| abstract |
When acquiring and displaying a plurality of types of moving images, an exposure amount is appropriately adjusted for each moving image. SOLUTION: First and second oxygen saturation measurement light for measuring oxygen saturation of blood hemoglobin, normal light such as white light, and a narrow band component having a high extinction coefficient for a blood vessel of a specific depth The object is sequentially irradiated with the illumination light for blood vessel emphasizing, and the reflected images are sequentially captured by the image sensor. By this imaging, an oxygen saturation observation moving image, a normal observation moving image, and a blood vessel enhancement observation moving image are acquired. Among these, brightness information is acquired from an oxygen saturation observation image that is a key moving image. Based on the brightness information and the light amount ratio between frames, the light amounts of the first and second oxygen saturation measurement lights, the normal light, and the blood vessel enhancement illumination light to be irradiated in the next frame are set. Further, the exposure time of the image sensor in each next frame is set based on the brightness information and the exposure time ratio between frames. Based on the set light amount and exposure time, each illumination light is emitted and imaged. [Selection] Figure 6 |