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:
Dec. 14, 1993
Filed:
Mar. 19, 1992
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
An apparatus for controlling rotation of a spindle motor includes a lock detection unit, a memory unit, a comparison unit, and a control unit. When the lock detection unit detects the lock state of the time base servo loop, a voltage corresponding to the frequency of a read RF signal is stored in the memory unit. When the control unit detects that the rotation velocity of the spindle motor greatly deviates from a normal rotation velocity, it effects a control so as to accelerate or decelerate the spindle motor in dependency upon a compared result of the comparison unit which makes a comparison between a voltage corresponding to the frequency of the read RF signal and a voltage stored in the memory unit.