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:
Aug. 05, 2003
Filed:
Jul. 22, 1998
John C. Tsai, Saratoga, CA (US);
Excel Precision, Inc., Santa Clara, CA (US);
Abstract
A servo track writing apparatus ( ) for writing servo tracks ( ) on a media disk ( ) of a disk drive assembly ( ) having a Positioning arm ( ) with a through hole ( ) therein. The writing apparatus ( ) has a laser source ( ) which directs a source beam ( ) through a polarizing beam splitter ( ) and a quarter-wave plate ( ) to either pass through the through hole ( ) and reflect off of the media disk ( ) as a reflected beam ( ), or to be reflected from regions of the positioning arm ( ) proximate to the through hole ( ) as a reflected beam ( ). The writing apparatus ( ) further has a remote tracking arm ( ) with two photodiodes ( ) suitably mounted thereon to receive the reflected beams ( ). The tracking arm (42) is caused by a motive means ( ) to precisely track the positioning arm ( ) of the disk drive assembly ( ). A laser interferometer ( ) is then used to detect an optical target (60) mounted on the tracking arm ( ) and determine positioning for writing of the servo track ( ).