| 摘要 |
A cam locus of the cam surface (G1) on the image plane side of the first group cam groove (27) of the rotating cylinder (21) has an angle to a flat surface where the optical axis crosses perpendicularly. In a case in which the cam follower (25) engages with (abuts on) the cam surface (G1) on the image plane side, an impact force is dispersed into the optical axis direction and into the rotating direction of the rotating cylinder (21), and a load which the cam follower (25) and the male helicoid (31) of the rotating cylinder (21) receive is reduced. Additionally, when the first group lens system (11) is pressed by a light load such as a hand operation by a user and the like, the cam follower (25) of the first group lens movement frame (15) engages with (or abuts on) the cam surface (G1) on the image plane side, and an angle of the cam surface (G1) is an angle that an occurring force in the rotating direction is so as to be a moving direction from the collapsed position (S1) to the wide angle end position (W1). Therefore, the rotating cylinder (21) does not rotate easily, and when the load is removed, returns to a position before the load is received.
|
