System, method, and apparatus for detecting signal-to-noise ratio decay in perpendicular magnetic recording
US7173415B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2005 |
| Grant date | Feb 6, 2007 |
| Priority date | — |
| Expiry date | Aug 4, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic test module runs on a spin stand to detect amplitude decay and noise evolution at the same time. Signal-to-noise ratio (SNR) decay is directly measured. The recording performance is correlated better with SNR instead of signal only. The thermal stability of the system is evaluated more accurately with this SNR decay method. A heater is placed under the media disk, and a remote sensing thermometer and temperature controller form a subsystem to set up desired environmental temperature. The heater creates a heated band and the read/write head flies above the heated band. The temperature control system may be removed when SNR decay measurement is performed under room temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.