| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and device for determining heat treatment, capable of easily determining whether or not the execution of the heat treatment of a magneto-optical information recording medium is carried out properly. SOLUTION: A laser beam from an LD11 is applied to a magneto-optical disk 33 by predetermined power for heat treatment. After the heat treatment, the laser beam of power smaller than the power during the heat treatment is applied to the heat-treated area. The reflected light of the laser beam of small power is made incident on photodetectors 24 and 26, and the reflected light quantities of P and S waves are detected. A differential detection circuit 27 detects the level of a magneto-optical signal corresponding to the heat-treated area based on the reflected light quantities of the P and S waves. A controller 28 determines whether the level of the magneto-optical signal detected by the differential detection circuit 28 is within a permissible range or not. If it is outside the range, the power of the laser beam for the heat treatment is adjusted, the treatment of the magneto-optical disk is canceled, or the message of that effect is displayed and so on. COPYRIGHT: (C)2005,JPO&NCIPI
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