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:
Oct. 20, 1998
Filed:
Apr. 01, 1997
Mark J Schaenzer, Eagan, MN (US);
Zine-Eddine Boutaghou, Vadnais Heights, MN (US);
Subrahmanyan Nagarajan, Burnsville, MN (US);
Ramesh Sundram, Eden Prairie, MN (US);
Seagate Technology, Inc., Scotts Valley, CA (US);
Abstract
An asperity height sensing head and method of using the same are disclosed. The head includes multiple magnetoresistive (MR) sensors carried by a first rail of a slider adjacent to the air bearing surface (ABS) and positioned a distance L.sub.p from each other. Asperity height estimating circuitry coupled to each of the multiple MR sensors detects a number N of the MR sensors which exhibit a change in resistance as a result of contact between the ABS and a first asperity on the surface of the disc. The asperity height estimating circuitry estimates the height H.sub.A of the first asperity as a function of the number N, as a function of the pitch angle .theta..sub.p , and as a function of the distance L.sub.p.