Measurement of slider clearance by inducing collision of the slider with disk surface
US7119979B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2004 |
| Grant date | Oct 10, 2006 |
| Priority date | — |
| Expiry date | Jun 30, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for measuring the clearance of a slider over a rotating disk by inducing a collision between the slider and the disk is described. After the normal flying height of the slider is established, the slider is driven into a collision with the rotating disk surface by applying a DC or AC voltage between the slider and the disk. The clearance data can be extracted from the induced collision by measuring a parameter, such as the change in the amplitude of the readback signal from the magnetic sensor, which is related to fly-height at the normal fly-height and at the disk surface. The two data points can then be used to derive the clearance. One embodiment uses a single beam interferometer to derive the vibrational displacement of the collision event.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.