Endoscope system and method for imaging exposure control

摘要

In a special observation mode, an oxygen saturation frame period, a normal frame period, and a vessel pattern frame period are repeatedly performed. A brightness detector detects the brightness of a latest frame image of an oxygen saturation video image, being a key video image. The intensity of light to be applied in the next oxygen saturation frame period is determined from the detected brightness. From the determined light intensity and a light intensity ratio among frames, the intensity of light to be applied in the next normal frame period and the next vessel pattern frame period is calculated. The exposure time of the next oxygen saturation frame period is determined from the detected brightness. From the determined exposure time and an exposure time ratio among frames, the exposure time of the next normal frame period and the next vessel pattern frame period is determined.

主权项

1. An endoscope system comprising:
a lighting section for sequentially and repeatedly applying a plurality of types of illumination light having different wavelength bands to an internal body portion; an image sensor for sequentially capturing reflected light from said internal body portion in each frame period in which said illumination light is applied, and producing a plurality of types of frame images corresponding to said types of illumination light; a video image processing unit for independently producing a plurality of modes of video images corresponding to said plurality of types of frame images, based on said plurality of types of frame images; a display section for displaying said plurality of modes of video images; a brightness detector for detecting brightness of a specific mode of video image out of said plurality of modes of video images; an exposure condition determiner having a memory for storing correlation in exposure conditions among said plurality of modes of video images, calculating said exposure condition of all of said plurality of modes of video images including said specific mode of video image based on said brightness detected by said brightness detector and said correlation, and determining exposure conditions of said plurality of modes of video images to said calculated conditions in a transition among said plurality of modes; and
an exposure controller for regulating exposure of said image sensor in accordance with said determined exposure conditions.