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:
Jun. 29, 1993
Filed:
Jul. 10, 1991
Shigeaki Wachi, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A spindle servo system for a magneto-optical recording/playback apparatus, comprising a PLL circuit lockable in phase by sample servo pits formed on a track of a magneto-optical disc; a phase comparator for comparing the phase of a signal, whose period corresponds to the output of the PLL circuit, with the phase of a reference frequency signal; and a resonator having a reference frequency conforming to the eccentricity cycle of the disc. In this servo system, the rotation period of a spindle motor for driving the disc is controlled in accordance with the output of the phase comparator and the output of the resonator. The PLL circuit includes a voltage-controlled crystal oscillator, and the resonator is excited in conformity to the output of the phase comparator to control the rotation frequency of the spindle motor, thereby reducing the jitter component included in the output of the PLL circuit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile