Optical disk apparatus and information recording apparatus
US7145851B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2003 |
| Grant date | Dec 5, 2006 |
| Priority date | — |
| Expiry date | Aug 21, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2562
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In the CAV recording, it is necessary to vary the recording-system clock frequency in accordance with movement of a recording position, and conventionally a signal generated by multiplying a wobble signal is used as the recording-system clock. However, since the wobble signal is easily susceptible to influences of a disk and a pick-up and its quality is prone to be deteriorated by an influence of a large amount of light at the time of recording etc., it is difficult to maintain jitters of the recording-system clock to a sufficiently low value. To resolve this problem, instead of generating a recording-system clock signal from the wobble signal that is susceptible to noise, a necessary recording-system clock frequency is calculated from the address information that has been modulated into the wobble signal and recorded therein, and a signal of this frequency is generated from a stable reference signal source, such as a quartz oscillator, by a synthesizer method and used as the recording-system clock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.