Optical information medium
US6822937B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2001 |
| Grant date | Nov 23, 2004 |
| Priority date | — |
| Expiry date | Apr 4, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/25718
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multi-layer information medium wherein layer-specific information unique to the particular layer has been adequately recorded, and delay in the access to the recorded data associated with reading of the layer-specific information is suppressed. Such multi-layer information medium is also provided at low cost. The optical information medium has at least two information-storing layers each storing recorded information and/or tracking servo information, and at least one of the information-storing layers is a data layer storing recorded information, and at least one of said information-storing layers is recorded or read by the recording beam or the reading beam which has passed through other information-storing layer(s), and in this medium, the data layer has layer-specific information unique to the particular data layer recorded therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.