Patent ID: 6963694

Claim:
A lens barrel comprising: an annular ring which is non-rotatable and includes at least one circumferential guide groove formed on an inner peripheral surface thereof, said circumferential guide groove being open at an end of said annular ring via at least one insertable/removable aperture extending in an optical axis direction; a first rotatable ring supported inside said annular ring and rotatable about a rotational axis extending in a direction of said optical axis, said first rotatable ring including at least one rotation-guiding projection slidably engaged in said at least one circumferential guide groove; a second rotatable ring which rotates together with said first rotatable ring and is capable only of axial movement relative to said first ring, said second rotatable ring including at least one engaging projection slidably engaged in said at least one circumferential guide groove together with said at least one rotation-guiding projection, wherein said at least one engaging projection is insertable into and removable from said at least one circumferential guide groove in said optical axis direction through said at least one insertable/removable aperture at a first assembling/disassembling angular position of said first rotatable ring and second rotatable ring; and a coupling ring which is positioned inside said first rotatable ring and said second rotatable ring to be non-rotatable relative to said annular ring, said first rotatable ring and said second rotatable ring coupled by said coupling ring to be rotatable with respect to said coupling ring, wherein a coupler provided between said coupling ring and said second rotatable ring is configured to be disengaged in said optical axis direction at a second assembling/disassembling angular position of said first rotatable ring and second rotatable ring; wherein said first assembling/disassembling angular position and said second assembling/disassembling angular position are substantially the same angular position.