| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of effectively canceling laser noise from a reproduced RF signal. <P>SOLUTION: Main and front light receiving parts 17A and 17B, a first differential amplifier 21A for generating a reproduced RF signal having laser noise components canceled from the output signals of the light receiving parts 17A and 17B, a first feedback resistor 22A, a second differential amplifier 21B, a second feedback resistor 22B and an arithmetic operation circuit 23 are constituted on one integrated circuit element. Thus, the characteristics of the light receiving part for the reproduced RF signal and the light receiving part for a laser noise canceling signal are approximated to each other, and the characteristics of amplifier circuits for amplifying the output signals of the light receiving parts are approximated to each other. A propagation delay difference generated between the reproduced RF signal containing the laser noise component to be inputted to the arithmetic operation circuit and the laser noise canceling signal is reduced as much as possible, the phases of the laser noises of both signals are matched with each other, and a large noise canceling effect is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
