated light to a focal spot, a first radiation blocking member (806) located in a plane of said focal spot and having an aperture (812) at said focal spot, a second radiation blocking member (804) located between the focus lens and the first blocking member, the second blocking member having a pair of parallel slits for allowing light to pass, and a collimating lens (808) for collimating the light passing through said aperture of the first blocking member.
Claim 9
Dependent Claim
27 words
A system as claimed in claim 8, wherein the slits are spared apart a distance greater than the diameter of the aperture of the first blocking member.
Claim 10
Dependent Claim
90 words
A system as claimed in claim 2, wherein the filter comprises a focus lens for focusing said collimated light to a focal spot, a first radiation blocking member located in a plane of said focal spot and having an aperture at said focal spot, a second radiation blocking member located between the focus lens and the first blocking member, the second blocking member having an annular shaped aperture for allowing light to pass, and a collimating lens for collimating the light passing through said aperture of the first blocking member.
Claim 11
Dependent Claim
27 words
A system as claimed in claim 10, wherein the diameter of the annular aperture is greater than the diameter of the aperture of the first blocking member.
Claim 12
Dependent Claim
35 words
A system as claimed in claim 2, wherein the filter comprises a beamsplitter (832) and a hologram (834) attached to the beamsplitter, the hologram transmitting uncollimated light and reflecting collimated light back into the beamsplitter.
Claim 13
Independent Claim
75 words
A method for operating an optical data storage system comprising the steps of: generating a beam of light; focusing the beam of light to a data surface of an optical medium having a plurality of data surfaces; receiving a reflected light beam from the optical medium and filtering out light other than that light reflected from the desired data surface; and generating a data signal responsive to the filtered reflected light from the optical medium.
References Cited (Backward Citations)
No citation records indexed.
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