| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens barrel capable of performing a smooth relative rotation operation, while having a drip-proof structure, in the lens barrel in which a circumferential groove is formed by a pair of groove forming flanges in one of two relatively rotating cylindrical members, a bayonet pawl fitted into the circumferential groove is formed in the other one of the two relatively rotating cylindrical members, and a cutout for guiding the bayonet pawl into the inside of the circumferential groove is formed in a specific rotation angle position in a pair of groove forming flanges and the bayonet pawl. SOLUTION: In the drip-proof bayonet structure of the lens barrel, one of the inner circumferential edge and outer circumferential edge of a seal ring is fixed to the cylindrical member on a side having the circumferential groove and a pair of groove forming flanges, and an elastic annular lip comprising the other one of the inner circumferential edge and outer circumferential edge of the seal ring is brought into elastic contact with the cylindrical member on the side having the bayonet pawl so that the bayonet pawl comes into contact with the groove forming flange not having the cutout of a pair of groove forming flanges. COPYRIGHT: (C)2011,JPO&INPIT |
