Optical information storage medium
US6540397B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 5, 2001 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Apr 5, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information medium comprising at least two data layers for bearing recorded information, and a servo layer for bearing tracking servo, information which is independently formed from the data layers; wherein the medium is used with a recording or reading system wherein a data beam for recording or reading the data in the data layer and a servo beam for reading the tracking servo information in the servo layer are used, and the servo layer is read by the servo beam that had passed through the data layer; and a filter layer is disposed between the data layer and the servo layer, and the filter layer exhibits higher absorption to the data beam than to the servo beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.