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:
Mar. 18, 2008
Filed:
Aug. 12, 2005
Jen-yuan Chang, San Jose, CA (US);
Christopher A. Gimenez, San Jose, CA (US);
Robert P. Harshberger, Jr., San Jose, CA (US);
Jr-yi Shen, Sunnyvale, CA (US);
Jen-Yuan Chang, San Jose, CA (US);
Christopher A. Gimenez, San Jose, CA (US);
Robert P. Harshberger, Jr., San Jose, CA (US);
Jr-Yi Shen, Sunnyvale, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A system for reducing written-in high-frequency repeatable run-out track mis-registration occurring during writing of servo information onto a hard disk implementable in a hard disk drive is described. The system includes an excitation frequency adjuster enabled to adjust excitation frequencies away from mechanical modes to provide desired rotation speed of a servo track writer. The mechanical modes are present in said hard disk drive. The system also includes an excitation level adjuster enabled to adjust excitation level to provide a desired DC gain level associated with a motor controller of the servo track writer. The system further includes an excitation frequency content adjuster enabled to adjust excitation frequency content to provide desired current profile of the motor controller, such that a reduction of written-in high frequency repeatable run-out track mis-registration is realized.