Calculating a heater power that compensates for laser induced writer protrusion for a heat-assisted magnetic recording device
US10607646B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 2019 |
| Grant date | Mar 31, 2020 |
| Priority date | — |
| Expiry date | May 28, 2039 |
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 (HAMR) slider relative to a magnetic recording medium. The slider comprises a writer, a writer heater, and a near-field transducer (NFT). For each of a plurality of different head-to media spacings a test tone is written to a track of the medium, the test tone is read and a Discrete Fourier Transform (DFT) of an amplitude of the read test tone is captured. A first DFT curve is generated at a beginning of writing the test tones. A second DFT curve is generated at a saturated state of writing the test tones. An amount of horizontal shift between the first and second DFT curves is computed. The amount of horizontal shift corresponding to writer heater power required to compensate for NFT clearance offset due to laser induced writer protrusion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.