| 摘要 |
<p>There is provided an optical option attachment ring (10) which has the same substantially cylindrical contour as a lens barrel (50) and no projection and includes a ring body (20) into which a lens barrel (50) is inserted, a clamping ring (30) rotatably fastened on the periphery of the ring body (20), an elastic member (40) arranged between the ring body (20) and the clamping ring (30) and an abutting portion (34) which is provided on the clamping ring (30) and abuts on the elastic member (40) according to the rotational position of the clamping ring (30) to elastically deform the elastic member (40) to cause at least a part of the elastic member (40) to project further inwards than the inner peripheral surface (22) of the ring body (20) and to be positioned in a groove formed in the lens barrel (50).</p> |
