An imaging mechanism includes: an imaging device a light receiving section that is provided on one surface of the imaging device a cover member that covers the one surface of the imaging device and the light receiving section and a lens unit that has a plurality of lenses including a plano-convex lens having a flat portion and a lens barrel, and that is optically coupled to the light receiving section, the lens barrel fixing the plurality of lenses, wherein the plano-convex lens having the flat portion is provided at a closest position to the imaging device in the plurality of lenses such that the flat portion faces the imaging device, and the flat portion protrudes from an end of the lens barrel toward the imaging device and is fixed to the cover member.
