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Patent US845851A successfully refreshed from Google Patents.
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EP0304299A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

An optical disc drive

Assignee: Sony Corp
•
Filing: 1988-08-18
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Granted: —
•
Expires: 2008-08-18
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Abstract

Abstract An optical disc drive that employs a velocity feedback loop for detecting the moving velocity (SV20) of an optical pickup, thereby to enable the optical pickup to seek a target recording track of an optical disc. The number of tracks (DT) to the target recording track is calculated on the basis of a signal derived from the optical pickup and a target velocity signal is supplied to the velocity feedback loop in accordance with the calculated result, whereby the moving velocity of the optical pickup can be controlled to become [0] at a timing (time point) at which the optical pickup reaches the target recording track.

Inventors

  • 👤 Shigeaki Wachi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-05 08:03
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/085; G11B7/08505; G11B7/08511; G11B7/08529

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 86 words
An optical disc drive having a seek control circuit for driving an optical pickup to reach a target recording track, comprising: a) velocity feedback means for controlling a moving velocity of said optical pickup by detecting a velocity thereof; and b) seek control means for calculating the number of remaining tracks to said target recording track on the basis of a signal derived from said optical pickup and for supplying a target velocity signal to said velocity feedback means on the basis of the calculated result.
Claim 2
Dependent Claim 86 words
An optical disc drive having a seek control circuit for driving an optical pickup to reach a target recording track, comprising: a) velocity feedback means for controlling a moving velocity of said optical pickup by detecting a velocity thereof; and b) seek control means for calculating the number of remaining tracks to said target recording track on the basis of a signal derived from said optical pickup and for supplying a target velocity signal to said velocity feedback means on the basis of the calculated result.
Claim 3
Dependent Claim 29 words
An optical disc drive as claimed in claim 1, in which said seek control means includes a down counter and a digital-to-analog converter which generate said target velocity signal.
Claim 4
Dependent Claim 29 words
An optical disc drive as claimed in claim 1, in which said seek control means includes an up/down counter and a digital-to-analog converter which produce said target velocity signal.
Claim 5
Dependent Claim 18 words
An optical disc drive according to claim 3 further comprising correcting menas for correcting said target velocity signal.
Claim 6
Dependent Claim 33 words
An optical disc drive as claimed in claim 4, in which said seek control means includes emphasis means for emhasizing said target velocity signal when said up/down counter is in its up-count state.
Claim 7
Dependent Claim 29 words
An optical disc drive according to claim 1 further comprising bang-bang control means for bang-bang controlling said velocity feedback means when there remain a few tracks to be seeked.

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