OPTICAL INFORMATION RECORDING AND REPRODUCING DEVICE AND METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To make it possible to obtain a tracking error signal with a comparatively simple technique and to obtain a focus error signal having high reliability. SOLUTION: A light beam is emitted toward a disk 2 from an integrated type laser coupler 6. A beam splitter 3 guides the light beam reflected by the disk 1 to the integrated type laser coupler 6 and a detecting section 5. The integrated type laser coupler 6 generates a focus error signal from the light beam reflected by the disk 1. The light detecting section 5 generates a tracking error signal from three light beams to which a light beam is separated to three beams by a grating 4 and reflected by the disk 1 by a three beam method.