Patent EP0463728A2 successfully refreshed from Google Patents.
EP0463728A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Increasing storage density of information storage media
Assignee: Quantum Corp
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Filing: 1991-05-16
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Granted: —
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Expires: 2011-05-16
Abstract
Abstract A light detection apparatus includes at least one re-imaging lens that re-images a light beam reflected from an optical storage medium, to form an image of a light spot formed by the light beam on the storage medium. At least one detector detects a selected portion of the image. The selected portion of the image contains only such information as is encoded on a region of the optical data storage medium that is illuminated by a corresponding portion of the light spot.
Inventors
- 👤 Neville K.S. Lee
- 👤 T. Lam Quocdung
- 👤 Peter Van Roekens
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:59
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/13; G11B7/131; G11B11/00; G11B11/10; G11B11/105; G11B11/10532; G11B11/10541; G11B11/10543; G11B7/135; G11B7/1372; G11B7/1381; G11B7/14
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
90 words
A light detection apparatus for an optical data storage system, comprising at least one re-imaging lens for re-imaging a light beam reflected from an optical storage medium to form an image of a light spot formed by said light beam on said storage medium, and at least one detector for detecting a selected portion of said image, said selected portion of said image containing only such information as is encoded on a region of said optical data storage medium that is illuminated by a corresponding portion of said light spot.
Claim 2
Dependent Claim
49 words
A light detection apparatus in accordance with claim 1 wherein said light detection apparatus further comprises a blocking device for allowing a selected portion of said light beam comprising said selected portion of said image to pass toward said detector, while blocking an unselected portion of said light beam.
Claim 3
Dependent Claim
140 words
A light detection apparatus in accordance with claim 2 wherein said blocking device comprises a plate comprising a pinhole aperture, said plate being located in the vicinity of the image plane of said re-imaging lens, said re-imaging lens re-images onto said plate said light beam reflected from said storage medium, in a manner such that said light beam forms on said plate said image of said light spot formed by said light beam on said storage medium, said image on said plate is centered on said aperture, a central portion of said light beam comprising a central portion of said image passes through said aperture, and a peripheral portion of said light beam comprising a peripheral portion of said image is blocked by said plate, and said detector detects said portion of said light beam that passes through said aperture.
Claim 4
Dependent Claim
50 words
A light detection apparatus in accordance with claim 3, wherein said light detection further comprises a collimating lens for collimating said portion of said light beam that passes through said aperture, and said detector detects said portion of said light beam that passes through said aperture and said collimating lens.
Claim 5
Dependent Claim
17 words
A light detection apparatus in accordance with claim 3 wherein said storage medium is a magneto-optical disk.
Claim 6
Dependent Claim
92 words
A light detection apparatus in accordance with claim 5 wherein said magneto-optical disk contains domains that rotate an angle of polarization of said light beam as said light beam reflects off of said magneto-optical disk, said light detection apparatus further comprises a polarization splitter for splitting said portion of said light beam that passes through said aperture into two parts each having an intensity proportional to a respective component of polarization of said reflected light beam, and there are two said detectors for respectively detecting said two parts of said light beam.
Claim 7
Dependent Claim
67 words
A light detection apparatus in accordance with claim 3 wherein said re-imaging lens has a focal length that is greater than a focal length of an objective lens that focuses said light beam on said storage medium and that collimates said light beam after reflection from said storage medium, and said image on said plate is a magnified image of said light spot on said storage medium.
Claim 8
Dependent Claim
104 words
A light detection apparatus in accordance with claim 3 wherein said central portion of said image corresponds to a central portion of said light spot on said storage medium, said central portion of said light spot covering a location on said storage medium at which a domain of information is stored, and said peripheral portion of said image corresponds to a peripheral portion of said light spot on said storage medium, said peripheral portion of said light spot covering locations on said storage medium at which domains of information other than said domain covered by said central portion of said light spot are stored.
Claim 9
Dependent Claim
93 words
A light detection apparatus in accordance with claim 1 wherein said at least one detector comprises at least one light-sensitive detection element, said combination detector is located in the vicinity of the image plane of said re-imaging lens, and said at least one re-imaging lens re-images said light beam reflected from said storage medium, in a manner such that said light beam forms on said detector said image of said light spot formed by said light beam on said storage medium, and said selected portion of said image covers said light-sensitive detection element.
Claim 10
Dependent Claim
72 words
A light detection apparatus in accordance with claim 9 wherein said at least one detector is a combination detector comprising an array of said light-sensitive detection elements, said image on said combination detector comprises a plurality of image portions covering a plurality of respective said light-sensitive detection elements, and each said image portion is an image of a portion of said light spot formed by said light beam on said storage medium.
