Optical information recording medium, optical information recording/reproduction method, and optical information recording/reproduction apparatus
US6862740B2 · kind B2 · utility
2Cited by
4References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 11, 2004 |
| Grant date | Mar 1, 2005 |
| Priority date | — |
| Expiry date | May 11, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/256
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information recording medium in which the ranges of the refractive index and thickness of a protective layer in a case where the protective layer is constituted by a plurality of layers are newly specified the refractive index and thickness of the protective layer are determined in these ranges, thereby ensuring that even if variation in thickness of the protective layer to ±3 μm is tolerated, spherical aberration in the optical information recording medium is substantially to within 30 mλrms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.