Record carrier having a servo track with position information in accordance with a modulation type and permanent information in accordance with a different modulation type, and apparatus for scanning the record carrier

摘要

A record carrier ( 1 ) has a servo track ( 4 ) indicating an information track ( 9 ) intended for recording information blocks. The servo track ( 4 ) has a periodic variation of a physical parameter at a predetermined frequency, usually called wobble. The servo track has modulated parts for encoding position information according to a predetermined type of modulation. The record carrier includes a management area in which the servo track includes permanent data. The permanent data is encoded using a different type of modulation, but using the variations of the same physical parameter. Direct digital modulation ( 41 ) is proposed for the different type of modulation.