Optical disc tracking system with switching of tracking error signals at boundary between track guide and track address

摘要

A tracking system for positioning a light spot onto a magneto-optic disc having a beam guide track preformatted thereon, includes a main light beam and two auxiliary light beams, and a circuit for switching between a low frequency component of a tracking error signal, detected by respective auxiliary light beam detectors, and a tracking error signal detected by a main light beam detector.