Patent ID: 8665689
Filing Date: 2014-03-04
Classification: G11B

Abstract:
1. A method of driving an optical disc drive compatible with multiple types of multilayer optical discs, wherein each of the multiple types of multilayer optical discs comprises multiple information layers that include a reference layer on which management information, including information about the type of the multilayer optical disc is stored, at least one more information layer on each of which layer number information indicating its own place in the multiple information layers and information about the total number of the information layers included are both stored, and a cover layer, wherein during a loading process of a multilayer optical disc carried out by the optical disc drive, the method comprises the steps of: wherein the step (A) includes setting a spherical aberration setting of the optical disc drive to a value at which the shallowest layer of a multilayer optical disc among the multiple types of multilayer optical discs having a thinner cover layer than any of the other multiple types of multilayer optical discs that the optical disc drive is compatible with, has its spherical aberration minimized, and setting the focus position of the light beam on one of the information layers of the multilayer optical disc, which is located closer to the surface of the multilayer optical disc than the reference layer is and on which the layer number information and the total number information are stored, and performing a focus control and a tracking control on that information layer.