Disk drive using multiple servo timing marks that form a code of unique interrelated bit patterns
US5903410A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1997 |
| Grant date | May 11, 1999 |
| Priority date | — |
| Expiry date | Mar 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/085
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A data recording disk drive has a plurality of servo sectors containing error-detectable and error-correctable servo timing marks (STMs). Each STM is represented as a pattern of n bits of digital information, with each track having a set of m unique STM patterns, and wherein each of the m unique STM patterns of n bits has a minimum sliding distance d to every other STM pattern in the set, where d is greater than one. The error-tolerant STMs are achieved by the use of a set or code of fixed STM bit patterns, where the STM patterns have a specified minimum Hamming distance against all the patterns in the search, called the sliding distance d. These STM patterns may include any bits associated with the servo sectors, such as bits indicating track index, servo sector number, and recording head number. The disk drive includes STM decoding circuitry that recognizes valid STMs when the sliding distance between the repeating preamble pattern and the STM patterns are within predetermined limits defined by the power of the code. The disk drive allows a tradeoff between error correction power and error detection power, within the limits defined by the code. The STM decoding circuitry is adapt…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.