| 摘要 |
PROBLEM TO BE SOLVED: To keep an erase power at a proper value even if the ambient temperature fluctuates. SOLUTION: In this optical recording and reproducing device, after an optical head (laser diode 14) output has been detected by a monitor sensor 1, its peak value is taken out by an envelope detector 9 via a noninversion broad band amplifier 6 and an inversion amplifier 8. This peak value is inputted to a current amplifier 13 via an amplifier 10 and a comparator 12, and according to the input, a current is inputted to the optical head from the current amplifier 13. This current according to the input corresponding to an erase power. Since an emitting state of the laser diode is detected from the start until the end of the recording operation, and the erase power operates so as to always match with a reference value, it is possible to keep the erase power at a proper value even if the ambient temperature fluctuates. |
