Image sensor

An image sensor comprising:

• a first column line and a second column line extending in a first direction and being adjacent to each other in a second direction intersecting with the first direction;
• a plurality of pixels each connected to respective ones of the first column line and the second column line;
• a readout circuit configured to obtain a reset voltage and a pixel voltage from each of the plurality of pixels;
• a bias circuit including,
• a first current circuit configured to output a first bias current, the first current circuit including a plurality of first transistors, and
• a second current circuit configured to output a second bias current, the second current circuit including a plurality of second transistors, the plurality of second transistors having substantially a same size as the plurality of first transistors;
• a switching circuit configured to, during two sequential time periods, connect the first column line and the second column line to different ones of the first current circuit and the second current circuit while disconnecting the first column line and the second column line from another one of the first current circuit and the second current circuit by,
• connecting the first current circuit to the first column line and connecting the second current circuit to the second column line, in response to the readout circuit obtaining the reset voltage and the pixel voltage through the first column line, and
• connecting the first current circuit to the second column line and connecting the second current circuit to the first column line, in response to the readout circuit obtaining the reset voltage and the pixel voltage through the second column line;
• and
• a current mirror circuit including,
• a first current mirror circuit configured to control the first current circuit to output the first bias current, and
• a second current mirror circuit configured to control the second current circuit to output the second bias current.