| 摘要 |
The present invention relates to a method, an apparatus and a record carrier for controlling radiation power and/or field strength during a reading operation from a magneto-optical recording medium comprising a storage layer and a read-out layer. An expanded domain leading to a pulse in a reading signal is generated in said read-out layer by copying a mark region from said storage layer to said read-out layer upon heating by said radiation power and by applying an external magnetic field. A pulse pattern in the reading signal is analyzed. The analyzing result is compared with run length characteristics of the data stored in said storage layer. The radiation power and/or the magnetic field strength are controlled on the basis of the comparison result. Thus, much less or no disc capacity has to be reserved for radiation power and/or magnetic field calibration, since the user data can be used for this purpose. |
