Patent EP0404942A1 successfully refreshed from Google Patents.
EP0404942A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical disk and movement control of its optical spot
Assignee: Sony Corp
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Filing: 1989-04-18
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Granted: —
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Expires: 2009-04-18
Abstract
Abstract The method of the present invention comprises detecting a recording pattern, which is different for each track, in each of track groups consisting of a predetermined number N of tracks recorded in advance on an optical disk (1), generating a tracking signal SET whose signal level changes on the positive and negative sides of a target track To as the center, and moving the optical spot to the target track To on the basis of this tracking signal SET. In this manner, it becomes possible to prevent uncontrollable movement of the optical spot and align the optical spot to a desired recording track within a short period of time.
Inventors
- 👤 Seiji Kobayashi
- 👤 Norio Nishida
- 👤 Naoya Eguchi
- 👤 Shunji Yoshimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:29
CPC Classifications
G; G11; G11B; G11B21/00; G11B21/02; G11B21/10; G11B7/00; G11B7/08; G11B7/085; G11B7/08505
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
(1) An optical disk apparatus comprising an optical disk on which recording patterns different for each track in each group of tracks consisting of a predetermined number N of tracks are recorded in advance, record track detection means for detecting said recording patterns for detecting the record tracks traversed by the light spot, tracking signal generating means for generating tracking signals changed in signal level on positive and negative sides of a target track as center, on the basis of the results of detection by said record track detection means, and light spot scanning means for moving the light spot as far as the target track on the basis of said tracking signals.
Claim 2
Dependent Claim
85 words
(2) The optical disk apparatus according to claim 1 characterized in that it comprises discriminating means for discriminating that the difference in the number of tracks between the record track scanned by the light spot and the target track has become equal to one half the prescribed number of tracks N constituting the group of tracks, and in that said light spot scanning means is actuated in dependence upon the results of discrimination by said discriminating means and on the basis of said tracking signals.
Claim 3
Dependent Claim
42 words
(3) The optical disk apparatus according to claim 1 characterized in that said record track detection means performs a control such that a tracking error signal is supplied to said light spot scanning means when the light spot reaches the target track.
Claim 4
Dependent Claim
22 words
(4) The optical disk apparatus according to claim 1 characterized in that said light spot scanning means comprises fine adjustment actuating means.
Claim 5
Dependent Claim
48 words
(5) The optical disk apparatus according to claim 4 characterized in that said light spot scanning means further comprises gross adjustment actuating means driven .as a function of the difference in the number of tracks between the record track scanned by the light spot and the target track.
Claim 6
Dependent Claim
91 words
(6) A method for controlling the movement of a light spot in an optical disk apparatus comprising detecting record tracks traversed by the light spot by detecting the recording patterns previously formed on an optical disk, said recording tracks being different for each track in each group of tracks consisting of a predetermined number N of tracks, generating tracking signals changed in signal level on positive and negative sides about a target track as center, and moving said light spot to the target track on the basis of said tracking signals.
Claim 7
Dependent Claim
80 words
(7) The method for controlling the movement of a light spot in an optical disk apparatus according to claim 6 comprising discriminating that the difference in the number of tracks between the record track scanned by the light spot and the target track becomes equal to one half the predetermined number N constituting the group of tracks, and switching the amount of controlled movement of the light spot based on the tracking signals in dependence upon the results of discrimination.
References Cited (Backward Citations)
No citation records indexed.
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