A frame period duration of a frame period is adapted by delaying a start of a next frame period.
Compared to addressing a pixel (11) each frame period, for signals having a duration of more than one frame period, a large amount of power is saved.
For example, the longer frame period may be an elongated frame period, which is the longest period during which each of the voltage waveforms has a respective constant voltage value.
Normal operation is performed by alternately repeating the video scan period (T11) and the still image rest period (T12) using a single still image frame period as a unit.
Pixel circuits in an image sensor are sampled repetitively during an image frame period.