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. 03, 1989
Filed:
Nov. 24, 1986
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
An actuator which carries a magnetic head of a disk memory seeks a track on the disk by being actuated by a pair of trapezoidal drive currents, which have no or less power spectrum at the frequency coinciding with the mechanical resonance frequency of the positioning mechanisms. A trapezoidal waveform whose ratio of an upper side to a bottom side is adjusted depending on seek stroke. The mechanical resonance frequency may be within the range of the power spectrum of the trapezoidal drive currents so long as it coincides with the characteristic frequency with a zero power spectrum. A constant velocity region which has no current flowing into the actuator between the first positive trapezoidal current and the second negative trapezoidal current is provided when the seek stroke is long.