Patent ID: 8517927

Claim:
A medical instrument for observing an interior of a subject to be examined, comprising: an image pickup unit incorporated in a medical instrument body, for picking up an image of the subject to be examined from an observation window; a rotary cover having a cylindrical shape and provided rotatably on an outer circumferential portion of the medical instrument body so as to cover the image pickup unit, the rotary cover being provided with an inlet port, and an opening on the outer circumferential portion of the rotary cover for exposing the image pickup unit; a multi-bladed fan provided on an inner perimeter of the rotary cover and configured to take in air from the inlet port and exhaust an airflow for preventing adherents from sticking to the observation window by rotation of the rotary cover; a fixing unit for indwelling and fixing the medical instrument body inside the subject to be examined; and a drive unit incorporated in the medical instrument body, for driving the rotary cover to be rotated, wherein the rotary cover rotates and moves to a position where the opening aligns with the observation window in accordance with a timing of a frame rate of the image pickup unit.