OPTICAL INFORMATION DEVICE AND OPTICAL INFORMATION DEVICE CONTROL METHOD

摘要

When a spherical aberration generated on an optical recording medium is optically corrected, there has been a problem of irradiation power change of an output on an objective lens side due to a change of a signal level detected by a light quantity detector in response to the correction value. An optical information device is provided with a laser (2) for projecting optical beams; an objective lens (9) and the like for focusing the optical beams projected from the laser (2) on an optical recording medium (10); a spherical aberration correcting means (24), which is arranged on an optical axis of the optical beams connecting the laser (2) and the objective lens (9) and corrects a spherical aberration generated on the optical recording medium (10); a polarization beam splitter (5) for splitting the optical beams projected from the laser (2) into a plurality of beams; a light quantity detector (15) which receives one of the optical beams split by the polarization beam splitter (5) and outputs an electric signal corresponding to the receiving light quantity; a laser power control means (21), which controls the projection power of the laser beam source based on the electric signal from the light quantity detector (15); and a controller (23), which performs correction, such as to changethe projection power of the laser (2) in response to a correction quantity of the spherical aberration correcting means (24).