Tracking and focus control system for optical disk apparatus

摘要

An optical disk apparatus comprising an optical element for dividing the reflected light into a plurality of light beams for generating a tracking error signal and a focus error signal, and deflecting these light beams into different directions from each other, a first calculating means for calculating the focus error signal on the basis of outputs from said photodetecting means, and a second calculating means for calculating the tracking error signal on the basis of the outputs from said photodetecting means in accordance with a structure of a track. The second calculating means outputs a tracking error signal by a push-pull method when a track has a successive groove. The second calculating means outputs a tracking error signal by a heterodyne method when a track has only a row of pits.