Patent ID: 7889228

Claim:
A signal processing device for an endoscope characterized by comprising: an analog signal processing circuit that processes an analog output signal outputted from a solid image-pickup device, which has an image area and an optical black area performing photoelectric conversion, includes a function of varying an amplification ratio, and is mounted on the endoscope, to extract signal components photoelectrically converted by the image area; a first signal clamp circuit for clamping an analog reference signal which is unaffected by a defective pixel in the optical black area so as to adjust into an input range of the analog signal processing circuit and inputting it to the analog signal processing circuit; and a second signal clamp circuit for, with respect to the output signal from the analog signal processing circuit, clamping the signal in the optical black area using output signals of at least the number of pixels larger than the number of pixels in a horizontal direction in the optical black area.