A CCD image sensor has an imaging surface composed of an effective pixel area and OB areas, and first and second light receiving element groups on even-numbered and odd-numbered columns respectively in the imaging surface. These light receiving element groups have separately-controllable exposure times, and they are set to low and high sensitivities. An imaging device includes this CCD, a memory storing defective pixel information of the OB areas, an OB clamping circuit for applying an OB clamp processing to the light receiving element groups, and an image processing circuit for generating image data from the output signals of the light receiving element groups after the OB clamp processing. Referring the defective pixel information, a CPU sets one of the light receiving element groups having more OB defective pixels to low sensitivity, and the other having less OB defective pixels to high sensitivity.