Position determination using circular shift codes
US7679850B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 2007 |
| Grant date | Mar 16, 2010 |
| Priority date | — |
| Expiry date | Jul 14, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59661
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A shift code that consists of N-symbol code words is provided as an L-symbol “master sequence” in which no sub-sequence of N symbols repeats, where L≦SN and S is the number of code symbols. A decoder determines a location in the code from N decoded symbols. The code locations may, for example, correspond to radial positions, or other position, times, and so forth. In one embodiment, the master sequence is continuously written to a data storage disk during a spiral write operation and a reader on a given circular track reads at least N symbols from the portion of the spiral that crosses the track and determines a code word. The radial position of the reader is then determined based on the location of the code word in the code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.