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:
Feb. 09, 1988
Filed:
Aug. 29, 1986
Yasuichi Hashimoto, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A speed control apparatus includes a speed signal-holding circuit. Even if a discrete portion occurs in the position signal, i.e., if an abnormal signal component is included in the speed signal derived from position signal differentiation, the speed signal held by the holding circuit is output to prevent erroneous operation caused by the abnormal signal. In a magnetic disk apparatus incorporating the speed control apparatus, the magnetic head is driven before a seek instruction is completely input, and the position signal phases are switched at proper timings, thereby reliably performing both speed and positioning control operations of the magnetic head, at high speed.