Recording medium, method and apparatus for recording, and method and apparatus for reproducing
US7123574B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2005 |
| Grant date | Oct 17, 2006 |
| Priority date | — |
| Expiry date | Oct 4, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a recording medium which is circular and has first and second recording layers, the first and second recording layers each include one or more first tracks extending concentrically or spirally and one or more second tracks extending concentrically or spirally, each of the one or more first tracks and the one or more second tracks includes a plurality of first sectors and a plurality of second sectors, each of the plurality of first sectors includes first and second regions, each of the plurality of second sectors includes third and fourth regions, first and second grooves are formed in each of the second and fourth regions, the first and second grooves extending concentrically or spirally and oscillating sinusoidally, oscillation of the first groove has a first oscillation characteristic at a first prescribed position in the second region, oscillation of the second groove has a second oscillation characteristic at a second prescribed position in the fourth region, and the first and second oscillation characteristics are different from each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.