Shock resistant lens device

A zoom lens comprising a camera mountable barrel section, front and rear lens mounts axially movable in said barrel section, a rotatable cylindrical cam carried by and restricted against longitudinal movement relative to said barrel section and having a first track, a first follower longitudinally movable with said front mount and slidably engaging said first track, said zoom lens being characterized in the provision of a first stop section defined by a ring of greater diameter than and engaging said first follower and being longitudinally movable with said front mount, a second stop section stationary relative to said barrel section, and in the path of movement of said first stop section and abutting said first stop section when said front mount is at the rearmost position thereof with said first follower being forward of the rear end of said track, a first frame including an axial first sleeve helicoidally coupled to said first mount and projecting rearwardly from said front mount and having said first follower radially projecting therefrom, a second follower radially projecting from said rear mount and a pair of longitudinally extending first and second guide tracks formed in said barrel section, said first track being defined by a first cam slot formed in said cam and said cam having a second cam slot formed therein, said first follower slidably engaging said first cam slot and first guide track and said second follower slidably engaging said second cam slot and said second guide track.

A zoom lens barrel mechanism for an optical system which has an optical axis and at least first and second lens elements, said first lens element being disposed closest to an object and being movable along said optical axis both upon focusing and zooming operations while said second lens element is moved only upon zooming operation, said barrel mechanism comprising:

• a fixed cylinder;
• manually operable means movable in rotational and axial directions with respect to said fixed cylinder for effecting focusing and zooming operations;
• means for holding said first lens element and being responsive to said rotational and axial movements of said manually operable means;
• intermediate member connected to said holding means to be axially moved when said holding means axially moves in response to the axial movement of said manually operable means for focusing;
• means for driving said second lens element in accordance with the axial movement of said intermediate member, said driving means including co-operative cam and engaging means which are movable relative to and in contact with one another when said intermediate member is axially moved;
• stopper means integrally movable with said intermediate member;
• and
• stop means provided on said fixed cylinder so as not to move in axial direction, said stop means being engaged by said stopper means until said engaging means reaches the end of said cam means when said intermediate member is moved away from the object.

A zoom lens barrel mechanism for an optical system which has an optical axis and at least first and second lens elements, said first lens element being disposed closest to an object and being movable along said optical axis both upon focusing and zooming operations while said second lens element is moved only upon zooming operation, said barrel mechanism comprising:

• a fixed cylinder;
• manually operable means movable in rotational and axial directions with respect to said fixed cylinder for effecting focusing and zooming operations;
• means for holding said first lens element and being responsive to said rotational and axial movements of said manually operable means;
• intermediate member connected to said holding means to be axially moved when said holding means axially moves in response to the axial movement of said manually operable means for focusing;
• means for driving said second lens element in accordance with the axial movement of said intermediate member, said driving means including co-operative cam and engaging means which are movable relative to and in contact with one another when said intermediate member is axially moved;
• stopper means integrally movable with said intermediate member;
• and
• stop means provided on said fixed cylinder so as not to move in axial direction, said stop means including a pair of engaging portions respectively engaged by said stopper means until said engaging means reaches one of the ends of said cam means.

A barrel mechanism for a zoom lens system including a first lens element, a second lens element and a common optical axis therefor, said barrel mechanism including:

• a first lens holder for holding said first lens element and having a portion extending to the frontmost of said barrel mechanism;
• a second lens holder for holding said second lens element;
• a manual member rectilinearly movable along said optical axis accompanying said first lens holder;
• an intermediate member movable along said optical axis in response to the rectilinear movement of said first lens holder;
• a cam-slot coupling for driving said second lens holder in accordance with the movement of said intermediate member;
• and
• a stop member for restricting the range of the movement of said intermediate member.