Patent AT-E400830-T1: [Translated] OPTICAL OPTION MOUNTING RING

The optical option attachment ring (10) of the present invention includes a rotator (40) having an abutting surface (41) that projects inward from the inner circumferential surface (20a) of the ring body (20) and abuts the front end (31) of the lens barrel (30) as well as an arcuate portion (42) that follows the upper end of the abutting surface (41). The optical option attachment ring (10) further includes a resilient member (B) that applies an urging force to the rotator (40) to rotate in the direction opposite to the above-mentioned rotation direction and a stopper (45) that abuts at least one of the one end (21) and the other end (22) so as to restrict the rotation caused by the urging force of the resilient member (B).