Patent ID: 6932763

Claim:
An endoscope light source apparatus comprising: a condensing optical system for condensing source light; a light guide for guiding the light from the condensing optical system to the endoscope front end; an aperture blade disposed between the light guide and the condensing optical system and which moves in a direction perpendicular to an optical axis of the condensing optical system and which is shaped to have an outline converging toward a front end in a moving direction, to have a base section which is large enough to fully shield a ray bundle from the condensing optical system, to have a front-end blade section which has a width smaller than the diameter of the ray bundle, and to have a front edge which forms a straight line; and an aperture driving circuit for driving the aperture blade so that all light in proximity of a central region of the ray bundle is shielded earlier than that in the outer regions during dimming.