Einrichtung zur korrelierten Doppelabtastung

There is provided a correlative double sampling (CDS) device which can effectively and efficiently remove noise from video signal. The CDS device includes at least two sample-and-hold circuits for sampling a video signal output from an image sensor and outputting a predetermined DC level signal, and a differential amplifier. The correlative double sampling device also includes a clamping circuit for DC-clamping a video signal output from the image sensor and applying the DC-clamped signal to the sample-and-hold circuits. At least two re-sample-and-hold circuits are provided for re-sampling the signal output from the sample-and-hold circuits. A level correcting portion is used for correcting the output level of one of the sample-and-hold circuits and one of the re-sample-and-hold circuits, and outputting a signal whose phase is synchronized with the output of the re-sample-and-hold circuits. Sampling noise is removed by alternately passing the output signals of the re-sample-and-hold circuits and the level correcting portion according to a predetermined signal.