In an amplifying type MOS sensor having a 3-transistor construction, when a frame rate is raised, an accumulation time of a frame just after the switching of a drive mode becomes short. When a gain correction is made to compensate a lack of accumulation time, a deterioration in picture quality is caused. A read out scan and a reset scan are executed in parallel in the frame before the switching of the drive mode, thereby preventing that a time period for resetting a pixel is overlapped with a time period for holding a pixel signal into a holding unit.