| 摘要 |
PROBLEM TO BE SOLVED: To make an optical pickup head device to be hardly effected by extraneous noise by allowing first I-V converting parts to output signals which change to positive directions when light beams are made incident on light receiving parts and second I-V converting parts to output signals which change to negative directions when light beams are made incident on light receiving parts. SOLUTION: A photodetecting device 52 which is constituted of a p type silicon substrate has six light receiving parts 511 to 516 and six I-V converting parts 511B to 516B. A beam 7A, a beam 7B and a beam 7C are respectively received with light receiving parts 511 to 514, with a light receiving part 515 and with a light receiving part 516. I-V converting parts 511B to 516B convert current signals I1 to I6 into voltage signals V1 to V6 respectively by receiving the current signals I1 to I6 which are to be outputted from the light receiving parts 511 to 516. The I-V converting parts 513B and 514B and remaining four I-V converting parts are respectively made to be noninversion type current to voltage transforming units and inversion type current to voltage transforming units. When light beams are made incident on respective light receiving parts, the inversion type units and the noninversion type units respectively output signals changing to the positive directions and signals changing to the negative directions as the signals V1 to V6. |
