| 摘要 |
In an optical pickup, the sum signal -VMAIN of the light receiving sections A, B, C and D of a main photo diode is applied to an inversion amplifier Amp9, and the sum signal VMAIN is applied to a data processor section and a mirror signal arithmetic section. An inversion amplifier Amp10, on the side of sub photo diodes, receives the sum of the sum signal -VSUB E and a corrected signal C*VMAIN which is obtained by adjusting the sum signal VMAIN of the main photo diode with a variable resistor VR1. The output of the inversion amplifier Amp10 becomes a regular sub beam receiving signal VSUB which is obtained by subtracting a correcting signal whose voltage is equal to the main beam leakage signal from the sub photo diode sum signal VSUB E. The regular sub beam receiving signal is applied to the mirror signal arithmetic section.
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