Patent ID: 7858916

Claim:
A readout circuit for an imaging device comprising a pixel array having a plurality of columns of pixels, said readout circuit comprising: a plurality of sample and hold circuits; a switching circuit for selectively switching, during readout of an image from said pixel array, each of said pixel columns of said pixel array to one of said plurality of sample-and-hold circuits such that each of said columns of pixels is connected to one of said sample and hold circuits during readout of a row of pixels, said switching circuit performing said selectively switching in a varying fashion during readout of said image from said pixel array such that during said image readout a column of pixels is connected to different sample and hold circuits to reduce the perception of column-wise fixed pattern noise in said image, and a controller for generating a plurality of different matches between one of said columns of said pixel array and one of said sample and hold circuits during said image readout and providing a first control signal to said switching circuit indicating said matches, said first control signal indicating which of said columns is to be coupled to which one of said sample and hold circuits, wherein said controller generates such matches such that an interval between matching is a periodic interval, and wherein said controller generates a match such that matching is done randomly.