Timing recovery for optical disc drive high frequency modulation
US8000193B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 2009 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Feb 11, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2541
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for recovering clock timing from a hi-phase modulated portion of an HFM signal. The signal includes transitions between high and low levels. A clock count is initiated upon detection of a first transition, which corresponds to an expected clock timing of the signal. The count is stopped upon detection of a second transition. An actual clock count includes a number of clock cycles occurring between the transitions based on the expected timing. A first expected clock count between transitions is identified if the actual clock count between the transitions falls within a first range of clock counts. A first error between the actual and first expected clock counts is determined. A second expected clock count between transitions is identified if the actual clock count between transitions falls within a second range of clock counts. A second error between the actual expected clock counts is determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.