| 摘要 |
The present invention, for providing an endoscope including an illumination unit that can substantially evenly illuminate the entire observation region of a forward field of view and a sideward field of view without obstructing a wide field of view, includes: a first objective lens 21 that forms an image of an observation object in the forward direction of an insertion portion 2; a second objective lens 22 that forms an image of the observation object in the sideward direction of the insertion portion; a first light guide 31a that is provided adjacent to an outer circumference of the second objective lens and guides illumination light to a distal end of the insertion portion; a second light guide 32a that is provided on a proximal end side of the second objective lens and guides the illumination light to the distal end of the insertion portion; a forward-illuminating lens 31 formed by a ring-shaped optical portion 31b having a ring shape that has an optical directivity and is disposed so as to surround an outer circumferential side of the first objective lens, and a light-guiding portion 31 c that causes the illumination light to be incident on the ring-shaped optical portion; a sideward-illuminating lens 32 including a prism that causes the illumination light to be emitted in the sideward direction of the insertion portion and causes a part of the illumination light to be emitted in the forward direction of the insertion portion, wherein the light-guiding portion includes a light incident surface 31 d and two light reflecting surfaces 31e, the two reflecting surfaces causing the illumination light to be incident to inside of the ring-shaped optical portion. |
