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:
Jul. 12, 1988
Filed:
Sep. 02, 1986
Tooru Yamagishi, Tokyo, JP;
Victor Company of Japan, , JP;
Abstract
A rotation control apparatus controls a rotation frequency of a disc which is to be rotated at a constant linear velocity. The rotation control apparatus comprises a circuit for obtaining a first signal having a first frequency proportional to a rotation frequency of the disc, a circuit for comparing the first signal with a second signal having a second frequency which successively increases, and a control device for obtaining a present rotation frequency of the disc from the second signal which is obtained at a time when the first and second frequencies become equal to each other. The control device supplies to a motor which rotates the disc a driving signal which is obtained from the present rotation frequency in a recording mode, so that the disc rotates at the constant linear velocity.