| 摘要 |
<P>PROBLEM TO BE SOLVED: To sufficiently secure a 300-500MHz transmission band required in recording and reproducing to/from a blue ray disk, even when a PD diameter is made as large as 1Φ so that center alignment of a condenser lens and the PD can be made unnecessary. <P>SOLUTION: The photo diode 11 is connected to a low-impedance amplifier circuit 13 via a low-impedance transmission line 12. In this case, two pairs of pattern lines connected in parallel are used as the low-impedance transmission line 12 to realize the low-impedance, and also a base-grounded mirror complementary circuit is used as the amplifier circuit 13 to realize the low-impedance. Thus, even when the PD diameter is made as large as 1Φ so that the center alignment of the condenser lens and the PD can be made unnecessary, the 300-500MHz transmission band required when performing recording and reproduction to/from the blue ray disk can be sufficiently secured. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
