Optical information recording and reproducing medium
US7489620B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 2003 |
| Grant date | Feb 10, 2009 |
| Priority date | — |
| Expiry date | Apr 1, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Optical information recording and reproducing medium 10 has two recording layers of first and second recording layers 12 and 14, from a laser beam incident surface side. In each control area 21, recording layer management information containing at least information indicating recording states of a plurality of areas into which the inside of data recording area 22 of each recording layer is divided is recorded. When recording or reproducing is performed on the second recording layer 14, the recording layer management information is checked, and a laser beam output is changed based on a recording state of an area corresponding to the first recording layer 12.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.