PROBLEM TO BE SOLVED: To provide an endoscope system capable of adjusting the exposure amount of each of a plurality of kinds of video images in acquiring and displaying the images.SOLUTION: A subject is irradiated sequentially with first and second oxygen saturation level measurement light beams for measuring the oxygen saturation level of blood stream hemoglobin, normal light such as white light, and illumination light for emphasizing a blood vessel having a narrow-band component having a light-absorbing coefficient for a blood vessel of a specific depth, and reflected images are sequentially picked up with an image pickup element. The image pickup enables to obtain an oxygen saturation level observation video image, a normal observation video image and a blood vessel emphasizing observation video image. Of these images, the oxygen saturation level observation image as a key video image enables to obtain brightness information. The light quantities of the first and second oxygen saturation level measurement light, the normal light and the blood vessel emphasizing illumination light which are emitted in each next frame are set on the basis of the light quantity ratio between the brightness information and frames. The exposure time of an image pickup element in each next frame is set on the basis of the ratio of exposure time between the brightness information and frames. The emission of each of illumination light beams and image pickup are executed on the basis of the set light quantities and the exposure time.COPYRIGHT: (C)2013,JPO&INPIT【課題】複数種類の動画を取得・表示する際に、各動画について適切に露光量を調整する。【解決手段】血中ヘモグロビンの酸素飽和度を測定するための第1及び第2酸素飽和度測定光、白色光などの通常光、及び特定深さの血管に対して吸光係数が高い狭帯域成分を有する血管強調用照明光を順に被検体に照射し、その反射像を撮像素子で順に撮像する。この撮像により、酸素飽和度観察動画、通常観察動画、血管強調観察動画を取得する。これらのうち、キー動画となる酸素飽和度観察画像から明るさ情報を取得する。この明るさ情報とフレーム間の光量比に基づいて、次の各フレームで照射する第1及び第2酸素飽和度測定光、通常光、及び血管強調用照明光の光量を設定する。また、明るさ情報とフレーム間の露光時間比に基づいて、次の各フレームでの撮像素子の露光時間を設定する。それら設定された光量及び露光時間に基づいて、各照明光の発光と撮像が行われる。【選択図】図6
