| 摘要 |
PURPOSE:To decrease or eliminate a reset noise component by adjusting the width of a reset pulse and the position of a transfer pulse driving an output amplifier circuit and setting a signal charge holding time and a reset noise holding period of an output signal so as to satisfy a specific equation. CONSTITUTION:There is a time difference of DELTA=(T-taur-r)/2 between the signal pulse train and the reset noise pulse train of an output signal shown in Fig. (C), and the difference DELTA is set to 0-T/2 by adjusting the width taur of a reset pulse phiR and the signal charge holding time tau. Thus, the difference DELTA is matched to a phase difference pi/2+npi of a carrier of an m-order harmonic of the output signal and DELTA=(pi/2+n)/(momegap) is attained (where n=0,1-m-1), then the signal component is extracted by the synchronous detection multilying the carrier of the m-order harmonic of the signal pulse train in Fig. (C) onto a local signal cos(momegapt). Since the carrier of the m-order harmonic of the noise pulse train is shifted by 90 deg. to the local signal, no noise component is detected. The setting condition to the width of the phiR and the tau is determined as tau+taur=T(2m-2m- 1)/2m (where m=1,2...). |
