Record carrier having an improved modulated servo track for more reliable synchronization and an 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 represented by marks. The servo track (4) has a periodic variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information at regular intervals. The modulated parts start with a bit sync element and are of a data type having a data bit element or of a word sync type having a word sync element. The bit sync element and the data bit element are modulated according to a same predetermined type of modulation of the periodic variation. The modulated parts further include modulated parts (40, 41) of an isolated bit sync type only having the bit sync element.