Tracking synchronisation for record disc replay - extracts recorded synchronisation information for comparison with intrinsic signal synchronisation by using interlock circuits

摘要

The equipment is for tracking the spiral information carrier, e.g. groove, on a flat disc by mechanical, optical or other means. The equipment controls the drive to prevent replay of the same track twice or jumping a track, thus missing information. The signal picked up from the track is checked by a regular signal also picked up and used as a synchronisation control. If the signal being replayed from the disc is video, the address signal can be located in flyback periods. The disc (1) is rotated on a turntable (2) with a motor drive (3). The pick up unit (4) feeds signal to the demodulator (5) and the address signal is picked out of the demodulated signal (a) and fed to interlock circuits (8, 9) where it is compared with the picture synchronisation signals (c, d). A signal monitor condition (i) appears at the output of a gate (12).