Patent ID: 7857751

Claim:
An electronic endoscope system, comprising: a video-scope; an illumination apparatus that illuminates a normal light and an excitation-light from said video-scope onto an object, said normal light reflected from the object, and said excitation-light causing the object to enter into an excited state, so that the object emits fluorescence; an imaging device that is provided on said video-scope, and that receives the reflected normal light and the fluorescence, so as to capture a normal image and a fluorescent image, respectively; and an image synthesizing processor that synthesizes said normal image and said fluorescent image into a synthesized image, a color difference signal of said synthesized image being the same as a color difference signal of said normal image, and a luminance signal of said synthesized image Ys being obtained by mixing a luminance signal of said normal image Yw and a luminance signal of said fluorescent image Yf in accordance with the relationship: Ys=α×Yw+β×Yf where α+β=1, α≧0, β≧0 and where α and β are settable by a manually operable input switch.