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:
May. 30, 1989
Filed:
Sep. 16, 1987
Stephen F Edel, San Jose, CA (US);
Michael L Workman, San Jose, CA (US);
Kenneth G Yamamoto, San Jose, CA (US);
Mantle M Yu, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A data recording disk file with a voice coil motor (VCM) actuator and a digital servo control system for positioning the read/write heads to selected concentric data tracks includes means for calculating the factor relating acceleration of the heads to VCM input current. This permits each disk file to compensate for any variation in the nominal VCM physical parameters, thus enabling VCMs to be manufactured to less demanding tolerances. The disk file also calculates a unique acceleration factor for each head position during movement of the heads from one track to another, thereby improving the arrival time of the heads to the target track. During an initialization procedure, the disk file performs a track seek, during which VCM current and head velocity information are acquired and used by the microprocessor in the digital servo control system to calculate a value representing an average actual acceleration factor unique to that disk file. This value, together with predetermined constants representing the characteristic relationship of acceleration factor to head position in a disk file with a nominal VCM, are used by the microprocessor to calculate the actual acceleration factor for each head position during a track seek.