Abstract: To read out signals from a solid-state image sensor having a plurality of photodiodes arranged in a two dimensional form, there are provided a first driving circuit for generating a driving pulse group for a normal readout operation, and a second driving circuit for producing a driving pulse group for an electronic zooming-in imaging operation as a driving circuit for generating a pulse group by which the solid-state image element is driven. When the solid-state image sensor is driven by the pulse group supplied from the first driving circuit, the signals of the photodiodes of two rows adjacent to each other in a vertical direction are mixed with each other and then read out. When, on the other hand, the solid-state image sensor is driven by the pulse group supplied from the second driving circuit, the signals of the photodiodes of the two rows adjacent to each other in the vertical direction are separately read out at different time instants, and then written in a memory.