PROBLEM TO BE SOLVED: To provide an endoscope apparatus deviating ultrasonic oscillation to improve the use efficiency, and efficiently removing stain on the outer surface of a transparent optical element.SOLUTION: The endoscope apparatus includes: an inserting portion inserted into a body cavity and having a distal end disposed with the optical element 32 an ultrasonic transducer 37 disposed in the inserting portion and generating an ultrasonic oscillation f and a diffraction grating 40 disposed on the outer surface of the inserting portion or a side surface of the optical element 32 and deviating the ultrasonic oscillation f within an effective diameter d of the optical element 32. An oscillating surface of the ultrasonic transducer 37 is tilted relative to a grating surface of the diffraction grating 40 so that the interval is increased toward the effective diameter d of the optical element 32.COPYRIGHT: (C)2012,JPO&INPIT【課題】超音波振動の利用効率が向上するように偏向し、透明な光学部材の外表面の汚れを効率よく除去できる内視鏡装置を提供すること。【解決手段】内視鏡装置は、体腔内に挿入され、先端部分に光学部材32が配設された挿入部と、挿入部内に配設され、超音波振動fを発生させる超音波振動子37と、挿入部の外表面、または光学部材32の側面に配設され、超音波振動fを光学部材32の有効径d内に偏向する回折格子40と、を具備し、超音波振動子37の振動面が回折格子40の格子面に対して、光学部材32の有効径d側に向けて間隔が広がるように傾けて配置した。【選択図】図6
