Patent ID: 8526277
Filing Date: 2013-09-03
Classification: G11B

Abstract:
1. A method for determining a type of an optical disk, the method comprising: focusing a laser beam of a first type on the disk to generate a first optical reflection signal; generating a first spherical aberration estimate based on a degree of dispersion and strength of the first optical reflection signal, wherein the degree of dispersion of the first optical reflection signal is divided by the strength of the first optical reflection signal to obtain the first spherical aberration estimate; focusing a laser beam of a second type on the disk to generate a second optical reflection signal; generating a second spherical aberration estimate based on a degree of dispersion and strength of the second optical reflection signal, wherein the degree of dispersion of the second optical reflection signal is divided by the strength of the second optical reflection signal to obtain the second spherical aberration estimate; and determining the type of the disk based on the first spherical aberration estimate and the second spherical aberration estimate.