Patent ID: 8189268

Claim:
A lens unit, comprising: a lens, through which light from an object enters; a lens barrel for holding the lens; an optical path extending member provided within the lens barrel toward the rear of the lens, for extending the focal point of the lens toward the rear side thereof to enable adjustment of positions of the lens to a predetermined state, based on observation results obtained after observing a focal image of the lens with a microscope in a state that the optical path extending member is provided in the lens barrel; a receiving portion having a receiving surface, for receiving a front end facet of the optical path extending member within the lens barrel that faces toward the lens, formed at a portion of the lens barrel; and a mounting portion positioned further rearward from a rear end facet of the optical path extending member, having a guide insertion aperture that extends in a direction perpendicular to the receiving surface, and a mounting surface that extends in a direction parallel to the receiving surface at the periphery of the guide insertion aperture, formed at a portion of the lens barrel.