HAMR writer pole length characterization
US9183859B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 11, 2014 |
| Grant date | Nov 10, 2015 |
| Priority date | — |
| Expiry date | Nov 11, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present disclosure generally relates to a HAMR head and techniques and apparatus for HAMR writer pole length characterization. One or more bits may be magnetically written on a disk using a leading edge of the writer pole at a first polarity. The disk may be moved under a body of the writer pole to magnetically write the one or more bits in the disk at a second polarity that is opposite to the first polarity to generate a feedback pulse having a signal amplitude. The signal amplitude of the feedback pulse may be measured as a function of writing frequency. A first effective length of the writer pole may be determined based on the measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.