Frommer Lawrence & Haug LLP
Method of setting power for a reproducing beam to be applied to a magneto-optical disc, and method of reproducing data from a magneto-optical disc
An object of the invention is to provide a method of setting power for a reproducing beam applied to a rotating magneto-optical disc to reproduce data signals therefrom in the magnetically induced super resolution (MSR) mode, thereby to heat the signal-recording layer of the disc sufficiently even if the disc warps and to attain an adequate MSR effect. Another object of the invention is to provide a method of reproducing data from such a magneto-optical disc. To set power for the reproducing laser beam, calibration is carried out for at least two points on the radius of the magneto-optical disc, and optimal powers for these points are calculated. From the optimal powers, the power for the reproducing beam is calculated by curvilinear approximation and set for a given position on the magneto-optical disc. The margin of power for the reproducing beam can be thereby increased. Data can therefore be reliably reproduced in the MSR mode from the magneto-optical disc that has a signal-recording layer whose magnetic characteristic greatly depends on temperature.
Sony Corporation
G G G
G11B G11B G11B
inventional inventional inventional
Kenji
Yamazaki