Patent attributes
An electronic endoscope has a video-scope with an image sensor and a video-processor. The video-scope has an objective lens and an illuminating lens in a tip portion. Further, the electronic endoscope has a luminance calculator and a light-amount adjuster. The luminance calculator divides the total area of a subject image into a plurality of division areas, defines weighted areas from the plurality of division areas in accordance with the tip characteristics of the video-scope, and calculates a total luminance value of the subject image by putting priority on predetermined weighted areas relative to the other areas. The light-amount adjuster adjusts the quantity of light illuminating the subject in accordance with the total luminance value.