Lens barrel

A lens barrel comprising:

• a front lens frame which supports a front lens group and includes a first cam follower, said front lens frame being guided linearly in an optical axis direction without rotating about said optical axis;
• a rear lens frame which supports a rear lens group and includes a second cam follower;
• a cam ring driven to rotate about said optical axis, said cam ring including a continuous cam groove in which said first cam follower and said second cam follower are engaged;
• wherein said continuous cam groove includes a first moving section for moving said front lens group in said optical axis direction;
• a first accommodation section for moving said front lens frame behind a position of said front lens frame of which said first follower is engaged in said first moving section;
• a second moving section for moving said rear lens group in said optical axis direction;
• and a second accommodation section for moving said rear lens frame behind a position of said rear lens frame of which said second follower is engaged in said second moving section, said second accommodation position including an accommodation position at which said rear lens frame is positioned rearmost, in that order from one end of said continuous cam groove;
• and
• a guiding mechanism for allowing said rear lens frame to rotate about said optical axis relative to said front lens frame when said second cam follower is engaged in a vicinity of said accommodation position of said second accommodation section, and for prohibiting said rear lens frame from rotating about said optical axis relative to said front lens frame while allowing said rear lens frame to move only in said optical axis direction relative to said front lens frame when said second cam follower is engaged in a section of said second cam groove which includes said second moving section and excludes said vicinity of said accommodation position;
• wherein said second accommodation section is formed to firstly make said rear lens frame move in said optical axis direction while making said rear lens frame rotate about said optical axis relative to said front lens frame via said second cam follower engaged in said second accommodation section, and to subsequently make said front lens frame guide said rear lens frame in said optical axis direction without making said rear lens frame rotate about said optical axis when said first cam follower of said front lens frame moves from said first accommodation section to said second moving section by rotation of said cam ring.