Patent ID: 8961404
Filing Date: 2015-02-24
Classification: A61B

Abstract:
1. An endoscope apparatus, comprising: a transparent member that is provided at a distal end of an insertion portion of an endoscope and opposed to an image pickup optical system; a transducer that is attached to an inner surface of the transparent member; a diffraction grating that is provided on an outer surface of the transparent member, and converts an ultrasound vibration from the transducer into a surface acoustic wave which propagates on the outer surface of the transparent member; and an absorption portion that is provided at an outer peripheral portion of the transparent member, and deflects the propagated surface acoustic wave to a surface different from the outer surface to absorb the surface acoustic wave, wherein the transparent member has a first region, which absorbs the surface acoustic wave and a second region which reflects the surface acoustic wave, at an outline portion to be an outer surface contour, the first region is a region which the surface acoustic wave reaches by being propagated onto the outer surface in a direction of an observation field of view from the diffraction grating, and the second region is a region which the surface acoustic wave reaches by being propagated onto the outer surface in a direction opposite from the direction of the observation field of view from the diffraction grating, and wherein in the second region of the transparent member, a reflection surface is formed, which reflects the surface acoustic wave, which reaches the reflection surface by being propagated onto the outer surface, in a direction opposite from an incident direction.