Patent ID: 8164997

Claim:
An optical disc apparatus for conducting information recording or reproduction on an optical disc, the optical disc apparatus comprising: an object lens for focusing laser light; a drive part for driving the object lens; a light sensing part for sensing reflected light from the optical disc; a spherical aberration correction part for correcting spherical aberration; and an acquisition part for acquiring a correction quantity of the spherical aberration, wherein the acquisition part calculates and acquires the spherical aberration correction quantity of the first layer on the basis of the spherical aberration correction quantity adjusted in the second layer and an interlayer distance determined by standards, wherein if an attached optical disc is an optical disc comprising at least one first layer which is an unrecorded or additionally recordable recording layer and comprising at least one second layer which is a recording layer having a place already recorded even partially or a reproduction dedicated layer, then the acquisition part acquires a spherical aberration correction quantity of the second layer on the basis of reflected light from the second layer and acquires a spherical aberration correction quantity of the first layer on the basis of the spherical aberration correction quantity of the second layer.