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:
Jan. 31, 1989

Filed:

Jun. 17, 1986
Applicant:
Inventors:

Kenichi Nagasawa, Kanagawa, JP;

Hiroyuki Takimoto, Kanagawa, JP;

Mitsuhiro Otokawa, Kanagawa, JP;

Hiroo Edakubo, Tokyo, JP;

Susumu Kozuki, Tokyo, JP;

Keiji Satoh, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 7715 ; 360107 ;
Abstract

There is disclosed an information signal reproducing apparatus for reproducing information signals from a magnetic record bearing medium on which information signals are recorded with pilot signals of four different frequencies recurrently superimposed thereon. The apparatus comprises magnetic heads which are arranged to reproduce said information signals and said pilot signals by tracing said magnetic record bearing medium and an erasing head which is arranged to trace said magnetic record bearing medium in equal tracing direction to that of said magnetic heads and which is able to erase at least the information signals recorded on said magnetic record bearing medium and to reproduce said pilot signals. At the time of controlling a tracing position of said magnetic heads relative to said magnetic record bearing medium, four local pilot signals having the same frequencies as those of said pilot signals, respectively, are recurrently generated in a predetermined rotation. The state of said pilot signals reproduced by said magnetic heads is monitored, using said four local pilot signals and the tracing position on said medium of said magnetic heads is controlled, depending upon the state of said pilot signals. The level of a specific pilot signal from among said pilot signals reproduced by said erasing head is detected and the generating sequence of the local pilot signals is changed over, depending upon a result of such detention. According to such construction it is possible to effect the tracking control with high precision and high response speed.


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