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. 15, 2009
Filed:
Mar. 31, 2006
Michael Alex, Freemont, CA (US);
LI Tang, Freemont, CA (US);
Michael Alex, Freemont, CA (US);
Li Tang, Freemont, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
The present invention provides a method and apparatus for quantifying stress and damage in magnetic heads. A change in a performance parameter of a magnetic recording head is characterized. The head is stressed by loading it onto and flying it over a rough zone of the recording medium. A post-stress read-back signal is read from the bit pattern written on the recording medium using the head subsequent to the stressing of the head. A performance parameter of the head is calculated using the post-stress read-back signal. The performance parameter of the head calculated using the post-stress read-back signal is compared to a performance parameter of the head calculated using a pre-stress read-back signal to characterize a change in performance of the head resulting from the stressing of the head.