Apparatus for reading an optically readable record carrier.

摘要

In order to be able to displace the light beam to a position on the disc determined by a given address code on an optically readable record carrier (2) comprising information provided with address codes and recorded in substantially concentrical tracks for the purpose of accurate reading, the track pitch and the write velocity with which the information has been recorded on the relevant disc is determined prior to reading. To this end the light beam is displaced from a position with a known address code successively across a given first and second number of tracks and the address code is read after each displacement. The track pitch and the write velocity is calculated from the data obtained so that the relation between the track number and the address code is accurately laid down.