OPTICAL PICKUP DEVICE AND INFORMATION RECORDING/REPRODUCING DEVICE

摘要

In the case of performing tracking correction and CTC by using three beams, an irradiation position of the sub-beam is surely and correctly adjusted. The irradiation position of the sub-beam on a disk plane of an optical disc (DK) is adjusted by changing the angle of a diffraction grating (211) arranged in an optical pickup device (PU). In the adjustment, the angle of the diffraction grating (211) is adjusted by three steps of (i) rough adjustment, (ii) initial fine adjustment, and (iii) continued fine adjustment.