Claim 11
Dependent Claim
17 words
A light detection apparatus in accordance with claim 10 wherein said storage medium is a magneto-optical disk.
Claim 12
Dependent Claim
90 words
A light detection apparatus in accordance with claim 11 wherein said magneto-optical disk contains domains that rotate an angle of polarization of said light beam as said light beam reflects off of said magneto-optical disk, said light detection apparatus further comprises a polarization splitter for splitting said light beam reflected from said magneto-optical disk into two parts each having an intensity proportional to a respective component of polarization of said reflected light beam, and there are two said combination detectors for respectively detecting said two parts of said light beam.
Claim 13
Dependent Claim
31 words
A light detection apparatus in accordance with claim 12 wherein there are two said re-imaging lenses that respectively re-image said two parts of said light beam onto said two combination detectors.
Claim 14
Dependent Claim
26 words
A light detection apparatus in accordance with claim 12 wherein there is one said re-imaging lens that re-images said reflected light beam onto said polarization splitter.
Claim 15
Dependent Claim
89 words
A light detection apparatus in accordance with claim 9, wherein said light detection apparatus further comprises a processor for processing outputs of said light-sensitive detection elements, said processor produces a plurality of differential signals, each said differential signal corresponding to an output of a said light-sensitive detection element in a first said detector minus an output of a said corresponding light-sensitive detection element in a second said detector, and said processor analyzes said differential signals to detect domains of information smaller than said light spot on said storage medium.
Claim 16
Dependent Claim
30 words
A light detection apparatus in accordance with claim 15 wherein said processor is adapted to detect simultaneously domains of information contained in a plurality of tracks on said magneto-optical disk.
Claim 17
Dependent Claim
47 words
A light detection apparatus in accordance with claim 16, wherein said at least one detector is a combination detector comprising a plurality of rows of said light-sensitive detection elements arranged to detect simultaneously domains contained in a plurality of distinct and respective tracks on said magneto-optical disk.
Claim 18
Dependent Claim
169 words
A light detection apparatus in accordance with claim 17, wherein said optical storage medium comprises a plurality of servo pads, a pair of said servo pads being encoded in proximity to a center line of each of a plurality of tracks of data on said optical storage medium, said processor produces first and second signals corresponding to intensity of light reflected from first and second servo pads of a said pair of servo pads and detected by a detection element in a tracking row of said combination detector, compares said first signal with said second signal, and adjusts fine tracking of said light detection apparatus by an amount proportional to a difference between said first and second signals in a manner such that said tracking row of said light-sensitive detection elements is aligned with a said track, and said at least one detector is constructed in a manner such that each said row is aligned with a said track when said tracking row is aligned with a said track.
Claim 19
Dependent Claim
46 words
A light detection apparatus in accordance with claim 9 wherein said portion of said light spot on said storage medium, which corresponds to said image portion covering said light-sensitive detection element, covers a location on said storage medium at which a domain of information is stored.
Claim 20
Dependent Claim
70 words
A light detection apparatus in accordance with claim 9 wherein said at least one re-imaging lens has a focal length that is greater than a focal length of an objective lens that focuses said light beam on said storage medium and that collimates said light beam after reflection from said storage medium, and said image on said plate is a magnified image of said light spot on said storage medium.
Claim 21
Dependent Claim
68 words
A light detection apparatus in accordance with claim 1 wherein said optical storage medium comprises a magnetic layer for storing said information, and a refraction layer overlying said magnetic layer, said information encoded on said magnetic layer comprises domains smaller than a wavelength of said light beam, and said refraction layer has an index of refraction high enough to enable said light detection apparatus to resolve said domains.
Claim 22
Dependent Claim
123 words
An optical data storage media drive comprising a light source for producing a light beam, an objective lens for focusing said light beam on a storage medium, and for collimating said light beam after reflection from said storage medium, and a light detection apparatus comprising at least one re-imaging lens for re-imaging said light beam collimated by said objective lens to form an image of a light spot formed by said light beam on said storage medium, and at least one detector for detecting a selected portion of said image, said selected portion of said image containing only such information as is encoded on a region of said optical data storage medium that is illuminated by a corresponding portion of said light spot.
Claim 23
Dependent Claim
49 words
A storage media drive in accordance with claim 22 wherein said light detection apparatus further comprises a blocking device for allowing a selected portion of said light beam comprising said selected portion of said image to pass toward said detector, while blocking an unselected portion of said light beam.
