Patent ID: 8657738
Filing Date: 2014-02-25
Classification: A61B

Abstract:
1. An endoscope system comprising: an imaging device having a varifocal imaging optical system mounted in a distal end of an endoscope, the distal end being inserted into a test subject to capture images of a target site inside the test subject through the imaging device; a light source for emitting illumination light; a light guide for conducting the illumination light from the light source to the distal end of the endoscope to project the illumination light toward the target site, the light guide comprising a first fiber bundle consisting of optical fibers of a first numerical aperture and a second fiber bundle consisting of optical fibers of a second numerical aperture larger than the first numerical aperture, the first and second light bundles having respective inlet ends for entry of the illumination light from the light source and respective outlet ends placed in the distal end of the endoscope; a light volume control mechanism switchable between a second fiber bundle unblocking position allowing the illumination light from the light source to enter the second fiber bundle and a second fiber bundle blocking position blocking the illumination light from entering the second fiber bundle; and a control device for controlling the light volume control mechanism, the control device setting the light volume control mechanism in the second fiber bundle blocking position in a close-up inspection mode, wherein the imaging optical system has a focal length equal to or longer than a predetermined value, to project the illumination light only from the first fiber bundle in the close-up inspection mode.