Information recording/reproducing apparatus
US6980496B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2002 |
| Grant date | Dec 27, 2005 |
| Priority date | — |
| Expiry date | Jul 7, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1353
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An information recording/reproducing apparatus includes an optical device, a photo-detector and a calculation unit. The optical device irradiates light beams, including one main beam and at least two sub-beams with respect to an information recording medium. The photo-detector receives return lights of the main beam and sub-beams to output light detection signals. The calculation unit produces a tracking error signal and a position information signal based on the light detection signals. The optical device irradiates the at least two sub-beams onto positions shifted to opposite sides of a center of the guide track, respectively, when the main beam is being irradiated onto a center of the information recording track. Thus, the apparatus produces the tracking error signal and the position information signal by utilizing a common optical system and a common signal processing system and thereby executes tracking servo control and random access processing with high accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.