| 摘要 |
<p>There is provided an optical pickup device capable of eliminating adjustment of position of a diffraction grating upon assembling, suppressing the fluctuation of the differential push-pull signal amplitude, and canceling the push-pull offset. The optical pickup device (200) includes a diffraction grating (230) of a special shape having two types of grating grooves arranged adjacent to each other in accordance with a groove pitch provided on the surface of the optical disc (50), the numerical aperture, the optical beam wavelength, and pitch decided according to the effective diameter when applying an optical beam to the optical disc (50). In order to suppress each push-pull signal generated by the plus and minus primary diffraction light, a reflected light of the 0-th diffraction light and the plus and minus primary diffraction light from the optical disc (50) is detected and each signal corresponding to the light reception result is outputted to a reproduction unit (150), a control unit (130), and an actuator servo circuit (140).</p> |
