Patent ID: 6459662
Filing Date: 2002-10-01
Classification: G11B

Abstract:
A device reproducing of information recorded on a plurality of layers of an optical disk, comprising:information reading means (60) for illuminating said optical disk (1) with a beam and detecting light reflected from said optical disk (1) to read said information; interlayer-distance detection means (55) for detecting first spacings between said layers in a mounted said optical disk (1) at a plurality of points different in a distance from a center of said optical disk (1); storage means (57) for storing said first spacings detected by said interlayer-distance detection means; and control means (55) for using said first spacings stored in said storage means to calculate a second spacing between a first layer and a second layer of said optical disk (1) when information is being reproduced from said first layer and for thereby controlling said information reading means to focus said beam on said second layer so that information is reproduced from said second layer when information is being reproduced from said first layer.