Heat-assisted magnetic recording device capable of detecting head malfunction based on different currents of sensors
US9653121B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2016 |
| Grant date | May 16, 2017 |
| Priority date | — |
| Expiry date | Mar 18, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method comprises storing a first laser current value in response to a photodetector sensing that a threshold current for a laser diode of a HAMR head has been reached, the photodetector situated proximate the laser diode. The method also comprises storing a second laser current value in response to a sensor sensing that the threshold current for the laser diode has been reached, the sensor situated away from the laser diode. The method further comprises determining a difference (delta) between the first and second laser current values, repeating the storing and determining processes during subsequent use of the laser diode, and detecting a change in the delta indicative of a malfunction of the head.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.