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. 18, 1977
Filed:
Dec. 06, 1973
Makoto Yamamoto, Hachioji, JA;
Hironobu Katayama, Sagamihara, JA;
Hitachi Electronics, Ltd., Tokyo, JA;
Nippon Hoso Kyokai, Tokyo, JA;
Abstract
A hybrid servo control system for controlling, for example a rotation of a capstan driving motor or a head motor of a video tape recorder comprises at least an integral control loop including an analog phase comparator for detecting in an analog mode a phase difference between a signal related to the rotation of the capstan driving motor or the head motor to be controlled and a reference signal so as to produce an analog amount corresponding to said phase difference, an analog-digital converter for converting said analog amount into a digital amount and a digital frequency modulator for frequency modulating in a digital mode clock pulses with said digital amount.