Patent ID: 8582403

Claim:
An optical disc apparatus comprising: a layer-to-layer jump control section for controlling a layer-to-layer jump of a focus position from one of multiple information layers, which are stacked in a multilayer optical disc, to another, the multilayer optical disc comprising at least four information layers; a spherical aberration correcting section having the ability to make a spherical aberration correction adaptively to each of the multiple information layers in the optical disc; and an S-curve signal detecting section for detecting an S-curve signal from any of the information layers after the layer-to-layer jump of the focus position has been started, wherein the spherical aberration correcting section makes a spherical aberration correction to set the value of the S-curve signal of an intermediate layer to be larger than the value of the S-curve signal of the information layer at which the focus position was located when the layer-to-layer jump was started and the target information layer of the layer-to-layer jump, the intermediate layer being one of the two information layers that are adjacent to the target information layer, and the two information layers being between the information layer at which the focus position was located when the layer-to-layer jump was started and the target information layer, wherein in response to the S-curve signal which is detected from the intermediate layer, the layer-to-layer jump control section starts to decrease the shift velocity of the focus position during the layer-to-layer jump.