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:
Sep. 03, 1985

Filed:

Feb. 22, 1983
Applicant:
Inventors:

Yoshimi Iso, Yokohama, JP;

Shigeki Inoue, Toyokawa, JP;

Tsutomu Noda, Yokohama, JP;

Shinichi Ohashi, Chigasaki, JP;

Assignee:

Hitachi, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 44 ; 369 46 ; 369 33 ; 369 32 ;
Abstract

An information reproducing apparatus having a tracking servo control loop for causing an information reading unit including device for detecting a tracking error signal for tracking an information bearing track on a disc, to track the information bearing track in accordance with the tracking error signal so as to reproduce information in accordance with an information signal read by the information reading unit. A circuit for extracting a discrimination signal for discriminating a negative feedback region of the tracking error signal is provided so that a tracking servo control loop is closed in the negative feedback region.


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