摘要 |
The optical recording device including a reading head (11) and a reading laser (7) for encoding optical data (3) on a CD (1) as two dimensional (i.e. pit length and pit depths (13, 15)) optical data (3) along a spiral track, one of the data streams may be used to implement a hologram on the data recording surface, the preferred form of the invention uses a uniform pit depth within each pit, causing pit depth to vary only from pit to pit and not within a single pit, the second data stream relies on the primary data stream for much of the necessary error correction required in dense data transmission media. |