| 摘要 |
PROBLEM TO BE SOLVED: To provide a push-pull signal generating device whose size is made small and whose cost is reduced, while maintaining noise included in generated push-pull signals to be at a low level. SOLUTION: A first photoelectriclly converted signal Sc1 is amplified by a first signal adjusting circuit c2 with a first gain and a second photoelectrically converted signal Sc3 is amplified by a second signal adjusting circuit c4 with a second gain. Then, at least one of the first gain and the second gain is determined so that the peak level and the bottom level of the difference signals between the output signal of the first signal adjusting circuit and the output signal of the second signal adjusting circuit have a prescribed relationship. Consequently, the levels of prescribed noise components included in the output signals of the first signal adjusting circuit and the output signals of the second signal adjusting circuit, respectively, are made approximately equal to each other and the noise component included in the push/pull signal Swb outputted from a difference signal generating circuit c5 is reduced efficiently. COPYRIGHT: (C)2005,JPO&NCIPI
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