| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk device capable of generating a monitor signal which is hardly affected by noise even when the power ratio of a mark and a space increases during high-fold speed recording. <P>SOLUTION: A monitor amplifier 6 which extracts laser light emission power as an electric signal is provided with a function of switching gains. Then a large monitor gain is selected for a low-power light emission period corresponding to super-power light emission and then a signal having a large signal amplitude can be transmitted to a signal processing unit even in the low-power light emission period. <P>COPYRIGHT: (C)2009,JPO&INPIT |
