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. 20, 1976
Filed:
Aug. 01, 1973
Mitsuo Fujita, Tokyo, JA;
Naoaki Sakaki, Murayama, JA;
Victor Company of Japan, Limited, Yokohama, JA;
Abstract
The invention provides an apparatus for controlling the rotation of a rotating body in a recording and/or reproducing apparatus. First, the apparatus detects the rotational speed of the rotating body, as it is driven by a DC motor. Detection is in terms of a frequency which is n times the speed, in which n>> 1. Second, there is a detection of the rotational phase of the rotating body. The DC motor is driven to rotate in accordance with a controlling signal obtained by using first and second output error signals responsive to the first and second detections. The DC motor is driven by means for superimposing an AC signal generated with a constant period and the first and second output error signals. The superimposed signals are sliced at a predetermined level to perform 'ON' - 'OFF' operations and a smooth output to control the driving rotation of the DC motor.