Image sensor

The utility model provides an image sensor, which comprises a pixel array and a row selection control line, and is characterized in that focusing photosensitive pixel units in focusing pixel columns included in the pixel array are partially shielded so as to obtain output values of the focusing photosensitive pixel units, and focusing control is carried out based on the output values; the row selection control line receives a row selection control signal and controls and selects a pixel unit needing to be read according to the row selection control signal to read out a pixel signal; the image sensor reads pixel lines in the pixel array line by line in a normal working mode; in the combined readout mode, at least two pixel rows at intervals of odd-numbered rows receive row selection control signals at the same time, focusing photosensitive pixel units which receive the row selection control signals at the same time in focusing pixel columns and non-focusing photosensitive pixel units at intervals of odd-number