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

Abstract

A record carrier () has a servo track () indicating an information track () intended for recording information blocks. The servo track () 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 () is proposed for the different type of modulation.