SEKTORINDELAD OPTISK SKIVA MED SYNKRONISERINGSSEKTIONER VARS INDIKATORDELS SIGNAL LIGGER INOM ETT FREKVENSOMRADE DER ADRESSDELENS SIGNAL ER SVAG SAMT ANORDNING FOR DESS UPPTECKNING OCH LESNING

摘要

A disc-shaped record carrier having an information track which is divided into a plurality of sectors per track circumference. Each sector is divided into a data section, in which the data can be recorded, and a synchronizing section. This synchronizing section consists of an optically detectable relief structure and comprises an indicator portion and an address portion. The address portion contains the information about the track number and the sector number. The indicator portion serves to define the beginning of the address portion unambiguously and for this purpose has such a relief structure that the indicator signal produced after cooperation with the radiation beam has a frequency which is clearly distinguishable from signal components resulting from the address portion.