Apparatus and method for internal calibration of normalized playback transfer curve in a hard disk drive
US7420759B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 31, 2006 |
| Grant date | Sep 2, 2008 |
| Priority date | — |
| Expiry date | Apr 21, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2516
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Method calibrates an assembled hard disk drive for read head accessing rotating disk surface, by estimating non-linearity of that playback device based on two data patterns, which have a short transition-pair waveform and a long transition-pair waveform. By linearly constructing a simulated long transition-pair waveform from the short transition-pair waveform and aligning it with the long transition-pair waveform, non-linear distortion is estimated, creating the transfer curve as product of this process. The transfer curve is used to compensate the read data of a track to create the adjusted read data, which is used to decode the track being read. The adjusted read data is the product of this process. The hard disk drive including the transfer table. Second method using transfer table to create adjusted read data for track, the processor, embedded circuit and hard disk drive implementing this method. Manufacturing embedded circuit as product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.