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:
Nov. 20, 2007
Filed:
Aug. 19, 2004
Lawrence M. Bryant, Palo Alto, CA (US);
Sundeep Chauhan, Edina, MN (US);
David Shiao-min Kuo, Palo Alto, CA (US);
Lawrence M. Bryant, Palo Alto, CA (US);
Sundeep Chauhan, Edina, MN (US);
David Shiao-Min Kuo, Palo Alto, CA (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
A rotating recording device, such as an electron beam recorder, is provided with a dual encoder arrangement. A first encoder is employed as a spindle motor controller and located at a first end of a spindle. A second encoder is mounted at a turntable adjacent to a recording surface and used as a position, velocity or clock source for recording the pattern on the substrate. Eccentricity of the mounting of the second encoder is measured against the more accurately mounted spindle control encoder and compensated by a digital clock generating system using a digital phase locked loop.