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.
Patent No.:
Date of Patent:
Jan. 12, 1982
Filed:
Jan. 30, 1979
Applicant:
Inventor:
Tooru Fujishima, Yokohama, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04N / ; G11B / ;
U.S. Cl.
CPC ...
369 45 ; 369 44 ; 360 77 ; 250201 ; 250202 ;
Abstract
For focus and tracking controls for a pickup of an optical-type video disc player, wobbles are simultaneously applied to focus and tracking adjustment mechanisms. The wobble for focus and the wobble for tracking are effected by two signals 90.degree. phase-shifted from each other. The respective informations representative of focus and tracking errors are separately detected in a synchronous detection manner using the same two signals to provide focus and tracking control signals.