Lens barrel incorporating the rotation transfer mechanism

A digital camera comprising a body and a lens barrel housed in the body, the lens barrel having a rotation transfer mechanism, the rotation transfer mechanism comprising:

• a pair of rotatable rings, adjacent ends of which are opposed to each other in a rotational axis direction extending in an optical axis direction;
• at least one axial-direction projection extending in said rotational axis direction;
• at least one axial-direction recess in which said axial-direction projection is positioned, said axial-direction projection and said axial-direction recess respectively located on one and the other of said adjacent ends of said pair of rotatable rings;
• at least one rotation transfer groove located on an inner peripheral surface of the one of said pair of rotatable rings that has said axial-direction projection, wherein a circumferential position of said rotation transfer groove corresponds to a circumferential position of said axial-direction projection, such that a portion of said rotation transfer groove in said rotational axis direction is associated with said axial-direction projection;
• a driven rotational member having at least one rotation transfer protrusion engaged in said rotation transfer groove, said rotation transfer protrusion slidably movable in said rotation transfer groove in said rotational axis direction and configured to transmit rotation of said pair of rotatable rings to said driven rotational member;
• and
• at least one optical element configured to be driven by said driven rotational member.