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:
Sep. 10, 2002
Filed:
Jul. 12, 1999
David C. Waugh, Oklahoma City, OK (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
Apparatus and method for reducing the generation of acoustic noise in a disc drive. A seek is carried out to move a head from an initial track to a destination track on a corresponding disc surface using a servo circuit which outputs a series of current command values indicative of successive magnitudes of current to be applied to an actuator motor. A velocity profile provides a sequence of demand velocities indicative of the desired velocity at each of a succession of time periods during the seek. Closed loop velocity control is achieved by comparing the actual velocity of the head to the corresponding demand velocity and adjusting the current in relation to the velocity error therebetween. During initial stages of the seek, however, open loop control is initially performed using a current profile table which shapes the initial stages of current to a desired waveform, irrespective of the velocity profile and the velocity error.