Servo decoder for decoding an error correcting servo code recorded on a disc storage medium
US6005727A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Jan 28, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5547
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A servo decoder is disclosed for disc storage systems that operates according to a novel coding scheme capable of accurately decoding detected codewords representing servo track address during seek operations, even when the recording head flies between two adjacent tracks, and capable of correcting errors in the detected codedwords caused by noise in the read signal, such as inter-symbol interference. In a first embodiment, the coding scheme comprises an error correcting code (ECC) capable of correcting a predetermined number of bit errors in the detected codewords. To achieve the equivalent effect of a conventional Gray code, the codewords are arranged such that adjacent track addresses differ by a number of bits equal to the minimum distance of the ECC code. In a second embodiment, the servo code corrects certain minimum distance error events associated with a trellis type sequence detector. To achieve the equivalent effect of a conventional Gray code in this embodiment, the codewords are arranged such that adjacent track addresses differ by a number of bits relative to the minimum distance error events corrected. In this manner, when the recording head spans two adjacent tracks …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.