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:
Dec. 13, 2005
Filed:
Apr. 01, 2004
Craig N. Fukushima, Monte Sereno, CA (US);
Kevin I. Tzou, San Jose, CA (US);
Mantle Man-hon Yu, San Jose, CA (US);
Craig N. Fukushima, Monte Sereno, CA (US);
Kevin I. Tzou, San Jose, CA (US);
Mantle Man-Hon Yu, San Jose, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A disk drive manufacturing method calibrates the stitching gain of a position error signal (PES) by sampling servo information from a quadrature servo pattern while the head is maintained at the quarter-track positions and then calculating the kurtosis of the distribution of the PES values calculated from the samples. Because the kurtosis is a measure of the deviation from a normal or Gaussian distribution, the kurtosis of a PES distribution is used to optimize the stitching gain value through iteration until the kurtosis is close to zero, indicating that the PES with the optimal stitching gain values has a near-Gaussian distribution. The stitching gain calibration is performed for all heads and for multiple tracks across the surface of the disk for each head. The resulting values of stitching gain, each associated with a head and track, are stored in the disk drive memory and recalled during operation of the disk drive.