PORTEUR D'INFORMATION EN FORME DE DISQUE EXPLORABLE PAR VOIE OPTIQUE, ET SERVANT DE MILIEU D'EMMAGASINAGE D'INFORMATION, DISPOSITIF POUR LA FABRICATION D'UN TEL PORTEUR D'INFORMATION, DISPOSITIF POUR L'ENREGISTREMENT D'INFORMATION DANS UN TEL PORTEUR D'INFORMATION ET DISPOSITIF POUR LA LECTURE DE L'INFORMATION D'UN TEL PORTEUR

摘要

An optically readable record carrier for storing digitally coded information having a power spectrum with a substantially zero level at a predetermined frequency. The information is recorded on and/or reproduced from substantially parallel elongated tracks on the record carrier which have a periodic undulation at the aforesaid predetermined frequency. Such undulation generates a clock signal for synchronizing the recording and/or reproduction of the digitally encoded information on the tracks, and does not interfere with the recording or reproduction of such information. Apparatus is disclosed for forming such tracks on the record carrier.