Method of focus error signal adjustment in optical disk device and optical disk drive
US7630279B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 2006 |
| Grant date | Dec 8, 2009 |
| Priority date | — |
| Expiry date | Dec 3, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0945
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for a focus error signal adjustment in an optical disk device which shapes a focus error signal and enables a high-accuracy focus servo is provided.In a DVD-RAM having an emboss data zone and a rewritable data zone, a focus error signal is generated with the DVD-RAM remaining still in a position where an emboss pit is not formed in the rewritable data zone, and a waveform of the FE signal is shaped so that the waveform is symmetrical with respect to a reference point. Then, the FE signal is generated in the emboss data zone and an amplitude of the FE signal is adjusted. The amplitude of the signal which is obtained by increasing the the amplitude of the FE signal whose amplitude is adjusted by approximately 6 dB is applied to the amplitude of the focus error signal in the rewritable data zone. Consequently, a high-accuracy focus servo based on the FE signal, whose amplitude is adjusted and waveform is shaped, can be achieved without an error caused by the emboss pit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.