To provide a display system which enables power consumption to be reduced. An imaging device operates in first and second imaging modes. In the first imaging mode, a digital processing circuit converts a third imaging data captured by a first pixel into a digital data and supplied the data to a display device. In the second imaging mode, an analog processing circuit detects a difference data between first and second imaging data and sets a determination signal to an active value in accordance with the difference data. A display device operates in first and second display modes. In the first display mode, an image data is updated to display an image. In the second display mode, an image is displayed without an update of an image data. The switching of the imaging mode and the display mode is performed by setting the determination signal to an active value.