Patent ID: 6902527

Claim:
An endoscope system comprising: an endoscope provided with a solid-state imaging device having therein an electron multiplication mechanism to vary an electron multiplication rate and change a sensitivity of the solid-state imaging device based on sensitivity control pulses supplied; a signal processing unit for processing a signal output from the solid-state imaging device; a light source unit for irradiating an object; a sensitivity control unit for controlling a sensitivity by controlling the number or amplitude of the sensitivity control pulses to vary the electron multiplication rate, the sensitivity control unit controlling the number of sensitivity control pulses or amplitude of the sensitivity control pulses so that a level of a signal from the solid-state imaging device may be of a predetermined value; and an automatic-gain control adapted for supplementarily amplifying a signal output from the solid state imaging device of which the sensitivity has been controlled so that the level of the signal becomes a predetermined level if it is lower than the predetermined level.