| 摘要 |
<p>A dual layer pre-recorded optical disc (12) includes a transparent substrate (14), a partially reflective layer (16), a transparent spacer layer (18), and a highly reflective layer (20). One pattern of data pits (15) is provided on the substrate, adjacent the partially reflective layer, and another pattern of data pits (19) is provided on the spacer layer, adjacent the highly reflective layer. 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 (30) is focused upon. The dual layer disc has twice the data storage capacity of conventional single layer discs.</p> |
