Method and apparatus to control pole tip protrusion
US7027251B1 · kind B1 · utility
9Cited by
29References
55Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 6, 2003 |
| Grant date | Apr 11, 2006 |
| Priority date | — |
| Expiry date | Jan 6, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0018
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus to control the amount by which thermal expansion causes a write head to extend toward a disk is provided. In one aspect, a single write operation uses two or more different write currents. A first write current is initially used, and is large enough to achieve desired magnetic flux at the disk. After the write current heats and expands the arm tip, and extends it toward the disk surface, the write current is reduced, to avoid or postpone the time at which thermal expansion might cause the tip to contact the disk, or cause other undesirable effects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.