LENS BARREL AND OPTICAL INSTRUMENT

PROBLEM TO BE SOLVED: To make fixing of a lens holding member to a base member by adhesion easy even when an adhesion part is provided at a part not exposed to a barrel outer periphery, and reduce a leak of an adhesive agent.SOLUTION: A lens barrel 200 has: a base member 501; a lens holding member 701 that holds a lens L3b, and is fixed to the base member by adhesion, in which one of the base member and the lens holding member has a through-hole part 5012a that penetrates in an optical axis direction, and other thereof has a convex part 7013 that is inserted into the through-hole part from one side in the optical axis direction,; and a closing member 504 that is arranged so as to close an opening, around the convex part on the one side, of the through-hole part. Inside the through-hole part, an adhesive agent 1000 is arranged that contacts with the convex part and the closing member.SELECTED DRAWING: Figure 14 【課題】接着部が鏡筒外周に露出しない箇所に設けられていてもレンズ保持部材のベース部材に対する接着による固定を容易とし、接着剤の漏出も低減する。【解決手段】レンズ鏡筒２００は、ベース部材５０１と、レンズＬ３ｂを保持してベース部材に接着により固定されるレンズ保持部材７０１とを有する。ベース部材およびレンズ保持部材のうち一方は光軸方向に貫通する貫通穴部５０１２ａを有し、他方は貫通穴部に光軸方向における一方の側から挿入される凸部７０１３を有する。貫通穴部の上記一方の側における凸部の周囲の開口を塞ぐように配置された閉塞部材５０４を有する。貫通穴部内に、凸部と閉塞部材とに接する接着剤１０００が配置される。【選択図】図１４