Optical disk apparatus capable of generating clock accurately
US6975569B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 2001 |
| Grant date | Dec 13, 2005 |
| Priority date | — |
| Expiry date | Oct 8, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10595
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital signal processor (1045) arithmetically determines a comparison level for comparing each signal component by determining a comparison level of comparators (1033 and 1034) for comparing a fine clock mark signal such that a larger weight is assigned to the comparison level of the signal component already compared. The comparators (1033 and 1034) compare the fine clock mark signal with reference to a level set on a peak side and a level set on a bottom side. When digital signal processor (1045) receives the comparison signal from one of the comparators (1033 and 1034) prior to the comparison signal sent from the other, the digital signal processor produces a fine clock mark detection signal FCMT based on the comparison signal sent from a comparator (1047). Thereby, the clock can be accurately produced based on the fine clock mark signal even when a signal component having a larger amplitude than that of the fine clock mark signal is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.