EP0139332A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for reproducing information from a disc-shaped optically readable record carrier
Assignee: Koninklijke Philips NV
•
Filing: 1984-10-10
•
Granted: —
•
Expires: 2004-10-10
Abstract
Abstract 57 A method is described of mitigating the adverse effects of a loss of track in a "compact-disc-digital-audio" player by constantly detecting the position just before losing track and, after tracking has been restored, to go to said position or, in particular, to a position which appears so much later as is necessary to reach this position.
Inventors
- 👤 Theodoor Antoon Jozef Schlösser
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 14:18
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/095; G11B27/00; G11B27/36; G11B19/00; G11B19/02; G11B19/04; G11B21/00; G11B21/02; G11B21/08; G11B21/081; G11B21/083; G11B21/085; G11B7/0946; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2537; G11B2220/2545
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
206 words
An apparatus for reproducing information contained in tracks on a disc-shaped optically readable record carrier which information includes a position code which is a continuous indication of the radial-position on said record carrier, which apparatus comprises : - an optical system for projecting a light beam on the record carrier, - a detector which is arranged in the light beam which has been modulated by the information structure on the record carrier, for supplying a signal which is modulated by the information recorded on the record carrier, - a radial-position control circuit for controlling the radial position of the spot formed on the record carrier by the light beam, - a position code detector for extracting said position code frcm the detected signal, - a track-loss detection circuit for generating a signal which is indicative of the condition that the spot formed by the light beam no longer follows the track, characterized by - a storage circuit for storing a position code read at an instant prior to the instant of losing track , - means for applying a start-position code which is dictated by said stored position code to the radial-position control circuit for restarting the reproduction at a position determined by said start-position code.
Claim 2
Independent Claim
206 words
An apparatus for reproducing information contained in tracks on a disc-shaped optically readable record carrier which information includes a position code which is a continuous indication of the radial-position on said record carrier, which apparatus comprises : - an optical system for projecting a light beam on the record carrier, - a detector which is arranged in the light beam which has been modulated by the information structure on the record carrier, for supplying a signal which is modulated by the information recorded on the record carrier, - a radial-position control circuit for controlling the radial position of the spot formed on the record carrier by the light beam, - a position code detector for extracting said position code frcm the detected signal, - a track-loss detection circuit for generating a signal which is indicative of the condition that the spot formed by the light beam no longer follows the track, characterized by - a storage circuit for storing a position code read at an instant prior to the instant of losing track , - means for applying a start-position code which is dictated by said stored position code to the radial-position control circuit for restarting the reproduction at a position determined by said start-position code.
Claim 3
Dependent Claim
32 words
An apparatus as claimed in Claim 1, characterized in that the means for applying the start-position code generate a start-position code which appears a specific tine interval after the stored position code.
Claim 4
Dependent Claim
48 words
An apparatus as claimed in Claim 2, characterized in that the means for applying the start-position code generate a start-position code which follows the stored position code after a time interval which corresponds to the time taken by the loss of track and the restoration of normal reproduction.
Claim 5
Dependent Claim
86 words
An apparatus as claimed in Claim 3, characterized in that there is provided a second storage circuit for storing a position cede read upon locking in to another position on the record carrier after a loss of track and the means for applying the start-position code conprise a circuit for determining the interval between the start-position code to be generated and the position code stored in the first storage circuit as a function of the difference between the position codes stored in the two storage circuits.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.