The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 31, 1988

Filed:

Mar. 12, 1985
Applicant:
Inventors:

Keiichi Matsumoto, Tokorozawa, JP;

Yoshio Aoyagi, Kawagoe, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 43 ; 360 77 ; 360 73 ;
Abstract

A system for playing back information recorded on a recording disc includes a first servo control system responsive to a tracking error signal, which adjusts the position of an information reading point of a pickup relative to the recording track on the recording disc, and a second servo control system responsive to a synchronizing signal contained in the playback information signal, which adjusts the speed of rotation of the recording disc. The system is further provided with first detection means responsive to the tracking error signal for detecting a condition where the information reading point has moved across a predetermined number of sections of recording track in a radial direction of the recording disc, and a second detection means responsive to the synchronization signal for detecting a condition where the synchronization signal is not read out up to a predetermined number regularly, and a control means for suspending the servo control operation of at least one of the first and second servo control systems in accordance with output signals of the first and second detection means.


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