Dual layer optical medium having multilayered spacer layer between reflecting layers
US5993930A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1998 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Aug 21, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A dual layer pre-recorded optical disc includes a transparent substrate, a partially reflective layer, a transparent spacer layer, and a highly reflective layer. One pattern of data pits is provided on the substrate, adjacent the partially reflective layer, and another pattern of data pits is provided on the spacer layer, adjacent the highly reflective layer. The transparent spacer layer comprises at least two sublayers. The partially reflective layer may be made of silicon carbide. A substrate-incident beam can be used to read data encoded in either data pit pattern depending on which layer the laser is focused upon. The dual layer disc has twice the data storage capacity of conventional single layer discs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.