Claim 24
Dependent Claim
144 words
A storage media drive in accordance with claim 23 wherein said blocking device comprises a plate comprising a pinhole aperture, said plate being located in the vicinity of the image plane of said re-imaging lens, said re-imaging lens re-images onto said plate said light beam collimated by said objective lens, in a manner such that said light beam forms an image on said plate that is an image of a light spot formed by said light beam on said storage medium, said image on said plate is centered on said aperture, a central portion of said light beam comprising a central portion of said image passes through said aperture, and a peripheral portion of said light beam comprising a peripheral portion of said image is blocked by said plate, and said detector detects said portion of said light beam that passes through said aperture.
Claim 25
Dependent Claim
50 words
A storage media drive in accordance with claim 24, wherein said light detection further comprises a collimating lens for collimating said portion of said light beam that passes through said aperture, and said detector detects said portion of said light beam that passes through said aperture and said collimating lens.
Claim 26
Dependent Claim
17 words
A storage media drive in accordance with claim 25 wherein said storage medium is a magneto-optical disk.
Claim 27
Dependent Claim
92 words
A storage media drive in accordance with claim 26 wherein said magneto-optical disk contains domains that rotate an angle of polarization of said light beam as said light beam reflects off of said magneto-optical disk, said light detection apparatus further comprises a polarization splitter for splitting said portion of said light beam that passes through said aperture into two parts each having an intensity proportional to a respective component of polarization of said reflected light beam, and there are two said detectors for respectively detecting said two parts of said light beam.
Claim 28
Dependent Claim
68 words
A storage media drive in accordance with claim 25 wherein said re-imaging lens has a focal length that is greater than a focal length of said objective lens that focuses said light beam on said storage medium and that collimates said light beam after reflection from said storage medium, and said image on said combination detector is a magnified image of said light spot on said storage medium.
Claim 29
Dependent Claim
104 words
A storage media drive in accordance with claim 25 wherein said central portion of said image corresponds to a central portion of said light spot on said storage medium, said central portion of said light spot covering a location on said storage medium at which a domain of information is stored, and said peripheral portion of said image corresponds to a peripheral portion of said light spot on said storage medium, said peripheral portion of said light spot covering locations on said storage medium at which domains of information other than said domain covered by said central portion of said light spot are stored.
Claim 30
Dependent Claim
77 words
A storage media drive in accordance with claim 22 wherein said at least one detector comprises at least one light-sensitive detection element, and said at least one re-imaging lens re-images said light beam collimated by said objective lens, in a manner such that said light beam forms on said detector said image of said light spot formed by said light beam on said storage medium, and said selected portion of said image covers said light-sensitive detection element.
Claim 31
Dependent Claim
88 words
A storage media drive in accordance with claim 30 wherein said at least one detector is a combination detector comprising an array of said light-sensitive detection elements, said combination detector is located in the vicinity of the image plane of said re-imaging lens, said image on said combination detector comprises a plurality of image portions covering a plurality of respective said light-sensitive detection elements, and each said image portion is an image of a portion of said light spot formed by said light beam on said storage medium.
Claim 32
Dependent Claim
17 words
A storage media drive in accordance with claim 31 wherein said storage medium is a magneto-optical disk.
Claim 33
Dependent Claim
90 words
A storage media drive in accordance with claim 32 wherein said magneto-optical disk contains domains that rotate an angle of polarization of said light beam as said light beam reflects off of said magneto-optical disk, said light detection apparatus further comprises a polarization splitter for splitting said light beam reflected from said magneto-optical disk into two parts each having an intensity proportional to a respective component of polarization of said reflected light beam, and there are two said combination detectors for respectively detecting said two parts of said light beam.
Claim 34
Dependent Claim
31 words
A storage media drive in accordance with claim 33 wherein there are two said re-imaging lenses that respectively re-image said two parts of said light beam onto said two combination detectors.
Claim 35
Dependent Claim
26 words
A storage media drive in accordance with claim 33 wherein there is one said re-imaging lens that re-images said reflected light beam onto said polarization splitter.
Claim 36
Dependent Claim
89 words
A storage media drive in accordance with claim 30, wherein said light detection apparatus further comprises a processor for processing outputs of said light-sensitive detection elements, said processor produces a plurality of differential signals, each said differential signal corresponding to an output of a said light-sensitive detection element in a first said detector minus an output of a said corresponding light-sensitive detection element in a second said detector, and said processor analyzes said differential signals to detect domains of information smaller than said light spot on said storage medium.
