Patent ID: 7247135
Filing Date: 2007-07-24
Classification: A61B

Abstract:
1. An electronic endoscope apparatus having a video-scope with an image sensor and a video-processor, comprising: a light source that illuminates an object, an object image being formed on the image sensor, image-pixel signals being generated by the image sensor; a luminance calculator that calculates a luminance level indicating a brightness of an object image on the basis of the image-pixel signals; a controller that calculates and outputs a manipulated value in accordance with a luminance-difference between the luminance level and a reference luminance level indicating a standard brightness of the object image, said controller setting a non-sensitive band including a standard point corresponding to the reference luminance level; and a brightness adjuster that adjusts the brightness of the object image in accordance with the manipulated value, said controller outputting a non-activating manipulated value so as not to activate said brightness adjuster when the manipulated value is inside the non-sensitive band; wherein the controller offsets the manipulated value so as to lower the absolute value of the manipulated value when the manipulated value is outside the non-sensitive band along a first direction that increases the brightness and a second direction that decreases the brightness by a half of a width of the non-sensitive band, the controller offsetting the manipulated value so as to maintain a linear relationship between the manipulated value and the luminance difference.