Determination of the quality of an erase process for perpendicular magnetic recording disks
US7969675B2 · kind B2 · utility
1Cited by
2References
12Claims
0Family size
Assignee
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Key dates
| Filing date | Nov 7, 2008 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Jun 2, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2516
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods and test systems are disclosed for determining the quality of an erase process for perpendicular magnetic recording (PMR) disks. After performing an erase process on a PMR disk and before the PMR disk is assembled into a hard disk drive, a first test pattern of magnetization pulses is written to a region of the PMR disk. A second test pattern is subsequently read from the region of the PMR disk. The second pattern of magnetization pulses is analyzed in relation to the first test pattern and measured to determine the quality of the erase process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.