Optical disc having plural grooves of different depths
US6842420B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2004 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Jan 9, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24076
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The width and/or depth of guide grooves on the disc substrate surface are changed in each data recording layer and the guide groove depth of the recording film layer is appropriately shaped in each data recording layer to provide a high density, high recording capacity optical disc. The optical disc has plural substrate layers each having plural guide grooves; plural data recording layers laminated on the substrate layers, each of the plural data recording layers having a recording film for recording data over the guide grooves; and an intermediate layer between the plural data recording layers. The guide groove width is different on each substrate layer. The guide grooves of the data recording layers formed according to the guide grooves of the substrate layer have the same pitch in each data recording layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.