| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the offset of a laser power monitor circuit including a PD from giving adverse effects on monitor output voltage. <P>SOLUTION: In adjusting the output voltage of the laser power monitor circuit 12 to a prescribed value with prescribed laser power by changing an external variable resistance for adjusting output voltage, the output voltage is adjusted by changing the variable resistance so that a difference between a high level of an output pulse from the laser power monitor circuit 12 when an LD 11 is OFF and a low level of an output pulse when the LD 11 is ON becomes voltage of a target adjusting value, so that the offset of the laser power monitor circuit 12 is prevented from giving adverse effects on the monitor output voltage, and the accuracy of recording, reproducing or the like in an optical pickup can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT |
