公开(公告)号：GB2486428A

公开(公告)日：2012-06-20

申请号：GB201021144

申请日：2010-12-14

Applicant: ST MICROELECTRONICS RES & DEV

Inventor： STORM GRAEME ,  PURCELL MATTHEW ,  TOLMIE DEREK ,  MOORE JOHN KEVIN ,  WIGLEY MICHAEL

IPC: H04N5/378 ,  H04N5/347

Abstract: An image sensor comprising a pixel array in which each pixel column comprises at least two column bit-lines, a readout input circuit comprising a plurality of first inputs and a second input with each of the first inputs and the second input being connected via a capacitance to a single comparator input node and a readout comparator circuit connected to the single comparator input node. Each of the first inputs receives, in parallel, an analogue signal acquired from the output of one or more of the pixels via the column bit-line. The analogue signals vary during a pixel readout period and have a first level during a calibration period and a second level during a read period. The analogue signals at the first inputs and a reference signal from a time varying reference circuit on the second input are constantly read onto their respective capacitances during both the calibration period and the read period. The readout comparator circuit compares an average of the signals on each of the plurality of first inputs to the reference signal.