| 摘要 |
PURPOSE:To enable reliable detection of a state of lowering of the quantity of light of an irradiation laser, before a serious fault is caused thereby, by a construction wherein a changeover is made to an output of a first power at the time of an ordinary recording operation, and at the time of a self-diagnosis, the changeover is made to an output of a second power so as to conduct a recording operation. CONSTITUTION:Two kinds of powers of a first light power generating circuit 12 for which the power is set to be somewhat higher than an optimum reference power and of a second write power generating circuit 13 for which the power is set to be equal to an optimum recording power or somewhat lower than it, are used as reference potentials of write powers. At the time of a self-diagnosis, a second write power set to be equal to the optimum recording power or somewhat lower than it is used. Then information is recorded thereby in an area for a test provided outside a user area on a disk and it is judged from the information reproduced whether record reproduction is normal or not. According to this constitution, a state of lowering of the quantity of light of an irradiation laser can be detected reliably before a serious fault is caused by the lowering. |
