| 摘要 |
PURPOSE:To output only signal components by offsetting the noise components of an output signal which consists of a period including noise only and no signal components and a period including the signal components and the noise by switching said output signal at every respective period then outputting by means of an inversion amplifier and an in-phase amplifier. CONSTITUTION:A CCD image pickup element 10 is driven by a driving circuit 11 so that its output signal consists of the first period tF including noise only and no signal components, the second period tS including the signal components and the noise components, and a resetting period tR which is for resetting in one. picture element period. This output signal is supplied to the inversion amplifier 13 and the in-phase amplifier 14. The outputs of these two amplifiers are switching-controlled by gate pulses A and B from a gate pulse circuit 16 so that an inversed noise and an in-phased noise are alternately outputted. Accordingly, the inversed noise and the in-phased noise are offset each other by an integral circuit 17, and only the signal components are taken by out through an LPF 19.
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