A TV observation system for endoscopes has an illumination system including a light source for emitting light to illuminate an object and a light transmitting section for transmitting the light from the light source to the distal end of an endoscope. The light transmitting section is constructed with a single fiber and satisfies a condition: PHI 1> PHI 2where PHI 1 is the area of the entrance end of the single fiber and PHI 2 is the area of the exit end thereof.
