Patent ID: 7725013

Claim:
An electronic endoscope comprising: a video-scope with an image sensor; a light source that emits illuminating-light for illuminating an object; an image sensor driver that outputs pulse signals for transferring charges accumulated in said image sensor in each field/frame interval, said image sensor driver outputting a pulse signal for discarding accumulated charges on the basis of a charge accumulation interval; a luminance detector that detects a luminance of an object image on the basis of image-pixel signals read from said image sensor; a single rotary shutter comprising a light-transmitting portion that transmits the illuminating-light, and a shield portion that blocks the illuminating light, said single rotary shutter being configured to rotate while the light-transmitting portion and the shield portion alternately cross a light-path of the illuminating-light; and a brightness adjuster that controls said rotary shutter to change an irradiation-interval of the illuminating-light in a field/frame interval in accordance with the charge accumulation interval, said brightness adjuster shifting a rotation-phase of said rotary shutter by changing a rotation-speed of the rotary shutter on the basis of the detected luminance, so as to maintain a brightness of the object image at a proper brightness.