| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head device and an optical information recording/reproducing device, capable of detecting radial tilting even for a highly sensitive draw type and rewritable disk having no signals recorded therein. SOLUTION: A beam emitted from a semiconductor laser 1 is divided into three beams, a 0th-order beam as a main beam, and ± 1st-order diffracted beams as sub-beams, by a diffraction optical element 3, and track error signals are detected respectively from the main and sub beams. By the operation of the diffraction optical element 3, the intensity distributions of the main and sub beams made incident on an objective lens 6 are different from each other, and thus the phases of track error signals are shifted between the main and sub beams when radial tilting is present in a disk 7. From the phase sifting of the track error signals, a radial tilt signal is obtained. |
