OPTICAL PICKUP

PROBLEM TO BE SOLVED: To reduce crosstalk noise of a tracking signal into a focus signal to improve focus control performance in an optical pickup having a one-plane, two-wavelength diffraction grating and a two-wavelength laser generator.SOLUTION: A main beam and sub-beams branched by a one-plane, two-wavelength diffraction grating and reflected from the surface of an optical disc are incident on light receiving elements. In the light receiving elements, relative positions of the one to receive the main beam and those to receive the sub-beams are shifted in a linear-speed direction. The amount of positional shift is determined based on the characteristic, relative to the relative positions of the light receiving elements, of the leak-in amount of the tracking signal into the focus signal detected by the main beam and sub-beams.