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:
Jul. 29, 2008
Filed:
Dec. 15, 2006
Kenneth James Dougherty, San Jose, CA (US);
Gary Allan Herbst, San Jose, CA (US);
Jong Ming Lin, Cupertino, CA (US);
Kenneth James Dougherty, San Jose, CA (US);
Gary Allan Herbst, San Jose, CA (US);
Jong Ming Lin, Cupertino, CA (US);
Hitachi Global Storage Technologies Netherlands, Amsterdam, NL;
Abstract
A self-servowriting (SSW) method that, with the actuator fully engaged against a compliant structure (e.g., a crashstop), first writes a tightly-spaced open-loop sequence of servo bursts in a segmented spiral path and then continues writing this tightly-spaced sequence under closed-loop servo control while reading back amplitude information from the servo bursts written earlier until the tightly-spaced burst pattern extends over several read-write head (RWH) offset intervals. With the actuator still engaged against the compliant structure, this tightly-spaced startup sequence is then read back by the closed servo control loop to write a number of concentric servo seed tracks, which are then self-propagated across the remainder of the disk surface to produce a final servopattern.