Patent ID: 7742385
Filing Date: 2010-06-22
Classification: G11B

Abstract:
1. Optical data carrier in disc format having at least one CD layer having optically readable CD data structures whose lengths, to suit EFM modulation, are between 3 times and 11 times a basic length T, wherein 3 times the basic length T (the 3T value) is at least 0.9 micrometers, 11 times the basic length (the 11T value) is at least 3.3 micrometers, from that surface of the data carrier through which the CD layer is read, the CD layer is situated at a depth of less than 1.1 mm, the data carrier has exactly one further data layer, namely a DVD layer, the CD layer and the DVD layer are read from opposite sides of the data carrier, and the data carrier has a DVD substrate of a thickness of less than 0.570 mm, and at least 0.55 mm.