Head-medium contact detection using an oscillating electromagnetic force
US9721603B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 2016 |
| Grant date | Aug 1, 2017 |
| Priority date | — |
| Expiry date | Aug 16, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/6076
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus comprises circuitry configured to apply an AC signal having a frequency to one of a slider of a recording head and a magnetic recording medium. The applied AC signal causes an oscillation in an electrostatic force and clearance between the slider and the medium at the frequency of the AC signal. A thermal sensor is configured to generate a sensor signal at the AC signal frequency in response to sensing changes in temperature resulting from the oscillating clearance. A detector is coupled to the circuitry and the thermal sensor. The detector is configured to detect one or both of head-medium spacing changes and head-medium contact using a phase of a first harmonic or an amplitude of a second harmonic of the thermal sensor signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.