Patent ID: 8531566

Claim:
An image sensor, in particular a CMOS image sensor, for electronic cameras, having a plurality of light-sensitive pixels ( 101 ) arranged in rows and columns, wherein all or at least some of the pixels ( 101 ) of a column are connected to a respective common column line ( 103 ), and wherein the image sensor has a respective signal preprocessing device ( 105 ) for one or more of the column lines ( 103 ) to process exposure signals generated by the pixels which can be applied to the respective column line ( 103 ), wherein the image sensor is made selectively to apply one of at least two test input signals to the column lines ( 103 ), wherein each column line ( 103 ) is connected at least to a respective first switch ( 110 ) and a respective second switch ( 111 ), wherein the respective column line ( 103 ) can be selectively connected via the first switch ( 110 ) to a first test signal line ( 106 ) or via the second switch ( 111 ) to a second test signal line ( 107 ); wherein a register ( 115 ) is provided which is made to control the first and second switches ( 110 , 111 ) for each column line ( 103 ) separately so that the respective column line ( 103 ) is selectively connected to the first test signal line ( 106 ), to the second test signal line ( 107 ) or to no test signal line; wherein a respective control logic ( 112 ) is provided between the register ( 115 ) and the first and second switches ( 110 , 111 ) of each column line ( 103 ); wherein the control logics ( 112 ) at the input side are connected to a respective register output ( 116 ) and to a common line ( 117 ); and wherein the control logics ( 112 ) are made to actuate in dependence on a control signal at the common control line ( 117 ) either the respective first switch ( 110 ) or the respective second switch ( 111 ) in dependence on the condition of the respective register output ( 116 ).