Method for characterizing a read head based on write-induced magnetic read center shifts and read sensitivity changes in the read head
US5914594A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1997 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Mar 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0016
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for characterizing a head in a hard drive assembly based on a magnetic read center shift and a read sensitivity change of the head. A disk attached to a hard disk drive assembly having a plurality of tracks each having a track centerline is provided. One of the tracks has a plurality of sectors, one of the sectors having a servo field with an A burst, a B burst and a C burst, where the A burst and the C burst have a common boundary located at a track centerline and where B burst has a center that is positioned along the track centerline. Each sector also has a data field. The read element is aligned with the B servo burst and a write excitation field is applied to the write element. The amplitudes of an A burst and a C burst located in a following sector of the track are then read to provide an A burst amplitude value and a C burst amplitude value. The steps of writing and reading are repeated for a predetermined number of times to obtain a set of A burst amplitude values and a set of C burst amplitude values. A value representing an instability of the read element based on the set of A burst amplitude values and the set of C burst amplitude values is then calculated. The …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.