EP0313394A2
Expired / Lapsed
EP
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Method and apparatus for recording and reproducing information
Assignee: Nippon Conlux Co Ltd
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Filing: 1988-10-21
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Granted: —
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Expires: 2008-10-21
Abstract
Abstract A method and an apparatus for recording and reproducing information comprising irradiating a light spot for recording and reproducing information and a plurality of light spots for tracking an information-recording region of an optical information-recording medium including tracks or guiding, projecting reflected beams from the optical information-recording medium due to said light spot for recording and reproducing information and plurality of light spots for tracking on a photosensor, and selecting two outputs from a plurality of electrical outputs for tracking from said photosensor to provide tracking-control signals.
Inventors
- 👤 Kenjiro Kachi
- 👤 Kazuo Noda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 17:36
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0938; G11B7/002; G11B7/0033; G11B7/12; G11B7/13; G11B7/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
85 words
A method for recording and reproducing information comprising: irradiating a light spot for recording and reproducing information and a plurality of light spots for tracking on an information-recording region of an optical information-recording medium including tracks for guiding; projecting reflected beams from the optical information-recording medium due to said light spot for recording and reproducing information and plurality of light spots for tracking on a photosensor; and selecting two outputs from a plurality of electrical outputs for tracking from said photosensor to provide tracking-control signals.
Claim 2
Independent Claim
85 words
A method for recording and reproducing information comprising: irradiating a light spot for recording and reproducing information and a plurality of light spots for tracking on an information-recording region of an optical information-recording medium including tracks for guiding; projecting reflected beams from the optical information-recording medium due to said light spot for recording and reproducing information and plurality of light spots for tracking on a photosensor; and selecting two outputs from a plurality of electrical outputs for tracking from said photosensor to provide tracking-control signals.
Claim 3
Dependent Claim
28 words
A method for recording and reproducing information according to claim 1 wherein the reflected beams are projected on a photosensor which is divided into a plurality of elements.
Claim 4
Dependent Claim
34 words
A method for recording and reproducing information according to claim 1 and claim 2 wherein the reflected beams are projected on the photosensor via a focusing lens, a semi-transparent film and a cylindrical lens.
Claim 5
Dependent Claim
27 words
A method for recording and reproducing information according to claim 1 wherein the electrical outputs for tracking from the photosensor unit are read out by switching connectors.
Claim 6
Independent Claim
116 words
An apparatus for recording and reproducing information comprising: a light source for projecting at least three light spots for information read-out and for tracking on an optical information-recording medium including tracks for guiding; a photosensor for detecting information; plural pairs of photosensors for following tracks which are located at predetermined positions relative to the photosensor for detecting information; switching connectors to which a pair of photosensors for following tracks are connected on one side and on another side relative to said photosensor for detecting information, respectively; and a circuit for obtaining a difference between two signals which are outputs from the switching connectors, to perform tracking control so that said difference between two signals becomes zero.
Claim 7
Independent Claim
116 words
An apparatus for recording and reproducing information comprising: a light source for projecting at least three light spots for information read-out and for tracking on an optical information-recording medium including tracks for guiding; a photosensor for detecting information; plural pairs of photosensors for following tracks which are located at predetermined positions relative to the photosensor for detecting information; switching connectors to which a pair of photosensors for following tracks are connected on one side and on another side relative to said photosensor for detecting information, respectively; and a circuit for obtaining a difference between two signals which are outputs from the switching connectors, to perform tracking control so that said difference between two signals becomes zero.
Claim 8
Dependent Claim
22 words
An apparatus for recording and reproducing information according to claim 5 wherein said photosensor for detecting information is divided into four elements.
Claim 9
Dependent Claim
20 words
An apparatus for recording and reproducing information according to claim 5 wherein said switching connectors are a pair of switches.
References Cited (Backward Citations)
No citation records indexed.
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