| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens barrel less liable to be damaged even if it is subject to force in the direction of an optical axis. SOLUTION: In the lens barrel, a helicoid screw valley portion 1a and a circumferential groove 1b continuing from the helicoid screw valley portion 1a are formed on the inner circumference of a fixed cylinder 1. Also, a helicoid screw mountain portion 2a that is screwed into the helicoid screw valley portion 1a and engages with the groove 1b is formed on the outer circumference of the rotating cylinder 2. A helicoid reinforcement member 2b is firmly inserted into part of the helicoid screw mountain portion 2a. Even if the cylindrical portion is subject to force in the direction of an optical axis, the lens barrel has a structure less liable to be damaged by the increase of the mechanical strength by the installation of the helicoid reinforcement member 2b. COPYRIGHT: (C)2009,JPO&INPIT |