Claim 37
Dependent Claim
30 words
A storage media drive in accordance with claim 36 wherein said processor is adapted to detect simultaneously domains of information contained in a plurality of tracks on said magneto-optical disk.
Claim 38
Dependent Claim
47 words
A storage media drive in accordance with claim 37, wherein said at least one detector is a combination detector comprising a plurality of rows of said light-sensitive detection elements arranged to detect simultaneously domains contained in a plurality of distinct and respective tracks on said magneto-optical disk.
Claim 39
Dependent Claim
169 words
A storage media drive in accordance with claim 38, wherein said optical storage medium comprises a plurality of servo pads, a pair of said servo pads being encoded in proximity to a center line of each of a plurality of tracks of data on said optical storage medium, said processor produces first and second signals corresponding to intensity of light reflected from first and second servo pads of a said pair of servo pads and detected by a detection element in a tracking row of said combination detector, compares said first signal with said second signal, and adjusts fine tracking of said light detection apparatus by an amount proportional to a difference between said first and second signals in a manner such that said tracking row of said light-sensitive detection elements is aligned with a said track and said at least one detector is constructed in a manner such that each said row is aligned with a said track when said tracking row is aligned with a said track.
Claim 40
Dependent Claim
46 words
A storage media drive in accordance with claim 30 wherein said portion of said light spot on said storage medium, which corresponds to said image portion covering said light-sensitive detection element, covers a location on said storage medium at which a domain of information is stored.
Claim 41
Dependent Claim
71 words
A storage media drive in accordance with claim 30 wherein said at least one re-imaging lens has a focal length that is greater than a focal length of said objective lens that focuses said light beam on said storage medium and that collimates said light beam after reflection from said storage medium, and said image on said combination detector is a magnified image of said light spot on said storage medium.
Claim 42
Dependent Claim
78 words
A storage media drive in accordance with claim 22 wherein said storage media drive further comprises said optical storage medium, said optical storage medium comprises a magnetic layer for storing said information, and a refraction layer overlying said magnetic layer, said information encoded on said magnetic layer comprises domains smaller than a wavelength of said light beam, and said refraction layer has an index of refraction high enough to enable said light detection apparatus to resolve said domains.
Claim 43
Independent Claim
89 words
A method of detecting a light beam reflected from storage media in an optical data storage system, comprising the steps of re-imaging a light beam reflected from an optical storage medium to form an image of a light spot formed by said light beam on said storage medium, and detecting a selected portion of said image, said selected portion of said image containing only such information as is encoded on a region of said optical data storage medium that is illuminated by a corresponding portion of said light spot.
Claim 44
Dependent Claim
41 words
A method in accordance with claim 43 further comprising the step of allowing a selected portion of said light beam comprising said selected portion of said image to pass toward said detector, while blocking an unselected portion of said light beam.
Claim 45
Dependent Claim
131 words
A method in accordance with claim 44 wherein said step of re-imaging said light beam reflected from said storage medium comprises re-imaging said light beam onto a plate comprising a pinhole aperture, in a manner such that said light beam forms on said plate said image of said light spot formed by said light beam on said storage medium, said image on said plate is centered on said aperture, a central portion of said light beam comprising a central portion of said image passes through said aperture, and a peripheral portion of said light beam comprising a peripheral portion of said image is blocked by said plate, and said step of detecting said selected portion of said image comprises detecting said portion of said light beam that passes through said aperture.
Claim 46
Dependent Claim
47 words
A method in accordance with claim 45 wherein said method further comprises the step of collimating said portion of said light beam that passes through said aperture, and said step of detecting said selected portion of said image comprises detecting said collimated portion of said light beam.
Claim 47
Dependent Claim
15 words
A method in accordance with claim 46 wherein said storage medium is a magneto-optical disk.
Claim 48
Dependent Claim
97 words
A method in accordance with claim 47 wherein said magneto-optical disk contains domains that rotate an angle of polarization of said light beam as said light beam reflects off of said magneto-optical disk, said method further comprises the step of splitting said portion of said light beam that passes through said aperture into two parts each having an intensity proportional to a respective component of polarization of said reflected light beam, and said step of detecting said collimated portion of said light beam that passes through said aperture comprises detecting said two parts of said light beam.
Claim 49
Dependent Claim
25 words
A method in accordance with claim 46 wherein said image on said plate is a magnified image of said light spot on said storage medium.
Claim 50
Dependent Claim
102 words
A method in accordance with claim 46 wherein said central portion of said image corresponds to a central portion of said light spot on said storage medium, said central portion of said light spot covering a location on said storage medium at which a domain of information is stored, and said peripheral portion of said image corresponds to a peripheral portion of said light spot on said storage medium, said peripheral portion of said light spot covering locations on said storage medium at which domains of information other than said domain covered by said central portion of said light spot are stored.
