METHOD AND DEVICE FOR MASTERING A COPY-PROTECTED OPTICAL DISC AND COPY-PROTECTED OPTICAL DISC

摘要

The invention concerns a copy-protected disc of the double spiral type, wherein there is a protective zone where a secondary spiral (PB) is embedded between the turns of a main spiral (PA), the pitch of each spiral turn from an adjacent turn maintaining the standard value. To enable non-disturbed playback with standard reproducing devices, an offset of k sectors is provided between sectors of a common address (n) on each of the two spirals. Additionally, there are provided filling zones (FAcc, FDec) at the beginning and at the end of the useful portion of the secondary track (PB) to avoid the risks of gaps or collapse between the tracks. The invention is applicable to copy-protected discs and their manufacture.