Optical disk apparatus
US7948839B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2007 |
| Grant date | May 24, 2011 |
| Priority date | — |
| Expiry date | Nov 19, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00718
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk apparatus includes: an optical pickup unit for reading out information recorded on an optical disk; a demodulation circuit for demodulating digital data from an output signal of the optical pickup unit; and a controller for performing a servo control based on the output signal of the optical pickup unit. When performing a focus/tracking control in a recess and a protrusion of a guide groove of the optical disk, the controller obtains a focus control gain difference between the recess and the protrusion by comparing focus offsets with respect to variations in amplitudes of signals from the optical disk for the recess and the protrusion, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.