Record carrier having a servo track with non-modulated parts at a first frequency and modulated parts at a second frequency, 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 represented by marks, the servo track (4) having a periodic variation of a physical parameter at a first frequency and modulated parts for encoding record carrier information. The modulated parts have a bit synchronization element constituted by a phase modulation of the periodic variation and a data part having data bits of the record carrier information encoded by direct digital modulation. Alternatively, the modulated parts include a second frequency, which is substantially different from the first frequency, for encoding data bits of the record carrier information, the second frequency being a integral multiple N of the first frequency. A recording and/or playback device has a device for recording/reading the information blocks and for reading the record carrier information.