| 摘要 |
The invention concerns an improved optical compact disc, or CD, on which the data, with a binary digital format, are physically memorised as pits and lands of the disc surface along a spiral-shaped track running all along the surface of the disc, said track being scanned, during the data reading phase by a reading optical apparatus, by the reading optical apparatus with a constant linear velocity (CLV), the CD being characterised in that it provides at least a first portion of the track that is scanned, during the data reading phase, with a CLV included between 0.1 m/s and 1.2 m/s, preferably included between 0,9 m/s and 1.2 m/s, and/or at least a second portion of the track wherein the consecutive involutions of the spiral are separated by a constant track pitch included between 1.3 and 1.6 mu m, preferably of 1.4 mu m. |