Claim 51
Dependent Claim
100 words
A method in accordance with claim 43 wherein said step of re-imaging said light beam reflected from said storage medium comprises re-imaging said light beam onto a detector comprising at least one light-sensitive detection element, in a manner such that said light beam forms on said detector said image of said light spot formed by said light beam on said storage medium, and said selected portion of said image covers said light-sensitive detection element, and said step of detecting said selected portion of said image comprises detecting said selected portion of said image by means of said light-sensitive detection element.
Claim 52
Dependent Claim
70 words
A method in accordance with claim 51, wherein said at least one detector is a combination detector comprising an array of said light-sensitive detection elements, said image on said combination detector comprises a plurality of image portions covering a plurality of respective said light-sensitive detection elements, and each said image portion is an image of a portion of said light spot formed by said light beam on said storage medium.
Claim 53
Dependent Claim
15 words
A method in accordance with claim 52 wherein said storage medium is a magneto-optical disk.
Claim 54
Dependent Claim
99 words
A method in accordance with claim 53 wherein said magneto-optical disk contains domains that rotate an angle of polarization of said light beam as said light beam reflects off of said magneto-optical disk, said method further comprises splitting said light beam reflected from said magneto-optical disk into two parts each having an intensity proportional to a respective component of polarization of said reflected light beam, and said step of detecting said image portions comprises detecting said image portions of said two parts of said light beam by means of said light-sensitive detection elements of two respective said combination detectors.
Claim 55
Dependent Claim
36 words
A method accordance with claim 54 wherein said step of re-imaging said light beam onto said at least one combination detector comprises respectively re-imaging said two parts of said light beam onto said two combination detectors.
Claim 56
Dependent Claim
54 words
A method in accordance with claim 54 wherein said step of re-imaging said light beam onto said at least one combination detector comprises re-imaging said reflected light beam onto a polarization splitter that splits said light beam reflected from said magneto-optical disk into said two parts that are detected by said two combination detectors.
Claim 57
Dependent Claim
71 words
A method in accordance with claim 51, further comprising the steps of producing a plurality of differential signals, each said differential signal corresponding to an output of a said light-sensitive detection element in a first said detector minus an output of a corresponding said light-sensitive detection element in a second said detector, and analyzing said differential signals to detect domains of information smaller than said light spot on said storage medium.
Claim 58
Dependent Claim
34 words
A method in accordance with claim 57 wherein said step of analyzing said differential signals to detect domains comprises simultaneously detecting domains of information contained in a plurality of tracks on said magneto-optical disk.
Claim 59
Dependent Claim
45 words
A method in accordance with claim 58, wherein said at least one detector is a combination detector comprising a plurality of rows of said light-sensitive detection elements arranged to detect simultaneously domains contained in a plurality of distinct and respective tracks on said magneto-optical disk.
Claim 60
Dependent Claim
172 words
A method in accordance with claim 59, wherein said optical storage medium comprises a plurality of servo pads, a pair of said servo pads being encoded in proximity to a center line of each of a plurality of tracks of data on said optical storage medium, said method further comprises the steps of producing first and second signals corresponding to intensity of light reflected from first and second servo pads of a said pair of servo pads and detected by a detection element in a tracking row of said combination detector, comparing said first signal with said second signal, and adjusting fine tracking of said light detection apparatus by an amount proportional to a difference between said first and second signals in a manner such that said tracking row of said light-sensitive detection elements is aligned with a said track, and said at least one detector is constructed in a manner such that each said row is aligned with a said track when said tracking row is aligned with a said track.
Claim 61
Dependent Claim
44 words
A method in accordance with claim 51 wherein said portion of said light spot on said storage medium, which corresponds to said image portion covering said light-sensitive detection element, covers a location on said storage medium at which a domain of information is stored.
Claim 62
Dependent Claim
26 words
A method in accordance with claim 51 wherein said image on said combination detector is a magnified image of said light spot on said storage medium.
Claim 63
Dependent Claim
74 words
A method in accordance with claim 43 wherein said optical storage medium comprises a magnetic layer for storing said information, and a refraction layer overlying said magnetic layer, said information encoded on said magnetic layer comprises domains smaller than a wavelength of said light beam, and said refraction layer has an index of refraction high enough to enable said domains to be resolved during said step of detecting said selected portion of said image.
References Cited (Backward Citations)
No citation records indexed.
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