| 摘要 |
PROBLEM TO BE SOLVED: To accurately and easily determine the degradation of a laser light source. SOLUTION: The signal recording of a laser light source operates under controlling of constant current pulse of a vias APC. Therefore, a laser light (peak power for deleting operation, cool power and target power for recording operation) in the signal recording mode is detected by a front photo detector, and the result is integrated and is converted from analog to digital, and then it is subject to offset cancellation and level normalization so as to obtain an absolute value of the peak power. After the value is compared with a reference value, a difference between them is used to judge the degradation of the laser light source. In addition, the sequential operation is conducted while a light is being emitted in a recording mode of low double speed. COPYRIGHT: (C)2006,JPO&NCIPI
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