| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device constituted in such a manner that the spherical aberrations by the deviation in the thickness of an optical disk and the fluctuation in wavelength and the comatic aberrations by the inclination of the optical disk are corrected by forming at least two light spots so as to be focused at the optical disk. SOLUTION: This optical pickup device includes a light source which projects light, an optical path changing means which changes the progression route of incident light, an objective lens, an optical branching means which branches the incident light to at least two beams of the light including the first and second light, a photodetector which has first and second photodetecting parts to respectively receive the first and second light reflected from the optical disk and made incident through the optical path changing means and a delay which delays the time of the second signal so as to match the synchronization between the first and second signals detected through the first photodetecting part and the second photodetecting part and subjected to photoelectric conversion. The device also includes a signal processing section which corrects the thickness deviation of the optical disk from the first and second signals matched in synchronization. |
