Patent ID: 7432962

Claim:
A method of broadening a dynamic range of a solid-state image sensor including photosensitive cells, each being made up of a main region and a subregion respectively provided with higher and lower photosensitivity, and allowing signal charges to be read out from the main region and the subregion separately, comprising the steps of: reducing a quantity of light to be incident on each photosensitive cell; reading out a signal charge from the main region of the photosensitive cell under a reduced quantity of incident light; amplifying, at an analog stage, the signal charge read out with different gains to thereby generate a high gain-up signal and a low gain-up signal; digitizing the high gain-up signal and the low gain-up signal; and combining the high gain-up signal with the low gain-up signal digitized; whereby the dynamic range of the solid-state image sensor is broadened by use only of the main region.