Lens barrel and a zoom lens barrel

A lens barrel comprising:

• a front lens support member which supports a front lens group and is guided in an optical axis direction without rotating about said optical axis;
• a rear lens support member which supports a rear lens group and is guided in said optical axis direction without rotating about said optical axis;
• and
• a support frame movement mechanism for moving said front lens support member and said rear lens support member between respective ready-to-photograph positions and respective accommodation positions located behind said respective ready-to-photograph positions, in said optical axis direction;
• wherein said support frame movement mechanism brings said front lens support member and said rear lens support member into contact with each other at said respective accommodation positions without causing said front lens group and said second lens group to come into contact with each other.

A lens barrel having an optical system including of a plurality of lens groups, said lens barrel comprising:

• a lens supporting frame to which a frontmost lens group of said plurality of lens groups is supported;
• a first moving frame to which said lens supporting frame is supported via male and female screw-threaded portions meshing with each other, one and the other of said male and female screw-threaded portions being formed on said lens supporting frame and said first moving frame, respectively;
• a second moving frame to which a rear lens group of said plurality of lens groups which is positioned behind said frontmost lens group is supported;
• and
• a support frame movement mechanism for moving said first moving frame and said second moving frame between respective ready-to-photograph positions and respective accommodation positions located behind said respective ready-to-photograph positions in a direction of an optical axis;
• wherein a supporting position of said lens supporting frame, relative to said first moving frame in said optical axis direction, is adjusted via said male and female screw-threaded portions during assembly;
• and
• wherein said support frame movement mechanism brings said lens supporting frame and said second moving frame into contact with each other when positioning said first moving frame and said second moving frame at said respective accommodation positions without causing said frontmost lens group and said rear lens group to come into contact with each other regardless of said adjustment of said supporting position of said lens supporting frame.

A lens barrel comprising:

• at least one lens group which moves in an optical axis direction;
• a ring member which is provided around said lens group, said ring member having a photographing aperture at a front end thereof;
• and
• at least one barrier blade positioned at said front end of said ring member, said barrier blade being driven to open and close said photographing aperture;
• wherein a frontmost surface of said lens group is formed as a convex surface;
• wherein said barrier blade includes a concave surface which is formed on a rear surface thereof so that a shape of said concave surface corresponds to a shape of a corresponding portion of said frontmost surface;
• and
• wherein said barrier blade is driven to open and close said photographing aperture in a plane perpendicular to said optical axis at a position where collision between said barrier blade and said convex front surface of said lens group is avoided due to the presence of said concave surface.

A lens barrel comprising:

• front and rear lens groups guided in a direction of an optical axis without rotating about said optical axis;
• a first support frame which supports said front lens group, said first support frame including a first cam follower;
• a second support frame which supports said rear lens group, said second support frame including a second cam follower;
• and
• a cam ring which is driven to rotate about said optical axis, said cam ring including a first groove portion and a second groove portion in which said first cam follower and said second cam follower are engaged, respectively;
• wherein said first groove portion includes a first operating section for moving said front lens group to a position wherein a photographing operation is performed;
• and a first accommodation section for moving said front lens group to a first accommodation position which is located behind a position of said front lens group in said optical axis direction when said first cam follower is positioned in said first operating section;
• wherein said second groove portion includes a second operating section for moving said rear lens group to perform said photographing operation;
• and a second accommodation section for moving said rear lens group to a second accommodation position which is located behind a position of said rear lens group in said optical axis direction when said second cam follower is positioned in said second photographing section;
• and
• wherein at least one of said first accommodation section and said second accommodation section is formed to allow corresponding at least one of said first cam follower and said second cam follower to move in said optical axis direction in corresponding said at least one of said first accommodation section and said second accommodation section.

A lens barrel comprising:

• a plurality of lens groups guided in an optical axis direction without rotating about said optical axis;
• a plurality of support frames which support said plurality of lens groups, respectively;
• a plurality of cam followers formed on said plurality of support frames, respectively;
• and
• a cam ring which is driven to rotate about said optical axis, said cam ring including a plurality of cam grooves in which said plurality of cam followers are engaged, respectively;
• wherein each of said plurality of cam grooves comprises:
• a operating section for moving corresponding one of said plurality of lens groups to perform a photographing operation;
• and
• an accommodation section for moving said corresponding one lens group to an accommodation position which is located behind a position of said corresponding one lens group in said optical axis direction when corresponding one of said plurality of cam followers is engaged in said operating section;
• wherein at least one of said accommodation sections is formed to allow said corresponding one cam follower to move in said optical axis direction in said accommodation section.