Health monitoring for head of a heat-magnetic recording device using a writer-reader offset
US10043540B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 2017 |
| Grant date | Aug 7, 2018 |
| Priority date | — |
| Expiry date | Aug 2, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.