OPTICAL DISC HAVING SERVO-TRACK PORTIONS AND SECTOR ADDRESSES AND APPARATUS

摘要

22 Record-carrier body provided with a relief structure of optically detectable servo-track portions and sector addresess and apparatus for forming said structure. A record carrier body is describe provided with sector addresses (12) and servo-track portions (13). As the maximum width of the servo-track portions is at least 60% of the track period (Pr), in a direction transverse to the track direction, and is at least of the order of twice the maximum width of the sector-address areas (15), it is possible to obtain an improved tracking signal in addition to a satisfactory address signal. An improved information signal can be obtained by recording the information (22) in the lands between the servo tracks. Fig. 7.