OPTICAL RECORDING AND REPRODUCING APPARATUS, OPTICAL HEAD APPARATUS, OPTICAL DISC DRIVE APPARATUS, METHOD FOR CONTROLLING TRACKING, AND OPTICAL DISC

摘要

PURPOSE: An optical recording and reproducing apparatus and a tracking control method are provided to maintain compatibility with a currently used optical recording medium, to stably perform recording and reproducing of a high density recording medium, and to obtain a tracking error signal without defect. CONSTITUTION: An optical recording and reproducing apparatus(1) has a drive unit(2) for rotating a recording medium, an optical head(4) for applying light to the recording medium being rotated by the drive units to record data signals on the recording medium or reproducing data from the recording medium, and a signal processing circuit(5) for processing a signal detected by the optical head. The optical head comprises a light source for emitting light, an objective lens, and signal detecting units. The objective lens has a numerical aperture(NA) more than 0.5 and less than 0.6 or the same.