| 摘要 |
PROBLEM TO BE SOLVED: To detect the life or abnormality of an MD drive by detecting its state. SOLUTION: Laser projection time measurement processing is performed at a step S1 and the value of a laser projection time accumulating timer is read in at a step S2; and source voltage data are read in at a step S3 and temperature data are read in at a step S4. A source voltage and temperature are computed at a step S5, the voltage-converted value of a laser forward current is read in at a step S6, and a laser forward current value is computed at a step S7. The laser forward current initial value is read out and a laser forward current value/laser forward current initial value is computed at a step S8. It is judged at a step S9 whether or not there is an abnormal value and when so, the contents of the abnormal state are outputted at a step S10, but when not or after the processing of the step S10 is completed, the computation results of the accumulated value of a laser projection time, the laser forward current/laser forward current initial value, and the source voltage and temperature are recorded at a step S11. |
